Category Archives: Cold War

Ikarus 214

Cold War, Yugoslavia, , ,

Yugoslavia flag Federal People’s Republic of Yugoslavia (1948-1967)
Multi-Role Twin Engined Aircraft – 23 Built

The Ikarus 214 [otpisani.niceboard.com]
After World War Two, the new Communist Yugoslavian Air Force Command began a long process of restoring the destroyed aviation industry. The first attempts were made in the late 1940s, when several new and experimental designs were built, including the Ikarus 214. While most of these would remain prototypes or be built in small numbers, they would serve as a base for future developments and the experience gained would be used in the following years.

History

The first steps towards rebuilding the new Communist Yugoslav aviation industry were made during the war on 24th October 1944. Negotiations with representatives of many pre-war aircraft manufacturers about the possibility of reviving the devastated aircraft industry were held at Zemun near the capital city of Belgrade. Many pre-war aircraft industry designers and engineers would survive the war, and would be used to form the base of the future Yugoslav aviation industry.

Ikarus 214 D Prototype in Flight [paluba.info]
Two years later (23rd February 1946), the Aeronautical Technical Institute created a competition for the development of four new designs. One was for a flying school and tourism aircraft, while the others were for a two-seater basic trainer, an advanced trainer, and a multi-seat trainer version that could potentially be used as a transport plane. The Aeronautical Technical Institute was a pre-war institution which was responsible for placing orders and monitoring new aircraft development. During the period of 1947 to 1952, several different designs, including the maritime role, what would become the Ikarus 214, were produced. 

Constructor Group No.5, under the leadership of the aircraft engineer and professor Sima Milutinović, received orders to design a light two-engined transport and bomber crew trainer aircraft under the military designation 214. After the calculations and drawings were completed, the production of the first prototypes began in 1948 at the Ikarus factory. By 1949, two prototypes were completed and were designated 214P and 214D.

Name

The original military designation of this plane was simply 214. After the first two prototypes were built, the manufacturer’s name, Ikarus, was added to the designation. However, some sources call it the type 214 or simply the 214. This article will use the 214 designation for the sake of simplicity.

Technical Characteristics

The 214 was designed as a low wing, twin engine, mixed construction plane. Despite being primarily intended as a transport and trainer plane, the 214’s fuselage was designed to be able to withstand bomber duties. The fuselage had an unusual design and was built by combining two monocoque “sandwiches” (two light skins placed around a thick core) shell construction (same as on the British de Havilland Mosquito which was in use with the Yugoslavian Air Force.) The 214’s fuselage was large and had plenty of room for use as a transport or passenger aircraft.  The 214 passenger version had 7 seats placed behind the pilot’s cockpit. On both sides of the fuselage, there were two rounded and two elongated windows. The 214 (except the later built 214PP and AM-2) had a large and fully glazed round shaped nose with good all round forward visibility.

The Improved 214AM-2 Anti-Submarine Variant
The 214 prototypes were powered by the weaker Ranger SVG-770C engines.

The wings were made of wood and consisted of two box shaped longerons. The whole wing was covered with birch glue. The twin tail vertical and horizontal stabilizers were also made of wood. The rudder and the elevator were made of duralumin and covered with canvas.

The first engine used by the two prototypes was the air-cooled Ranger SVG-770C providing 520 hp, with the two-bladed Hamilton standard type propellers. The second prototype, and all subsequent aircraft were equipped with the stronger nine-cylinder air-cooled Pratt & Whitney R-1340-AN-1, which delivered 600 hp. Four fuel tanks were placed in the wing longerons, with a total fuel load of 780 liters (206 gallons.) The 214 used B-95 gasoline as its main fuel.

The Ranger SVG-770C Engine [vazduhoplovnetradicijesrbije.rs]
The landing gear retracted (except on the first prototype) into the rear engine nacelles but was not completely covered. The rear tail wheel was fixed but was provided with a brake system. The landing gear was hydraulically driven.

The pilot’s cockpit was positioned above the front fuselage and provided a good all-around view. In the cockpit there were positions for two crew members (pilot and assistant) and dual controls which were connected with the rudders and elevators with wire. However, this flight control system was flawed, because it took a few seconds before the plane responded to the command given by the pilot, for example during turns, climbs, or descending maneuvers. This made the 214 particularly difficult to fly during harsh and bad weather. 

The front glazed nose provided a good all around forward view.

Inside the cabin were several flight instruments, such as the airspeed and altitude indicators (type Teleoptik 456-6 and 452, the 214AS version had two altitude indicators), two variometers (type Teleoptik 26B), a turn and slip indicator (type 441-0), a horizontal situation indicator (type Teleoptik 32C, the 214AS version was equipped with two), a magnetic compass (type 443-0), two engine tachometers, fuel and oil gauges, landing gear indicator, and thermometer. Additional equipment for the crew’s safety included parachutes, fire extinguishers, oxygen bottles, and heating & ventilation. In the first series of aircraft produced in 1958, a SCR-522 radio unit was installed This radio had 8 watts of power with a range of 50-290 km (30-180 mi) depending on altitude. The 214F version was equipped with a Rudi Čajevac radio-telephone.

One of the prototypes was armed with three 7.92 mm MG-15 machine-guns, one forward fixed, one on the side (not specified whether  it could be aimed) and one in the rear facing turret. The decision to use older captured German MG-15s was most likely based on the fact that the 214 was to be used as a trainer aircraft, with better and more modern armament reserved for front  line aircraft. The 214 could also be equipped with a bomb load of four 50 kg (110 lb) bombs. Weapons were rarely installed on the production versions, as they were used mostly for transport.

First Test Flights

The 214 made its first flight on 7th August 1949, at the Zemun airfield near Belgrade. Immediately, there were problems with the lack of an adequate retractable landing gear. As a temporary solution and to speed up the testing process, the engineers simply reused the landing gear from an Il-2 (which was in use by the Yugoslav Air Force), but for technical reasons it was not retractable and remained fixed. There were also problems with inadequate propellers, as the 214 prototypes had to use propellers designed for a single engine aircraft. Despite the fact that it was never intended to be used with a fixed landing gear, military officials demanded that the flight tests begin as soon as possible. During its first test flight, one of the two engines simply stopped working. The pilot made a turn back towards the airfield, but the 214 could not maintain altitude and the plane crashed killing the test pilot Lieutenant Sima Nikolić.

An investigation that was subsequently conducted found that the fixed landing gear and the poor choice of propellers created too much drag. The single working engine could not overcome this drag. In addition, the vertical tail surfaces proved to be inadequate.

Prior to this accident, the engineers and designers predicted, at least in theory, that the 214 could maintain a constant altitude with only one working engine. In case of such a scenario, the test pilots were instructed to fly to the large and open Borča field,  Belgrade, and land there. Why the pilot decided to return to Zemun airfield instead of proceeding to the instructed field was impossible to determine. Despite this accident, the development of the 214 would go on.

The second prototype was fully completed by December 1949. In order to avoid accidents, the second prototype spent almost two years being redesigned and tested. Unfortunately, there is no information about any flights made during this period, but it is possible that some were conducted. This plane received larger vertical tail surfaces and a new landing gear. More intense flight tests were made from 1951 on. During this time, different trainer configurations were tested. These were basic training variants with three crew members and no armament, a bomber training variant with four crew members with up to three machine guns and bombs, and as a passenger transport variant with two crew members, six passengers, and no armament.

The Pratt & Whitney R-1340-AN-1 became a standard production engine on the 214. [vazduhoplovnetradicijesrbije.rs]
During 1954 and 1955, the second 214 prototype was equipped with Pratt & Whitney R-1340-AN-1 engines. It made its first flight with these engines on the 16th of September 1955 without any problems. In 1957, the second prototype was modified for use as a photo-reconnaissance aircraft (serving as the basis for the later 214F variant). This prototype would be used in this role until September of 1959, when the plane was lost in an accident. 

In 1955, it was decided to put the 214 into limited serial production. It  began in 1957 (or 1958 depending on the sources) and, by the time it ended in 1960, a total of 21 (or 20 depending on the source) 214 planes were produced. 

Anti-Submarine role

In 1958, a decision was made by the Yugoslavian Air Force for the adaptation of the 214 for anti-submarine operation. The first series of 214s produced was allocated to the 97th Air Regiment (this unit was renamed into the 97th Anti-Submarine Regiment in November 1958). The first group of pilot officers from the 97th Air Regiment was moved to Zemun airfield for training on the 214 in October 1958. All pilots from the 97th Air Regiment (which was equipped with British de Havilland Mosquitos) completed training by July 1959. In the period of 1959 to 1960, there were 41 pilots in training, but the number was reduced to 25 in 1961 and 1962. The entire training process was carried out under the leadership of World War II veteran Captain Okanović i Semolić.

As the 214 lacked any equipment for anti-submarine operations, it could be used only in reconnaissance missions, and only weather permitting where visibility was good. In 1960, there were plans to improve the 214’s anti-submarine performance by adding the necessary equipment. One modified aircraft, under the new 214PP (No. 61004) designation, was tested by Captain Petar Savić on the 6th of May 1960. Two years later, a new anti-submarine version, 214AM2 (No.61015), also known as 214M-2, was tested in June 1962 by pilot Aleksandar Prekrasov. Both versions had a fully enclosed nose instead of the standard glazed one (the sources are not clear, but it appears that other 214  were also equipped with an enclosed nose). In addition, the 214AM2 was provided with a radar placed below the front nose. However, this improved version was still not up to the task of anti-submarine duties. Even if the crew spotted an enemy submarine, it could hardly do anything. Due to equipment delays, more extensive testing was not possible before 1963. The 214AM2 was tested in Batajnica (near Belgrade) and later in Pula on the Croatian coast. The tests of the 214AM2 were completed by 1965, and the results of these tests assessed the variant as partially successful. 

Even before these tests were completed, in May 1964, by the order of the Secretary of National Defense, the 97th Anti-Submarine Regiment was reorganized as 97th Auxiliary and Support Regiment and supplied with C-47 transport planes. The 214 was still in use with this unit but mostly in a transport role. This decision to remove the 214 from the anti-submarine role was based on the fact that they were not sufficiently equipped, and could not effectively engage submarines. The 214 would be used by this unit up to 1966, when they were removed from service.

The 214F 

Front view of the 214F version.

In 1960, three aircraft, designated as 214F, were built in the Ikarus factory to be used as photo-reconnaissance planes. The main difference was the removal of the seats inside the plane’s fuselage and replacing them with positions for a cameraman, his assistant, and  camera equipment. 

Limited Operational Service Life

Despite being designed to fulfill several different roles, the 214 (beside the two anti-submarine modifications) was mostly used as a light transport and sometimes for day and night bomber crew training. The aircraft that were used in this role received the 214AC or 214P designations and, in total, 18 were built of this version. The basic transport and training variant had 7 seats placed behind the cockpit, with four on the right, and three on the left side. In some sources, the passenger number is listed as 8. The idea to use the 214 as a light bomber was rejected due to the rapid development of more advanced fighter-bombers. The 214 had many technical problems during its operational use, such as inadequate radio equipment, problems with the control of the wing flaps, inadequate electric equipment for night flights, and cracks that would appear in the propeller spinners after extensive use. 

A parachute group in front of a 214 prior to take-off. [vazduhoplovnetradicijesrbije.rs]
Rear view of a 214. The Yugoslav flag (blue, white and red with a red star in the middle) was often painted on the tail. [otpisani.niceboard.com]

The 214 was mostly used by the Yugoslavian Air Force as a transport plane.

In Civilian Service

By 1966, only six 214 transport versions were still operated by the Yugoslavian Air Force. The next year, these six were withdrawn from service and given to the Aeronautical Association of Yugoslavia for use. They were registered as passenger planes with two crew members and seven passengers. These received the following civilian markings based on their stations: YU-ABN in Ljubljana, YU-ABO in Vršac, YU-ABT in Novi Sad, YU-ABS in Zagreb, YU-ABR in Sarajevo and YU-ABP in Skopje.

In 1968, only four were listed as operational and, by 1970, they were removed from the civilian registers. While they remain stored, some parachute flights were carried out after 1970. In the following years, all except one were scrapped. This aircraft (No.60019) was given to the Yugoslav Aviation Museum near the Capital of Belgrade in 2001. The plane is in a poor state of repair and is waiting for restoration. Due to the financial difficulties of the museum, there is only a small chance that it will be restored in the near future.

This is a civilian 214 stationed in Sarajevo. [paluba.info]
The only surviving 214 (No.60019) aircraft can be seen in the Belgrade Aviation Museum. [Wikipedia]

Production Run

As previously mentioned, the decision for the production of the 214 was made in 1955. By the time the production ended in 1960, a small series of 21 aircraft was produced (excluding the two prototypes.) Many sources state that around 20 were built but, according to Č. Janić. and O. M. Petrović, 21 were built (18 214AC and 3 214F). The problem with determining the exact number of produced aircraft lies in the fact that, in some sources, the three produced 214F include the prototype which was modified for this role. Despite the fact that the production began during 1957 (by Ikarus), the whole process was slow and, by the 1st of January 1959, only six 214 were built. Only one was built in 1957 and an additional five during 1958. By January 1st 1962, there were 21 aircraft in service with the Yugoslavian Air Force, with 17 fully operational. In the following years, there were no accidents and an average of between 15 and 18 were fully operational at any given time. In order to increase the 214’s operational service life, one additional factory (Vazduhoplovno-Tehnicki Remontni Zavod) was opened in Zagreb for the production of spare parts and repairs. The Ikarus factory, due to its  involvement  in other projects, was  exclusively involved in the production of spare parts from 1962 to 1964.

Due to the small numbers built, the 214 had only a few different variants.

  • 214P and 214D prototypes – Two prototypes built and tested with different engines.
  • 214F – 3 built as photo-reconnaissance planes. 
  • 214AC (214P) – Main production version. 18 were built as trainer/passenger planes.
  • 214PP – One production aircraft was modified for anti-submarine operation.
  • 214AM-2 – One production aircraft was modified as an improved anti-submarine variant.

Conclusion 

Despite not being a successful design, the 214 did see operational use in the Yugoslav Air Force. As only small numbers were built, the model’s role was limited. The 214’s greatest success was that it helped rebuild the destroyed Yugoslavian aircraft industry and the designers and engineers gained additional experience in working with more modern aircraft designs.

Ikarus 214 Specifications
Wingspan 53 ft 2 in / 16.2 m
Length 38 ft 9 in / 11.2 m
Height 13 ft  / 3.95 m
Wing Area 320 ft² / 29.8 m²
Engine Two nine cylinder air-cooled P&W R-1340-AN-1 with 600 hp
Empty Weight 3,740 lbs / 3,970 kg
Maximum Takeoff Weight 11,080 lbs / 5,025 kg
Fuel Capacity 780 l
Maximum Speed 227 mph / 365 km/h
Cruising speed 186 mph / 300 km/h
Range 670 mi / 1,080 km
Maximum Service Ceiling 23,000 ft / 7,000 m
Crew One pilot and One copilot
Armament
  • Three 7.92 mm MG-15 Machine Guns
  • Bomb load of four 50 kg bombs

Gallery

Illustrations by Carpaticus

Ikarus 214
Ikarus 214AM-2 Anti-Submarine Variant
Ikarus 214 in Civilian Service

Credits

 

Yakovlev EG Side View Illustration

Yakovlev EG

Cold War, Soviet Union, , , ,

USSR flag USSR (1946)
Coaxial Rotor Helicopter – 1 Built + 1 Incomplete

The modified Yakovlev EG prototype in flight. (Yakovlev OKB) Colorization by Amazing Ace

The EG (also known as the Yak-M-11-FR-1, Sh or Yak-EG) was a prototype helicopter designed in 1946 by the Yakovlev OKB. The EG was designed with a coaxial rotor configuration and had an ambitious performance estimation. Through manufacturer testing, it was revealed that the EG had very undesirable handling characteristics and excessive vibrations when the helicopter reached around 20 mph (30 km/h). These flaws caused the cancellation of the EG project and the completed prototype was converted to an aerosani in 1955 and donated to a farm in the Kazakh SSR. The Kamov OKB would later go on to develop the coaxial rotor configuration further.

History

Lessons of the Second World War showed the world the importance of adopting and developing modern technologies. Throughout the war, autogyros and helicopters became increasingly relevant with several countries’ militaries and saw a dramatic increase in development. The Soviet Union had a very limited selection of these machines during the war, and looked to develop this technology and expand their arsenal. In 1946, the esteemed Yakovlev OKB initiated a project for an experimental coaxial rotor helicopter design. The project was given the nickname of “EG”, for “Experimental Helicopter” (Экспериментальный Геликоптер / Eksperimentahl’nyy ghelikopter). When the task of designing the EG was first announced to the design team, a flabbergasted staff member exclaimed “Shootka?” (шутыш), which roughly translates to “Are you kidding?”. This then led the EG to unofficially be referred to as the “Sh”, a running joke in the design team. Another designation which referred to the EG was “Yak-M-11FR-1”, which referred to the engine that the helicopter would use. The origin of this designation is unknown, but it does not appear to be official.

