An impressive photo of freshly produced Yak-10 sit on the Dolgoprudny airfield awaiting delivery. [Yefim Gordon]The Yakovlev Yak-10 was a four-seat multipurpose light aircraft designed in 1944 as a replacement for the Polikarpov U-2 (Po-2), a biplane which served as a liaison and passenger transport aircraft. Although the Yak-10 successfully passed state acceptance trials in January of 1945, it proved rather unsatisfactory with Soviet Air Force pilots, and thus, only 41 examples, including the prototype, were produced in 1946 before being replaced by the redesigned and superior Yak-12 light aircraft in 1947. Though unsuccessful in service, the Yak-10 provided valuable experience in light aircraft design and served as a stepping stone for the more successful Yak-12.
History
In early 1944, the Soviet High Command was beginning to realize the obsolete nature of the Polikarpov U-2 (Po-2) in its liaison role. In the wake of the quickly advancing aircraft industry, Yakovlev OKB (Experimental Design Bureau) was called upon to design a multipurpose light aircraft capable of performing liaison missions, ferrying passengers, cargo, and aerial ambulance duties for the Air Force to replace the Po-2. In response, Yakovlev OKB initiated a project with G.I. Gudimenko assigned as chief engineer and work commenced on a four-seat, high-wing monoplane using the firm’s pre-war AIR-6 design as a basis, which had similar traits. The new aircraft design was assigned the designation of Yak-14.
Due to the rather obscure nature of the project’s development, it is unknown when the first prototype was produced, but it is most likely sometime before or in early January of 1945. First flown by test pilot F.L. Abramov, the Yak-14, powered by a 5-cylinder, air cooled Shvetsov M-11FM radial engine producing 145 hp, proved to have unacceptable handling characteristics. This prompted minor redesigning and modifications to the prototype which would address the issues that emerged from the test flight. Amongst the various modifications, the aircraft was also redesignated as the Yak-10 (the Yak-14 designation would later be reused for a 1947 assault glider project). With the completion of modifications, the Yak-10 was resubmitted for state testing. The aforementioned handling characteristic issues appeared to have been addressed, and the Yak-10 passed state trials in June of 1945.
Yak-10 Blueprint Drawing
Now authorized for service, production of the Yak-10 was assigned to the No. 464 aircraft plant in Dolgoprudny (Долгопру́дный), approximately 12 mi / 20 km north of Moscow. A total of 40 models were produced in 1946, which were then delivered to air force units. An important difference between the prototype and production models was the conversion from the 145 hp M-11FM engine to the 160 hp M-11FR engine. During the Yak-10’s service life, several variants were designed. These included a dual-control trainer variant known as the Yak-10V, an aerial ambulance variant capable of carrying two stretchers and a doctor known as the Yak-10S, an experimental floatplane variant known as the Yak-10G, and an experimental ski landing gear conversion without a proper designation. Due to the scarcity of documents regarding the Yak-10, it is unknown how many Yak-10V and Yak-10S models were produced, but the Yak-10G and Yak-10 with ski gear were converted from standard Yak-10 models. Curiously, the Yak-10 also had a competitive experimental low-wing development in 1944 known as the Yak-13 (originally designated the Yak-12, which is unrelated to the 1947 development) which featured a split landing flap and various smaller modifications. Though the Yak-13 was superior to the Yak-10 in speed, the Yak-10 possessed operational advantages and thus won the favor of the Soviet high command. Though the Yak-13 was considered to be produced alongside the Yak-10, the act was deemed economically unviable and thus the Yak-13 remained a one-off prototype.
