Gasuden Kōken-ki

Empire of Japan, WW2,

 Empire of Japan (1937)
Long Range Research Aircraft- 1 Built

The Gasuden Kōken-ki was Japan’s attempt at building a world record setting plane for the longest distance covered in a non-stop flight. First conceived in 1931 to surpass John Polando and Russell Boardman’s flight, the Kōken-ki would have a slow development finally completed and ready for flight on August 8th of 1937. Though 6 years late and many other world records for distance had been set, the Kōken-ki still managed to prove its worth on May 13th of 1938 where it made a non-stop flight in a closed-circuit course in Japan covering 7239.58 mi (11651.011 km), a record that Japan would hold until 1939.

History

In the 1920s and 1930s, many countries were competing against each other for setting aviation-related world records, be it endurance, speed or distance. The goal of establishing a long distance world record was one of the most popular ambitions a country could have. The 1931 world record was established by John Polando and Russell Boardman, flying a Bellanca J-300 Special nicknamed “Cape Cod” from Floyd Bennett Field in New York to Istanbul, Turkey. The distance covered by these two men spanned 5011 miles (8066 km). The Empire of Japan was by no means idle in the conquest for setting the world record. The Kōkū Kenkyūjo (Aeronautical Research Institute) began to formulate a design proposal in the latter half of 1931 for a plane that would be able to beat Polando and Boardman’s record flight. The Kōkū Kenkyūjo was on good terms with the Tokyo Imperial University, and convinced them to put their design forward to the Monbushō (Ministry of Education). The design proposal moved rapidly through the approval process and eventually made its way to the Kokkai (Diet). Relatively confident in the design, the Kokkai approved the Kōkū Kenkyūjo’s design and provided them with a monetary grant.

A factory worker fitting parts on the tail section of the Kōken-ki. (Arawasi)

With adequate funding and support of the government, the Kōkū Kenkyūjo began to formally investigate the matter of designing the plane. The plane was now named the Kōken-ki (航研機). The man responsible for overseeing the project was Dr. Koroku Wada, with professor Keikichi Tanaka assisting him. Many members of the design staff were from the engineering department of the Tokyo Imperial University. Various committees were also formed for the purpose of designing the Kōken-ki. It would take two years until the basic design was completed. By the time the design was finished in August of 1934 however, another world record had been set by French aviators by the names of Maurice Rossi and Paul Codos. The French aviators were able to surpass the previous record set by Polando and Boardman by 645 miles / 1038 km by flying their Blériot 110 monoplane from New York to Rayak, Syria on August 5th of 1933. The Japanese were confident that they would soon be able to best this record, as they’d designed the Kōken-ki to endure 8078 miles (13000 km) of flight.

The next step for the Kōken-ki was construction, but this process would be slow as the advanced design of the Kōken-ki had to be completed first. Various components and tooling would be manufactured the following year. The Tokyo Gas and Electric Industry (known as Gasuden) was selected to be the manufacturer of the airframe, while Kawasaki Kokuki KK. was selected to manufacture the powerplant, which would be a licensed Japanese made version of the German BMW VII engine. Once the advanced design was completed, construction began. Due to the fact that Gasuden was relatively inexperienced with metal fabrication, the construction of the Kōken-kid would be delayed. The major components of the Kōken-ki were finally completed on March 31st of 1937, and were promptly moved to a hanger owned by the Teikoku Kaibo Gikai (Imperial Maritime Defence Volunteer Association) at Haneda Airport where it was to be assembled. On August 8th of 1937, the assembly was completed and the Kōken-ki was ready for its maiden flight.

Test pilots for the plane were carefully selected as testing the potential record setter was a matter of great importance to the Japanese. A decision was finally made with Major Yuzo Fujita as the pilot, Master Sergeant Fukujiro takahashi as the co-pilot and Flight Engineer 

From left to right is Major Fujita Yuzo, Flight Engineer Sekine Chiaichi and Master Sergeant. (Arawasi)

Chikakichi Sekine as the flight engineer. All of these men belonged to the Imperial Japanese Army’s Rikugun Kokugijutsu Kenkyū (Air Technical Research Institute) and had been involved with the design of the Kōken-ki since the start. The long awaited maiden flight finally took place on May 25th of 1937. The test flight went well with no problems to report, so plans for the Kōken-ki’s official record setting flight was set in motion. More test flights had to be completed, so the three men continued fly the Kōken-ki. Meanwhile, the Soviet Union’s own Tupolev ANT-25 made its record flight on June 18th of 1937 where it flew from Moscow over the North Pole and landed in Vancouver, Washington. This flight took the Russian pilots 63 hours and covered 5670 mi (9130 km). The Japanese however, were not concerned as the Kōken-ki’s range was surely able to surpass this. 

The first attempt for setting the world record was conducted by Japan on November 13th of 1937. Unfortunately for the Japanese, a landing gear failure surfaced and the Kōken-ki had to be grounded for months until May 10th of 1938. This second attempt was also met with a problem, as the autopilot system malfunctioned. This problem was far simpler to remedy than the landing gear, and was rapidly repaired. On May 13th at 4:55 AM, the Kōken-ki successfully took off from Kisarazu Naval Air Base near Tokyo Bay to break the world record. To verify the authenticity of the flight, Imperial Japanese Navy Lieutenant-Commander Tomokazu Kajjiki was to monitor the

A poster advertising Nisshin’s salad oil, with the Kōken-ki displayed in the background. (Arawasi)

flight as he was the Fédération Aéronautique Internationale’s (World Air Sports Federation) representative for Japan. The flight plan of the Kōken-ki was to follow a square shaped course that would lead to Choshi from Kisarazu, then to Ohta and back to Kisarazu. Many minor problems occurred during the flight, such as a tear in the water cooler. The Kōken-ki flew the square course for 29 laps nonstop, and finally completed its task of setting the world record, amassing a total distance of 7239.58 mi (11651.011 km). The Kōken-ki landed back at Kisarazu at 7:21 PM of May 15th after almost 63 hours. Upon landing, the flight of the Kōken-ki was officially approved as a world record by the FAI. It is noteworthy that the Kōken-ki was reported to still have about 132 US gallons (500 L) of fuel left, meaning that it could have potentially flown another 745 mi (1200 km). Nonetheless, it was an achievement which made the nation proud. The Kōken-ki was then featured on many advertisement posters in Japan.

The Japanese were able to hold the world record for about 15 months before being beaten by the Italians in August of 1939. The Italians flew a Savoia-Marchetti SM.82 and covered a distance of 8038 mi / 12936 km over a closed-circuit course. Nonetheless, the flight by the Kōken-ki was still an incredible feat for the Japanese, as it was the first and only Japanese plane to obtain a FAI world record at the time. After the record setting flight, the Kōken-ki would mostly remain in the Kaibo Gikai hangar where it was first assembled. Occasionally, the Kōkū Kenkyūjo would and perform test flights for various purposes. After the Kōken-ki was past its prime, the Japanese wanted to see if they could further improve their long distance flight. In the eyes of professor Hidemasa Kimura, the Kōken-ki was only useful for challenging the world record for distance, but not for anything else. As such, Kimura decided to design a plane which would be capable of flying from Tokyo to New York, a route spanning 6737 mi (10842 km). The work of this would result in the Tachikawa Ki-77, or A-26.

From left to right, Chikaichi, Takahashi and Fujita receiving the Japanese “Yokosho” medal for their feat. (Arawasi)

The Kōken-ki flew for the last time on June 14th of 1939 as a commemoration for Major Fujita, the pilot of the record flight who was killed in combat in China.  After Major Fujita’s funeral flight, the Kōken-ki was stored in the Haneda Airport and remained there for the entire duration of World War II in relatively pristine condition. However after Japan surrendered, American occupational forces began to arrive and began a long process of demilitarizing Japan. Upon reaching Haneda airport, all of the Japanese planes there ,military or not, were targeted for destruction. The Kōken-ki and every other Japanese plane present at the airport was towed to the field and burnt in a mass pile, thus bringing an ungraceful end to the Kōken-ki.

Design

A closeup on the Kawasaki-built BMW VIII engine.

The Gasuden Kōken-ki had an all-metal semi-monocoque fuselage which housed a Kawasaki-built German BMW VIII engine driven by a Sumitomo SW-4 two-bladed metal-shrouded wooden propeller. The wings of the Kōken-ki were carefully designed with the intent of allowing it to operate in thinner air. The cantilever wings were constructed using a Kōken-ki Model 4 aerofoil shape, with about 17.5% thickness. The wingtips however, had a different material which was Kōken-ki Model 11 alloy. This aerofoil only had 4% thickness. The resulting wings had an aspect ratio of 8.7. As the plane was designed with range and endurance in mind. 14 fuel tanks were installed in the wings allowing for 1538 US gallons (5822 L) of fuel. A system was also installed which would allow the fuel to even out in all the tanks in order to maintain center of gravity. The landing gear of the Kōken-ki was retractable in order to reduce drag and once retracted, fairings would cover the landing gear wells. The cockpit was set on the left side of the plane, giving it an asymmetrical design. The Kōken-ki’s windshield could be extended and folded in order to reduce drag. Only when taking off and landing would it be extended. This design was a hindrance for the pilots as they reported poor visibility and control. The Kōken-ki was completely metal, with the exception of fabric covers which were fitted over the control surfaces and wings.

Operators

  • Empire of Japan – The Gasuden Kōken-ki was operated solely by Japanese pilots for all the flights it flew.

Gasuden Kōken-ki
Wingspan 91 ft 7 in / 27.9 m
Length 49 ft 5 in / 15.1 m
Height 11 ft 9 in / 3.6 m
Wing Area 939.7 ft² / 87.3 m²
Wing Loading 21.6 lb/ft² / 105.9 kg/m²
Power Loading 25.3 lb/hp / 11.5kg/hp
Engine 1x Kawasaki-built BMW VIII 12-cylinder water cooled V-engine (715 hp)
Propeller 1x Sumitomo SW-4 two-bladed metal-shrouded wooden propeller
13 ft 1.5 in / 400 cm
Fuel Load 1538 US gallons / 5822 L
Empty Weight 9314 lb / 4225 kg
Loaded Weight 20317 lb / 9216 kg
Maximum Speed 155 mph / 250 kmh at Sea Level
152 mph / 244 kmh at 6562 ft / 2000 m
Cruising Speed 131 mph / 211 kmh at 6562 ft / 2000 m
Range 8078 mi / 13000 km
Maximum Service Ceiling 11187 ft / 3410 m
Crew 1x Pilot
1x Co-Pilot
1x Flight Engineer

Gallery

Kōken-ki sideart by Ed Jackson
The Kōken-ki being prepped for flight by ground crew and an armed guard. (Arawasi)
The Kōken-ki taking off. (Arawasi)
Underside view of the Koken with its gear retracted.
The Kōken-ki in the factory during construction. Note the exposed engine. (Arawasi)
Engineers working on the Kōken-ki. (Arawasi)
A poster advertising Nitto’s black tea. The Kōken-ki is featured in the background. (Arawasi)
A 1939 postage stamp commemorating the Kōken-ki’s record flight. (Arawasi)
A replica of the Koken-ki on display in a museum in Japan

A Series of Youtube Videos on the World Record Attempt:

Sources

Takenaka, K. (2007). Koken Long-range Research-plane., Swopes, B. (2017). 13–15 May 1938., Tupolev ANT-25 Soviet Long Range Record Setter. (n.d.). Fiddler’s Green., Mikesh, R. C., & Abe, S. (1990). Japanese aircraft, 1910-1941. Ann Arbor, MI: Naval Institute., Dyer, E. M. (2015). Japanese Secret Projects: Experimental Aircraft of the IJA and IJN 1922-1945. Ian Allan Publishing. Images: Side Profile Views by Ed Jackson – Artbyedo.com, Other images from http://arawasi-wildeagles.blogspot.com/

 

Republic F-74 Thundercloud (Fictional)

Fake Aircraft

usa flag USA (1946)
Fictional Prototype Fighter Bomber – 11 Built

Inspired by the Kyushu J7W and Curtiss-Wright XP-55, the P-later-F-74’s radical wing designs lifted its position in aviation history to the jet age’s dawn. With a canard layout and its inverted, swept-back gull wings, this little-known fighter-bomber was a broad new attempt at close air support by Republic Aviation. Meet the unnamed member of the “Thunder family” – F-74 Thundercloud.