A detailed cutaway drawing of the modified Yakovlev EG prototype. (Yakovlev OKB)

Responsibility over the project was given to chief designer S.A. Bemov, with I.A. Erlikh as his aide. The EG was envisioned as a coaxial rotor configuration while powered by a 5-cylinder air-cooled Shvetsov M-11FR-1 radial engine producing 140 hp. When the initial design was completed in early 1947, the design team built a flying scale model of the EG to prove the viability of the coaxial rotor design. The scale model was given the designation of ED 115, with the digits referencing OKB-115, the plant designation for Yakovlev OKB.

The modified prototype Yakovlev EG sits on the Yakovlev OKB’s premise with it’s rotor fins folded. (Yakovlev OKB)

After verifying the EG’s design, construction of the actual prototype commenced. The prototype was completed sometime in the summer of 1947 and was promptly subjected to manufacturer’s trials. The EG prototype performed 40 tethered flights (total of 5 hours flight time) before being authorized to perform the first free flight test on December 20, 1947. Through extensive testing, it was revealed that the center of gravity was too far to the rear, which led the team to remove the tail and tailskid and relocate the oil tank behind the cockpit. In early 1948, the M-11FR-1 engine was removed, replace by an experimental M-12 radial engine, a development of the M-11. The first test flight with this engine was conducted on April 9th, but the engine proved troublesome and forced the team to refit the M-11FR-1 engine. Flight tests continued until July 8, 1948, with a total of 75 free flights conducted (total of 15 hours flight time).

Despite the EG showing relatively decent results, it suffered from excessive vibration, loss of stick force and phugoid instability once the machine approached 20 mph (30 km/h). This severely restricted the EG’s practicality and thus warranted the project’s cancellation. The coaxial rotor design configuration was given to Kamov OKB to further develop, while the Yakovlev OKB moved onto more conventional helicopter configurations. A second prototype was in construction but was never completed and was scrapped when the program was canceled. The sole completed prototype was preserved at the Moscow Aviation Institute for a couple of years before being converted to an aero-sleigh by students between 1954 and 1955. The converted sleigh was then donated to a farm in the Kazakh SSR and the fate beyond that is unknown. Photos of this new conversion do not exist. Though ultimately ending up as a failure, the EG was an important stepping stone in Soviet helicopter development and was quite special in the sense that it was the Yakovlev OKB’s first helicopter design.

Design

The original configuration of the Yakovlev EG with a horizontal tail, tail bumper and endplate fins. (Yakovlev OKB)

The Yakovlev EG was a coaxial rotor helicopter powered by a 5-cylinder air-cooled Shvetsov M-11FR-1 radial engine producing 140 hp. The engine drove co-axial two-bladed rotors using a transmission system which featured a centrifugal clutch, a 90-degree gearbox and a cooling fan. Fuel tanks were placed under the gearbox while the oil tank was next to the engine. The rotors (made of laminated pine and hardwood) spun in opposite directions at 233 rpm. Both collective and cyclic pitch control was provided through the rotor’s fully articulated hub mount. The EG’s fuselage consisted of simple welded steel tubes which had D1 duraluminium skin all around except for the engine compartment. The rear fuselage, which was covered with fabric, gradually tapered off to form a fin which was accompanied by a horizontal stabilizer supplemented by two endplate tips. The tail and the horizontal stabilizer would be removed later on in the test phase due to the offset center of gravity. The EG had a non-retractable tricycle landing gear with vertical shock absorber struts. The glazed cockpit compartment could house two pilots, which would enter through doors on either side of the fuselage.

Operators

  • Soviet Union – The Yakovlev EG was designed with the intent of serving the Soviet Union. The EG was evaluated by Yakovlev OKB but was deemed to be unfit for service due to the excessive vibration and loss of stick control and phugoid instability when the helicopter reached speeds around 20 mph (30 km/h).

Yakovlev EG
Fuselage Length 21 ft 5.1 in / 6.53 m
Engine 1x 5-cylinder air-cooled Shvetsov M-11FR-1 radial engine (140 hp)
Rotor Diameter 31 ft 9.7 in / 10 m
Empty Weight 1,936 lb / 878 kg
Takeoff Weight 2,249 lb / 1,020 kg
Climb Rate 610 ft per minute / 3.1 m per second
Maximum Speed 58 mph / 93 km/h – Estimated

Approximately 43.5 mph / 70 km/h – Actual
Range 146 mi / 235 km – Estimation based on 58 mph / 93 kmh Top Speed
Hover Ceiling 820 ft / 250 m
Flight Ceiling 8,860 ft / 2,700 m – Estimated*

* – Testing never exceeded 590 ft / 180 m
Crew 1x Pilot

1x Co-Pilot

Gallery

Yakovlev EG Side View Illustration
Side View Profile of the Yakovlev EG by Ed Jackson
A desktop model of the Yakovlev EG. This model does not have the tail components presented. (Yakovlev OKB)
The modified Yakovlev EG prototype in flight. (Yakovlev OKB)
A side view of the original configuration of the Yakovlev EG with a horizontal tail, tail bumper and endplate fins. (Yakovlev OKB)
A side view of the modified prototype Yakovlev EG sitting on the Yakovlev OKB’s premise with it’s rotor fins extended. (Yakovlev OKB)

Sources

Northrop’s Early LRI Contenders

Cold War, US, , , , ,

USA flag old United States of America (1953)
Long Range Interceptor Proposals [None Built]

Detailed drawing of the N-144, with cutaway section

Born from the Long Range Interceptor program, the first of Northrop’s contenders were three aircraft that had large delta wings and overall similar shapes and designs. The first, the N-126, started as a modified version of Northrop’s F-89D Scorpion fighter but would become its own unique aircraft by 1954. The second, the N-144, was a large four-engine interceptor design that dwarfed current bombers of the time and could carry an impressive arsenal. The third, the N-149, differed the most from its two siblings. It was much smaller and used General Electric engines over Wright engines. The N-144 was the most successful out of the entire program, but would prove to be too costly and a maintenance nightmare if produced. The N-126 and N-149 would also not meet expectations, as did none of the other competitors in the doomed program.

The LRI Competition

At the start of the Cold War, it was realized that if a Third World War would ever happen, defending the mainland United States from airborne threats would be a top priority. ICBMs and nuclear missiles are the go-to threat everyone imagines when they think of the Cold War, but these wouldn’t be operational until the late 1950’s. In the early years, nuclear weapons would be deployed by strategic bombers and these would be the major threat. Intercepting these long range aircraft would be of the utmost importance if the war went hot in the 1950’s. Developing an aircraft able to reach these bombers and destroy them led to the creation of the modern interceptor. Most countries had begun developing an interceptor of their own. At the forefront was the United States Long Range Interceptor program (LRI). This program originated in early 1952, with Major General L.P. Whitten of the Northeast Air Command noticing that a capable aircraft would be able to takeoff and intercept enemy bombers using the warning time of the Semi-Automatic Ground Environment (SAGE) system, which was an integrated defense network of SAM, radar and fighters across the US and Canada, able to intercept enemy bombers well before they were able to reach the United States. Although the idea was put out, no official requirements for the idea came about until December of 1953, when the Air Council put out extremely demanding needs. The aircraft would need to be airborne in two minutes from getting the scramble alert. Maximum speed would be Mach 1.7 with a range of 1,000 nm (1,850 km). Combat ceiling would be 60,000 ft (18,000 m) with a climb rate of 500 ft/min (150 m/min). The aircraft would be minimally armed with forty-eight 2.75 inch rockets, eight GAR-1A Falcon AAMs or three unguided nuclear rockets. This requirement became known as Weapon System WS-202A. Most companies developed submissions, but McDonnell and Northrop had an early start with a long range interceptor design being conceived very early on, well before an official requirement had been requested. Northrop had three aircraft designs that would fit the requirement for WS-202A; the N-126, N-144 and N-149. All three were visually similar to each other and shared concepts and equipment with one another.

Northrop N-126: The Delta Scorpion

Bottom view of the N-126 Delta Scorpion model [US Secret Fighter Projects]
The first of the designs Northrop submitted was the N-126 Delta Scorpion. This aircraft actually began development months before an official requirement was put out. The design was submitted in February of 1953 and was essentially a Northrop F-89D Scorpion modified with a new delta wing design and Wright YJ67 engines. The aircraft received a performance review sometime in 1953 along with McDonnell’s two-seat version of the F-101 Voodoo. Neither design was chosen for production. The N-126 did show promise, as it came close to meeting the very first requirements and it was supported by the Air Defense Command. However, the predicted first flight in twenty-one months was a bit too optimistic and the design was disliked by the United States Air Force Headquarters, as it didn’t exactly meet requirements compared to the F-101 variant. Northrop pushed this early design and adamantly tried to acquire production.

Front quarter view of the N-126 Delta Scorpion model [US Secret Fighter Projects]
They were quick to begin working on an improved design that would be longer and yield better results. It took over fifty concept designs before they found a suitable improvement. The aircraft itself no longer resembled the F-89D Scorpion it got its name from, but the name would stick until the end of the project. This new design was submitted in August of 1954. The N-126 was now much sleeker, with a forty-five degree delta wing and two underwing Wright J67-W-1 engines (Allison J71-A-11 engines were a weaker alternative choice). The delta wings all three projects used provided lower weight than generic straight wings and minimized drag. The trailing edge of the wing would have a split speed brake on the outer surface, an aileron located in the middle and a feature on the inboard section only referred to as an “altitude flap”. For the landing gear, a bicycle configuration with two wheels on each gear would be mounted directly under the aircraft, with a smaller landing gear being placed under the wings.

For armament, the aircraft would use the required eight Falcon AAMs and forty-eight rockets being mounted in a 20 ft weapon bay. Four external hardpoints would allow extra ordnance to be carried, such as bombs or extra missiles. Alternative loadouts included any combination of four AIR-2A unguided nuclear rockets, six Sidewinders, or two Sparrow guided missiles. The N-126 would use the Hughes E-9A fire control system, one of the few remnants carried over from the F-89. The E-9A would be linked to a long-range search radar that would have a range of 100 nm (185 km). For fuel, one large internal tank and two smaller tanks in the wings would hold 4,844 gal (22,025 l). Extra drop tanks could be mounted under the wings and offer an additional 1,600 gal (7,275 lit). For its predicted mission, the N-126 would be able to launch and engage enemy bombers twenty-seven minutes after scramble. Northrop expected a prototype would be ready for a first flight by June of 1957.

Northrop N-144: The Monstrous Interceptor

Color photo of the N-144 model [US Secret Fighter Projects]
The N-144 was the second design Northrop submitted. It was made to offer the best results in regard to the WS-202A requirements. It resembled the N-126 but was much larger and had four J67 engines. The N-144 dwarfed its siblings, competitors, and even several current bombers of the time. With a wingspan of 78 ft and a length of 103 ft, this was no small aircraft. In comparison, the Convair B-58 supersonic bomber had a wingspan of 56 ft and a length of 96 ft (interesting to note, a plan to convert the B-58 into a long range interceptor was proposed).

Its appearance wasn’t the only thing carried over from the N-126. The E-9A fire control system, its accompanying scanner, and its landing gear design (now with four wheels on the main gear) were all reused in the N-144. The N-144 also had a forty-five degree delta wing like the N-126. The N-126 and N-144 would both have their engines on pylons on the wings. This configuration allowed much more powerful engines to be used and a simpler intake system compared to having the engines be built into the body, not to mention the layout being much safer in the event of a fire.

Top down view of the N-144 model. Note the 45 degree delta wing [US Secret Fighter Projects]
The N-144 utilized many features that would directly improve the aerodynamics of the aircraft. The aircraft would have low wing loading which would increase its cruise altitude and improve takeoff and landings. The addition of a horizontal tail, which isn’t often seen in delta wing designs, gave the N-144 improved handling and stability over designs that lacked the horizontal tail (see the Convair F-102 Delta Dagger for example). When the aircraft would be supersonic, the wing would have a chord flap that would retract into the wing to reduce drag. Area ruling was a feature involving tapering the center of the fuselage which would reduce drag while the aircraft was flying at supersonic speeds. Most current delta wing designs utilized area ruling, but none of Northrop’s interceptors surprisingly did. Northrop ruled that the advantages would only affect supersonic flight, and not provide anything useful during subsonic flight. Having no area rule also made the aircraft simpler in design and easier to produce. Northrop’s studies into the delta wing expected to see performance increase as time went on, with more modifications and better engines being used on the N-144 if it went into production. With these expected improvements, Northrop theorized a 14% improvement in top speed and service ceiling.

Frontal view of the massive N-144 model. The size of its engine pods are evident. [US Secret Fighter Projects]
For armament, the N-144 would still utilize the standard eight Falcon AAMs and forty-eight rockets, but could also carry twelve Falcon AAMs, six AIR-2A Genie (Ding Dong) rockets, 452 2.75 in FFAR rockets or 782 2 in (5.1 cm) rockets internally in any order. External hardpoints could also be fixed for carrying bombs or more ordnance. For fuel, a large fuel tank would be in the wings and fuselage and could carry 6,910 gal (31,419 l) of fuel. Given the size of the aircraft, Northrop advertised that it could be used in alternative roles.

Northrop N-149: The Opposite End

Model of the N-149. The additional fuel tanks can be seen. [US Secret Fighter Projects]
The N-149 was the third and final design submitted by Northrop for WS-202A. Submitted in July of 1954, the N-149 was almost the polar opposite of the N-144. Instead of opting for raw power and utilizing four engines, the N-149 was meant to be the smallest option available while still performing just as well as its competitors. In comparison, the N-126 would be 85 ft (25.9 m)long with a wingspan of 62 ft (19 m), while the N-149 would be 70 ft (21.5 m) long with a wingspan of 50 ft (15.5 m). This size decrease would save cost, space and fuel consumption. The N-149 used the same wing layout as the previous entries and would also retain the E-9A fire control system and accompanying radar. Given the advancements of the N-144’s wings, it is likely the N-149 would also benefit from them as well. The N-149 did not use Wright J67 jet engines like the N-126 and N-144, but would instead use General Electric J79 engines. These engines were longer than the J67 but would benefit the aircraft, given its small size, to achieve the required speed and rate of climb. The bicycle landing gear with outer wing gear was once again used, but now with two wheels on each gear like the N-126. The armament for the N-149 was less than its predecessors, but it would make up for weapons in the amount able to be built. Once again, eight Falcon AAMs and forty-eight 2.75in rockets were standard, but alternative armaments would be a single Sparrow AAM, four Sidewinder AAMs, another 105 2.75 in rockets or 270 2 in rockets. Additional armament could be mounted on four external hardpoints like the N-126 and N-144, however, two of these would be taken up by external fuel tanks. These tanks would be 600 gal (2,730 l). The majority of the fuel would be in a large tank that spanned the fuselage and into the wings and would carry 2,050 gal (9,320 l) of fuel. Northrop expected a first flight of the aircraft by the summer of 1957.

The Program Concludes

Detailed drawing of the N-149 with cutaway

Although Northrop is the center of this article, Boeing, Douglas, Lockheed, Martin, McDonnell, North American, Chance-Vought, Grumman and Convair all submitted designs. When the assessment of all the designs was completed, it was concluded that none of the proposals exactly met up the set requirements. The N-144, however, came the closest to meeting the specification. After assessment, the N-144 had a predicted speed of Mach 1.76, a combat ceiling of 58,500 ft (17,800 m) and a combat range of 1,015 nm (1,880 km).

McDonnell’s design came close, as it could go faster and reach the same altitude, but its range was much less compared to the N-144. Materials Command was not too keen of the N-144 and it is obvious why. The cost, production and maintenance of it would be tremendous. Given its four engines, the aircraft would require much more maintenance compared to its two-engine competitors. Producing such a large aircraft would be extremely costly given its size and engine count. The best option for performance would also be the worst option considering its cost.

Its siblings didn’t meet the specifications as well. No reason was put out as to why the N-126 failed the competition, but given the state of the program, it can easily be assumed it didn’t meet either the range, speed, or altitude requirements. The N-149 did have a specified reason for its rejection, though. After taking off at full power and reaching its maximum height, it would only offer 20 minutes of flight, with 5 minutes at full power for combat. Having your aircraft destroy as many bombers before reaching their target is necessary and only 5 minutes wouldn’t be sufficient to fulfill its duty. Ultimately, WS-202A wouldn’t produce any aircraft. The requirements had gone too high, and the companies wouldn’t be able to produce a cost effective aircraft in time that would meet the expected specifications. The program would go on to become the new LRI-X program in October of 1954, and Northrop would be one of three companies tasked with creating a new interceptor, which their Delta-Wing trio would surely influence in a number of ways.

Variants

  • Northrop N-126 (February 1953) – The 1953 N-126 Delta Scorpion was an improvement upon the F-89D Scorpion by having a delta wing and YJ67 engines.
  • Northrop N-126 (1954) – The 1954 version of the N-126 no longer resembled the F-89 but was now longer and more streamlined.
  • Northrop N-144 – The N-144 would be the second design submitted to the LRI competition. It was much larger than the other two submissions and would utilize four engines.
  • Northrop N-149 – The N-149 was the smallest of the three designs and was meant to be the best performing for its size. It looked visually similar to the N-126 but would carry slightly less ordnance and utilize Gen Elec XJ79-GE-1 jet engines over the Wright J67-W-1s.