The Yak-10 prototype, still known as the Yak-14 at the time this photo was taken. [Yefim Gordon]In Soviet service the Yak-10 proved to be lacking in terms of performance, which also impacted the aircraft’s ability to be adapted to more roles. Within a year of the Yak-10’s fielding, the Yakovlev OKB was once again called upon to produce a better aircraft. In early 1947, the bureau initiated another project to fulfill the demands of the Air Force. G.I. Gudimenko was once again assigned as chief engineer, but now M.A. Shchyerbina, M.N. Beloskurskii and L.L. Selyakov joined the team as designers. The new project was designated as the Yak-12 (recycled from the Yak-13’s initial designation) and was essentially a redesigned Yak-10 that featured a redesigned rear fuselage contour and a shallower upper decking. Along with some other modifications to the wings, structure and fuselage, the Yak-12 would undergo flight testing within the same year. Though slower than the Yak-10 in speed, the Yak-12 proved to be more versatile for other roles and had greater operational characteristics. Such improvement was deemed satisfactory by the Air Force and mass production thus commenced. The success of the Yak-12 overshadowed the Yak-10 and all examples were withdrawn soon afterwards. The Yak-12 would be produced in the thousands with dozens of variants and conversions designed. It would see service with several Eastern Bloc countries, as well as the People’s Republic of China, Mongolia and possibly Cuba (it is unknown if they operated this type). The Yak-12 was saw military service well into the 1970s but were all retired prior to the 21st century. Several Yak-12 models are still flown to today for recreation, airshows and other roles.
The Yak-10, despite passing state acceptance trials, was still an operational failure and saw only limited production. However, the Yak-10 was an important stepping stone in the development of the Yak-12, which was much more successful and had a fruitful service life within the Soviet Union and several other countries.
Design
A Yak-10 flies over the Moskva River near the Moscow suburbs. [Yefim Gordon]The Yakovlev Yak-10 was a four-seat, high-wing, single-engine multipurpose light aircraft designed in 1944. The standard production Yak-10 was powered by a 5-cylinder air-cooled Shvetsov M-11FR radial engine providing 160 hp, accompanied by a two blade aluminum VISh-327 propeller. The Yak-10’s fuselage and tail was of metal construction while the wings were wooden. The wooden wings possessed a thickness to chord ratio of 11% and utilized the Clark YH airfoil. The fuselage consisted of a welded tubular steel truss while the tail possessed duralumin frames. Fabric was utilized throughout the entire aircraft for skinning. Twin bracing struts constructed of airfoil section steel tubes joined the wings and fuselage. The Yak-10 also had a non-retractable undercarriage in a taildragger configuration. It consisted of pyramid type, rubber-sprung main units and had a castoring tailwheel.
The same Yak-10 above parked at the Chkalovskaya AB during state acceptance trials at NII VVS. [Yefim Gordon]The Yak-10V dual control trainer variant would have featured a new set of controls next to the regular pilot seat. This would allow a co-pilot to fly while both pilots sat side by side. The Yak-10S ambulance variant would have a hatch on the port side of the fuselage for loading stretchers. A total of two stretchers could be accommodated in the Yak-10S along with a seat for a doctor. The Yak-10G featured the replacement of the conventional landing gear with floats previously used in the Yakovlev OKB’s previous AIR-6 multipurpose light aircraft design. Little is known about this variant, but it is known that it did not go into production due to the loss of performance caused by the floats’ drag. The experimental Yak-10 ski conversion had the landing gear replaced by Canadian manufactured wood skis of 6 ft 3 63/64 in x 1 ft 25/64 in / (1,930 x 340 mm). These skis weighed 44.7 lb (20.25 kg). The tail wheel was also replaced by a ski which measured at 1 ft 6 7/64 in x 4 47/64 in (460 x 120 mm) and weighed 4.25 lb (1.93 kg). This modification caused the aircraft’s performance to deteriorate and proved to be only capable of operating in rolled-down airfields. Consequently, the type was not adopted for use.
Variants
Yak-10 – Standard production variant powered by a 5-cylinder air-cooled Shvetsov M-11FR radial engine providing 160 hp.
Yak-10V – Dual control trainer variant of the Yak-10. An unknown amount were produced.
Yak-10S – Medical variant of the Yak-10 which featured a hatch on the port side of the fuselage for loading stretchers. The passenger compartment could accommodate two stretchers and one doctor. It is unknown how many Yak-10S models were manufactured.