History

After Japan’s surrender in 1945, the U.S. Naval Technical Mission to Japan immediately commenced. Found at an abandoned hangar of the Itazuke Air Base, an aircraft with a radical design caught everybody’s eyes. This is the Kyushu J7W Shinden, an interceptor with a canard layout and a pusher engine at the back, similar to the U.S. Army’s XP-55 Ascender. Along with other interesting Japanese designs, the J7W was dismantled, crated, and shipped to the U.S.

Immediately after the Second World War, USAAF launched their next generation multirole strike fighter program. The winning project of the contract would be awarded the codename P-74. However, most major companies such as North American and Lockheed were busy creating their first jets, leaving Republic Aviation the only participant. Impressed by the J7W’s perfect integration of nose-mounted weapons and the large but streamlined fuselage that houses powerful engines, Republic decided to give it a shot, as a then-intermediate candidate of the P-84 Thunderjet.

Design

The F-74 was an all-metal, monocoque, low-wing cantilever monoplane. Its unique canard layout consisted of a pair of compound delta wings that integrated an inverted “gull wing” design with a pair of dihedral wing tips that houses the ailerons, and a pair of smaller, less swept back trapezoidal canards at the front of the aircraft, immediately behind and above the modular weapon bay. Two vertical stabilizers are positioned at the joint between the main wing and the wingtips, with anti-skid wheels on the bottom. A pair of long and narrow side intakes drew upcoming air into the rear-mounted, air-cooled radial engine (R-3350 or 4360) that drove a set of four wide paddle blade style constant speed propellers [1].

The nose-mounted weapon bay could be easily swapped at any frontline airfield to suit different combat scenarios, ranging from the basic “six-pack” .50 machine guns to a pair of powerful 37mm cannons. The powerful R-4360 engine also allowed an assortment of weapons to be carried under its wing pylons, ranging from unguided rockets, general purpose and napalm bombs, to machinegun pods that further enhance the aircraft’s firepower.

Not Your Average Cumulonimbus

Only one year after Republic “won” the contract by being the sole participant, on 17th August 1946, the XP-74-A-0-RE prototype flew for the first time. With a R-3350 engine and simulated counterweights instead of guns, the aircraft displayed favorable control characteristics. Its low-speed handling was surprisingly well for an aircraft this size, thanks to its large wing area and powerful pitching leverage provided by the front-placing canards. The only two complaints of the test pilot were its large torque on the takeoff roll and the fragile rear propeller he broke on landing. The first problem was addressed by applying more trim, with the second one solved by adding a pair of anti-skid wheels under the vertical stabilizers.

However, the Army paused the XP-74 project in favor of the jets. The project was also overshadowed inside Republic themselves, because their jet replacement of the P-47 Thunderbolt – the XP-84 Thunderjet – already took to the skies six months before XP-74 did. All testings were halted and the project group was dissolved, despite the emergence of another high-altitude interceptor variant, the XP-74B.

Luckily, the newly-formed USAF changed the fate of this plane one year later. Facing threats of probable “Communist-containing” wars (Korean War and subsequently Vietnam War), the Air Force needs a reliable attacker with a large payload as a suitable backup to the new and unreliable jets. The Thundercloud was revived under the name of F-74. Republic offered the USAF an improved version, dubbed as the F-74D. With a powerful R-4360 radial engine and four 20mm AN/M3 cannons, this machine could rain down deadly ordnances at an incredible efficiency [2]. Five D-variants fought during the Korean War, with one of them later modified for the Project GunVal, carrying four T-160 cannons as an experimental configuration. After the retirement of all F-74s, some were acquired by NACA and later NASA as X-74s for experimental airfoil research.

Variants

  • XP-74A-0-RE – Initial prototype for the USAAF. First flight on 15th Aug. 1946. No armament, R-3350 engine.
  • YP-74A-1-RE – Small pre-production series starting from Dec. 1946. Armed with 6 Browning M3 12.7mm MGs. 5 built.
  • P-74B – High-altitude heavy interceptor variant. 2x 37mm M10 cannons and 2x M3 12.7mm MGs. R-4360 engine with supercharger. None built.
  • F-74D-1-RE – Ground attack variant for the USAF. 4x 20mm AN/M3 cannons, R-4360 engine without supercharger. 5 built, 3 converted from A-1 variant in 1949.
  • F-74D-2-RE – Testbed for T-160 autocannons during Project GunVal in 1953. 4x 20mm T-160 cannons. 1 converted from F-74D-1.
  • X-74A – Two aircraft served for NACA and later NASA for experimental airfoil research. R-4360 engines with supercharger. 2 converted from YP-74A pre-production models.

Operators

  • [USA] – Evaluated by the U.S. Army and later Air Force. 8 deployed in the Korean War. Retired 1953[3]. 2 used by NACA/NASA. Fate unknown.

 

Republic XP-74/YP-74/F-74 Specifications
Wingspan 41 ft 2 in / 12.54 m
Length 44 ft 2 in / 13.46 m
Height 15 ft 1 in / 4.59 m with landing gears
Wing Area 322.05 ft² / 29.92 m²
Engine 1x R-3350-23 (2,200 hp) (A model only)

1x R-4360-31 (3,000 hp) (other variants)
Empty Weight 11,000 lb / 4763 kg
Maximum Takeoff Weight 19,000 lb / 8618 kg
Fuel Capacity 1514 L internal, up to 3x 416L drop tanks
Climb Rate 15m/s at sea level (D-1 model)
Maximum Speed 430 mph / 692 kmh at 10,000 ft / 3,048 m
Cruising Speed 400 mph / 644 kmh
Range 750 mi / 1207 km on internal fuel, D model
Maximum Service Ceiling 36,900 ft / 11,200 m for A-1

26,000 ft / 7,925 m for D-1
Crew 1x Pilot
Armament A-1:

6x 12.7mm Browning M3 (400 rpg)

B:

2x 12.7mm Browning M3 (400 rpg)

2x 37mm Browning M10 (60 rpg)

D-1:

4x 20mm AN/M3 (250 rpg)

D-2

4x Ford T-160 (150 rpg)

Gallery

 

Sources

“Literally Fake News”, The Fake News Department of the United States of America, September 1946., “The Republic F-74D” official promotion booklet, Republic Aviation, 1949., “A Brief History of the Rice Field Attackers in Korea and Vietnam”, Tingwong Sum, 1983., Images: Side Profile Views by Ed Jackson – Artbyedo.com

 

Mitsubishi G7M “Taizan”

Empire of Japan, WW2, , , ,

 Empire of Japan (1941)
Strategic Bomber- 1 Scale Mockup Built

The Mitsubishi G7M “Taizan” (泰山/Great Mountain) was a planned long range strategic bomber for Imperial Japan’s Army Air Service. Developed out of the need for a bomber capable of striking the continental United States, the Taizan would face a series of developmental problems, ultimately leading to the cancellation of the project.

History

Prior to the start of World War II, Japan had foreseen that in a potential future conflict with the United States, it would require a long range bomber capable of striking the US mainland. In order to fulfill this requirement, a review was conducted in 1941 of all the Imperial Japanese Navy’s bomber aircraft in service. It was revealed that the entirety of the Japanese bomber arsenal was incapable of striking targets in the United States from the Japanese airfields. The Mitsubishi G4M “Betty” was one of Japan’s newest aircraft being pushed into service. Despite its superior range of 3,749 mi (6,043 km) compared to previous IJN bombers, it still was not sufficient enough to strike the US mainland or targets deep in the Soviet Union. As a result of this, the Naval Kōkū Hombu (Aviation Bureau) issued the 16-shi specification in 1941 for a long range bomber. The 16-shi specification would call for a bomber capable of flying at least 361 mph (580 km/h) with a maximum range of 4,598 mi (7,340 km).

Interested in this specification, Mitsubishi’s staff began work on a design that would meet the criteria set by the Kōkū Hombu. Mitsubishi engineer Kiro Honjo (the designer of the G3M and G4M) proposed a four engine design, but this was promptly rejected by the Kōkū Hombu. As a result, another Mitsubishi engineer by the name of Kijiro Takahashi submitted his own design. Upon inspection by the Kōkū Hombu, Honjo’s design was approved and given the green light to proceed. Within Mitsubishi, the 16-shi design was known as the “M-60”. Takahashi’s design was to be powered by two “Nu” engines. The Nu was a 24 cylinder liquid cooled engine which was able to provide 2,200 hp at 16,404 ft (5,000 m) but, due to the start of Operation Barbarossa, Germany was unable to export machinery and tools needed to manufacture the Nu engine. Unfortunately for Takahashi, this turn of events would prevent his design from being completed. As a result of this, Takahashi fell out with the Kōkū Hombu and Kiro Honjo would take over the M-60 project. This time, Honjo followed the Kōkū Hombu’s suggestion and used two engines instead of his idea of four. Under Honjo’s lead, the Taizan’s power plant was changed to two 18 cylinder Mitsubishi Ha-42-11 engines capable of generating 2,000 hp each. It was also seen that Honjo’s design was less aerodynamic than Takahashi’s due to the weaker engines and heavier armament.