Operators

  • United States of America – All three designs would have been operated by the United States Air Force had they been constructed.

Northrop N-126 Delta Scorpion (1954) Specifications
Wingspan 62 ft 3 in / 19 m
Length 85 ft / 25.9 m
Wing Area 1,050 ft² / 97.7 m²
Engine 2x 13,200 Ibs ( 58.7 kN ) Wright J67-W-1 Jet engines
Weights 75,830 lbs / 34,400 kg (Gross)
Fuel Storage 4,844 gal / 22,025 l
Maximum Speed 1,183 mph / 1,903 km/h at 35,000 ft / 10,700 m
Cruising Speed 793 mph / 1,276 kmh
Range 800 nm / 1,500 km
Climb Rate 2.45 minutes to 40,000 ft / 12,000 m
Maximum Service Ceiling 59,600 ft / 18,000 m (Point Interception Role)

56,200 ft / 17,000 m (Area Interception Role)
Crew 1 Pilot

1 Radar Operator
Main Proposed Armament
  • 8x GAR-1 Falcon AAM
  • 48 2.75in (7 cm) FFAR
Alternative Armament Loadouts
  • 4x Ding Dong Unguided Nuclear Rockets
  • 6x Sidewinder AAMs
  • 2x Sparrow AAMs
  • 1x 1,640 lbs (744 kg) bomb

Northrop N-144 Specifications
Wingspan 78 ft 10 in / 24 m
Length 103 ft 6 in / 31.5 m
Wing Area 1,700 ft² / 158.1 m²
Engine 4x 13,200 Ibs ( 58.7kN ) Wright J67-W-1 Jet engines
Weights 113,700 lbs / 51,500 kg (Gross)

91,600 Ibs / 41,550 kg (Combat)
Fuel Storage 6,910 gal / 31,420 l

44,940 Ib / 20,390 kg
Maximum Speed (Mach 2.04) 1560 mph / 2520 km/h at 34,000 ft / 10,000 m
Cruising Speed (Mach 1.06) 810 mph / 1300 km/h
Range 1,015 nm / 1,880 km
Climb Rate 1.9 minutes to 40,000 ft / 12,000 m
Maximum Service Ceiling 63,000 ft / 19,202 m (Point Interception Role)

60,000 ft / 18,288 m (Area Interception Role)
Crew 1 Pilot

1 Radar Operator
Main Proposed Armament
  • 8x GAR-1 Falcon AAM
  • 48 2.75in (7 cm) FFAR
Alternative Armament Loadouts Internal Storage

  • 12x Falcon AAM
  • 6x AIR-2 Genie (Ding Dong) Missiles
  • 452 2.75 in FFAR
  • 782 2in (5.1cm) Rockets

External Hardpoints

  • Unknown type of bombs mounted on 4 hardpoints.

Northrop N-149 Specifications
Wingspan 50 ft 10 in / 15.5 m
Length 70ft 6 in /21.5 m
Wing Area 700 ft² / 65.1 m²
Engine 2x 9,300 Ibs ( 41.3 kN ) Gen Elec XJ79-GE-1 Jet engines
Weight 43,400 Ibs / 19,700 kg
Fuel Storage 2,050 gal / 9,320 lit

13,310 Ibs / 19,690kg
Maximum Speed (Mach 1.51) 1160 mph / 1860 km/h at 35,000 ft / 10,700 m
Cruising Speed (Mach 1) 770 mph / 1230 km/h
Range 770 nm / 1,430 km
Climb Rate 3.1 minutes to 40,000 ft / 12,000 m
Maximum Service Ceiling 55,700 ft / 17,000 m (Point Interception Role)

52,800 ft / 16,000 m (Area Interception Role)
Crew 1 Pilot

1 Radar Operator
Main Proposed Armament
  • 8x GAR-1 Falcon AAM
  • 48 2.75in (7 cm) FFAR
Alternative Armament Loadouts Internal Storage

  • 1x Sparrow II AAM
  • 4x Sidewinder AAMs
  • 105x 2.75in (7 cm) rockets (original 48 on top of this)
  • 270x 2in (5.1 cm) rockets

External Hardpoints

  • 4x Hardpoints for additional weapons (2 are used for fuel tanks)

Gallery

Northrop N-126 – Artist Impression of the Delta Scorpion in USAF Prototype Stage
Northrop N-144 – Artist Impression of the N-144 the in Late Prototype Stage
Northrop N-149 – Artist Impression of the N-149 in service with the 171 Fighter Interceptor Squadron, Michigan, circa 1960s

 

3-Way drawing of the N-126 Delta Scorpion [US Secret Fighter Projects]
3-Way drawing of the N-149 [US Secret Fighter Projects]
Underside quarter view of the N-126 model [US Secret Fighter Projects]

3 view drawing of the N-126 Delta Scorpion
A photo of the N-126 Delta Scorpion in wind tunnel testing

3-Way drawing of the N-149 [US Secret Fighter Projects]
Colored photo of the N-149 model. Note the tail has been slightly damaged. [US Secret Fighter Projects]
Rear view of the N-149 model. Damage to the tail is evident here. [American Secret Projects: Fighters & Interceptors, 1945-1978]
Credits

Operation Plumbbob – Pascal B Cap

Cold War, US, , ,

USA flag old United States of America (1957)
Underground Nuclear Test Shaft Cap – 1 Built

This photo depicts the smoke after the detonation of Ranier, an underground nuclear test very similar to Pascal B

The brainchild of one ambitious American astrophysicist during the course of U.S. nuclear tests yielded the first manmade object in Earth’s orbit. The four foot round steel cap was launched into orbit in late August 1957 by the United States, beating the USSR’s Sputnik 1 to orbit by one month and nine days, scoring a major victory in the space race for the Americans. This feat has gone largely unrecognized by most historians.

History

Dr. Robert R. Brownlee

During Operation Plumbbob, which was a series of nuclear tests performed by the United States in 1957, Dr. Robert Brownlee was tasked with determining methods for containing nuclear blasts underground. Initially working from a detonation performed at the bottom of an open shaft, and progressively adding additional ‘plugs’ of concrete to ‘tamp’ the explosion.

The first empty shaft test was called Pascal A, and performed on July 26, 1957. It’s significance was characterized by the fact that it was the first contained underground nuclear test ever performed. The bomb was placed at the bottom of a shaft of about 500 feet in depth, around 3 feet in diameter. The blast yield was much greater than anticipated, estimated at around 55 tons which caused quite a stir at the test site when it was detonated. A concrete collimator with a thickness of five feet was lowered about halfway down the shaft with a detector installed on top. The concrete and detector were presumably vaporized in the explosion, which occured at night and caused a “big blue glow in the sky,” according to Test Director Robert Campbell.

Pascal B

Nevada Test Site Entrance

The next test, Pascal B, attempted to measure the effect of installing a concrete plug just above the bomb, still deep at the bottom of a 500 foot shaft, with a steel cap installed at the end, where the shaft met the surface. The concrete plug, also serving as a collimator for test instruments as in Pascal A, was placed above the bomb. The plug was estimated to have weighed 2 tons.

The shaft diameter for Pascal B was 4 feet in diameter, with a round solid steel cap, 4 inches thick welded to the top. The weight of the cap was estimated to be 2,000 lb (900 kg). Dr. Brownlee designed his calculations to estimate the time and measurements of the nuclear blast’s shockwave in meeting the cap. The estimated time for the shockwave’s arrival was 31 milliseconds. It was anticipated that the pressure and temperature would launch the cap away from the shaft at an extremely high velocity, although this would not necessarily be directly a result of the explosion, since the cap was located too far from the bomb at the bottom of the shaft. Rather, the vaporization and resulting superheated gas of the 2 ton concrete collimator plug placed above the bomb would actually turn the shaft into a ‘giant gun.’ The cap was estimated to achieve a velocity six times the escape velocity of the Earth. A high speed camera was installed nearby with the hopes of capturing the cap’s departure, to hopefully obtain a calculation of the cap’s speed as it left the shaft.

At the Nevada Test Site on August 27, 1957 at 3:35 PM local time, Pascal B was detonated with a yield of 300 tons. The fireball reached into the blue Nevada sky, launching the cap as expected. The high speed camera recorded the cap above the hole in only one frame of the resulting film. The anticipated velocity values combined with the framerate of the camera did not yield any specifically useful measurements, leading Dr. Brownlee to sum up the speed of the cap as “going like a bat!” The original calculation of six times the escape velocity of the Earth of 41.75 miles per second (67.2 km/sec) seemed to have been approximately correct. Other calculations by Carey Sublette that attempt to estimate the expanding gas of the vaporized concrete collimator indicate a similar figure of around five times the escape velocity.

First Manmade Object in Earth Orbit

Contemporary satellite photo of the test site, NTS U3d

Whether or not the cap actually made it to space is still a topic of debate. No trace of the cap was ever found anywhere near the test site. Some say it would have been vaporized in the same manner as a meteorite burning up upon entry into Earth’s atmosphere. Still others theorize that the object may have made it into Earth’s orbit. For the purposes of this article, it is assumed that the cap made it into Earth’s orbit.

The cap would not be the first manmade object in space. That honor belongs to a V-2 rocket launch in Nazi Germany on October 3, 1942, which crossed the Kármán line which is considered to be the boundary of space at an altitude of 100 km (62 miles).

Aside from the Pascal B cap, the most generally agreed upon first manmade object in Earth’s orbit is Sputnik 1, launched on October 4, 1957. If the cap in fact achieved orbit, it would have beaten Sputnik by 1 month and 9 days. This fact has yet to be widely recognized, with most people and historians believing that the USSR achieved the first object in orbit.

Design

3 View Drawing of the Cap by Ed Jackson

The steel cap round, 4 inches thick, was welded to the end of the round metal test shaft, 4 feet in diameter. The cap was presumably not painted or covered with any sort of coating. More than likely the cap was machined locally along with the other significant large scale industrial milling, machining, and fabrication to facilitate the testing operations in support of Operation Plumbbob.

The cap has yet to be found in orbit by NASA, however its exact position still may yet be discovered. At only 4 feet in diameter, dark in color, and at an unknown orbital position, it is difficult to estimate its potential location.

Operators

  • United States – Originally launched from the Nevada Test Site in 1957, the Pascal B Cap remains in service in Earth’s orbit despite its unknown location.

Pascal B Cap Specifications
Diameter 4 ft / 1.22 m
Thickness 4 in / 10.16 cm
Initial Propellant 64.6 lb Plutonium Pit Nuclear Bomb with PBX 9401 and 9404 explosives
Weight 2,000 lb / 907 kg [estimated]
Climb Rate 41.75 miles per second (67.2 km/sec) [estimated]
Maximum Speed 150,300 mph / 241,884 kmh
Range ∞ mi / ∞ km
Maximum Orbital Altitude 574,147 ft / 924,000 km [estimated]
Crew Unmanned
Armament
  • Ramming Impact Capability
  • Sharp Edges
  • High Velocity Steel Fragment & Debris

Gallery

Artist conception of the current state of the cap in orbit by Ed Jackson

Sources

North American F-86A Sabre

Cold War, US, , , , ,

USA flag old United States of America (1947)
Jet Fighter – 554 Built

F-86A-1-NA Sabre 47-630 in flight (North American Aviation)

The iconic F-86A got its first official production underway with the A series in 1947, with the initial examples fulfilling many testing duties, followed by a larger second production batch for active service. The development of these first Sabres would address many teething problems with the aircraft’s engines, speed brakes, and weaponry.  The A models, alongside many other first generation American jet aircraft would go on to see a few short years of service in the Korean theatre as well as defense of the United States before being eclipsed by the relatively rapid development of more advanced jet designs.

History

The P-86A was the first production version of the Sabre. North American had received an order for 33 production P-86As on November 20, 1946, even before the first XF-86 prototype had flown. The P-86A was outwardly quite similar to the XP-86, with external changes being very slight. About the only noticeable external difference was that the pitot tube was moved from the upper vertical fin to a position inside the air intact duct.

Major Richard L. Johnson, USAF with F-86A-1-NA Sabre 47-611 and others at Muroc AFB, 15 September 1948. (F-86 Sabre, by Maurice Allward)

The first production block consisted of 33 P-86A-1-NAs, ordered on October 16, 1947. These were known as NA-151 on North American company records. Serials were 47-605 through 47-637. Since there were officially no YP-86 service test aircraft, this initial production block effectively served as such.

The first production P-86A-1-NA (serial number 47-605) flew for the first time on May 20, 1948. The first and second production machines were accepted by the USAF on May 28, 1948, although they both remained at Inglewood on bailment to North American for production development work. Aircraft no. 47-605 was not actually sent to an Air Force base until April 29, 1950. It remained at WPAFB until May of 1952, when it was retired to storage at the Griffiss Air Depot.

In June of 1948, the P-86 was redesignated F-86 when the P-for-pursuit category was replaced by F-for-fighter

By March of 1949 the last F-86A-1-NA (47-637) had been delivered. Most of the 33 F-86A-1-NAs built were used for various tests and evaluations, and none actually entered squadron service.

The first production block to enter squadron service was actually the second production batch, 188 of which were ordered on February 23, 1949. They were assigned the designation of F-86A-5-NA by the USAF, but continued to be carried as NA-151 on company records. Serials were 48-129 to 48-316. These were powered by the J47-GE-7 jet engine. Deliveries began in March of 1949 and were completed in September of 1949.

A contract for 333 additional F-86As was received on May 29, 1948, and the final contract was approved on February 23, 1949. These aircraft were assigned a new designation of NA-161 on North American company records, but continued to be designated F-86A-5-NA in USAF records. Their serials were 49-1007 to 49-1229. These were powered by the General Electric J47-GE-13 engine which offered 5200 pounds of static thrust. The cockpit wiring was simplified. New 120-gallon drop tanks, developed specifically for the F-86, were introduced during this production run. Deliveries commenced in October of 1949 and were completed by December of 1950. The 282nd F-86A aircraft had a redesigned wing trailing edge with shorter chord aileron and greater elevator boost. Deliveries commenced October 1949 and ended in December 1950.

First Deployment

The first USAF combat organization to receive the F-86A was the First Fighter Group based at March AFB in California, with the famous “Hat in the Ring” 94th Squadron being the first to take delivery when they traded in their F-80s for the F-86A-5-NA during February of 1949. The 27th and 71st Squadrons were equipped with F-86A-5-NAs next, and by the end of May of 1949 the group had 83 F-86As on strength. This group was charged with the aerial defense of the Los Angeles area, which, coincidentally, is where the North American Aviation factory was located. Next to get the F-86 the the 4th Fighter Group based at Langley AFB, charged with the defense of Washington, D.C, and then the 81st Fighter Group, based at Kirtland AFT and charged with the defense of the nuclear bomb facilities at Alamogordo, New Mexico. Next came the 33rd Fighter Group based at Otis AFB in Massachusetts, charged with defending the northeastern approaches into the USA. In January of 1950, all air defense units were redesignated as Fighter Interceptor Groups (FIGs) or Fighter Interceptor Wings (FIWs) as a part of the Air Defense Command.

Origin of the “Sabre” Name

In February of 1949, there was a contest held by the First Fighter Group to choose a name for their new fighter. The name *Sabre* was selected, and was made official on March 4, 1949.

Reserves

The first Sabres that went to Reserve units were assigned to the 116th Fighter Interceptor Squadron of the Air National Guard, which received its first F-86As on December 22, 1950.

The following Wings were issued with the F-86A:

  • 1st Fighter Interceptor Wing (27th, 75st and 94th Squadrons)
  • 4th Fighter Interceptor Wing (334th, 335th, 336th Squadrons)
  • 33rd Fighter Interceptor Wing (58th, 59th and 60th Squadrons)
  • 56th Fighter Interceptor Wing (61st, 62nd, 63rd Squadrons)
  • 81st Fighter Interceptor Wing (78th, 89st, 92nd Squadron)

The F-86A was replaced in active USAF service by the F-86E beginning in the autumn of 1951. As F-86As left active USAF service, they were refurbished, reconditioned and transferred to Air National Guard units in the United States. The first ANG units to get the F-86A were the 198th Squadron in Puerto Rico, the 115th and 195th Squadrons at Van Nuys, California, the 196th at Ontario, and the 197th at Phoenix, Arizona.

Record Breaker

In the summer of 1948, the world’s air speed record was 650.796 mph, set by the Navy’s Douglas D-558-1 Skystreak research aircraft on August 25, 1947. Like the record-setting Lockheed P-80R before it, the Skystreak was a “one-off” souped-up aircraft specialized for high speed flight. The USAF thought that now would be a good time to show off its new fighter by using a stock, fully-equipped production model of the F-86A to break the world’s air speed record.

Major Richard L. Johnson on the day of his record-breaking flight, September 15th, 1948 (

To get the maximum impact, the Air Force decided to make the attempt on the speed record in the full glare of publicity, before a crowd of 80,000 spectators at the 1948 National Air Races in Cleveland, Ohio. The fourth production F-86A-1-NA (serial number 47-608, the cold weather test aircraft) was selected to make the record attempt, and Major Robert L. Johnson was to be the pilot. According to Federation Aeronautique Internationale (FAI) rules, a 3km (1.86 mile) course had to be covered twice in each direction (to compensate for wind) in one continuous flight. At that time, the record runs had to be made at extremely low altitudes (below 165 feet) to enable precise timing with cameras to be made.