Yak-10G – Experimental floatplane variant of the Yak-10. A single Yak-10 was modified to carry AIR-6 type floats in 1946. The Yak-10G underwent manufacturer’s tests but this type was not accepted for mass production, likely due to the degradation of performance generated by the floats’ drag.
Yak-10 (Skis) – Experimental conversion of a Yak-10 to replace the conventional landing gears with Canadian manufactured wooden skis. A single example was converted from a standard model in February of 1947 but was rejected for service as the skis caused the Yak-10’s performance to deteriorate. The ski variant was also deemed only capable of being operated from rolled-down airfields, thus limiting the operable areas.
Yak-13 – Development of the Yak-10 in 1944 which saw a redesigned low-wing configuration, a split landing flap and various smaller modifications. The engine was also switched to a M-11FM radial engine producing 145 hp. The Yak-13 was superior to the Yak-10 in terms of performance, but this aircraft was not accepted for mass production as the Yak-12 was deemed better in some regards and as a result, the Yak-13 remained a one-off prototype. This variant was originally designated as the Yak-12 but the name was changed to Yak-13 during trials and the designation was reused for the 1947 development project of the Yak-10.
Yak-12 – Redesigned variant which first appeared in 1947. The Yak-12 featured a redesigned rear fuselage contour and a more shallow upper decking. Though the base model was slightly inferior to the Yak-10 in speed, the redesigned variant proved more capable in other aspects and was thus mass produced and replaced the Yak-10 in service.
Operators
Soviet Union – The Yakovlev Yak-10 and it’s variants were briefly operated by the Soviet Air Force from 1946 to 1947 before being replaced by the superior Yak-12.
Yakovlev Yak-10 – Standard ModelYakovlev Yak-10 – Standard Model in Alternate LiveryYakovlev Yak-10 – Air AmbulanceYakovlev Yak-10 – Float Variant
The prototype Yak-10G floatplane variant sits in a river awaiting flight trials. [Yefim Gordon]A Yak-10 flies over the Moskva River near the Moscow suburbs. [Yefim Gordon]A white painted Yak-10S ambulance variant. The port hatch for loading stretchers is visible beside the cross. [Yefim Gordon]
Static model of the standard P.105. [British Secret Projects]The Boulton-Paul P.105 is a little known single-engine aircraft meant to fill a variety of carrier-based roles. To do so, the P.105 would utilize a unique and innovative design that involved having interchangeable fuselage and cockpit modules that would pertain to a certain mission, and could be changed quickly to fill a needed role aboard carriers or other airbases. The design was not picked up for unknown reasons but its story doesn’t end there. The design would develop further into the P.107, a land-based escort version of the P.105. The P.107 would have a rear-facing turret and a twin boom tail design to allow greater traverse of the gun. This design wouldn’t be adopted either and the program would conclude before the war’s end.
History
Late in the Second World War, the Royal Naval Air Arm began seeking out an aircraft design that would be able to fill both the fighter and bomber roles. Having one aircraft perform multiple roles would eliminate the specialization of carrier-borne aircraft needed to fill the fighter, dive bomber, and torpedo bomber roles. No official requirement was ever put out to build such an aircraft, but several companies had begun developing aircraft that would fit this role, which had become known as the “Strike Fighter”. Westland, Blackburn, Fairey and Boulton-Paul would all develop designs that correspond to the strike fighter role. Boulton-Paul’s aircraft design would be known as the P.105.
Boulton-Paul is a lesser-known aircraft company which only had a single major type of aircraft enter mass production during the Second World War: the Defiant. The Defiant reflected a lot of their aircraft designs, which were all somewhat unorthodox. . In the Defiant’s case, it was a fighter with a rear turret. Boulton-Paul were much more successful in developing turrets for use on other aircraft, such as the Handley-Page Halifax, Blackburn Roc (which they co-developed alongside Blackburn), Lockheed Hudson and the late war Avro Lincoln. Despite having only one combat aircraft enter production, Boulton-Paul had a very active development section, although most of their designs would stay on the drawing board, with a few being lucky enough to receive prototypes. The designs came from an engineer named J. D. North, who was the main aircraft designer for Boulton-Paul. Before work started on their Strike Fighter design, North had been working on their P.103 and P.104 designs for the Naval Air Arm. The P.103 was an ultra-fast fighter design that utilized a contra-rotating propeller and a Griffon 61 or Centaurus engine. The P.103 wasn’t picked up for production, but North would use many aspects of the P.103 in the P.105. The contra-rotating propeller would once again be used, while the engine would start as a Griffon 61 but shift over to a Centaurus engine later.