On October 31st of 1942, an evaluation was conducted on the work done so far, and a performance estimation gave the Taizan a range of 3,454 mi (5,559 km) and a speed of 332 mph (518 km/h) at 16,404 mi (5,000 m). Falling short of the original 16-shi specification, Mitsubishi scrambled to make adjustments but further revised estimates stated that the design didn’t see any improvements, and actually saw some deterioration. By the time the Taizan’s design was completed in late 1942 and ready for construction of a wooden mockup, a new 17-shi specification was released calling for a new bomber design. Kawanishi took up the design and created the K-100 bomber project. Seeing promise and a better alternative to the Taizan, the Kōkū Hombu ordered all work on the Taizan to be halted until the K-100 could be completed and evaluated. Kawanishi completed initial work on the K-100 and a comparison was made between K-100 and Taizan in the summer of 1943. The Taizan’s range differed significantly from the proposed normal range from 2,302 mi (3,705 km) to 1,726 mi (2,778 km). Due to the significant range reduction, the Kōkū Hombu stopped supporting the Taizan. With no more interest and reason to develop the Taizan, Mitsubishi would finally shelve the project and stop all work on it.

Design

From an exterior aesthetic point of view, the Taizan bears a striking resemblance to the German Heinkel He 177. The nose of the Taizan was rounded and glazed over, a new design not in use by any Japanese bombers at the time. The wings of the Taizan were mounted mid fuselage, and were to be constructed out of metal. Fabrics, however, were to be used for the cover of the Taizan’s ailerons and rudder.

Ordinance wise, the Taizan was to carry a maximum bomb load of 1,764 lbs (800 kg). The defensive armament underwent several changes. Takahashi’s Taizan design was to be armed with two 20mm Type 99 Mk.2 cannons and two 7.7mm Type 97 machine guns. Honjo’s initial design would carry two 20mm Type 99 Mk.2 cannons, two 13mm Type 2 machine guns and two 7.92mm Type 1 machine guns. Later on, the armament finalized at two 20mm Type 99 Mk.2 cannons and six 13mm Type 2 machine guns. There would have been one Type 99 Mk.2 in the nose and one in the tail. There would have been two Type 2 machine guns in the forward upper fuselage turret, two in the rear fuselage turret and two in ventral position, firing rearwards.

Operators

  • Empire of Japan – The Taizan would have been operated by the Imperial Japanese Navy Air Service.

 

Mitsubishi G7M1 “Taizan” *

*Estimated performance of Mitsubishi’s G7M1 proposal
Wingspan 82 ft / 25 m
Length 65 ft 6 in / 20 m
Height 20 ft / 6.09 m
Engine 2x Mitsubishi Ha-42-11 (2,000 hp)
Power Loading 8.8 lbs/hp / 3.99 kg/hp
Empty Weight 23,368 lbs / 10,600 kg
Usual Weight 35,273 lbs / 16,000 kg
Fuel Capacity 4,497 L / 1,188 US Gallon
Climb Rate 32,808 ft / 10,000 m in 10 minutes
Maximum Speed 344 mph / 544 kmh @ 26246 ft / 5,000 m
Typical Range 1,739 mi / 2,799 km
Maximum Range 4,598 mi / 7,400 km
Crew 7
Defensive Armament 6x 13x64mm Type 2 machine guns

2x 20×101mm Type 99 Mk.2 cannons
Ordnance / Bomb Load 1,764 lb / 800 kg – Maximum

Gallery

 

Artist’s conception of the operational G7M Taizan

Sources

Dyer, E. M. (2013). Japanese secret projects: experimental aircraft of the IJA and IJN 1939-1945. Burgess Hill: Classic., Aircrafts of Imperial Japanese Navy. (n.d.). Retrieved February 06, 2018, from http://zenibo-no-milimania.world.coocan.jp/epljn.html, Images: Side Profile Views by Ed Jackson – Artbyedo.com

 

Saab 340 AEWC

Modern Aviation, Sweden Modern, , ,

sweden flag Sweden (1997)
 Airborne Early Warning & Control (AEWC) Aircraft- 12 Built

The Saab 340B AEW&C and the Saab 2000 AEW&C are airborne early warning and control (AEW&C) airplanes that were developed from the basic Saab 340B airplane, a twin-engine turboprop regional airliner developed and built in partnership with the now defunct American aircraft manufacturer Fairchild Aircraft .  The model was named “Metro III” when manufactured by Fairchild Aircraft. The Saab 2000 AEW&C is based upon the Saab 2000 airliner,it being a variant of the basic Saab 340B model. These airborne radar models came from the inventiveness of the Flygvapnet, as the idea of fitting the basic transport model already in service emerged considering the gaps the Flygvapnet had regarding the type of air asset. This paid off as the Nordic nation is now equipped with an airborne and air control (flying) system that provides a very valuable tool for the Flygvapnet to monitor the Swedish skies and even abroad, as the post-Cold War era meant new missions beyond national defence for the Swedish Armed Forces in general. The basic 340B  version was, despite its initial non-military use, a display of technological advancement with advanced avionics and a product of the company’s desire to revive its interests in the civil market after the not entirely successful Saab Scandia 90, in the 50’s.

The Saab 340B AEW&C (Saab 340B) is a twin-engine turboprop medium size airliner, capable of carrying more than 30 passengers and with a conventional design, mainly for short-range regional flights. The main airframe is cylindrical, with the wings placed near the middle section of the airplane and of trapezoid and thin configuration. The nose is not rounded being rather sloped downwards, and the wings and horizontal control surfaces being angled upwards. The engines are not beneath the wings, as the configuration is that of a low-wing airplane; instead, they are placed above the wings and logically enrooted in them. The Saab 2000 differs from the basic model in the sense that it is larger, wider, slightly taller and with more wing area.

The Saab 340B AEW&C is powered by two General Electric CT7-9B turboprops of 1870 hp with a Dowty Rotol (or Hamilton Standard) 14RF19 four-blade constant speed propeller each, allowing the airplane to reach a cruise speed of 522 km/h (325 mph). The Saab 2000 AEW&C also has a different powerplant, being 2 Allison/Rolls Royce AE 2100A turboprop engines of 4,591 hp with a Dwoty Rotol six-bladed constant speed propellers each, having improved performance than the 340B version: for instance, the cruise speed it can reach is up to 629,68 km/h (391,26 mph).

Given the role of the airframes, both are fitted with an Ericsson Erieye (PS-890) radar installed above the main airframe, with a range of S-band, 3 GHz (GigaHertz) with a range of 160 degrees on each side. The radar is a rectangular pod, in contrast with the radars one would see on more classical AEW&C planes (for example the Boeing E-3 Sentry or the Ilyushin A-50). The radar has a range of 300-400 km capable of detecting sea and airborne targets.

History

The A 340B AEW&C (S 100B Argus) came to be with the idea of having a Swedish modified AEW&C asset and an alternative to the comparatively more expensive Boeing E-3 AWACS. The Flygvapnet was already operating with a Saab 340B for VIP transport, designated TP 100A, and that same airframe was to be the basis for the new airborne defence and air control radar. By the mid-90s, the first unit entered in service with the Flygvapnet. A total of six airframes were ordered: four with the radar already installed and two without the radar, prepared to have it installed when needed and serving as VIP transports during peacetime. As mentioned above, the Saab 340B AEW&C (S 100B Argus) is based upon the commercial airliner Saab 340B, which is a good platform given its structural characteristics, avionics, and performance. This airframe began its development in the 70s, with the propulsion system that it has being chosen as it was more economic than the jet propulsion system back then. It is reported that cost/efficiency considerations and the effects of the 1973 Oil Crisis made the company to pick the turboprop propulsion system. The US Airline Deregulation Act of 1978 gave further impulse for the basic model to be developed. This airplane was developed and built jointly with Fairchild Aircraft, mainly due to the fact that Saab thought the production capacity would not be enough. As a result, from 1980 to 1987, Fairchild was tasked with manufacturing the wings, the tail, and the engine nacelles. Saab, in turn, was tasked with manufacturing the main airframe, covering the 75% of development costs and the system integration and certification. The first Saab 340 flew in 1983, with the first airplane serving with an airline in 1984. After Fairchild ceased operations, Saab began to fully manufacture the Saab 340, doing so until 1999. The Saab 2000 came to be due to a decision in 1988 by Saab to develop an elongated version of the Saab 340 capable of carrying up to 50 passengers, having the same economic efficiency along with better climbing performance. Its first flight was in 1992, entering into service in 1994.

Currently, the S 340B AEW&C (S 100B Argus) operates in the Flygvapnet with 4 units sporting radar equipment and two additional units serving as VIP transports, ready to have the radars installed when needed. Its production was also finished in 1999, with 12 AEW&C units built: six for the Flygvapnet, 2 for the Royal Thai Air Force and 2 for the Pakistan Air Force, with 2 more under production for the United Arab Emirates Air Force. 2 modified airframes were loaned for the Hellenic Air Force from 2000 to 2003, while Greece received two Embraer RJ-145 AEW&C aircrafts fitted with the same Ericsson Erieye radars. It is noteworthy to state that of the basic airliner version, 460 units were built. Of the Saab 2000 airliner version, 63 were built; in turn, the Saab 2000 AEW&C version was introduced in 2010 for the Pakistan Air Force, with 8 units built so far and operating with the Pakistan Air Force, the Royal Saudi Air Force and the United Arab Emirates Air Force. Three more units would be delivered for the Pakistani Air Force.

Design

The Saab 340B AEW&C design is based on the Saab 340B commercial airliner, while the Saab 2000 AEW&C is based on the Saab 2000 commercial airliner. As such, the airframe is the basically the same except that the former has the radar placed above the airframe, and other electronic equipment installed in the airplane. The airplane is of a dihedral wing design, which  means the wings are placed at the base of the airframe and angled upwards. It had two turboprop engines and an airframe built entirely of aluminium with the same construction techniques other Saab military fighters had: usage of bonding instead of rivets, reducing the overall weight of the airplane. It also has wider horizontal stabilizers, a vibration control system in the cabin to reduce the noise from the engines, and more powerful engines (the two General Electric CT7-9B turboprops of 1870 hp).

The wing and the horizontal control surfaces or stabilizers are dihedral, with the angle of the former being more prominent than the angle of the main wings. Both the wings and the horizontal stabilizers are both of trapezoid shape, being very thin – or simply not having that much of surface area. The engines are located at a quarter of the main wings, close to the main airframe. The main wings are located at the middle of the airframe, with the airframe being of tubular shape. The bow section of the airframe has a shape that varies according from the view or perspective. From an upper view, it has a parabolic nose cone; from a side view the shape is divided, with the area between the very roof and the windscreen having and inclination of around 38 degrees negative, and from the lower section of the windscreen to the tip of the nose, an angle of 30 degrees negative. The tip of the nose from a side view is placed at the lower section of the airframe, with the interior bow section from where the frontal landing gear is placed, to the tip, having an angle upwards of 10 degrees. The central section of the airplane is of cylindrical shape.

The aft or stern section of the airplane comprises the horizontal and vertical control surfaces, and two ventral tails fins. The tail is of conventional type with a sort of “double-delta” configuration; this is, the surface having at the forward area different angles. The forward section of the tail, from the central area of the airframe to the area where the horizontal control surfaces are placed, has an angle of nearly 15 degrees. From the aforementioned section to the tip of the tail the angle is of 45 degrees. From an upper view, the rear section is of conical shape, whereas from a side view the upper area of the aft section is lightly going downwards, and the interior part has an upwards angle of around 15 degrees. The ventral fins are placed right beneath the horizontal control surfaces. The rudder dominates half of the tail. And there is an elongating radome at the very rear part of the aircraft. The landing gear is of tricycle configuration, with the frontal landing gear placed at the nose cone (beneath the cockpit) and the two landing gear trains placed beneath the engine gondolas, them being retractable with storage inside the engine gondolas.