On September 5, 1948, Major Johnson was ready to go and flew his F-86A-1-NA serial number 47-708 on six low-level passes over the course in front of the crowd at Cleveland. Unfortunately, timing difficulties prevented three of these runs from being clocked accurately. In addition, interference caused by other aircraft wandering into the F-86A’s flight pattern at the wrong time prevented some of the other runs from being made at maximum speed. Even though the average of the three runs that were timed was 669.480 mph, the record was not recognized as being official by the FAI.

Further attempts to set an official record at Cleveland were frustrated by bad weather and by excessively turbulent air. Major Johnson then decided to move his record-setting effort out to Muroc Dry Lake (later renamed Edwards AFB), where the weather was more predictable and the air less turbulent. On September 15, 1948, Major Johnson finally succeeded in setting an official record of 670.981 mph by flying a different F-86A-1-NA (serial number 47-611, the armaments test aircraft) four times over a 1.86-mile course at altitudes between 75 and 125 feet.

Design

F-86A-1 47-611 Conducting a Static 5-inch HVAR Rocket Firing Test (U.S. Air Force Photo)

The P-86A incorporated as standard some of the changes first tested on the third XP-86 prototype. The front-opening speed brakes on the sides of the rear fuselage were replaced by rear-opening brakes, and the underside speed brake was deleted. However, the most important difference between the P-68A and the three XP-86 prototypes was the introduction of the 4850 lb.s.t. General Electric J47-GE-1 (TG-190) in place of the 4000 lb.s.t. J35. The two engines had a similar size, the J47 differing from the J35 primarily in having a twelfth compressor stage.

The F-86A-1-NA fighters could be recognized by their curved windshields and the flush-fitting electrically-operated gun muzzle doors that maintained the smooth surface of the nose. These muzzle doors opened automatically when the trigger was pressed to fire the guns, and closed automatically after each burst.

The cockpit of the F-86A remained almost the same as that of the XP-86, although certain military equipment was provided, such as an AN/ARC-3 VHF radio, an AN/ARN-6 radio compass, and an AN/APX-6 IFF radar identification set. The IFF set was equipped with a destructor which was automatically activated by impact during a crash or which could be manually activated by the pilot in an emergency. This was intended to prevent the codes stored in the device from being compromised by capture by the enemy. The F-86A was provided with a type T-4E-1 ejection seat, with a manually-jettisoned canopy.

The F-86A-1-NA’s empty weight was up to 10,077 pounds as compared to the prototype’s 9730 pounds, but the higher thrust of the J-47 engine increased the speed to 673 mph at sea level, which made the F-86A-1-NA almost 75 mph faster than the XP-86. Service ceiling rose from 41,200 feet to 46,000 feet. The initial climb rate was almost twice that of the XP-86.

In the autumn of 1948, problems with the J-47-GE-1 engine of the early F-86As forced a momentary halt to F-86 production. It was followed by a few J47-GE-3s, and in December the J47-GE-7 became available, which offered 5340 lb.s.t. and full production resumed.

A close up of the early A models’ retractable gunport covers. (Julien of Britmodeller)

The F-86A-5-NA had a V-shaped armored windscreen which replaced the curved windscreen of the F-86A-1-NA. The A-5 would dispense with the gun doors at some point in its production in the interest of maintenance simplicity, although many A-5 examples can be seen with gun doors, many of them with the doors permanently open. A jettisonable cockpit canopy was introduced. The A-5 introduced underwing pylons capable of carrying a variety of bombs (500 and 1000-pounders) or underwing fuel tanks of up to 206 gallons in capacity. A heating system was provided for the gun compartments, and stainless steel oil tanks and lines were provided for better fire resistance.

In May of 1949, beginning with the 100th F-86A aircraft, an improved canopy defrosting system was installed and a special coating was applied to the nose intake duct to prevent rain erosion. Earlier airframes were retrofitted to include these changes. The 116th F-86A was provided with a new wing slat mechanism which eliminated the lock and provided a fully automatic operation.

Gun Sight & Radar

The P-86A was equipped with the armament first tested on the third XP-86 six 0.50-inch machine guns in the nose, three on each side of the pilot’s cockpit. The guns had a rate of fire of 1100 rounds per minute. Each gun was fed by an ammunition canister in the lower fuselage holding up to 300 rounds of ammunition. The ammunition bay door could be opened up to double as the first step for pilot entry into the cockpit. The P-86A had two underwing hardpoints for weapons carriage. They could carry either a pair of 206.5 US-gallon drop tanks or a pair of 1000-lb bombs. Four zero-length stub rocket launchers could be installed underneath each wing to fire the 5-inch HVAR rocket, which could be carried in pairs on each launcher.

An innovation introduced with the NA-161 production batch was a new type of gun aiming system. All earlier F-86As had been equipped at the factory with Sperry Mark 18 optical lead computing gunsight, which was quite similar to the type of gunsight used on American fighter aircraft in the latter parts of World War 2. When the pilot identified his target, he set the span scale selector lever to correspond to the wingspan of the enemy aircraft he was chasing. He then aimed his fighter so that the target appeared within a circle of six diamond images on the reflector. Next, he rotated the range control unit until the diameter of the circle was the same as the size of the target. When the target was properly framed, the sight automatically computed the required lead and the guns could be fired.

Beginning with the first NA-161 aircraft (49-1007), the A-1B GBR sight and AN/APG-5C ranging radar were provided as factory-installed equipment. This new equipment was designed to automatically measure the range and automatically calculate the appropriate lead before the guns were fired, relieving the pilot of the cumbersome task of having to manually adjust an optical sight in order to determine the range to the target. When activated, the system automatically locked onto and tracked the target. The sight image determined by the A-1B was projected onto the armored glass of the windscreen, and the illumination of a radar target indicator light on the sight indicated time to track target continuously for one second before firing. This system could be used for rocket or bomb aiming as well as for guns.

In the last 24 F-86A-5-NAs that were built, the A-1B GPR sight and AN/APG-5C ranging radar were replaced by the A-1CM sight that was coupled with an AN/APG-30 radar scanner installed in the upper lip of the nose intake underneath a dark-colored dielectric covering. The APG-30 radar was a better unit than the AN/APG-5C, with a sweep range from 150 to 3000 yards. The A-1CM sight and the APG-30 ranging radar were both retrofitted to earlier A-5s during in-field modifications. These planes were redesignated F-86A-7-NA. However, some F-86A-5-NAs had the new A-1CM GBR sight combined with the older AN/APG-5C radar. These were redesignated F-86A-6-NA.

Engines

Some consideration given to replacing the J47 engine with the improved J35-A-17 that was used in the F-84E. This engine was tested in the first XP-86. Flight tests between November 28, 1949 and March 1951 indicated that the performance remained much the same as that of the F-86A-1-NA but with a slightly better range. However, the improvement was not considered significant enough to warrant changing production models.

Some F-86As were re-engined with the J47-GE-13 engine, rated at 5450 lb.s.t., but their designation did not change.

All F-86As were initially delivered with the pitot head located inside the air intake duct. It was found in practice that false airspeed readings could be obtained due to the increased airflow within the intake duct, so North American decided to move the pitot head to the tip of a short boom that extended from the leading edge of the starboard wingtip. All F-86As were later retrofitted with the wingtip boom when went through IRAN (Inspect and Repair as Necessary). However, the pitot tube in the intake was never designed to provide airspeed input to the pilot, and the pitot tube in the intake was still there and was used to provide input for the engine.

Fuel

Internal fuel capacity of the F-86A was 435 gallons, carried in four self-sealing tanks. Two of the tanks were in the lower part of the fuselage, one of them being wrapped around the intake duct just ahead of the engine and the other being wrapped around the engine itself. The other two fuel tanks were in the wing roots. Usually the F-86A carried two 120-gallon drop tanks, although 206.5 gallon tanks could be fitted for ferry purposes.

Weapons

Ground attack weapons could be installed in place of the jettisonable underwing fuel tanks. Choices include a pair of 100, 500 or 1000-pound bombs, 750-pound napalm tanks, or 500 pound fragmentation clusters. Alternatively, eight removable zero-rail rocket launchers could be installed. These mounted sixteen 5-inch rockets. When external armament was fitted in place of the drop tanks, combat radius was reduced from 330 to 50 miles, which was not a very useful distance.

F-86A in Korea

Even though the initial skirmishes with MiGs in Korea had demonstrated that their pilots lacked experience and an aggressive approach, the MiG threat was very real and threw the USAF into a near panic. The USAF had nothing in Korea that could provide an effective counter if the MiG-15s were to intervene in large numbers.

In order to counter the MiG threat, on November 8 the 4th Fighter Interceptor Wing, which consisted of the 334th 335th, and 336th Squadrons, based at Wilmington, Delaware and equipped with the F-86A Sabre was ordered to Korea. Most of their pilots were seasoned veterans of World War 2 and they had shot down over 1000 Germans during that conflict. Prior to flying to the West Coast, the 4th FIG exchanged their older ’48 model F-86As for some of the best “low-time” F-86As taken from other Sabre units. The 334th and 335th FIS flew to San Diego and their planes were loaded aboard a Navy escort carrier. The 336th FIS went to San Francisco and was loaded aboard a tanker. Their F-86A aircraft arrived in Japan in mid-December. The aircraft were then unloaded and flown to Kimpo airfield in Korea.

However, before any of these Sabres could reach the front, on November 26, 1950, Chinese armies intervened with devastating force in Korea, breaking through the UN lines and throwing them back in utter confusion. The MiGs did not provide any effective support for this invasion, being unable to establish any effective intervention below a narrow strip up near the Yalu. The MiG pilots were relatively inexperienced and were poor marksmen. They would seldom risk more than one pass at their targets before they would dart back across the Yalu. Had the MiGs been able to establish and hold air superiority over the battle area, the UN forces may well have been thrown entirely out of Korea.

The first advanced detachment of 336th FIS F-86As arrived at Kimpo airfield south of Seoul on December 15. The first Sabre mission took place on December 17. It was an armed reconnaissance of the region just south of the Yalu. Lt. Col. Bruce H. Hinton, commander of the 336th Squadron, succeeding in shooting down one MiG-15 out of a flight of four, to score first blood for the Sabre. The rest of the MiGs fled back across the Yalu. On December 19, Col. Hinton led another four-plane flight up to the Yalu, where his flight met six MiGs who flew through his formation without firing a shot before dashing back across the Yalu. On December 22, the MiGs managed to shoot down a single Sabre out of a flight of eight without loss to themselves, but later that day the Sabres got their revenge by destroying six MiGs out a flight of 15. This loss spooked the MiG pilots, and they avoided combat for the rest of the month.

During December, the 4th Wing had flown 234 sorties, clashed with the enemy 76 times, scored eight victories, and lost one aircraft.

By the end of 1950, Chinese armies had driven UN forces out of North Korea and had begun to invade the South. The Sabres were forced to leave Kimpo and return to Japan which put them out of range of the action up at the Yalu.

Even though the Yalu was now out of range, on January 14, an F-86A detachment appeared at Taegu to participate as fighter bombers to try to halt the Chinese advance. The F-86A was not very successful in the fighter-bomber role, being judged much less effective than slower types such as the F-80 and the F-84. When carrying underwing ordinance, the F-86A’s range and endurance were much too low, and it could not carry a sufficiently large offensive load to make it a really effective fighter bomber. In these attacks, the underwing armament was usually limited to only a pair of 5-inch rockets.

Eventually, the Chinese advance ground to a halt due to extended supply lines and the relentless UN air attacks. The Chinese advance was halted by the end of January, and the UN forces began pushing them back. Kimpo airfield was recovered on February 10. The halting of the Chinese advance can be blamed largely on the inability of the MiGs to provide any effective support for the Chinese attack. Not only had no Chinese bombers appeared to attack UN troops, but no MiGs had flown south of the Yalu region to provide any air support.

The Chinese apparently did have plans for a major spring offensive to complete the task of driving the UN out of Korea. This plan was to be based on the construction of a series of North Korean air bases and for Chinese MiGs to use these bases as forward landing strips to provide air superiority over the North, preventing UN aircraft from interfering with the advance.

In early March, the MiGs began to become more active in support of this offensive, On March 1, MiGs jumped a formation of nine B-29s and severely damaged three of them. Fortunately, by this time the UN base at Suwon was now ready, and the Sabres were now able to return to Korea and reenter the fray over the Yalu. The Sabres of the 334th Squadron began their first Yalu patrols on March 6th, and the rest of the squadron moved in four days later. At the same time, the 336th Squadron moved to Taegu from Japan, so that they could stage Sabres through Suwon. The 4th Wing’s other squadron, the 335th, stayed in Japan until May 1.

MiG Alley

The strip of airspace in western Korea just south of the Yalu soon became known as “MiG Alley” to the Sabre pilots. The Sabres would arrive for their 25-minute patrols in five minute intervals. The MiGs would usually cruise back and forth at high altitude on the other side of the Yalu, looking for an opportune time to intervene. Very often they would remain on the north side of the river, tantalizingly out of reach. When the MiGs did choose to enter battle, the Sabres would usually have only a fleeting chance to fire at the enemy before the MiGs broke off and escaped back across the Yalu. The MiGs had the advantage of being able to choose the time and place of the battle. The MiG-15 had a better high-altitude performance than the F-86A. The MiG had a higher combat ceiling, a higher climb rate, and was faster at higher altitudes than the F-86A. Its superior high-altitude performance enabled the MiG to break off combat at will. Despite these handicaps, the F-86A pilots were far more experienced than their Chinese opponents and they were better marksmen. The Sabre was a more stable gun platform and had fewer high-speed instabilities than did the MiG-15. In addition, the F-86A was faster than the MiG-15 at lower altitudes, and an effective strategy was for the Sabre to force the battle down to lower altitudes where it had the advantage.

In April of 1951, the MiGs got a little bolder, and they would often make attempts to intercept B-29 formations that were attacking targets in the Sinuiju area up near the Yalu. The biggest air battle of that spring took place on April 12, when a formation of 39 B-29s escorted by F-84Es and F-86As were attacked by over 70 MiGs. Three B-29s were lost, whereas 14 MiGs were claimed destroyed, four by the escorting Sabres and ten by B-29 gunners.

On May 20, 1951, F-86A pilot Captain James Jabara became the world’s first jet ace when he shot down a pair of MiGs to bring his total to six.

No F-86As were lost in action during the first five months of 1951, and they flew 3550 sorties and scored 22 victories. Most of the attrition was caused by accidents rather than by losses in actual combat.

In June of 1951, the MiGs began to show more aggressive behavior, and their pilots began to get somewhat better. In air battles on June 17th, 18th, and 19th, six MiGs were destroyed but two Sabres were lost. Another Sabre was lost on June 11 when the 4th Wing covering an F-80 attack on the Sinuiju airfield shot down two more MiGs.

As the first year of the Korean War came to an end, it was apparent that the Sabre had been instrumental in frustrating the MiG-15’s bid for air superiority. Without control of the air, the Red Chinese were unable to establish their series of air bases and they were not able to carry out effective air support of their spring offensive, and the Korean War settled down to a stalemate on the ground.

The more-advanced F-86E began to enter action in Korea with the 4th Wing in July of 1951, replacing that unit’s F-86As on a one-by-one basis. The conversion to the F-86E was rather slow, and the last F-86A was not replaced until July of 1952.

Operators

  • U.S. Air Force – The U.S. utilized the F-86A extensively for the air defense of the Continental United States, while also seeing action in Korea in MiG Alley.

North American F-86A-5-NA Specifications
Wingspan 37 ft 1.5 in / 11.32 m
Length 37 ft 6.5 in / 11.44 m
Height 14 ft 9 in / 4.5 m
Wing Area 287.9 ft² / 26.8 m²
Engine 1x General Electric J47-GE-13 Turbojet Engine

5200 lbst
Weights
Empty 10,093 lb / 4,578 kg
Maximum Take Off 14,108 lb / 6,399 kg
Combat 13,791 lb / 6,255 kg
Climb Rate
Rate of Climb at Sea Level 7,470 ft / 2,277 m per minute
Time to 40,000 ft / 12,192 m 10.4 minutes
Maximum Speed
Sea Level 679 mph / 1,092 kmh
35,000 ft / 10,668 m 601 mph / 967 kmh
Takeoff Run 2,430 ft / 741 m
Range (with Drop Tanks) 660 mi / 1,062 km
Maximum Service Ceiling 48,000 ft / 14,630 m
Crew 1 pilot
Armament
  • 6x Browning M3 machine guns, 300 rounds per gun
  • A-1B GBR Gun Sight
  • AN/APG-5C Ranging Radar
  • 8x 5-inch HVAR Rockets
  • 2x 1000 lb bombs
  • 2x Drop Tanks – 206.5 U.S. Gal / 781.7 Liters

Gallery

Illustrations by Ed Jackson

F-86A-1 Sabre 47-611 – September 1948
F-86A-1 Sabre 47-630 – 1948
F-86A-5 48-0158 – 1949
F-86A-5 48-1257 – Korea 1951 – Flown by Capt. James Jabara
F-86A-5 Sabre 49-1080 February 1952 – Note the 5 inch HVAR Rocket Mounted inboard of the fuel tank

Sources:

  1. F-86 Sabre in Action, Larry Davis, Squadron/Signal Publications, 1992.
  2. The North American Sabre, Ray Wagner, MacDonald, 1963.
  3. The American Fighter, Enzo Angelucci and Peter Bowers, Orion, 1987.
  4. The World Guide to Combat Planes, William Green, MacDonald, 1966.
  5. Flash of the Sabre, Jack Dean, Wings Vol 22, No 5, 1992.
  6. North American F-86 Sabre, Larry Davis, Wings of Fame, Volume 10, 1998

 

Yakovlev Yak-10

Cold War, Soviet Union, , ,

USSR flag USSR (1946)
Multipurpose Aircraft – 41 Built

An impressive photo of freshly produced Yak-10 sit on the Dolgoprudny airfield awaiting delivery. [Yefim Gordon]
The Yakovlev Yak-10 was a four-seat multipurpose light aircraft designed in 1944 as a replacement for the Polikarpov U-2 (Po-2), a biplane which served as a liaison and passenger transport aircraft. Although the Yak-10 successfully passed state acceptance trials in January of 1945, it proved rather unsatisfactory with Soviet Air Force pilots, and thus, only 41 examples, including the prototype, were produced in 1946 before being replaced by the redesigned and superior Yak-12 light aircraft in 1947. Though unsuccessful in service, the Yak-10 provided valuable experience in light aircraft design and served as a stepping stone for the more successful Yak-12.