3 way drawing of the P.105. Note the spotter’s lower window. [British Secret Projects]The P.105 was meant to be a small, high-performing aircraft that could easily be converted to fill other roles, even carrier duties. To do so, it would use a unique idea. To fill the variety of carrier-borne roles, the P.105 would have modular cockpit and bomb bay sections. The interchangable modules included a torpedo-bomber (P.105A), reconnaissance aircraft (P.105B), fighter (P.105C) and dive-bomber (No designation given). Each section would have minor differences between them that fit their respective roles. With this system, more P.105 airframes could be stored in hangars and carriers, while the additional modules would take up less space than other aircraft specified for specific roles, thus increasing the combat capacity of the carrier the P.105 would be stationed on. Boulton Paul expected the aircraft to be very high performance and the P.105C version would be an excellent penetration fighter. Before any specifications were estimated, it was decided to switch from a Griffon 61 engine to the Centaurus inline engine. The brochure on the details of the aircraft was submitted to the RNAA, but no order for production came about. Exactly why it wasn’t adopted is unknown. The reasoning may come from the module system, as it could have been novel in concept, but complex in reality. Another reason could be that current aircraft at the time were deemed to have been performing adequately and didn’t need such a replacement.
3 way drawing of the P.107. Note the sliding aft canopy and smaller profile of the twin tail rudders. [British Secret Projects]Although the P.105 wasn’t granted production, its story continues in the Boulton-Paul P.107. The P.107 is an intriguing design since very little information pertaining to its development history is available, but its design and specifications has been found. It can be assumed the P.107 began development during or shortly after the P.105 had been created. The P.107 wouldn’t be operated by the RNAA, but instead by the Royal Air Force as a long-range escort fighter. Major differences between the P.107 and P.105 include the lack of folding wings, the removal of the torpedo blister, the addition of a turret and the switch from a single rudder to a twin tail design to improve the firing angle of the turret. The P.107 could also be configured for different roles, but it is unknown if it used the same module system the P.105 used. The P.107 wasn’t selected for production either.
Design
The Boulton-Paul P.105 had a conventional fighter layout. In the front, it would utilize a contra-rotating propeller that had reversible pitch. Originally, the design would have mounted a Griffon 61 engine but was changed in favor of the Centaurus engine instead. The wings on the P.105 were inverted gull wings, much like those on the Vought F4U Corsair or Junkers Ju 87 Stuka. To conserve space in carriers, the wings would be able to fold. The fuselage had the most interesting aspect of the P.105 overall and that was its interchangeable cockpit and lower fuselage modules. Each variant of the P.105 would use different modules that would pertain to the intended role it served. The P.105A was a torpedo bomber and would use the torpedo blister present under the tail. The P.105B was a reconnaissance aircraft, and its cockpit would sit a pilot and observer. It would use a glass hull beneath the observer to assist in spotting. The P.105C was an escort fighter and would be a one-man aircraft. The last was a dive-bomber version, which only has very sparse details available. The dive bomber would carry two 1,000 lb (450 kg) bombs, most likely in an internal bomb bay module. The tail of the aircraft would be a conventional rudder and tailplane arrangement. The armament of the P.105 was a standard two to four 12.7mm machine-guns in the wings of the aircraft, with the only deviation being the P.105C, which would use four 20mm cannons instead.