The Saab 2000 AEW&C has a similar structure to that of the 340, except that it is more elongated in width and length, the inferior section of the nose being entirely straight and the engines having more distance from the main fuselage. It also lacks the ventral tail fins the Saab 340B AEW&C (S 100B Argus) has.

The engines powering the aircraft are two General Electric CT7-9B turboprops of 1870 hp with a Dowty Rotol (or Hamilton Standard) 14RF19 four-blade constant speed propeller. Thanks to the powerplant, the airplane can reach a maximum cruising speed of 524 km/h (325,60 mph). The aircraft is fitted with devices to reduce the noise generated by the engines. The Saab 2000 AEW&C is powered by two 2 Allison/Rolls Royce AE 2100A turboprop engines of 4,591 hp with a Dwoty Rotol six-bladed constant speed propellers each, allowing a cruise speed of 629,68 km/h (391,26 mph).

The AEW&C version has the Ericsson Erieye radar placed above the central section of the airframe, supported by a series of pillars that connects it to the main airframe and with a slight inclination downwards from stern to bow. Ventral antennas are installed at the inferior area of the fuselage.

The canopy is of conventional type, typical of any commercial or transport aircraft, with two frontal windscreens, and a lateral windscreen at each side of the cockpit. The crew on the Saab 340 AEW&C (S 100B Argus) is normally six.

Fitting a civilian for defence duties

Perhaps surprisingly, the Flygvapnet lacked an airborne AEW&C system during the late Cold War, relying instead on either smaller airborne assets for surveillance or land radar stations. The Flygvapnet decided to close this gap by ordering Ericsson Microwave Systems to develop the PS-890 Erieye radar by the late 80s, with the airframe that would be used undergoing the first trials by the same period. This idea was, in fact, proposed back in the 70s but rejected. It was revived again in the Swedish Parliament (Riksdag) in 1982. As the Boeing E-3 Sentry AWACS was deemed too expensive, it is no surprise that the Saab 340 airliner was chosen by the Swedish Defence Materiel Administration as the platform for the airborne radar system. the Flygvapnet was already operating with a Saab 340B which was being operated as a VIP transport. In any case, it was a very good decision, considering the Saab 340B is a very economic airplane thanks to its powerplant’s configuration and the advanced basis avionics and electronics, which was hence an economic alternative to the E-3 Sentry. In combination with the Erieye radar, it makes a suitable platform for an airborne radar for Sweden. The Saab 2000 is an example of how this concept has evolved by incorporating the Erieye into an equally economical yet very capable airframe, which a derivative from the basic model.

The Eye of Odin

The radar installed in the Saab 340B AEW&C (S 100B Argus) is the Ericsson Microwave System Erieye PS-890 multi-mode active electronically scanned array (AESA) pulse-doppler radar, which makes the airplane a very remarkable AEW&C aircraft, considering its capacities. Its development began in 1985 after the Swedish Defence Materiel Administration, with a dummy dual-sided phased antenna being tested on the future platform, which was tested in trial two years later. It has 200 solid-state modules mounted in the antenna, with an S-band frequency and 3 GHz, with a ‘look’ on each side of 120 degrees and a reach of up to 300-400 km at an altitude of 6096 meters (20,000 ft). It has an altitude reach of up to 20 km (65,000 ft), yet leaves the nose and tail areas as blind spots. This shortcoming is compensated by the fact the radar – with this design in particular – can provide improved detection and better tracking thanks to the electronically scanned beam, at the point of being able to scan other areas while concentrating on a single target. Moreover, the PS-890 Erieye can detect and track fighters, helicopters, cruise missiles and even very small targets at the sea, as it has also a sea surveillance mode. Moreover, sectors deemed important can be scanned with different modes at a single moment, being capable of performing in electronically saturated environments and as an all-weather device, and can discern between friend and foes through its IFF capacities and devices.

This is suitable for the Flygvapnet considering that the dimensions it has to watch for are the air and the sea (even more as the Baltic sea is the most important body of water at the East, an area from which most of the threats have come historically, and even currently). As such, it can perform air and sea surveillance missions, Command and Control, Intelligence, control of own assets, surveillance and control of national borders, national assets and national economic zones, search and rescue, alert warning and air policing. The system is compatible with NATO airborne systems and standards.

The Erieye PS-890 radar has other electronic features, such as adaptive waveform generation with digital; pulse-coded electronic frames; signal processing and targeting, a track while scan device; low and medium pulse repetition frequency operating modes; frequency agility; target radar-cross section display; and air-to-air and sea surveillance modes.

Interestingly and despite the system being capable of receiving four multifunction workstations for airborne controllers, it can spare them as it has instead an onboard automatic systems datalink that can transmit to ground station the information gathered by the airborne radar, and with those same stations being capable of transmitting orders to the platform. The airplane and radar are both connected to the integrated Swedish Air Defence System and network StriC-90, thanks to this network, the airplane can maximize its operational performance, complementing in turn and even enhancing the capabilities of such system; this fact makes the Saab 340B AEW&C (S 100B Argus) airplanes very valuable assets in the Flygvapnet. And the same design of the radar module was the first of its kind, being also an alternative to the disc-shaped classical airborne radars. The radar developed by Ericsson is fitted in other similar airborne platforms such as the Embraer EMB-145/E-99 and the Bombardier Global 6000. It has now evolved into the Global Erieye airborne radar.

Variants of the Saab 340 AEW&C (S 100B Argus)

  • Saab 340 AEW&C / S 100B Argus – Airplanes having the PS-890/FSR-890 radar, and operated by the Royal Thai Air Force.
  • Saab 340B AEW&C 200 – Version fitted with the IS-340 Erieye radar
  • Saab 340B AEW&C 300 / S 100D Argus – Airplanes fitted with the upgraded PS-890/ASC-890 radar, capable of admitting from 1 to 4 operators.

Variants of the Saab 2000 AEW&C

  • Saab 2000 Erieye AEW&C – Version fitted with an airborne Erieye radar
  • Saab 200 MPA (Maritime Patrol Aircraft) – Version for Maritime Patrol and capable of performing ASW, ASuW, anti-piracy/anti-narcotics/anti-people smuggling, maritime counter-terrorism operations, search and rescue, support for special forces, SIGINT, and fisheries patrol, among other sea-based security tasks.

Operators

  • Sweden – The Flygvapnet operates four Saab 340 AEW&C (S 100B Argus) fitted with the Erieye radar, alongside 2 additional airframes serving as transport planes, ready to have the radar installed in case it is needed. The first airframes were received in 1994, entering fully in service between 1997 and 1999, and serving in the F16M wing at Malmstatt. Normally, there are no operators onboard, being rather used as a part of the integrated air defence network.
  • Greece – The Hellenic Air Force decided to acquire the Erieye radar system with 4 units to be installed in Embraer RJ-145 airplanes. While waiting for the newly acquired system to arrive, 2 Saab 340B AEW&C airplanes were loaned by the Greeks in the year 2000. The loaned units were modified, having two to three operator consoles, NATO IFF, communications and datalinks having a ground bases system for information processing fitted for Greek standards, but lacking the Swedish ECCM and also the cockpit display processing information from ground stations. These airplanes were returned to the Flygvapnet by 2003.
  • Thailand – The Royal Thai Air Force has two Saab 340 AEW&C that received in October 2012.
  • United Arab Emirates – The United Arab Emirates Air force requested 2 airplanes, with the units delivered being Saab 2000 AEW&C. Now operational.
  • Saudi Arabia – The Royal Saudi Air Force reportedly operates two Saab 2000 AEW&C for border surveillance.
  • Pakistan – This country operates four Saab 2000 AEW&C airplanes. 2 more are reportedly on order.

 

Saab 340 AEW&C – S 100 B Argus Specifications
Wingspan 70 ft 4 in / 21.44 m
Length 66 ft 8 in / 20.33 m
Height 22 ft 11 in / 6.97 m
Wing Area 450 ft² / 41.81 m²
Engine Two General Electric CT7-9B turboprops of 1870 hp with a Dowty Rotol (or Hamilton Standard) 14RF19 four-blade constant speed propeller.
Empty Weight 22,707 lb / 10,300 kg
Maximum Takeoff Weight 29,101 lb / 13,200 kg
Loaded Weight 7,500 lb / 3,401 kg
Climb Rate 2,000 ft / 10,2 m/s
Maximum Speed 285 mph / 528 kmh
Cruising Speed 285 mph / 528 kmh
Range 900.988 mi / 1,450 km
Maximum Service Ceiling 25,000 ft / 7,620 m
Crew 6
Electronics
  • An Ericsson Erieye (PS-890) radar.
  • Länk 16, HQII, IFF, secure voice, m.m.

 

Saab 2000 AEW&C Specifications
Wingspan 81 ft 3 in / 24.76 m
Length 89 ft 6 in / 27.28 m
Height 25 ft 4 in / 7.73 m
Wing Area 600 ft² / 55.7 m²
Engine Two Allison/Rolls Royce AE 2100A turboprops of 4152 hp with a Dowty Rotol six-blade constant speed propeller.
Empty Weight 30,424 lb / 10,800 kg
Maximum Takeoff Weight 50,625 lb / 22,800 kg
Loaded Weight 13,010 lb / 5,900 kg
Climb Rate 2,250 ft / 11,4 m/s
Maximum Speed 391,26 mph / 929,68 kmh
Cruising Speed 391,26 mph / 929,68 kmh
Range 2,301.55 mi / 3,704 km
Maximum Service Ceiling 30,000 ft / 9,144 m
Crew 7
Electronics
  • An Ericsson Erieye (PS-890) radar.
  • Länk 16, Self-protection systems, IFF/SSR, secure voice, ESM/ELINT, AIS; Command and Control devices such as consoles and a latest generation HMI.