History

In early 1944, the Soviet High Command was beginning to realize the obsolete nature of the Polikarpov U-2 (Po-2) in its liaison role. In the wake of the quickly advancing aircraft industry, Yakovlev OKB (Experimental Design Bureau) was called upon to design a multipurpose light aircraft capable of performing liaison missions, ferrying passengers, cargo, and aerial ambulance duties for the Air Force to replace the Po-2. In response, Yakovlev OKB initiated a project with G.I. Gudimenko assigned as chief engineer and work commenced on a four-seat, high-wing monoplane using the firm’s pre-war AIR-6 design as a basis, which had similar traits. The new aircraft design was assigned the designation of Yak-14.

Due to the rather obscure nature of the project’s development, it is unknown when the first prototype was produced, but it is most likely sometime before or in early January of 1945. First flown by test pilot F.L. Abramov, the Yak-14, powered by a 5-cylinder, air cooled Shvetsov M-11FM radial engine producing 145 hp, proved to have unacceptable handling characteristics. This prompted minor redesigning and modifications to the prototype which would address the issues that emerged from the test flight. Amongst the various modifications, the aircraft was also redesignated as the Yak-10 (the Yak-14 designation would later be reused for a 1947 assault glider project). With the completion of modifications, the Yak-10 was resubmitted for state testing. The aforementioned handling characteristic issues appeared to have been addressed, and the Yak-10 passed state trials in June of 1945.

Yak-10 Blueprint Drawing

Now authorized for service, production of the Yak-10 was assigned to the No. 464 aircraft plant in Dolgoprudny (Долгопру́дный), approximately 12 mi / 20 km north of Moscow. A total of 40 models were produced in 1946, which were then delivered to air force units. An important difference between the prototype and production models was the conversion from the 145 hp M-11FM engine to the 160 hp M-11FR engine. During the Yak-10’s service life, several variants were designed. These included a dual-control trainer variant known as the Yak-10V, an aerial ambulance variant capable of carrying two stretchers and a doctor known as the Yak-10S, an experimental floatplane variant known as the Yak-10G, and an experimental ski landing gear conversion without a proper designation. Due to the scarcity of documents regarding the Yak-10, it is unknown how many Yak-10V and Yak-10S models were produced, but the Yak-10G and Yak-10 with ski gear were converted from standard Yak-10 models. Curiously, the Yak-10 also had a competitive experimental low-wing development in 1944 known as the Yak-13 (originally designated the Yak-12, which is unrelated to the 1947 development) which featured a split landing flap and various smaller modifications. Though the Yak-13 was superior to the Yak-10 in speed, the Yak-10 possessed operational advantages and thus won the favor of the Soviet high command. Though the Yak-13 was considered to be produced alongside the Yak-10, the act was deemed economically unviable and thus the Yak-13 remained a one-off prototype.

The Yak-10 prototype, still known as the Yak-14 at the time this photo was taken. [Yefim Gordon]
In Soviet service the Yak-10 proved to be lacking in terms of performance, which also impacted the aircraft’s ability to be adapted to more roles. Within a year of the Yak-10’s fielding, the Yakovlev OKB was once again called upon to produce a better aircraft. In early 1947, the bureau initiated another project to fulfill the demands of the Air Force. G.I. Gudimenko was once again assigned as chief engineer, but now M.A. Shchyerbina, M.N. Beloskurskii and L.L. Selyakov joined the team as designers. The new project was designated as the Yak-12 (recycled from the Yak-13’s initial designation) and was essentially a redesigned Yak-10 that featured a redesigned rear fuselage contour and a shallower upper decking. Along with some other modifications to the wings, structure and fuselage, the Yak-12 would undergo flight testing within the same year. Though slower than the Yak-10 in speed, the Yak-12 proved to be more versatile for other roles and had greater operational characteristics. Such improvement was deemed satisfactory by the Air Force and mass production thus commenced. The success of the Yak-12 overshadowed the Yak-10 and all examples were withdrawn soon afterwards. The Yak-12 would be produced in the thousands with dozens of variants and conversions designed. It would see service with several Eastern Bloc countries, as well as the People’s Republic of China, Mongolia and possibly Cuba (it is unknown if they operated this type). The Yak-12 was saw military service well into the 1970s but were all retired prior to the 21st century. Several Yak-12 models are still flown to today for recreation, airshows and other roles.

The Yak-10, despite passing state acceptance trials, was still an operational failure and saw only limited production. However, the Yak-10 was an important stepping stone in the development of the Yak-12, which was much more successful and had a fruitful service life within the Soviet Union and several other countries.

Design

A Yak-10 flies over the Moskva River near the Moscow suburbs. [Yefim Gordon]
The Yakovlev Yak-10 was a four-seat, high-wing, single-engine multipurpose light aircraft designed in 1944. The standard production Yak-10 was powered by a 5-cylinder air-cooled Shvetsov M-11FR radial engine providing 160 hp, accompanied by a two blade aluminum VISh-327 propeller. The Yak-10’s fuselage and tail was of metal construction while the wings were wooden. The wooden wings possessed a thickness to chord ratio of 11% and utilized the Clark YH airfoil. The fuselage consisted of a welded tubular steel truss while the tail possessed duralumin frames. Fabric was utilized throughout the entire aircraft for skinning. Twin bracing struts constructed of airfoil section steel tubes joined the wings and fuselage. The Yak-10 also had a non-retractable undercarriage in a taildragger configuration. It consisted of pyramid type, rubber-sprung main units and had a castoring tailwheel.

The same Yak-10 above parked at the Chkalovskaya AB during state acceptance trials at NII VVS. [Yefim Gordon]
The Yak-10V dual control trainer variant would have featured a new set of controls next to the regular pilot seat. This would allow a co-pilot to fly while both pilots sat side by side. The Yak-10S ambulance variant would have a hatch on the port side of the fuselage for loading stretchers. A total of two stretchers could be accommodated in the Yak-10S along with a seat for a doctor. The Yak-10G featured the replacement of the conventional landing gear with floats previously used in the Yakovlev OKB’s previous AIR-6 multipurpose light aircraft design. Little is known about this variant, but it is known that it did not go into production due to the loss of performance caused by the floats’ drag. The experimental Yak-10 ski conversion had the landing gear replaced by Canadian manufactured wood skis of 6 ft 3 63/64 in x 1 ft 25/64 in / (1,930 x 340 mm). These skis weighed 44.7 lb (20.25 kg). The tail wheel was also replaced by a ski which measured at 1 ft 6 7/64 in x 4 47/64 in (460 x 120 mm) and weighed 4.25 lb (1.93 kg). This modification caused the aircraft’s performance to deteriorate and proved to be only capable of operating in rolled-down airfields. Consequently, the type was not adopted for use.

Variants

  • Yak-10 – Standard production variant powered by a 5-cylinder air-cooled Shvetsov M-11FR radial engine providing 160 hp.
    • Yak-10V – Dual control trainer variant of the Yak-10. An unknown amount were produced.
    • Yak-10S – Medical variant of the Yak-10 which featured a hatch on the port side of the fuselage for loading stretchers. The passenger compartment could accommodate two stretchers and one doctor. It is unknown how many Yak-10S models were manufactured.
    • Yak-10G – Experimental floatplane variant of the Yak-10. A single Yak-10 was modified to carry AIR-6 type floats in 1946. The Yak-10G underwent manufacturer’s tests but this type was not accepted for mass production, likely due to the degradation of performance generated by the floats’ drag.
    • Yak-10 (Skis) – Experimental conversion of a Yak-10 to replace the conventional landing gears with Canadian manufactured wooden skis. A single example was converted from a standard model in February of 1947 but was rejected for service as the skis caused the Yak-10’s performance to deteriorate. The ski variant was also deemed only capable of being operated from rolled-down airfields, thus limiting the operable areas.
  • Yak-13 – Development of the Yak-10 in 1944 which saw a redesigned low-wing configuration, a split landing flap and various smaller modifications. The engine was also switched to a M-11FM radial engine producing 145 hp. The Yak-13 was superior to the Yak-10 in terms of performance, but this aircraft was not accepted for mass production as the Yak-12 was deemed better in some regards and as a result, the Yak-13 remained a one-off prototype. This variant was originally designated as the Yak-12 but the name was changed to Yak-13 during trials and the designation was reused for the 1947 development project of the Yak-10.
  • Yak-12 – Redesigned variant which first appeared in 1947. The Yak-12 featured a redesigned rear fuselage contour and a more shallow upper decking. Though the base model was slightly inferior to the Yak-10 in speed, the redesigned variant proved more capable in other aspects and was thus mass produced and replaced the Yak-10 in service.

Operators

  • Soviet Union – The Yakovlev Yak-10 and it’s variants were briefly operated by the Soviet Air Force from 1946 to 1947 before being replaced by the superior Yak-12.

Yakovlev Yak-10 Specifications
Wingspan 39 ft 4 ½ in / 12.0 m
Length 27 ft 8 ⅝ in / 8.45 m
Wing Area 237 ft² / 22 m²
Wing Airfoil Clark YH Airfoil
Thickness / Chord Ratio 11%
Engine 1x 5-cylinder air-cooled Shvetsov M-11FR-1 radial engine (160 hp)
Propeller 1x two-blade aluminum VISh-327 propellers
Empty Weight 1,746 lb / 792 kg
Normal Loaded Weight 2,535 lb / 1,150 kg
Maximum Loaded Weight 2,712 lb / 1,230 kg
Fuel Weight 207 lb / 94 kg
Oil Weight 31 lb / 14 kg
Climb Rate 3,280 ft / 1,000 m in 5.5 minutes
Maximum Speed 124 mph / 200 kmh – Normal Loaded Weight

122 mph / 196 kmh – Maximum Loaded Weight
Landing Speed 49 mph / 79 kmh – Normal Loaded Weight

52 mph / 84 kmh – Maximum Loaded Weight
Takeoff Distance 853 ft / 260 m – Normal Loaded Weight

1,115 ft / 340 m – Maximum Loaded Weight
Landing Distance 919 ft / 280 m – Normal Loaded Weight

984 ft / 300 m – Maximum Loaded Weight
Range 358 mi / 576 km
Maximum Service Ceiling 11,155 ft / 3,400 m
Crew 1x Pilot
Load Capacity 3x Passengers

Yakovlev Yak-10S Specifications
Wingspan 39 ft 4 ½ in / 12.0 m
Length 27 ft 8 ⅝ in / 8.45 m
Wing Area 237 ft² / 22 m²
Wing Airfoil Clark YH Airfoil
Thickness / Chord Ratio 11%
Engine 1x 5-cylinder air-cooled Shvetsov M-11FR radial engine (160 hp)
Propeller 1x two-blade aluminum VISh-327 propellers
Empty Weight 1,808 lb / 820 kg
Normal Loaded Weight 2,579 lb / 1,170 kg
Maximum Loaded Weight 2,756 lb / 1,250 kg
Fuel Weight 207 lb / 94 kg
Oil Weight 31 lb / 14 kg
Climb Rate 3,280 ft / 1,000 m in 5.5 minutes – Normal Load Weight
Maximum Speed 128 mph / 206 kmh – Normal Load Weight
Landing Speed 45 mph / 73 kmh – Normal Load Weight
Takeoff Distance 748 ft / 228 m – Normal Load Weight
Landing Distance 633 ft / 193 m – Normal Load Weight
Range 376 mi / 605 km
Maximum Service Ceiling 11,483 ft / 3,500 m
Crew 1x Pilot
Load Capacity 2x Stretchers + Injured Personnel

1x Doctor

Gallery

Illustrations by Haryo Panji

Yakovlev Yak-10 – Standard Model
Yakovlev Yak-10 – Standard Model in Alternate Livery
Yakovlev Yak-10 – Air Ambulance
Yakovlev Yak-10 – Float Variant

The prototype Yak-10G floatplane variant sits in a river awaiting flight trials. [Yefim Gordon]
A Yak-10 flies over the Moskva River near the Moscow suburbs. [Yefim Gordon]
A white painted Yak-10S ambulance variant. The port hatch for loading stretchers is visible beside the cross. [Yefim Gordon]

Credits

North American XP-86 Sabre

Cold War, US, ,

USA flag old United States of America (1945)
Prototype Fighter – 3 Built

The first XP-86 Prototype 45-59598, flown by George Welch

The North American F-86 Sabre is one of the most well-known fighter aircraft of all time, marking the transition from the propeller to the jet turbine. It first entered service with the newly formed U.S. Air Force in 1949, and was instrumental in denying air superiority to Communist forces during the Korean War. After the war ended, many Sabres entered service with dozens of foreign air arms, becoming the primary fighter equipment of many Allied nations. It was built under license in Canada, Japan, Italy, and Australia. Its service was so long-lived that the last operational F-86 was not withdrawn from service until 1993.

History

The F-86 Sabre began its life as North American Aviation’s company project NA-134, which was originally intended for the US Navy. As the war in the Pacific edged toward its climax, the Navy was making plans to acquire jet-powered carrier-based aircraft, which it was could be pressed into service in time for Operation Olympic-Coronet, the invasion of Japan planned for May 1946. The Navy had planned to acquire four jet fighters, the Vought XF6U-1 Pirate, the McDonnell XFD-1 Phantom, the McDonnell XF2D-1 Banshee, and the North American XFJ-1 Fury.

Work on the NA-134 project began in the late autumn of 1944. The NA-134 had a straight, thin-section wing set low on a round fuselage. It featured a straight through flow of air from the nose intake to the jet exhaust that exited the aircraft under a straight tailplane. The wing was borrowed directly from the P-51D, and had a laminar-flow airfoil. It was to be powered by a single General Electric TG-180 gas turbine which was a license-built version of the de Havilland Goblin. The TG-180 was designated J35 by the military and was an 11-stage axial-flow turbojet which offered 4000 lb.s.t. at sea level. The Navy ordered three prototypes of the NA-134 under the designation XFJ-1 on January 1, 1945. On May 28, 1945, the Navy approved a contract for 100 production FJ-1s (NA-141).

At the same time that North American was beginning to design the Navy’s XFJ-1, the U.S. Army Air Force (USAAF) issued a requirement for a medium-range day fighter which could also be used as an escort fighter and a dive bomber. Specifications called for a speed of at least 600 mph, since the Republic XP-84 Thunderjet already under construction promised 587 mph. On Nov 22, 1944, the company’s RD-1265 design study proposed a version of the XFJ-1 for the Air Force to meet this requirement. This design was known in company records as NA-140. The USAAF was sufficiently impressed that they issued a letter contract on May 18, 1945 which authorized the acquisition of three NA-140 aircraft under the designation XP-86.

The Navy’s XFJ-1 design had to incorporate some performance compromises in order to support low-speed carrier operations, but the land-based USAAF XP-86 was not so constrained and had a somewhat thinner wing and a slimmer fuselage with a high fineness ratio. However, the XP-86 retained the tail surfaces of the XFJ-1.

The XP-86 incorporated several features not previously used on fighter aircraft, including a fully-pressurized cockpit and hydraulically-boosted ailerons and elevators. Armament was the standard USAAF equipment of the era–six 0.50-inch Browning M3 machine guns that fired at 1100 rounds per minute, with 267 rounds per gun. The aircraft was to use the Sperry type A-1B gun/bomb/rocket sight, working in conjunction with an AN/APG-5 ranging radar. Rocket launchers could be added underneath the wings to carry up to 8 5-inch HVARs. Self-sealing fuel tanks were to be fitted, and the pilot was to be provided with some armor plating around the cockpit area.

In the XP-86, a ten percent ratio of wing thickness to chord was used to extend the critical Mach number to 0.9. Wingspan was to be 38 feet 2.5 inches, length was 35 feet 6 inches, and height was 13 feet 2.5 inches. Four speed brakes were to be attached above and below the wings. At a gross weight of 11,500 pounds, the XP-86 was estimated to be capable of achieving a top speed of 574 mph at sea level and 582 mph at 10,000 feet, still below the USAAF requirement. Initial climb rate was to be 5,850 feet per minute and service ceiling was to be 46,000 feet. Combat radius was 297 miles with 410 gallons of internal fuel, but could be increased to 750 miles by adding a 170 gallon drop tank to each wingtip. As it would turn out, these performance figures were greatly exaggerated.

A mock-up of the XP-86 was built and approved on June 20, 1945. However, early wind tunnel tests indicated that the airframe of the XP-86 would not be able to reach the desired speed of 600 mph. It is highly likely that the XP-86 project would have been cancelled at this time were it not for some unusual developments.

Saved by the Germans

After the surrender of Germany in May of 1945, the USAAF, along with a lot of other air forces, was keenly interested in obtaining information about the latest German jet fighters and in learning as much as they could about secret German wartime research on jet propulsion, rocket power, and ballistic missiles. American teams were selected from industry and research institutions and sent into occupied Germany to investigate captured weapons research data, microfilm it, and ship it back to the US.

The First XP-86 Prototype in Flight Testing [San Diego Air & Space Museum]
By the summer of 1945, a great deal of German data was pouring in, much of it as yet untranslated into English. As it turned out, German aeronautical engineers had wind-tunnel tested just about every aerodynamic shape that the human mind could conceive of, even some ideas even only remotely promising. A particular German paper dated 1940 reported that wind tunnel tests showed that there were some significant advantages offered by swept wings at speeds of about Mach 0.9. A straight-winged aircraft was severely affected by compressibility effects as sonic speed was approached, but the use of a swept wing delayed the effects of shock waves and permitted better control at these higher speeds. Unfortunately, German research also indicated that the use of wing sweep introduced some undesirable wing tip stall and low-speed stability effects. American researchers had also encountered a similar problem with the swept-wing Curtiss XP-55 Ascender, which was so unstable that it flipped over on its back and stalled on one of its test flights.

In 1940, these German studies were of only theoretical interest, since no powerplants were available even remotely capable of reaching such speeds. However, such studies caught the attention of North American engineers trying to develop ways to improve the performance of their XP-86.

Going Supersonic

The first XP-86 prototype in what would be a temporary white paint scheme

The optimal design for an aircraft capable of high speeds produces a design that stalls easily at low speeds. The cure for the low-speed stability problem that was worked out by North American engineers was to attach automatic slats to the wing leading edges. The wing slats were entirely automatic, and opened and closed in response to aerodynamic forces. When the slats opened, the changed airflow over the upper wing surface increased the lift and produced lower stalling speeds. At high speeds, the slats automatically closed to minimize drag.

In August of 1945, project aerodynamicist L. P. Greene proposed to Raymond Rice that a swept-wing configuration for the P-86 be adopted. Wind tunnel tests carried out in September of 1945 confirmed the reduction in drag at high subsonic speeds as well as the beneficial effect of the slats on low speed stability. The limiting Mach number was raised to 0.875.

Based on these wind-tunnel studies, a new design for a swept-wing P-86 was submitted in the fall of 1945. The USAAF was impressed, and on November 1, 1945 it readily approved the proposal. This was one of the most important decisions ever made by the USAAF. Had they not agreed to this change, the history of the next forty years would undoubtedly have been quite different.

North American’s next step was to choose the aspect ratio of the swept wing. A larger aspect ratio would give better range, a narrower one better stability, and the correct choice would have to be a tradeoff between the two. Further tests carried out between late October and mid November indicated that a wing aspect ratio of 6 would be satisfactory, and such an aspect ratio had been planned for in the proposal accepted on November 1. However, early in 1946 additional wind tunnel tests indicated that stability with such a narrow wing would be too great a problem, and in March the design reverted to a shorter wingform. An aspect ratio of 4.79, a sweep-back of 35 degrees, and a thickness/chord ratio of 11% at the root and 10% at the tip was finally chosen.

All of these changes lengthened the time scale of the P-86 development in comparison to that of the Navy’s XFJ-1. The XFJ-1 took to the air for the first time on November 27, 1946, but the XP-86 still had almost another year of work ahead before it was ready for its first flight.

The first XP-86 prototype in flight during testing [North American Aviation]
On February 28, 1946, the mockup of the swept-winged XP-86 was inspected and approved. In August of 1946, the basic engineering drawings were made available to the manufacturing shop of North American, and the first metal was cut. The USAAF was so confident of the future performance of the XP-86, that on December 20, 1946 another letter contract for 33 production P-86As was approved. No service test aircraft were ordered. Although the 4000 lb.s.t. J35 would power the three XP-86 prototypes, production P-86As would be powered by the General Electric TG-190 (J47) turbojet offering 5000 lb.s.t.

The first of three prototypes, 45-59597, was rolled out of the Inglewood factory on August 8, 1947. It was powered by a Chevrolet-built J35-C-3 turbojet rated at 4000 pounds of static thrust. The aircraft was unarmed. After a few ground taxiing and braking tests, it was disassembled and trucked out to Muroc Dry Lake Army Air Base, where it was reassembled.

Test pilot George “Wheaties” Welch took the XP-86 up into the air for the first time on October 1, 1947. The flight went well until it came time to lower the landing gear and come in for a landing. Welch found that the nosewheel wouldn’t come down all the way. After spending forty minutes in fruitless attempts to shake the nosewheel down into place, Welch finally brought the plane in for a nose-high landing. Fortunately, the impact of the main wheels jolted the nosewheel into place, and the aircraft rolled safely to a stop. The swept-wing XP-86 had made its first flight.

On October 16, 1947, the USAF gave final approval to the fixed price contract for 33 P-86As, with the additional authorization for 190 P-86Bs. The P-86B was to be a strengthened P-86A for rough-field operations.

XP-86 number 45-59597 was officially delivered to the USAF on November 30, 1948. By that time, its designation had been changed to XF-86. Phase II flight tests, those flown by USAF pilots, began in early December of 1947. An Allison-built J35-A-5 rated at 4000 lbs of static thrust was installed for USAF tests. The second and third XP-86 prototypes, 45-59598 and 45-59599 respectively, joined the test program in early 1948. These were different from the first prototype as well as being different from each other in several respects. Numbers 1 and 2 had different fuel gauges, a stall warning system built into the control stick, a bypass for emergency operation of the hydraulic boost system, and hydraulically-actuated leading-edge slat locks. The number 3 prototype was the only one of the three to have fully-automatic leading-edge slats that opened at 135 mph. Numbers 2 and 3 had SCR-695-B IFF beacons and carried the AN/ARN-6 radio compass set.

The original XP-86 prototype was used for evaluating the effects of nuclear blasts on military hardware at Frenchman Flats. It was later scrapped. [This Day in Aviation]
In June of 1948, the new US Air Force redesignated all Pursuit aircraft as Fighter aircraft, changing the prefix from P to F. Thus the XP-86 became the XF-86. XP-86 number one was officially delivered to the USAF on November 30, 1948. The three prototypes remained in various test and evaluation roles well into the 1950s, and were unofficially referred to as YP-86s. All three prototypes were sold for scrap after being used in nuclear tests at Frenchman Flats in Nevada

Design

The three XP-86 prototypes flying in formation together in 1948 [National Archives]
Evolving from the NA-134 project with wings borrowed from a P-51, the XP-86 would eventually end up with a low swept wing mounted to a tubular fuselage, with a large jet intake opening at the nose. The plexiglass bubble canopy gave the pilot great visibility, and afforded the pilot a pressurized cockpit. The tail featured a swept back rudder with tailplanes angled upwards, marking a departure from the largely perpendicular angles seen on most of the Sabre’s propeller driven predecessors. The landing gear was a tricycle configuration, which helped balance the weight of the jet engine at the rear.

The wing of the XP-86 was to be constructed of a double-skin structure with hat sections between layers extending from the center section to the outboard edges of the outer panel fuel tanks. This structure replaced the conventional rib and stringer construction in that area. This new construction method provided additional strength and allowed enough space in the wing for fuel tanks.

The wing-mounted speed brakes originally contemplated for the XP-86 were considered unsuitable for the wing design, so they were replaced by a hydraulic door-type brake mounted on each side of the rear fuselage and one brake mounted on the bottom of the fuselage in a dorsal position. The speed brakes opened frontwards, and had the advantage that they could be opened at any attitude and speed, including speeds above Mach One.

The maximum speed of the XP-86 was over 650 mph, 75 mph faster than anything else in service at the time. The noise and vibration levels were considerably lower than other jet-powered aircraft. However, the J35 engine did not produce enough thrust, and the XP-86 could only climb at 4,000 feet per minute. However, this was not considered an issue, since the production P-86As were to be powered by the 5000 lb.s.t. General Electric J47.

The XP-86 could go supersonic in a dive with only a moderate and manageable tendency to nose-up, although below 25,000 feet there was a tendency to roll which made it unwise to stay supersonic for very long. Production Sabres were limited to Mach 0.95 below 25,000 feet for safety reasons because of this roll tendency.

For the second and third prototypes, the ventral brake was eliminated, and the two rear-opening side fuselage brakes were replaced by brakes which had hinges at the front and opened out and down. These air brakes were adopted for production aircraft.

Prototype number 3 was the only one to be fitted with armament. The armament of six 0.50-inch M3 machine guns were mounted in blocks of three on either side of the cockpit. Ammunition bays were installed in the bottom of the fuselage underneath the gun bay, with as many as 300 rounds per gun. The guns were aimed by a Mk 18 gyroscopic gunsight with manual ranging.

Possibly the First Supersonic Aircraft

George Welch Circa 1947 – [San Diego Air & Space Museum]
There is actually a possibility that the XP-86 rather than the Bell XS-1 might have been the first aircraft to achieve supersonic flight. During some of his early flight tests, George Welch reported that he had encountered some rather unusual fluctuations in his airspeed and altitude indicators during high speed dives, which might have meant that he had exceeded the speed of sound. However, at that time, North American had no way of calibrating airspeed indicators into the transonic range above Mach 1, so it is uncertain just how fast Welch had gone. On October 14, 1947, Chuck Yeager exceeded Mach 1 in the XS-1. Although the event was kept secret from the general public, North American test crews heard about this feat through rumors and persuaded NACA to use its equipment to track the XP-86 in a high-speed dive to see if there was a possibility that the XP-86 could also go supersonic. This test was done on October 19, five days after Yeager’s flight, in which George Welch was tracked at Mach 1.02. The tests were flown again on October 21 with the same results. Since Welch had been performing the very same flight patterns in tests before October 14, there is the possibility that he, not Chuck Yeager, might have been first to exceed the speed of sound.

In any case, the fact that the XP-86 had exceeded the speed of sound was immediately classified, and remained so for several months afterward. In May of 1948, the world was informed that George Welch had exceeded Mach 1.0 in the XP-86, becoming the first “aircraft” to do so, with an aircraft being defined as a vehicle that takes off and lands under its own power. The date was set as April 26, 1948. This flight did actually take place, but George Welch was not the pilot. In fact, it was a British pilot who was evaluating the XP-86 who inadvertently broadcasted that he had exceeded Mach 1 over an open radio channel. However, the facts soon became common knowledge throughout the aviation community. The June 14, 1948 issue of Aviation Week published an article revealing that the XP-86 had gone supersonic.

Variants

  • XP-86 45-59597 – The first prototype Sabre produced, was reconfigured many times with various test configurations. May have been the first aircraft to have gone supersonic in October 1947 with George Welch at the controls.
  • XP-86 45-59598 – The second prototype, had different production model speedbrake and flap configuration, various sensors and equipment installed for testing purposes.
  • XP-86 45-59599 – The third prototype, and the only Sabre prototype to have been armed, fitted with the standard six M3 Browning guns

Operators

  • United States – The prototypes were extensively tested by North American Aviation before being handed over to the U.S. Air Force in 1948.

North American XP-86 Specifications
Wingspan 37 ft 1.5 in / 11.32 m
Length 37 ft 6.5 in / 11.44 m
Height 14 ft 9 in / 4.5 m
Wing Area 299 ft² / 27.8 m²
Engine 1x Chevrolet J35-C-3 Turbojet Engine

4000 lbst
Fuel Capacity 410 US Gal / 1,552 L

750 US Gal / 2,839 L with wingtip drop tanks
Weights
Empty 9,730 lb / 4,413 kg
Gross 13,395 lb / 6,076 kg
Maximum Take Off 16,438 lb / 7,456 kg
Climb Rate
Rate of Climb at Sea Level 4000 ft / 1219 m per minute
Time to 20,000 ft / 6,096 m 6.4 minutes
Time to 30,000 ft / 9,144 m 12.1 minutes
Maximum Speed
Sea Level 599 mph / 964 kmh
14,000 ft / 4267 m 618 mph / 995 kmh
35,000 ft / 10,668 m 575 mph / 925 kmh
Takeoff Run 3,030 ft / 924 m
Range 297 mi / 478 km
Maximum Service Ceiling 41,300 ft / 12,588 m
Crew 1 pilot
Armament
  • 6x Browning M3 machine guns, 267 rounds per gun
  • Sperry type A-1B gun/bomb/rocket sight
  • AN/APG-5C ranging radar
  • Underwing Rocket Launchers, up to 8x 5-inch HVAR

Gallery

Illustrations by Ed Jackson

XP-86 – 1st Prototype 45-59597 circa 1947 note it bears the P for “Pursuit”
XP-86 – 1st Prototype 45-59597 circa June 1948 in white paint scheme, note the wingtip pitot probes
XP-86 – 1st Prototype 45-59597 circa 1948, note the additional test equipment behind the pilot’s seat
XP-86 – 2nd Prototype 45-59598 circa 1948
XP-86 – 3rd Prototype 45-59599 circa 1948

Credits

Shangdeng No. 1

Cold War, People's Republic of China,

PRC flag People’s Republic of China (1958)
Helicopter / Bus / Boat Hybrid – None Built

Perhaps the only known photo of the original Shangdeng No.1 model. (中国飞机全书: 第3卷)

Shangdeng No.1 was an overambitious design undertaken by the Chinese Shanghai Bulb Factory in 1958 to produce a multipurpose vehicle which could serve as a helicopter, a bus and a boat for the National Day celebrations. Vastly unknown both inside and outside of China, the Shangdeng No.1 can be considered one of the People’s Republic of China’s more obscure designs of the 1950s. Quietly canceled after the conclusion of National Day, the Shanghai Bulb Factory would never fulfill their promise of completing the design and preparing it for mass production. This could be attributed to a plethora of reasons, but information is scarce.

History

On October 1st 1958, the People’s Republic of China celebrated the ninth anniversary of the founding of the nation. As their personal way of celebrating this national holiday, representatives of the Shanghai Bulb Factory unveiled a model of a hybrid design as a gift to the government. Unorthodox and, some may rightfully argue, ridiculous in concept, this design (dubbed the “Shangdeng No.1” / “上灯” 1号) was meant to have served as a versatile multipurpose vehicle capable of acting as a helicopter, a boat and a small bus. Upon presenting this model to the government, they proclaimed that design and manufacturing work would be completed in 1959 thus allowing for mass production. However, this would never happen, as work on the project ceased shortly after the model was presented and the conclusion of National Day.

The reason for the cancellation is unknown, but one could speculate a number of reasons. First and foremost, the Shanghai Bulb Factory specialized in the production of lightbulbs, therefore they completely lacked any expertise, experience, qualified personnel and machinery required to design and in turn produce such a conceptually complicated vehicle. A second possible reason why the project was canceled was due to Mao Zedong’s “Great Leap Forward” campaign, which would have the entire country struggle to industrialize and collectivize. The Shangdeng No.1 could have been deemed as useless and thus canceled by the government so that the factory could focus its resources to fulfill government mandated quotas of lightbulb production. Lastly, the Shanghai Bulb Factory could have had no intention of developing the Shangdeng No.1 in the first place, and the model presented could have been just a demonstration to show off Chinese ingenuity and to boost the morale of the Chinese people in a small show of fanciful propaganda. These, however, are just theories to speculate on why the Shangdeng No.1 was canceled. Only one photo is known to exist of the Shangdeng No.1’s scale model presented during National Day.

In conclusion, the Shangdeng No.1 was an overambitious design concept explored by the Shanghai Bulb Factory which resulted in the presentation of a scale model on the ninth National Day of the People’s Republic of China. Absurd in concept, the Shanghai Bulb Factory would have had no possible way of delivering on their promise to produce such a vehicle as they certainly had little to no experience on vehicle design and machinery intended for light bulb production could only produce so little. The fact that a light bulb factory conceptualized this vehicle is quite interesting though, and, to their credit, an intended helicopter/bus/boat hybrid design would most certainly have raised a few eyebrows in the country and in the Western world, assuming that the design was feasible and successful.