Gallery

Saab 340 AEW Blueprint

 

 

Sources

Deagel.com. (2017). Saab 2000 AEW&C., Forecast International. (2000). Saab 2000 (Archived Report)., Fredriksson, U. (2004). Saab 340AEW. X-plane.org., Pike, J. (1999). S 100B Argus, Saab 340 AEW&C. FAS.org., SAAB. (n.d.). SAAB 2000 Erieye AEW&C Airborne Early Warning & Control., SAAB. (2009). SAAB 340B/Bplus. SAAB Aircraft Leasing. SAAB. (2013a). Erieye AEW&C Mission System., SAAB. (2013b). SAAB Airborne Surveillance Solutions. SAAB. (2015). High Quality and Support in Focus – Saab 340 & SAAB 2000., SAAB. (2016). The First Airborne Radar in Sweden Underwent Final Testing 20 Years Ago., SAAB. (n.d.). Erieye SAAB 2000 AEW&C System. The Spyflight Website. (2003). SAAB S100B AEW&C Argus. Images: 340AEW Royal Thai Airforce by Alec Wilson / CC BY-SA 2.0, 340AEW by Gnolam / CC BY-SA 3.0,  Side Profile Views by Ed Jackson – Artbyedo.com

Blohm & Voss BV 144

Weimar and Nazi Germany, WW2, , ,

nazi flag Nazi Germany (1940)
Prototype Passenger/Transport Plane – 2 Built

Born out of Deutsche Lufthansa’ vision of an advanced airliner to replace the aging Ju 52 after the war, the BV 144 is arguably one of the rather unique looking passenger airliner planes of the 20th century. Although designed by Blohm & Voss in 1940, the first flying prototype wouldn’t take to the air until 1944, when the development of the BV 144 was no longer relevant to its original purpose and the Germans were in full retreat.

History

With rapid advances in Western Europe throughout 1940, Nazi Germany was confident that the war would be over soon. With such conditions in mind, it was very reasonable for Deutsche Lufthansa to start drafting up plans for their commercial airliner services after the war. Looking for a new aircraft to replace their aging Junkers Ju 52 transport, Deutsche Lufthansa turned to Blohm & Voss in 1940 in hopes of an advanced airliner. The design was finalized in early 1941, and was ready to be constructed. With France recently defeated, the Germans decided to take advantage of the French industry and ordered two prototypes to be constructed at the Louis-Breguet Aircraft Company factory in Anglet, in the Nouvelle-Aquitaine province of France.

BV.144 in its assembly stage. Note the large forward lamp assembly in the nose.

Although construction started in 1941, the first prototype would not be completed until sometime between July and August of 1944. By this point, the war situation for Germany had became alarmingly worse and the BV 144 was no longer seen as important. Another factor which may have been the cause of the slow construction was the deliberate low effort put into construction by the French workers, as they didn’t wish to help Germany progress. Finally, in August of 1944, the first prototype of the BV 144 would take to the sky. Unfortunately for the Germans however, the Allied forces were moving rapidly through France after Operation Overlord. This meant the Germans were forced to abandon the BV 144 prototype due to their retreat.

After the Liberation of France, the Louis-Breguet Aircraft Company factory fell back into French hands, as well as the completed BV 144 prototype and the second unfinished prototype. Both were transported to Toulouse via road and received French registration numbers. Intrigued by the relatively advanced design, the French would continue testing the BV 144 post war. The second unfinished prototype was also completed by the French post war, but it is unknown whether or not this prototype flew before the termination of the BV 144 project once and for all. Both prototypes were scrapped.

Design

BV.144 seen with French markings

The BV 144 was an all metal monoplane with a distinguishing high wing design and a tricycle landing gear configuration. It would have been powered by two BMW 801 MA 18-cylinder engines generating 1600 horsepower. The wings were located at the shoulder position of the fuselage, giving the engines a large ground clearance. Combined with the relatively short tricycle landing gear, the design would be advantageous to passengers as the fuselage would be close to the ground, allowing much easier boarding and disembarking.

The cockpit consisted of a pilot and a co-pilot in a stepped cabin, as well as a compartment for a radio operator. Following this compartment, there would have been a cargo storage, a passenger compartment, a toilet and another cargo storage.  At the cost of some cargo and a less spacious passenger compartment, the passenger count could have been raised to 23 from the original 18.

BV.144-1
Forward view of the BV.144

Foreseeing problems with takeoff and landing, Blohm & Voss designed the plane with variable incidence wings, which meant there were electric-mechanical systems fitted into the BV 144 that allowed the wing to rotate 9 degrees around its tubular main spar within the plane. Such a system was previously tested in 1940 on the Blohm & Voss Ha 140V-3 hydroplane with success. This interesting system would have allowed the pilot to change the sweep angle of the wings during low speed landing and takeoffs without having to shift altitudes. It would also allow the pilot to have a slightly better view during landing. Along with that, long slotted flaps were also provided to aid in landing.

Side view of the BV.144 with French markings

Another interesting feature of the BV 144 was the aforementioned tubular main spar, which was patented by Richard Vogt, the chief designer for Blohm & Voss. Although quite light in terms of weight, the spar would have been able to provide excellent load carrying characteristics. On top of this, as a surprising feature, the spar could also have been used to carry extra fuel. The last notable feature of the BV 144 was the defrosting system located at both wingtips and the tail section. The system would have allowed the tips and tail to stay warm using heated air provided through an oil burner.

Operators

  • Nazi Germany – The BV 144 was intended to be used by the Deutsche Lufthansa, and possibly even the Luftwaffe as an advanced airliner meant for short-medium distance routes.
  • France – The French took over both prototypes of the BV 144 once the Germans retreated out of France and continue development of the plane postwar for a while before ultimately scrapping the project in the end.

Blohm & Voss BV 144
Wingspan 88 ft 7 in / 27 m
Length 71 ft 6 ¼ in / 21.8 m
Height 16 ft 5 ¼ in / 5.01 m
Wing Area 947 ft² / 88 m²
Engine 2x BMW 801 MA (1600 hp)
Fuel Load 1900 L (Gasoline)
Minimum Weight 17416 lb / 7900 kg
Maximum Weight 28660 lb / 13000 kg
Cruising Speed 255 mph / 410 kmh at 13123 ft / 4000 m
Maximum Speed 292 mph / 470 kmh
Service Ceiling 29848 ft / 9100 m
Range 963 mi / 1550 km
Crew 1x Pilot

1x Co-Pilot

1x Radio Operator
Payload Regular:

18x Passengers

Maximum:

23x Passengers

Gallery

The prototype BV 144 seen in a side profile illustration
A “What-if” paint scheme depicting the prototype BV 144 if it had seen service with Lufthansa during the mid forties.

Sources

Gunston, B. (1980). The illustrated encyclopedia of propeller airliners. New York: Exeter Books. , Kay, A. L., & Smith, J. R. (2002). German aircraft of the Second World War: Including helicopters and missiles. London: Putnam. , Lepage, J. (2009). Aircraft of the Luftwaffe: 1939-1945: An illustrated guide. Jefferson, NC: McFarland. , Images: Side Profile Views by Ed Jackson – Artbyedo.com

 

Project 337 [Fictional]

Fake Aircraft

Soviet Union (1941)
Biological Weapon – 1 Built

With recent study trips to Russia, the Plane Encyclopedia team has been working closely with the Russian Archives to record and scan aircraft performance data and various other aviation related documents. While doing this, the team has accidentally rediscovered a series of then-classified documents regarding a secret biological weapon designed in 1941 intended to be used on Berlin in an attempt to stop or at least delay the German advance on Moscow. Classified “Project 337” by the Soviets, the weapon would have been able to bring havoc on any city it was deployed on. Come read the story of the newly discovered Project 337!

History

In the early stage of Operation Barbarossa during the shift of fall to winter, the Soviet high command became increasingly worried and desperate for a way to halt or at least delay the seemingly unstoppable German advance. On September 29th of 1941, a top secret meeting was held at the Kremlin to discuss the current losses of the Soviet Union, and how to replace the lost equipment. With mostly desperate ideas such as using outdated equipment such as 19th century rifles and cannons taken from stockpiles. Finally, a serious and feasible idea was brought up, which was to bomb Berlin with biological weapons, causing the city to plunge into chaos, and to warrant the retreat of the Germans. With Stalin liking the idea, he immediately agreed and ordered the project to be finished no later than November 29th.

Unfortunately, the dimensions, location, team and materials used to develop Project 337 is unknown as the documents that specifies these are still classified and withheld by the Russian government. What is known however, is that the disease which would be used in Project 337 was tularemia.

This rather unclear photo shows what appears to be the finished Project 337 prototype, resembling a huge metallic peanut with the black canopy.

With extensive research in the Russian archives, two photos of Project 337 were able to be obtained. The first photo shows the roof of the weapon, which consisted of a bowl shaped canopy with more than a dozen holes. This would have been how the tularemia bacteria would be released. The second photo shows what seems to be the finished Project 337 prototype, which looked like a huge metallic peanut with the black canopy.

The upper section of the weapon, which consisted of a bowl shaped canopy with more than a dozen openings. This would have been how the tularemia bacteria would have been released.

On December 1st of 1941, Project 337 was completed and was now ready to be tested on Berlin. To carry such a weapon, the Soviet Air Force began looking for a capable heavy bomber which would be able to fly at tall heights. Although scarce, the bomber chosen was the Petlyakov Pe-8 bomber. A single Pe-8 was transferred from the Far East Regiments and modified to carry Project 337. As for personnel, experienced pilots Lieutenant Igor N. Timoshenko, Junior Lieutenant Dima I. Pokryshkin and Lieutenant Mikhail Gorkin were chosen to complete the task of dropping the prototype biological weapon on Berlin. These pilots were not told of the contents they were carrying, and was only instructed to fly to Berlin, drop the payload and return to base as the Soviets still wished to maintain the secrecy of the project.

On December 5th, Lieutenant Igor N. Timoshenko, Junior Lieutenant Dima I. Pokryshkin and Lieutenant Mikhail G. Gorkin took off in the Pe-8 carrying Project 337 at 8:31 PM from an undisclosed secret airfield. With the intent of maintaining stealth, the Pe-8 crew would have maintained radio silence in order to not get detected. Approximately 1 hour and 14 minutes into the flight, the Soviet ground crew were surprised to receive an emergency radio call from the aircrew. According to the recently declassified Soviet documents, the ground crew reported that Lieutenant Gorkin shout in the radio in panic that the Pe-8’s inner starboard engine caught fire, and that the plane was rapidly losing altitude. Lieutenant Gorkin decided the best thing to do was to perform an emergency landing, and he made this decision known to the ground crew. Unfortunately, the documents stated that contact was lost with the crew during the botched emergency landing. One of the documents dated April 1st of 1944 stated that efforts to locate the Pe-8 has failed, and that the plane likely crashed into a body of water. Due to the loss of the sole bomb, tests were unable to be completed and the project was set back. This led to the eventual abandonment of the project as the Soviets couldn’t afford to spend more time development such a weapon.

The final document which referenced Project 337 dated April 20th of 1948 mentioned that the incident which caused the destruction of the Pe-8 was improper maintenance. It is said that the mechanics responsible for the maintenance were executed, while the radio crew were sent to the gulag. Timoshenko, Pokryshkin and Gorkin’s families were all sent a letter stating that they died in combat as heroes. In conclusion, Project 337 can be considered a failure. With the current evidence that the Plane Encyclopedia team has, it is reasonable to assume that the Pe-8 carrying Project 337 is perhaps still out there buried beneath layers of mud, sand, or water, never to be seen by mankind again.

Sources

Rep. No. Поддельный источник, используемый для апрельских дураков (04.01.1944) (1944).

Rep. No. Полностью реальный источник, а не подделка (04.20.1948) (1948).