As details on this project are so scarce, it has led to some debate on the legacy of the design. A popular claim by numerous online sources is that, after the project was canceled, documents on the Shangdeng No.1 was transferred to the American Boeing firm, and that the Shangdeng’s tandem rotor design served as the inspiration of the Boeing CH-47 Chinook helicopter. This claim is unrealistic and vacuous, as the People’s Republic of China and the United States of America had no formal relations until the late 1960s / early 1970s, nearly a decade after the Chinook was serviced. Therefore, the concept of a Chinese light bulb factory transferring documents to and influencing a world-renowned aviation corporation would be extremely illogical and, frankly, impossible. The United States of America was also no stranger to tandem bladed helicopters designs, as numerous helicopters (eg. Piasecki HRP Rescuer, Piasecki H-21, etc) formerly and currently in service had these designs prior to the conceptualization of the Shangdeng.

Design

The design of the Shangdeng No.1 resembles a rectangular box with rounded edges. A tandem rotor blade configuration was used, and the conceptual power plant of the Shangdeng would have been an unspecified radial engine model capable of producing up to 450 hp, connected to both the front and the rear rotors. The cockpit located at the front of the helicopter would have allowed space for two pilots. Four passengers (or the weight equivalent in cargo) could have been held in the compartment located behind the cockpit. Windows were planned to be installed in the fuselage as can seen in the scale model. Relatively speaking, the Shangdeng’s dimensions are quiet small for a tandem rotor helicopter design. The Shangdeng was only 6 ft 7 in (2.00 m) tall, which would have likely made the interior compartment quite cramped.

Four static wheels were mounted in pairs in the front and rear part of the fuselage which would have moved the Shangdeng in its bus configuration. It is unknown whether or not the design would have allowed the tandem helicopter rotors to be folded in this configuration. If not, the blades could potentially be damaged in urban areas or crowded spaces. It is unknown if a separate transmission would have been connected to the wheels, but this would have certainly greatly complicated the design. If the vehicle in its bus configuration was meant to be propelled by the rotors, that would have been not only unacceptably inefficient, but would have also limited the paths it could travel and would have been highly dangerous to be next to. Steering in the wheeled mode is also unclear.

In its naval configuration, the Shangdeng would have been propelled by an unspecified amount of 15 in / 40 cm propellers in the rear, possibly with assistance from the wheels which would have provided limited propulsion in the water. Again, this would have probably been highly fuel-inefficient. Also, why would a helicopter, which can easily get between any two points by flying, be used as a boat is hard to fathom. How steering was achieved in the boat mode is unclear.

In the helicopter configuration, the Shangdeng would have just been propulsed by the rotor blades and radial engine. The problem of having someone trained both as a pilot, driver and skipper at the same time seems to have gone unnoticed by the designers. As the project did not progress beyond the conceptual model stage, intricate details regarding the Shangdeng No.1 are unknown. However, basic dimensions and estimated performances are provided by 中国飞机全书: Volume III, a book written by People’s Liberation Army Air Force (PLAAF) general Wei Gang (魏钢), former PLAAF model maker and artist Chen Yingming (陈应明) and aviation magazine author Zhang Wei (张维).

Operator(s)

  • People’s Republic of China – The Shangdeng No.1 would most likely have been operated by the various military branches and likely some civilian institutes if it were to see mass production.

Shanghai Bulb Factory Shangdeng No.1*

* – Statistics taken from中国飞机全书 (Vol. 3)
Length 32 ft 10 in / 10.00 m
Height 6 ft 7 in / 2.00 m
Engine 1x Unspecified Multi-Cylinder Radial Engine Model (450 hp)
Rotor Blade Length 26 ft 3 in / 8.00 m
Rotor Blade Spacing 22 ft / 7.00 m
Boat Propeller Length 15 in / 40 cm
Wheel Diameter 27.5 in / 70 cm
Maximum Takeoff Weight 4000 lbs / 1,800 kg
Climb Rate 6.6 ft / 2 m per second
Maximum Speed (Flying) 95 mph / 150 km/h
Maximum Speed (Driving) 60 mph / 100 km/h
Maximum Speed (Sailing) 7 mph / 12 km/h
Range 400 mi / 650 km
Maximum Service Ceiling 9,800 ft / 3,000 m
Crew 2x Pilot

4x Passengers

Gallery

Side Profile View Illustration by Ed Jackson

Sources

Yakovlev Yak-23

Cold War, Soviet Union, ,

USSR flag USSR (1947)
Jet Fighter – 310 Built

Yak-23 in Czechoslovak operational service. [airwar.ru]
The Yak-23 emerged as the final step of the Yak-15 and Yak-17 development series. It made its first flight in mid-1947, powered, ironically, by a British Rolls-Royce Derwent jet-engine. By the time it entered production, the engine was changed with a Soviet-built copy. Over 300 were built, but as more advanced planes were ready for service the Yak-23s were sold to several Eastern Bloc countries. There they remained in service until replaced with the MiG-15 in the mid-1950s.

History of the Yak-23 predecessor

The Soviets began developing jet powered aircraft in the 1930s, but the process was slow with no major progress. However, by the end of World War 2, the Soviets managed to come into possession of large quantities of German war technology, engines as well as experimental and operational jet aircraft.

In April 1945, by orders of the National Defense Committee of the Soviet Union, work on a new generation of jet-powered aircraft began. In the case of jet fighters, the minimum requirement was that it had to achieve a maximum top speed of 500 mph (800 km/h). As there were a number of captured German Junkers Jumo 004B1 and BMW 003 jet engines, it was proposed to try to use them in Soviet designs. These received the new Soviet designation RD-10 Reaktinyi Dvitagatel, which is Russian for “jet engine.” The design and work on the first power plant was given to the OKB-117 Experimental Design Bureau, under the designer Vladimir Y. Klimov in late April 1945. A few months later, a second order was given to develop a new RD-20 jet engine based on the German BMW 003 jet engine. As the Soviet scientists were not familiar with this technology, the entire development ran quite slowly. The first series of these engines was ready in 1946, but the performance turned out to be limited and almost useless.

The work on the new jet fighter program was also slow and largely fruitless. Projects like the MiG-13, La-7R and Yak-3RD were built in limited numbers and proved to be unsuccessful. One of the main reasons for so many failed projects was the fact that the Soviet designers used captured and complicated German jet technology as an inspiration. There had to be a change in the way the Soviet designers and engineers approached these technologies and developments. Since time was crucial, the designers were forced to adopt simpler solutions.

The development of Yak-Jumo aircraft would later led to the Yak-23. [talkbass.com]
Several new projects resulted from these decisions, one of which was the A.S.Yakovlev Yak-Jumo project. It was based on Yakovlev’s own analysis of German technology, especially the light weight, stepped fuselage and the forward position engine design. His first idea was to try to take advantage of the already existing piston engine-powered fighters and, if possible, install one or more jet engines on them. He reused one Yak-3 fighter and modified it to mount one rocket engine instead of the piston engine. Most parts of the Yak-3 were reused, wings, including the whole fuselage, tail surfaces, undercarriage and most in-built systems and equipment. The new engine was fitted in the forward part of the fuselage, but tilted at a 430’ angle with respect to the plane’s axis. Besides this, it was necessary to redesign the whole fuel system. A new redesigned cockpit was installed and the armament would consist of two 23 mm NS-23K autocannons each with 60 rounds of ammunition located above the engine. The German Jumo 004 engine was used and thus the project name was Yak-Jumo or Yak-3 Jumo (depending on the source).

The first prototype was completed and ready by late 1945. During its first several ground tests, many problems were reported. One of them was the excessive heating of the rear lower fuselage caused by the engine exhaust gases. A second complete and improved prototype was built in December 1945. It was equipped with the Soviet-built RD-10 which was a direct copy of the Jumo 004. Tests on the second prototype plane began during the second half of 1946. During these tests, several complaints were noted and the aircraft was returned to the factory in order to resolve these issues. By that time, this plane received a new military designation, the Yak-15.

On 12th September, 1946, an order for a limited production run was given by the Ministry of Aircraft Production. The Yak-15 and MiG-9s were first presented to the public during a military parade held in Moscow’s Red Square of that year.

Yak-23 Rear View [Avions Legendaires]
Due to the rapid development of Western jet aircraft, Soviet military authorities demanded improved and more advanced jet planes. The new fighters had to be able to reach a maximum speed of 620 mph (1,000 km/h), but mostly due to lack of adequate jet engines this was only successfully implemented in later, much more improved models like the MiG-17. This was the reason why some jet fighters were put into production despite much lower top speeds.

Due to obsolescence and new problems discovered during the Yak-15’s service, most were modified to be used as advanced trainers, but some were operated as standard fighters. Yakovlev was again tasked with the development of an improved jet fighter. It was required to have a significantly better aerodynamic layout and was to be powered by an RD-10 engine. Estimated maximum speed was to be around 527 mph (850 km/h) at an altitude of 16.400 ft (5,000 m). Besides this, a novelty was the installation of an ejection seat and armored glass plate for the windscreen. By September 1946, the first Yak-17 was ready for testing. These tests were considered successful, especially by the pilots who considered it to have good flying performance. Serial production was to start in the autumn of 1947. The Yak-17 would be built in relatively small numbers as more advanced designs would replace it in the following years, designs like the Yak-23.

History of the Yak-23

Drawing of the Yak-23’s internal components. [Airwar.ru]
Later development of new Yakovlev aircraft was characterized by several different methods of approaching development. One of the many Yakovlev design teams, lead by Leonid L. Selyakov, worked on a completely new design that would later lead to the Yak-25. The main goal of this project was to build a completely new aircraft. In addition to this team, a second team advocated for the improvement of the already existing Yak-15 and Yak-17 designs.

The second team’s design was a lightweight and with highly maneuverable jet fighter. This new fighter was to be powered by an RD-500 jet engine, which itself was based on a British Rolls-Royce Derwent 5 turbojet engine. The whole aerodynamic concept was taken from the older Yak-17, but improved with an all-metal construction. The new plane was a lightweight mid-wing monoplane, but with unswept wings and rear tail. The cockpit was placed at the middle of the fuselage and equipped with an ejection seat. To save weight, some modifications were done such as the omission of air brakes, the armor plate being removed, fuel tank capacity lowered, no pressurization fitted to the cockpit and decrease of the wing thickness. The calculated weight with these modifications was about 4,725 lbs (1,902 kg). By the time it entered production, there was a slight increase of weight. The main armament was also relatively light, as it consisted of only two 0.9 in (23 mm) cannons, with some 90 rounds for each cannon.

The work on this project began in the early 1947. Plant No.115 was tasked with the construction of the first operational prototype. On 17th June, 1947 the prototype, designated Yak-23-1 was completed. The first factory test flight was made on 8th July, 1947 by the test pilot M.I. Ivanov. The results of these first flights showed that the Yak-23-1 had a high rate of climb and excellent maneuverability. The maximum speed achieved was 578 mph (932 km/h) at low level. Some issues that were noted during these first flights were solved in time.

In September the same year, on the insistence of the Minister of Aircraft Production, Mikhail V. Khruniche, the Yak-23 was accepted for additional test trials. For this purpose, a second prototype was built, named Yak-23-2. For the series of new test flights, besides G.A.Sedov, the main test pilot, many more pilots were also chosen to test the Yak-23, such as A.G. Proshakov, Valentin, I. Khomvakov among others. By March 1948, these test flights were successfully completed. The Yak-23 displayed great maneuverability during flights. In contrast to other models, like Su-9 and MiG-9, the Yak-23 proved to have much better climb rate. But it was not without its problems: during acceleration, the forward fuselage tended to suddenly rise and the lack of air brakes made potential dog-fighting very difficult. At higher speeds it took a lot of time to slow down and the lack of a pressurized cockpit made the Yak-23 incapable of operating at high altitudes. The second prototype was lost on 14th July, 1948, during one of the many flight exercises for the planned military parade to be held at Tushino. During these exercises, an unknown object struck the wing of Yak-23-2 flown by M.I. Ivanov, which caused the wing to break and fall off. The pilot lost control and crashed to the ground. Ivanov died immediately and the aircraft was totally destroyed. A subsequent investigation found that the main culprit was a balance tab that was torn from the tail of one of the Tu-14 bombers that was flying above the Yak-23.

Despite these problems, the Yak-23 was considered a successful aircraft worthy of production. Plant No.31 was chosen for manufacturing. By mid-1949, the production began, however, at first, the process was slow due the lack of RD-500 engines. The first batch was not ready until October 1949. In the period of January to March 1950, some 20 aircraft were used to conduct more tests. These trials revealed that the Yak-23 had a few more problems to be worked out, such as smoke in the cockpit, among other small issues.. As these problems were considered minor and did not endanger the production of the Yak-23 at the time.

Design

Yak-23UTI Front View [Aero Concept]
The Yak-23 was designed as a lightweight, all-metal, mid-wing monoplane with unswept wings and tail surfaces. The long front fuselage was designed and constructed so that it could be easily changed or removed for ease of maintenance.

The external fuselage was made of 0.039 in (1 mm) thick duralumin sheets (D16AWTL) and the inner part was made of 0.031 in (0.8 mm) sheets. To protect the main landing wheels, a special cover was installed close to the exhaust nozzle. The lower part of the Yak-23 fuselage was covered with a specially designed heat resistant plate in order to protect the plane’s inner structure from any potential thermal damage. The two unswept wings were made of 17 ribs that were covered in 0.05-0.07 in (1.3-1.8 mm) duralumin panels. At the wing’s trailing edges, ailerons and flaps were fitted. The wings were made mostly of duralumin sheet metal. The wing ends were flat and it was possible to mount two external fuel tanks that were ejectable. The rear tail had a tapered design and was made of metal covered with duralumin sheets. There were no air brakes installed and this caused the Yak-23 to have some problems with maneuvering. This would be a major problem in any potential dogfight with other fighters.

The main engine was the RD-500 turbojet engine with 3,500 lbs (1590 kg) of thrust that was fitted with a single centrifugal compressor and nine cylindrical shaped combustion chambers. The engine had a diameter of 3.58 ft (1.09 m) and 6.76 ft (2.06 m) long. It was angled downwards by 4°30’ with respect to the plane’s centerline. This was not a perfect design choice as when the pilot accelerated the plane, it tended to suddenly pitch up. The main jet fuel was kerosene, stored in five large tanks mounted in the fuselage with a capacity of 240 gallons (910 liters) and two smaller 50 gallon (190 liters) tanks located in the wings. With this fuel capacity, the maximum operational range was around 640 mi (1,030 km). The Yak-23’s flight endurance was very low, with only one hour of operational flight. With this engine, the maximum speed achieved was 606 mph (975 km/h) with a climb rate of 6,693 ft (2,041 m) per minute. The air intake was located at the front, which split into two symmetrical ducts that passed under the cockpit. There was a headlight located in the air intake to help during landings.

The landing gear was a tricycle design typical of jet planes of the era. The front nose wheel retracted forward, while the larger rear wheels retracted into the fuselage sides. A built in shock absorber mechanism with double rebound system was used for the landing gear.

The Yak-23’s operational service life in the Soviet Union was very limited due to the rapid development of better jet planes. [Wikipedia]
The cockpit was located at the center of the upper fuselage. The cockpit was designed with a fixed windscreen with an armored glass panel and a rear sliding hood with non-armored glass. For the pilot to enter his seat, he had to climb on top of the wings. The Yak-23 was equipped with an ejection seat that could be used by the pilot in case of emergency. The ejection seat with parachute was activated with a command handle located next to the armrest of the seat’s right side. A small explosive charge was used to catapult the seat from the plane. The main command instruments were in the standard configuration. All instruments were placed ahead of the pilot and the rudder pedals were mounted at the floor. The pilot’s instrument panel was divided into three sections. In the central section were the main and most important flying instruments: M-46 Mach meter, PDK-45 compass, AGK-47A artificial horizon, and engine control indicators. Secondary controls were located at sides of the main control panel. An oxygen supply system with a capacity of 2.11 gal (8 l) with a KM-16 model mask was fitted in the cockpit. Electric power was provided by 1.5 kW GSK-1500 generator and 12A-10 type battery. For communication, a RSI-6K radio set and a RPKO-10M radio-direction finder/semicompass were used. Also, the SCh-ZM IFF (Identification Friend or Foe) system was used.

The offensive weapon load consisted of only two 0.9 in (23 mm) NR-23 cannons placed in the lower forward part of the fuselage. Available ammunition for these two cannons was limited with only 90 rounds per gun. The main weapons were aimed by the semi-automatic gyro gun sight placed above the pilot’s instrument panels. Additional offensive armament could consist of two 123 lb (60 kg) bombs attached in the place of the external fuel tanks.

Beside the Yak-23 fighter aircraft, a trainer version, the Yak-23 UTI, was developed. One Yak-23 (serial number 115001) was converted for this purpose. A second instructor cockpit was installed at the rear of the pilot’s seat. The prototype was tested from March to September of 1949, but this modification was ultimately deemed unsuccessful. A new attempt was made with the redesigned Yak-23 UTI-II. The fuselage was stretched by some 7.8 inches (200 mm) to the front, and this time the instructor was moved to the front. A special periscope was installed to allow the instructor to see what the pilot was doing in the rear seat. The armament was reduced to only one 0.5 in (12.7 mm) machine gun. Many more changes were made, which resulted in the third version, Yak-23 UTI-III. By this time, the more impressive MiG-15 UTI was entering production and so the Yak-23 UTI project was canceled.