Doc. No. Я люблю Энциклопедию (01.14.1943).

 

Kawasaki Ki-88

Empire of Japan, WW2, , , ,

 Empire of Japan (1943)
Prototype Fighter Interceptor – 1 Built

The Kawasaki Ki-88 was a fighter interceptor designed in 1942 with the intent of intercepting enemy aircraft heading towards vital military locations. The Ki-88 would never see service, as it was cancelled in 1943 after a mockup and partial prototype were constructed. Although considered by many to be the Japanese copy of the American Bell P-39 Airacobra due to the exterior aesthetic similarities, this is only speculation.

History

The origins of the Kawasaki Ki-88 began in August of 1942 when Tsuchii Takeo, a designer for Kawasaki, responded to a design specification put forward by the Imperial Japanese Army Air Service (IJAAS). The IJAAS determined that they needed an interceptor aircraft that would defend important military assets like airfields, gun emplacements, and others. The specification also stated that the aircraft had to be heavily armed, provide a stable gun platform and be easily flyable by new pilots.

Takeo began work on the Ki-88 and chose to use a 37mm Ho-203 cannon as the plane’s primary armament, with two 20mm Ho-5 cannons to complement the Ho-203. The placement of the guns prompted Takeo to place the engine behind the cockpit. Many sources state that this was done to copy the American Bell P-39 Airacobra, but that claim is debated. The P-39 Airacobra was in service at the time the Ki-88 was developed, but saw limited service with the United States. It did however, see service during the Battle of Guadalcanal. The Japanese were certainly aware of its existence and possibly captured an example of the P-39. If they did indeed capture an example, Takeo could have simply copied the gun and engine placement. It is important to note that such a “rear-engine” fighter configuration was a rarity in plane design at the time. Another common theory is that Takeo came to the same conclusion as H.M Poyer (designer of the P-39) did during the planning phase and designed the plane without copying the P-39. Other than the engine and gun placement, the two planes are quite dissimilar.

Takeo completed the Ki-88’s design in June of 1943. A full scale mockup and prototype were in the works in mid/late 1943, and estimated that the prototype would be completed in October of 1943. However, after the mockup and plans were inspected by representatives of the IJAAS, it was concluded that the Ki-88 had no real improvements over other designs of the time, and the top speed was only slightly better than the Kawasaki Ki-61 after calculations. The IJAAS immediately lost interest and ordered Kawasaki to cease all work on it.

Design

The Ki-88 was a single seater, single engine fighter powered by a Kawasaki Ha-140 engine producing 1,500hp while driving a propeller using an extension shaft. The radiator was placed under the cockpit at the bottom of the fuselage. There was an air intake placed beneath the fuselage on the left to provide cooling for the supercharger in the Ha-140.

The Ki-88 used a conventional landing gear, in which the main wheels could be retracted into the wings while the tail wheel stayed fixed. There was a fuel tank in each of the wings, beside the landing gear wells.

The size of the Ho-203 canon prevented Takeo from placing the engine into the nose which led him to place it behind the pilot’s cockpit, much like the American P-39 Airacobra. Moving the engine to the back of the cockpit was a smart move, as it theoretically would have made the plane a more stable gun platform. Under the Ho 203, on both sides of the nose, there were two 20mm Ho-5 cannons.

Operator(s)

  • Empire of Japan – The Ki-88 was supposed to have been operated by the Imperial Japanese Army Air Service, but never did so due to the design being deemed as inferior to the Ki-61 and was thus cancelled.

Kawasaki Ki-88*

*Estimated Performance
Wingspan 40.6 ft / 12.37 m
Length 33.4 ft / 10.18 m
Height 13.6 ft / 4.14 m
Wing Area 8,598 ft² / 27.49 m²
Engine 1x Kawasaki Ha-140 (1,500hp)
Empty Weight 6,503 lbs / 2,949 kg
Loaded Weight 8,598 lbs / 3,899 kg
Climb Rate 6 minutes & 30 seconds to 16,404ft (5,000m)
Maximum Speed 373 mph / 600 kph at 19,685ft (6,000m)
Range 745 mi / 1,198 km
Maximum Service Ceiling 36,089 ft / 11,000 m
Crew 1x Pilot
Armament 1x 37mm Ho-203

2x 20mm Ho-5

Gallery

 

Sources

Performance. Report No. 19b(4), USSBS Index Section 2 (Tech. No. 19b(4)). (n.d.)., Pacific Survey Reports and Supporting Records 1928-1947 Kawasaki Aircraft Industries Company, Ltd. (Kagamigahara, Gifu plant), Dyer, Edwin M. Japanese Secret Projects: Experimental Aircraft of the IJA and IJN 1939-1945. Classic, 2013., Francillon. (1987). Japanese aircraft of the Pacific war. Annapolis, Md: Naval Institute Press., Images: Side Profile Views by Ed Jackson – Artbyedo.com

 

Beechcraft XA-38 Grizzly

US, WW2

usa flag USA (1944)
Prototype Attack Plane – 2 Built

Colorized photos by Michael J.

The Beechcraft XA-38 Grizzly was an experimental attack aircraft stemming from a USAAF requirement for a two seated attack bomber. Two prototypes were constructed between 1944 and 1945, and saw extensive testing within the US. The Grizzly showed promising performance, but was ultimately cancelled due to the engines intended for use was given priority to the Boeing B-29 Superfortress and the inevitable victory of the Allies.

History

Bottom view of Beechcraft XA-38 (S/N 43-14407) in flight. (U.S. Air Force photo)

In 1942, the United States Army Air Force (USAAF) issued a requirement for a two seater attack bomber. Beechcraft was quick to respond, and proposed their design to the USAAF. The USAAF was very interested in the design, and ordered two prototypes to be constructed in December of the same year after granting the contract to Beechcraft. In anticipation of the two prototypes, the USAAF assigned serial numbers to them, being “43-14406” and “43-14407”.

 

Beechcraft specifically designed the Model 28 to be able to destroy gun emplacements, ships, armored vehicles and bunkers while keeping great maneuverability and able to remain airborne after being damaged. All of this would be done by the addition of a powerful 75mm T15E1. The task of developing the Grizzly was given to a team led by Bill Cassidy with Jess Vint and Alex Odevseff in charge of designing the armaments, Bill Irig in charge of the control surfaces, Gus Ericson in charge of the design of wings, Mervin Meyers in charge of hydraulics, Ralph Harmon in charge of the landing gear structure and Noel Naidenoff in charge of the engine compartment. The Grizzly is common thought to be a modified Model 18 design, but this is untrue. The Grizzly did take inspirations from the Model 18, though.

Beechcraft XA-38 during ground vibration tests. Tests were set-up to determine natural frequencies excited during engine operation. (U.S. Air Force photo)

The first Grizzly (43-14406) was delivered to the Army Air Force and flown on May 7th of 1944 by test pilot Vern L. Carstens. The first test flight went relatively well except for an unplanned touch-and-go during landing. This was due to Carsten’s inexperience with landing such a large plane. The first prototype had no armaments installed, but had a wooden mockup of the 75mm T15E1 cannon. In the next few test flights, the Grizzly proved itself to be very aerodynamically stable, and made a good impression with the designers. A memorable flight test includes a performance comparison between the Grizzly and a recently manufactured North American P-51B. The Grizzly and P-51B were put in a mock pursuit, and the P-51B was reported to have been unable to keep up. Afterwards on July 7th of 1945, the first Grizzly was transferred to Wright Field to be used by the USAAF. It then participated in 38 test flights from between October 13 and October 24 of 1944 flown by Captain Jack W. Williams. Williams affectionately noted that the Grizzly was a great aircraft and “very maneuverable” for an aircraft of its size. It is also interesting to note that the turrets on the first Grizzly were dummies.

Front view of Beechcraft XA-38 (S/N 43-14407) in flight. (U.S. Air Force photo)

The second Grizzly (43-14407) had its maiden flight on September 22nd of 1945, once again piloted by Carstens. The second prototype was intended for armament testing, so it had all weapons fitted. The 75mm T15E1 prototype cannon was already successfully tested the year before on July 1st. The second Grizzly flew a total of 38 hours afterwards in tests at Eglin Field in Florida.

As successful as the Grizzly was, it would never reach mass production status because of two reasons. The first reason was that the R-3350 engines were in short supply, as the Boeing B-29 Superfortress had top priority for the engines. Second, the war situation was already in America’s favor, thus cancelling out the need for such an aircraft. As a result, both of the Grizzlies were retired from active service. One was scrapped while the other one was transferred to the Davis-Monthan Airfield in Arizona, meeting an unknown fate.

Design

The XA-38 Grizzly was an all metal, two seat, twin engined semi-monocoque plane with cantilever wings, conventional landing gears, oleo-pneumatic shock absorbers and hydraulic brakes. It was powered by two Wright R-3350-43 Duplex Cyclone engines, the same engine that powered the Boeing B-29 Superfortress. The propellers measured at 4.32m (170in) each in diameter.

The plane used flush riveting and butted skin joints to give the plane its pristine, shiny look. The foil used to construct the wings were derived from the NACA 23000 series which was good for high and low speeds. The engine hub was made from stainless steel and aluminum alloy. The oil coolers were placed in the wings. Four fuel tanks were installed in the wings with a capacity of 2,422 litres (640 US Gallons). Two self-sealing fuel tanks were also placed behind the cockpit which can carry 681 litres (185 US Gallons) if needed to. There were pumps and connectors installed onto the tanks, which would stop fuel flow if the tanks took damage.

Beechcraft XA-38 (S/N 43-14407, the second and last XA-38 built). (U.S. Air Force photo)

As for armaments, the XA-38’s 75mm T15E1 was the defining feature. Could carry 20 rounds fed by a Type T-13 feeding system. There would be a Type N-6 reflector sight to help the pilot aim. The cannon would fire every 1.2 seconds if the pilot pressed the trigger button. Two .50cal (12.7mm) M2 Browning machine guns were installed under the cannon with 500 rounds each. The entire nose section of the XA-38 could be unhinged, where mechanics can easily access the guns for maintenance.

The Grizzly had two turrets, one located on the top of the fuselage and one on the bottom. The turrets were manufactured by General Electric and had two M2 Brownings each with 500 rounds. These two turrets were controlled by a single gunner seated in the rear fuselage. He would aim the guns with a periscope to control the turrets. Interestingly enough, the turrets can also be fixed to fire forward to accompany the T15E1. Ordinance wise, the XA-38 was designed to carry a wide range of things. It could have carried bombs, napalm, torpedoes, fuel tanks, smoke tanks and depth charges.

Operators

  • United States of America – The USAAF was the sole operator of the XA-38. The USAAF extensively tested the XA-38, and concluded it was a success. However, the XA-38 never reached mass production status.