Operational use

Despite its good flying characteristics the Yak-23, also known by its NATO designation “Flora,” was built in small numbers, 310 planes in total. Its operational service life in the Soviet Union was very limited, as it was operated by only a few fighter regiments located in the Caucasus and Volga military districts. As more modern planes were becoming available, the Yak-23 would be sold off to Eastern bloc countries such as Czechoslovakia, Bulgaria, Romania and Poland.

In Czechoslovak Service

Czechoslovakia had extensively negotiated with Soviet military officials in the 1950s about the purchase of new jet-powered fighters. These negotiations had been preceded by earlier ones, from which Czechoslovakia received one older Yak-17 under designation S-100. This sole aircraft was to be used as a basis for future local production. However, since this plan went nowhere, the Yak-17 was sent to a military museum and it was never used operationally. An agreement was made in November 1950 for a possible license production of the Yak-23 under a new name, S-101, and also for the engine under the M-02 name. The first group of 12 Yak-23s arrived in Czechoslovakia in late 1950. Their first public appearance of nine planes were used in a military parade on 6th May, 1951, the anniversary of the liberation of Czechoslovakia by the Soviet Red Army in WW2. A second group of 9 Yak-23s was allegedly received, possibly in 1951 or 1952, but precise information is lacking.

The Yak’s were first used by the 3rd Fighter Division, but as the more advanced MiG-15 arrived, the Yak-23s were given to the 11th Fighter Regiment, part of the 5th Fighter Division, from June to August 1951. By early 1952, this unit had 11 operational Yak-23s in total. One Yak-23 was lost in an accident on 16 October, 1952. In 1953, all available Yaks were given to the 51st Air Regiment, which was renamed as the 7th Air Regiment in October. By early 1954, there were 12 Yak-23s reported in service, of which 11 were operational.

Due to the purchase of newer types of aircraft, the Czechoslovakian military authorities thought that the Yak-23 plane was inadequate and outdated and so the original plans for a license production were dropped. By 1956, a decision was made to withdraw all Yak-23s from operational service. Only a small number of Yak-23s where ever used by the Czech Air Force, thought to be around 21, but the exact number is unknown. Most of these were sold, 10 to Poland in 1953, possibly 7 to Bulgaria, with one given to a military museum and at least one was lost in an accident.

In Bulgarian Service

Yak-23 put on display at the Bulgarian Air Force Museum [Deano’s Travels]
Bulgarian military officials purchased several Yak-17 UTI training variants and 12 Yak-23s from the Soviet Union in early 1951. These were used to form the 19th Fighter Regiment in March 1951. The first pilot to fly on one of the Yak-23s was Major Vasil Velichkov. On his first take-off, the engine suddenly stopped working and he was forced to land in a field near the airfield. Because it was necessary to train new pilots to fly the Yaks, some planes were supplied to the 2nd Training Combat Air Regiment, located at the Georgi Benkovski Flying School. In order to increase the number of units equipped with the Yak-23s, some 72 new planes were purchased from the Soviet Union in 1952. Around 7 Yak-23s were sold to Bulgaria by Czechoslovakia in early 1956. As in Czechoslovakia, the Yak-23 would not stay long in service, and by 1959 all were retired.

In Romanian Service

After the Second World War, the Romanian Military leadership had great plans for the revival of their shattered air force and acquiring modern jet planes. Some 60 Yak-23s were bought from the Soviet Union during the fifties, with the first 12 planes reaching Romania in early 1951. The total number of planes used is not known. As the more modern MiG-15 was received during 1953, the Yak-23 was considered obsolete and only small numbers were ever used. One Yak-23 was modified by the Romanian air engineers of the AEMV-2 (Atelierele de Reparații / Material Volant) to be used as a dual-command trainer aircraft. A new instructor cockpit was installed. This new modified plane was designated as Yak-23 DC (Dublă Comandă / double command), but only a single prototype was built.

On the 24th June, 1953, Romanian pilot Mihail Diaconu escaped to Yugoslavia in Yak-23, where he sought asylum. Not long afterwards, another pilot flying a MiG-15 flew over and later landed onto Yugoslav territory, most likely due to a navigation error. Both planes were thoroughly researched and tested. Pilots Todorović and Prebeg both flew the Yak-23 with more than 4 flight hours. Beside the flying performance, the weapon systems were also tested during 1954. According to the agreement between US and Yugoslav military officials (code name ‘Zeta’), the Yak-23 was disassembled and sent to the Wright-Patterson Air Force Base in order to test the progress of Soviet aviation technology. Test flights were conducted on 4th November and, by 25 November, it was ready to be sent back to Yugoslavia. The Yak-23 was disassembled, and loaded onto a C-124 and later flown to Pančevo airfield. The whole operation was a complete success as it remained a secret for nearly 40 years. After several months, this Yak-23 was returned to Romania, without the Soviets ever realizing where it was the whole time.

In Polish Service

A few of the Polish Yak-23s would be put in Museums. [Wikipedia]
After the Second World War, Poland was economically and militarily devastated. It took several years before the beginning of the renewal of Polish military power. The new Polish military leadership wanted to built up the shattered air force and, despite their plans to acquire a new jet fighter by 1948, this was not possible. The process of acquiring new jet fighters began only in the spring of 1950. The first negotiations with the Soviet Union focused on the acquisition of Yak-15s, but this was later changed to the Yak-17. Due to outbreak of the Korean war, Soviet authorities decided to supply their allies with larger numbers of newer jet fighters. On 6th January, 1951, Poland received its first Yak-23 planes. The planned production of the older Yak-17s was suspended in favor of the Yak-23 under the Polish designation G-3.

Besides the 1st Fighter Aviation Regiment (PLM for short in Polish) which had some 16 Yak-23, a second unit, the 2nd PLM was also supplied with this plane. To train the new pilots, Yak-17 UTI training planes were used. In mid-1952, all operational Yaks were used by five Fighter Regiments: 2nd PLM with 26, the 39th PLM with 19, the 40th PLM with 19, the 26th PLM with around 11 and the 29th PLM with 14 Yak-23. From 1953 onwards, according to the new Polish military strategy, the first line fighter units would be equipped with the new MiG-15, while second-line units received all available Yak-23s.

In the early fifties, the Western Allies were eager to examine and spy on the military power of the East. A simple way to do this was by using various types of balloons. They were used for propaganda, meteorological, and reconnaissance duties. The Polish Air Force was heavily engaged with shooting down these balloons.

The final fate of Polish Yak-23s was sealed by the start of licenced production of the MiG-15 (under the name Lim-1). The remaining Yak-23s were gradually phased out of service. All operational Yak planes were allocated to training units at Radom, where they were used for training new officers and pilots. Some Yak-23s were temporarily used as reconnaissance aircraft in the 21st PLZ (21st Scout Aviation Regiment). By late August 1954, all Yak-23s were moved to Radom. The ones that were not operational were cannibalized for spare parts. On 1st September, 1959, the remaining 39 Yak-23s were removed from the Polish Air Force and a few would be used as memorials. During its operational service in the Polish Air Force, several planes were lost in crashes but, in most cases, the pilots escaped without any injuries.

Albanian Yak-23

Albanian Air Force allegedly operated a unknown number of Yak-23. Possibly bought from Poland sometime after 1951, according to author Yefim G.

Hungary and the Yak-23

Hungary allegedly also used the Yak-17 and 23, but there is no documentation or any information to confirm this (Source Marian M.). But according to author Yefim G. an unknown number of Yak 23 were operated by the Hungarian Air Force during the 1955 to 1956. But this author does not specify the number of planes used nor describes in more detail operational service life.

Production and modifications

A relatively small number of planes of this type were ever produced. As more advanced planes were becoming rapidly available, there was no need to continue the production of the old Yak-23. Most of the Yak-23s produced would be later sold to Eastern bloc countries.

In total, 310 aircraft plus three prototypes were built by Plant No.31. The plant produced these in twelve series, with 25 to 26 aircraft in each batch. Production was stopped by the end of 1950.

Variants

  • Yak-23 – Main production aircraft
  • Yak-23 UTI – One Yak-23 was modified to be used as a fighter trainer. It did not enter production.
  • Yak-23 DC (Dublă Comandă) – Romanian experimental dual control trainer, only one tested.

Operators

  • Bulgaria – Used over 70 Yak-23s
  • Soviet Union – Operated only two fighter regiments equipped with the Yak-23
  • Romania – Some 60 Yak-23 were bought from the Soviet Union during the fifties
  • Poland – Used around 101 planes, under the designation G-3
  • Czechoslovakia – Operated around 21 aircraft (possibly more) under the designation S-101
  • Yugoslavia – Used one Romanian interned plane for experimenting with flying performance and weaponry
  • USA – Briefly tested one aircraft that was supplied by Yugoslavia
  • Hungary – Allegedly used this type of aircraft, but proof is lacking
  • Albania – Possibly operated a small numbers of Yak-23

Conclusion

The Yak-23, despite proving that it had good flying performance and good handling, had a rudimentary design and was produced too late to have any great impact or role in the Soviet fighter force. Due to the rapid development of jet technology, more advanced planes were soon ready for service like the La-15 or MiG-15. The Yak-23 finished its career in service with many Eastern Block air forces.

Although its operational service life was short and its significance was negligible, the Yak-23 was an example of how, with only a short time and using limited resources, a solid jet fighter could be designed and built by the Soviets.

Yakovlev Yak-23 Specifications
Wingspan 28 ft 7 in / 8.73 m
Length 26 ft 7.8 in / 8.12 m
Height 10 ft 10.3 in / 3,31 m
Wing Area 145.32 ft² / 13.5 m²
Engine One Klimov 3,505 lbs/1,590 kg thrust RD-500 turbojet engine
Empty Weight 4,409 lbs / 2,000 kg
Maximum Takeoff Weight 6,693 lbs / 3,306 kg
Fuel Capacity 1,290 l
Climb Rate 154 ft / 47 m per second
Maximum Speed
  • Near the ground
  • At altitude of 16.404 ft/5.000 m
  • At altitude of 32.800 ft/10.000 m
  • 575 mph / 925 km/h
  • 565 mph / 910 km/h
  • 539 mph / 868 km/h
Take-off run

Landing run
  • 600 yd /550 m
  • 710 yd /650 m
Range 640 mi / 1,030 km
Maximum Service Ceiling 32,800 ft / 10,000 m
Crew 1 pilot
Armament
  • Two nose-mounted 0.9 in (23 mm) cannons
  • Bomb load of 132 lb (60 kg)

Gallery

Illustrations by Haryo Panji https://www.deviantart.com/haryopanji

Soviet Yak-23
Soviet Yak-23 UTI
Polish Yak-23
Czech Yak-23
Bulgarian Yak-23

 One dual control Yak-23 was tested but the development was stopped, mostly due to production of more advanced MiG-based trainers. [Krasnayazvezda]
Yak-23 under construction in Plant No. 35 [Krasnayazvezda]
Yak-23 Side View [Aviastar]

Sources

Sikorsky S-70C-2 Black Hawk in Communist Chinese Service

Cold War, People's Republic of China, , , ,

PRC flag People’s Republic of China (1984)
Utility Helicopter – 24 Operated

The Sikorsky Black Hawk family is one of the most well-known helicopters of recent history. In its dozens of guises, it serves over 20 militaries worldwide. One of the lesser known operators is the People’s Republic of China. Initially purchased to be operated in the mountainous terrain of Tibet and Xinjiang, the Black Hawk eventually found itself as an aid relief helicopter in the 2008 and 2013 earthquakes in Sichuan and an inspiration for the design of the Harbin Z-20 helicopter.

History

S-70C-2 in combat excercises [dser.com]
The harsh geographic characteristics of Tibet and Xinjiang undoubtedly presented many tough problems to the People’s Liberation Army (PLA). The extreme altitudes of the Tibetan and Xinjiang plateaus make the duties of border troop outposts quite difficult, with Tibet being especially problematic. The Tibetan border alone spans nearly 3,728 mi / 6,000 km, with guard posts on mountains reaching over 13,123 ft / 4,000 m. The highest guardpost is the Shenxianwan (神仙湾) post at 17,650 ft / 5,380 m altitude. At these extreme altitudes the temperature is quite low with snow covering the mountains all year around, and the air is also oxygen deficient. All these factors combined make patrols and resupplying quite difficult for the border troops. Helicopters are the only viable option for resupplying missions as there are nearly no airstrips or adequate roads. The oxygen scarcity prevents helicopter engines from working to their full capacity, as well as reducing the rotor efficiency. This means that flying a helicopter up to that altitude is risky and difficult. Even if the helicopter can safely arrive, the amount of supplies that can be transported is severely limited and it would require several trips to fully resupply a base. In order to find a solution for this problem, China began to look into the international market for a high performing utility helicopter capable of operating at high altitudes and replacing the aging Soviet Mi-8 they were using for transport duties. Adopting the principle of “comparing three products and buying the best” (货比三家，择优选购), China chose three models of helicopters from various Western companies to compete for their business. The American Bell 214ST, Sikorsky S-70 Black Hawk and French AS332 Eurocopter were chosen as potential candidates and examples of these helicopters were promptly sent to Lhasa for flight trials in December of 1983.

S-70C-2 preparing for takeoff [seesaawiki.jp]
The flight tests were conducted on an airfield at an altitude of approximately 5,600 ft / 1,600 m and had all three helicopters fly to higher mountains. Upon reaching approximately 9,840 ft / 3,000 m, it was discovered that the power of all these helicopters dropped noticeably and the engines were not able to deliver sufficient amounts of thrust and the helicopters were unable to successfully complete the test flight. After three months of research, Sikorsky’s technicians were able to successfully address most of the issues and flight tests for the Black Hawk were continued. The improved Black Hawk was able to fly over the Tanggula Mountains at an altitude of over 17,060 ft / 5,200 m and land in the nearby Ali region. After numerous thorough examinations, the Black Hawk was ultimately crowned as champion and determined to be best suited for the Tibetan and Xinjiang environment. In July of 1984, the Chinese government officially placed an order for 24 unarmed S-70C-2 Black Hawk models, which would be specially built for China. They featured high performing General Electric T700-701A engines for high altitude flights and a nose-mounted weather radar. The first batch of Blackhawks would arrive in November of the same year, designated as civilian helicopters. The transaction cost China an approximated total of 140 million USD.

S-70C-2 LH92204 participates in an aid relief operation [Sina News]
Despite officially being classified as civilian helicopters, the S-70C-2 was used in a military capacity during their service with the People’s Republic of China. Initially assigned to the People’s Liberation Army Air Force (PLAAF) in 1986, the Blackhawks were later reallocated to the PLA’s air branch. In Chinese service, the Black Hawk would mostly be assigned to the Tibetan plateaus, where they resupplied and transported border troops. During the 1987 border skirmish with India, the Blackhawks were extensively used for tactical troop transport and supply runs in the Indo-Tibetan border region. The S-70C-2 was able to carry up to 8000 lbs / 3630 kg of equipment, 12 or 14 people in normal situations , and up to 19 people in emergency situations. Unfortunately for the Chinese, support and spare parts from Sikorsky would come to an abrupt end after the 1989 Tiananmen Square massacre. The result of this massacre greatly impacted Sino-American relations and future sales of military hardware were prohibited. It seems that Sikorsky made an attempt to reestablish relations with the Chinese in 1998 by asking the government to allow the sale of replacement engines and parts to the Chinese, arguing that the parts should no longer be considered military hardware. This request, if ever made, was rejected. It would appear that only 21 of the 24 Blackhawks purchased were in service after 2000. Three Blackhawks were supposedly written off during service, probably due to piloting error or equipment malfunctions. Numerous Blackhawks were deployed during the 2008 and 2013 earthquakes in Sichuan, China to administer aid relief, alongside numerous Soviet-era helicopters such as the Mi-8. The Blackhawks are still in service with the Chinese to this day, but will most likely be replaced by the Harbin Z-20.

China’s “Indigenous” Black Hawk

Harbin Z-20 [chinese-military-aviation.blogspot.com]
When taking in account of China’s long history of reverse engineering or copying technology from other countries, it should be no surprise that the Harbin Aircraft Manufacturing Company’s (HAMC) latest Z-20 (直-20, or Zhi-20) helicopter bears a striking resemblance to the Blackhawks. Believed to have been in development since 2006, the Z-20 finally took to the skies on December 23rd of 2013. Contemporary sources seem to suggest that the Z-20 possesses superior characteristics to the Black Hawk due to the refined design, but this has yet to be confirmed. As the Z-20 has only recently entered service and is still kept in relative secrecy. One can only speculate about its capabilities.

Variants Operated

  • S-70C-2 – The People’s Republic of China operated 24 examples of the S-70C-2 which were specially built for them by Sikorsky. This variant featured a nose-mounted weather radar, improved General Electric T700-701A engines for high altitude flights and various other improvements to the fuselage.

 Gallery

Illustrations by Ed Jackson www.artbyedo.com

Sikorsky S-70C-2 – LH92207
Sikorsky S-70C-2 – LH92210
S-70C-2 Hovering (Unknown source)
Detailed closeup of cockpit exterior (afwing.info)

S-70C-2 LH92206 transports a jeep during a military exercise [Sina News]
An unidentified S-70C-2 Black Hawk evacuates civilians in the Tibetan region. [Encyclopedia of Chinese Aircraft]
An unfortunate incident involving a unidentified S-70C-2 [Army Star]

Sources