Beechcraft XA-38 Grizzly
Wingspan 64 ft 4 in / 20.52 m
Length 51 ft 9 in / 15.77 m
Height 15 ft 6 in / 4.72 m
Wing Area 626 ft² / 58.15 m²
Engine 2x Wright R-3350-43 Duplex Cyclone (2,300hp)
Fuel Capacity 640 US Gallons / 2,422 L

Additional Tanks: 185 US Gallons / 681 L
Maximum Takeoff Weight 35,265 lbs / 15,996 kg
Empty Weight 22,480lbs / 10,197 kg
Wing Loading 56.3 lb/ft² / 275.1 kg/m²
Power Loading 7.67 lb/hp / 3.48 kg/hp
Climb Rate 2,600 ft/min / 792 m/min
Maximum Speed 330 mph / 531 km/h at Sea Level

348 mph / 560 km/h – at 5,000 ft / 1,525 m

370 mph / 595 km/h – at 17,000ft / 5,180m
Cruising Speed (75% Throttle)

289 mph / 465 km/h – at Sea Level

350 mph / 563 km/h – at 16,000 ft / 4,875 m

Range 1,625 mi / 2,615 km – at 225 mph / 362km/h

745 mi / 1,200 km – at 289 mph / 465 km/h

Service Ceiling 29,000 ft / 8,840 m
Crew 1x Pilot

1x Gunner/Observer
Forward Firing Armaments 1x 75mm T15E1 (20 rounds)

2x 12.7mm M2 Browning (500 rpg)
Defensive Armaments 2x 12.7mm M2 Browning (Upper Turret) (500 rpg)

2x 12.7mm M2 Browning (Belly Turret) (500 rpg)
Ordinance Planned Options:

  • Bombs
  • Fuel tanks
  • Napalm
  • Torpedoes
  • Depth Charges
  • Smoke Tanks

Gallery

Grizzly Prototype 314407 – armed with two 500 lb bombs

Sources

Beechcraft XA-38. (2008). National Museum of the US Air Force, Pearce, W. (2013). Beech Aircraft Company XA-38 Grizzly. Old Machine Press., Pelletier, Alain J. (2005). Beech aircraft and their predecessors. Putnam, Images:  Side Profile Views by Ed Jackson – Artbyedo.com, Colorized Images by Michael J.

Douglas XB-19

US, WW2

usa flag USA (1941)
Prototype Heavy Bomber – 1 Built

The XB-19 parked on the ground.

The XB-19 was a heavy bomber designed in 1935 to fulfill a request made by the United States Army Air Corps (USAAC) to develop an experimental heavy bomber with extreme range. Although slow in its development and obsolete by the time it was produced, it served as a test vehicle to evaluate plane and engine performances. The sole XB-19 was converted to a cargo transport plane and was eventually scrapped in 1949. The XB-19 was the largest plane operated by the USAAC and USAAF until the Convair B-36 came into service.

History

The roots of the XB-19 can be traced to 1935 on February 5th when the United States Army Air Corps (USAAC) commenced “Project D”. The purpose of Project D was to experiment with the maximum distances achievable with bombers. The USAAC contacted and discussed the project with Douglas Aircraft Company and Sikorsky. Douglas representatives agreed to the terms of the design and plans were made during a conference on June 5th, 1935. The initial plan was to begin the basic design on July 31st of 1935, detailed designs on January 31st of 1936, and have the plane physically produced by March 31st, 1938. The plan however was soon found out to be too ambitious, with the designers underestimating the work required. The designers would be plagued with a lack of proper funding and the sheer enormity of the task. The project would finally be completed in May of 1941, nearly four years after the original deadline.

Douglas XB-19 under construction. (U.S. Air Force photo)

Douglas Aircraft Company received a contract to the project in October of 1935 which required Douglas to create a general and detailed design of the plane, create a mockup of the plane and test the wing centre section, undercarriage, and engine nacelles of the plane. Douglas accepted the contract on October 18th. Later that year, the USAAC would evaluate the mockups provided by Douglas and Sikorsky. Douglas’s design was ultimately chosen, and was given the task of further developing the plane.

The XB-19 under construction at the Douglas Aircraft Factory located in Santa Monica, California. 1940.

The plane would be known as the “XBLR-2” (Experimental Bomber Long Range 2) in its early stages of development. The progress of developing the bomber proved to be tedious and slow. Lack of funding would severely hinder work on the plane. During that time the USAAC made a change to the requirements, the plane was suppose to be powered by four Allison XV-3420-1 engines producing 1,600 horsepower each, but was ordered to be replaced by four Wright R-3350 engines producing 2,000 horsepower each instead. This would also hinder work as the plane had to be slightly redesigned. As time went on, Douglas had to loan a Douglas OA-4A from the USAAC to test an experimental tricycle landing gear configuration intended for the XBLR-2. The tests proved to be a success. Later, the XBLR-2 would be redesignated as “XB-19” (Experimental Bomber 19). Douglas eventually managed to scrape together enough funds to produce a prototype, and the production was authorized on March 8th of 1938.

XB-19_38-471_at_Mines_Airfield_Colorized copy
The XB-19 parked at Mines Airfield. (Colorized by Michael J.)
Washing XB-19 at March Field 1941. (Colorized by Michael J.)

During its development, the Douglas company had many problems with the XB-19. They were forced to allocate more funds than initially expected, and needed design staff to work on other aircraft which had a more promising production future. They claimed the XB-19’s design was obsolete due to the production delays it suffered over the past three years and the fact that the plane’s weight was far heavier than expected. The Douglas company officially made a recommendation to cancel the XB-19 project on August 30th, 1938. This recommendation was denied by the USAAC. Interestingly enough, two years later, the USAAC would suggest that the slow development of the XB-19 already rendered the project obsolete when they removed the plane from the top secret classified list. The XB-19 would finally be completed in May of 1941.

The XB-19 parked on the ground next to a P-40 Kittyhawk.

Shortly after completion, the XB-19 was used in taxiing tests on May 6th, 1941. The flight test was scheduled to be on May 17th, but was postponed three times due to critical mechanical errors. The landing gear brakes were found to have defects, its engines had backfiring issues, and the propeller pitch control system had to be worked on. On June 27th however, the XB-19 would finally have its maiden flight. In the maiden flight, seven crewmembers were on board with Major Stanley M. Umstead in charge. The flight lasted 55 minutes from Clover Field in Santa Monica to March Field. The flight went by smoothly without any problems and was successful. Shortly afterwards, Donald Douglas would receive a congratulatory telegram from President Roosevelt. The USAAC unofficially accepted the XB-19 in October of 1941.

Eager observers watch the XB-19 preparing for its maiden flight. Clover Field, 1941.

After the Japanese attack on Pearl Harbour on December 7th of 1941, the United States was on high alert. The XB-19’s turrets were armed and a new layer of olive camouflage paint was applied, replacing its bare metal USAAC livery. It would make 4 more tests flights in California before being transferred to Wright Field on January 23rd, 1942 as another safety measure. By then, the XB-19 had over 70 hours of flight time.

The XB-19 was finally accepted officially by the USAAF in June of 1942 after minor modifications were made to the plane’s brake system. The contract cost to the United States government was $1,400,064. The Douglas Aircraft Company also spent $4,000,000 in personal company funds. The XB-19 was extensively tested by the USAAF for eighteen months to see the engine performances and different altitudes and the maneuverability of the aircraft.  The results of these tests would later go on to influence the design of the Boeing B-29 Superfortress and the Convair B-36. The XB-19 performed well in all aspects and was generally free of problems. The only problem noted however was the inefficient engine cooling process. Due to this, the cooling gills on the plane had to be open the whole time in longer flights, thus reducing the effective speed of the XB-19.

The XB-19 in flight over Santa Monica with an AT-6 following it.

After the XB-19 was thoroughly tested and experimented with, the USAAF no longer had a need for it. It was brought to the Wright Field and modified to be a cargo transport aircraft. It was refitted with Allison V-3420-11 engines and had its armaments removed. The new aircraft would be designated “XB-19A”. For the next two and a half years, the XB-19A would fly to numerous airfields within Ohio. It was documented to have been stationed at Wright Field, Patterson Field, Lockbourne Air Base, and Clinton Country Air Base. The XB-19A would make its last flight on August 17th, 1946, where it flew to the Davis-Monthan airfield in Arizona from Wright Field to be stored. It stayed in storage for three years before finally being scrapped in 1949, thus ending the legacy of the XB-19.

XB-19_in_flight_1942_Colorized copy
The XB-19 in flight some time in 1942. (Colorized by Michael J.)

To this day, only two wheels of the XB-19’s landing gear survives. One can be seen in the Hill Aerospace Museum in Oregon, and the other can be seen in the National Museum of the United States Air Force in Ohio.

The wheel of the XB-19 with a car and person for comparison.

Design

The XB-19 is described as a colossal, all metal low wing monoplane installed with a conventional tricycle landing gear. The two main wheels of the landing gears measured at 2.44 m (8 ft) in diameter, which was impressive for the time. The original design specifications ordered wanted the engines to be four Allison XV-3420-1, but was swapped for four Wright R-3350-5 engines instead with a three blade metal propeller with a 5.18 m (17 ft) diameter. The engines would be switched once again to Allison V-3420-11 after the plane was repurposed as a cargo transport aircraft. The plane could carry an impressive amount of fuel, at 38,178 L (10,350 US Gallons) in its auxiliary fuel tanks, with an optional 3,210 L (824 US Gallons) that could be stored in the bomb bay.

A shot of the underside of the XB-19 with the gear down.

The XB-19 carried 8,480 kg (18,700 lbs) of ordinance usually, but could be overloaded to 16,828 kg (37,100 lbs) if fuel was reduced significantly. As for armaments, the initial prototype was unarmed. Later though, two 37mm Oldsmobile T9 autocannons, five 12.7mm M2 Brownings and six M1919 Brownings were fitted to the plane. One T9 was fitted to the nose while the other was fitted to the upper front turret, each accompanied by a single M1919 machine gun. There would be one M1919 on each side of the bombardier’s position, and a M1919 on each side of the stabilizer. A single M2 Browning was fitted in the tail of the XB-19, two M2 Brownings on each side of the galley compartment, one in the bottom turret, and one in the upper powered turret.

In the crew compartment, there was eight seats and six bunks. The compartment could accommodate two flight engineers, and six relief crew members. The normal combat crew consisted of sixteen people. (Refer to Specifications Table).

The cockpit of the XB-19.

Variants

  • XB-19 – The original model and design. Initially developed as a long range heavy bomber for the USAAC, but was outdated by the time it entered service. It served as a “flying laboratory”, testing engine performances and plane handling. It was converted to the XB-19A after the USAAF no longer had use for it.
  • XB-19A – The XB-19A was a converted XB-19 using improved Allison V-3420-11 engines. It was used as a cargo transport aircraft after the air force was done experimenting with it. All armaments were removed. It was scrapped in 1949.

Operators

  • United States of America – The XB-19 and XB-19A was operated by the USAAC and USAAF throughout its service life.

 

Douglas XB-19
Wingspan 212 ft / 64.62 m
Length 132 ft & 4 in / 40.34 m
Height 42 ft / 12.8 m
Wing Area 4,285 ft² / 398.091m²
Wing Loading 32.6 lb/sq ft / 159.5 kg/sq m
Power Loading 17.5 lb/hp / 7.9 kg/hp
Engine 4x Wright R-3350-5 Duplex Cyclone (2,000 hp)
Fuel Capacity 10,350 US Gallons / 38,178 L – in auxiliary fuel tanks + 824 US Gallons / 3,120 L – in bombay (Optional)
Maximum Weight 140,000 lbs / 63,503 kg
Empty Weight 86,000 lbs / 39,009 kg
Climb Rate 650 ft/min / 198 m/min
Speeds Cruising: 135 mph / 217 km/h – Sea Level

Operational: 186 mph / 299 km/h – @ 15,700 ft / 4,785 m

Maximum Speed: 224 mph / 360 km/h – @ 15,700 ft / 4,785 m
Normal Range 5,200 mi / 8,369 km
Maximum Range 7,710 mi / 12,408 km
Service Ceiling 23,000 ft / 7,010 m
Crew 2x Pilots

1x Commander

1x Navigator

1x Engineer

1x Radio Operator

1x Bombardier

2x Flight Mechanics

1x Turret Operator

8x Gunners

6x Relief Crew

(24 Crew – 16 Active, 2 Emergency Stations, 6 Relief Crew)
Defensive Armament 2x 37mm Oldsmobile T9 Autocannon

5x 12.7mm M2 Browning

6x 7.62mm M1919 Browning
Normal Ordinance 18,700 lbs / 8,480 kg
Maximum Ordinance 37,100 lbs / 16,828 kg *

* – with reduced fuel load

 

Douglas XB-19A
Wingspan 212 ft  / 64.62 m
Length 132 ft 4 in / 40.34 m
Height 42 ft / 12.8 m
Wing Area 4,285 ft² / 398.091m²
Wing Loading 32.71 lb/sq ft / 159.8 kg/sq m
Power Loading 13.51 lb/hp / 6.1 kg/hp
Engine 4x Allison V-3420-11 (2,600 hp)
Loaded Weight 140,230 lbs / 63,607 kg
Empty Weight 92,400 lbs / 41,912 kg
Maximum Speed 265 mph / 426 km/h
Cruising Speed 185 mph / 298 km/h
Normal Range 4,200 mi / 6,759 km
Service Ceiling 39,000 ft / 11,885 m

Gallery

A spectacular shot of the XB-19 flying low. 1942.
XB-19A on the ground with Allison V-3420-11 engines.
Crewmen washing the XB-19 at March Field, some time in 1941.
The crew of the XB-19 operating in the cockpit.
XB-19A on the ground with Allison V-3420-11 engines.
XB-19 Before Scrapped
A photo of the XB-19 post-war before it was scrapped.

 

Sources

Bunker, Howard G. Development, Test and Acceptance of Douglas XB-19 Airplane, AAF No. 38-471. 1942, pp. 18–25, Development, Test and Acceptance of Douglas XB-19 Airplane, AAF No. 38-471., Francillon, René J. McDonnell Douglas aircraft since 1920. Putnam, 1988., Images:  Side Profile Views by Ed Jackson – Artbyedo.com, Colorized Images by Michael of PE

 

Tachikawa-Kokusai Ta-Gō

Empire of Japan, WW2

 Empire of Japan (1945)
Prototype Special Attack Aircraft – 3 Built

The Ta-Gō was an attempt at creating an easily made and cheap kamikaze aircraft in anticipation of Operation Downfall and Operation Olympic. The plane would have been used by special “shinpū” (kamikaze) units to ram advancing Allied tanks, infantry and boats. Fortunately for the Allies, the Ta-Gō project was cancelled once the Empire of Japan capitulated.

History

The concept of the Ta-Gō came in late 1944, when Japan was on its heels after losing the majority of its territories to the Allies. With the recent loss of Guam, Okinawa, Iwo Jima, and other islands, Japan was convinced that the American invasion of the Japanese mainland was inevitable. By 1945, Japanese factories and industries suffered from constant bombings by the USAAF. This led to the deprivation of much needed materials to produce planes and tanks. Because of this, much of the already existing aircrafts were designed to be built with wood. (Example: Ki-106 from Ki-84, D3Y from D3A). Even then, Japan’s industry could barely produce such planes due to the situation of the war.

Watching his country’s resources slowly depleting and the rapid advance of the Allies, IJA Captain Yoshiyuka Mizuyama wanted to make a difference. He wanted to design a simple, cheap and easily producible plane requiring minimum materials for designated kamikaze units. If the Ta-Gō was mass produced, it could easily fill already depleted kamikaze units, and would make kamikaze attacks more popular. Once Mizuyama finished designing the plane, he went to Tachikawa Hikōki Kabushiki Kaisha (Tachikawa Aircraft Company) and submitted his design. His design was however rejected because Tachikawa Hikōki simply could not afford to allocate resources for the Ta-Gō. It was also rejected due to the fact that Mizuyama’s design was not officially approved by the state.

Determined to initiate his project, Mizuyama looked around the city of Tachikawa until he discovered a small woodwork shop. He rented the shop and began constructing his first prototype with the help of his men. Around February of 1945, Tachikawa was firebombed by the USAAF. The workshop was completely destroyed along with the sole prototype. Still determined to initiate the project despite the major setback, Mizuyama approached Nippon Kokusai Kogyo K.K (Japanese International Aviation Industries Ltd) to continue his project. Luckily for him, Kokusai accepted his project. Since Kokousai accepted the project, they asked that Mizuyama redesign certain parts of the plane to so that it would require even less materials and manpower. The Kokusai design’s dimensions was significantly scaled down compared to Mizuyama’s original design and was simpler altogether.

Now satisfied that his work was accepted, he began building the new model of the Ta-Gō with help from Kokusai. The prototype was completed around the middle of June, and was test flown for the first time on June 25th, 1945 with an experienced pilot from Kokusai in the cockpit. The test pilot expressed obvious handling concerns and gave helpful tips to the designers. As a result, the Ta-Gō participated in more test flights and was modified on the drawing board. In the end, the blueprints for the production variant were finalized. Unfortunately for Mizuyama and Kokusai, the Empire of Japan surrendered to the Allies in August of 1945, and the Ta-Gō never entered production. Interestingly enough, the Allies discovered two variants for the Ta-Gō named “Gi-Gō” and “Tsu-Gō” after Kokusai surrendered all their documents. However, there is no known information on them today.

Tachikawa, funnily enough, took on the project too after the Kokusai prototype was completed and authorized by the Gunjushō (Ministry of Munitions) despite them rejecting the project earlier. Once the American Occupation forces arrived in Japan, they found the Tachikawa Ta-Gō incomplete. Once the Ta-Gō was accepted, it was given the designation Ki-128. It is not confirmed whether the designation was for the Kokusai or Tachikawa variant or both.

Design

The Ta-Gō was a single seated kamikaze plane made mostly out of plywood, fabric, and wood lathes. The original Ta-Gō design used wood lathes for the fuselage and structure, and used plywood and fabric for the outer skin and control surfaces. The pilot’s compartment featured a simple acrylic glass. The landing gear was fixed, meaning they couldn’t be retracted. It featured a Hitachi Ha-13 Ko 9-cylinder radial engine that produced 450hp, with thin steel sheets as the engine cowling. The only armament it could carry was a 500kg bomb, which cannot be released. Other than these details, little is known about the original Ta-Gō as hardly any evidence exists.

The refined design for Kokusai made the Ta-Gō much smaller than its original size. Due to this, the plane could no longer house the Hitachi Ha-13 Ko, and was replaced by the Hitachi Ha-47 11 producing 110hp instead. Because of the severe engine power decrease, the 500kg bomb load had to be changed to 100kg. Another change from the original design was the cockpit was open topped. The only thing that covers the pilot is a simple acrylic glass pane that shields from the wind. As for the engine, it was protected by an angular wooden cowling. The engine was paired with a two-blade fixed pitch wooden propeller. The engine mount was made of metal, with the fuel tank placed on top of the engine, thus using a gravity feed system. In between the acrylic glass pane and the fuel tank, there was an oil cooler. As for cockpit instruments, only the very basic and important ones were kept. Such instruments used were a compass, speedometer, altimeter, and engine-related gauges such as fuel and oil. The fuselage was also boxier than the original design. This design feature was extremely simple to manufacture, but was very un-aerodynamic.

The fuselage and structure was made with wooden spars and plywood, much like the original Ta-Gō. The wings were rectangular shaped, and were hinged near the landing gear, which allowed the the wings to fold upwards. The reason why the wings could be folded was because the Ta-Gō was suppose to be hidden in caves and take up less space in the factory line. The rudder and elevator of the Ta-Gō were both rectangular shaped. As for the landing gear, it was made out of steel tubing and paired with rubber wheels. Each landing gear was supported by a metal strut.

Variants

  • Original Ta-Gō: The original Ta-Gō was powered by a Hitachi Ha-13 Ko (450hp) and could carry a 500kg bomb. It was almost completed before being destroyed in a bombing raid. Only one photo of the original prototype is known to have existed.
  • Revised Ta-Gō:The revised Ta-Gō design featured a smaller airframe to save the factories effort and materials. As a result of this modification, the engine had to be changed to a Hitachi Ha-47 11 (110hp) and the bomb load was reduced to 100kg. Two of these were made. One was completed by Kokusai, test flown and evaluated while the other one by Tachikawa was incomplete.
  • Gi-Gō: The Gi-Gō was a late war development of the Ta-Gō. There is no information known about it to this date. The project was commenced by Kokusai.
  • Tsu-Gō: Like the Gi-Gō, the Tsu-Gō was developed very late in the war. No information about it has been discovered to this date. The project was commenced by Kokusai.

Operators

  • Empire of Japan – The Ta-Gō would have been used by special kamikaze units in both the army and navy.

Ta-Gō (Revised Version) 
Wingspan  8.90m | 29.2ft
Length  7.40m | 24.3ft
Height  3.87m | 12.7ft
Wing Area  5.10m² | 54.9ft²
Engine Hitachi Ha-47 11 (110hp)
Take-Off Weight  565.5kg | 1,290lbs
Empty Weight  345.5kg | 761lbs
Maximum Speed  195km/h | 121mph
Cruising Speed  179km/h | 111mph
Range  150km | 93 miles
Maximum Service Ceiling  4,600m | 15,091ft
Crew  1 (pilot)
Armament 1x 100kg bomb

Gallery

The never completed first Tachikawa prototype
Artist Interpretation of a completed first Tachikawa prototype

Sources

Dyer, E. (2009). Japanese Secret Projects : Experimental Aircraft of the IJA and IJN 1939-1945: Ian Allan Publishing.
Kokusai Ta-Gō. (n.d.). Retrieved August 06, 2017
Ta-Gō. (n.d.). Retrieved August 06, 2017
Beechy, Robert. “Imperial Japanese Army Air Service Aircraft Code Names & Designations.” Japanese Military Aircraft Designations. N.p., n.d. Web. 06 Aug. 2017.