Papercraft model of the P.107 [Kartonbau.de]The P.107 borrowed many aspects of the P.105 design, but changed some details to better fit its role. The engine and frontal section would stay the same, keeping the contra-rotating propellers and Centaurus engine. Reference materials refer to the aircraft as being able to convert from an escort fighter to either a fighter-bomber or photo reconnaissance aircraft. However, whether it was conventional conversion or via the module system the P.105 used is unknown, the latter being most likely. The wing design would stay the same, with the inverted gull wing style. Given its land-based nature, the wings no longer folded to conserve space and the torpedo blister under the tail was removed. Behind the pilot, a gunner would sit and remotely control two 12.7mm machine guns. The machine-guns would be housed within the aircraft, with only the ends of the barrel protruding out. To give the gunner a better firing arc, the single tailfin was switched to a double tailfin. The turret and twin tail design are the most obvious differences between the P.107 and P.105. The aircraft’s fuel would be stored in a main tank and two smaller drop tanks. Fuel amount was expected to give the aircraft a 3,000 mi (4,827 km) range, with up to 30 minutes of combat. The drop tanks could be switched for 2,000 Ib (900 Kg) of bombs. For offensive armament, the P.107 would use four 20m cannons mounted in the wings.
Papercraft model of the P.107 [Kartonbau.de]
Variants
Boulton Paul P.105A– Torpedo bomber version of the P.105.
Boulton Paul P.105B– Reconnaissance version of the P.105. This version would have a glazed hull for the observer.
Boulton Paul P.105C– Fighter version of the P.105.
Boulton Paul P.105 Dive bomber– Dive bomber version of the P.105. No designation was given to this design.
Boulton Paul P.107– Land-based escort fighter derived from the P.105. The P.107 was near identical to the P.105 but had a twin boom tail to allow better vision and turn radius for a rear mounted turret. Photo reconnaissance and fighter bomber versions of the P.107 are also mentioned.
Operators
Great Britain – Had it been built, the P.105 would have been used by the Royal Fleet Air Arm. The P.107 would have been used by the RAF for escort duty had it been built.
United States of America (1945)
Prototype Fighter – 3 Built
The first XP-86 Prototype 45-59598, flown by George Welch
The North American F-86 Sabre is one of the most well-known fighter aircraft of all time, marking the transition from the propeller to the jet turbine. It first entered service with the newly formed U.S. Air Force in 1949, and was instrumental in denying air superiority to Communist forces during the Korean War. After the war ended, many Sabres entered service with dozens of foreign air arms, becoming the primary fighter equipment of many Allied nations. It was built under license in Canada, Japan, Italy, and Australia. Its service was so long-lived that the last operational F-86 was not withdrawn from service until 1993.
History
The F-86 Sabre began its life as North American Aviation’s company project NA-134, which was originally intended for the US Navy. As the war in the Pacific edged toward its climax, the Navy was making plans to acquire jet-powered carrier-based aircraft, which it was could be pressed into service in time for Operation Olympic-Coronet, the invasion of Japan planned for May 1946. The Navy had planned to acquire four jet fighters, the Vought XF6U-1 Pirate, the McDonnell XFD-1 Phantom, the McDonnell XF2D-1 Banshee, and the North American XFJ-1 Fury.
Work on the NA-134 project began in the late autumn of 1944. The NA-134 had a straight, thin-section wing set low on a round fuselage. It featured a straight through flow of air from the nose intake to the jet exhaust that exited the aircraft under a straight tailplane. The wing was borrowed directly from the P-51D, and had a laminar-flow airfoil. It was to be powered by a single General Electric TG-180 gas turbine which was a license-built version of the de Havilland Goblin. The TG-180 was designated J35 by the military and was an 11-stage axial-flow turbojet which offered 4000 lb.s.t. at sea level. The Navy ordered three prototypes of the NA-134 under the designation XFJ-1 on January 1, 1945. On May 28, 1945, the Navy approved a contract for 100 production FJ-1s (NA-141).
At the same time that North American was beginning to design the Navy’s XFJ-1, the U.S. Army Air Force (USAAF) issued a requirement for a medium-range day fighter which could also be used as an escort fighter and a dive bomber. Specifications called for a speed of at least 600 mph, since the Republic XP-84 Thunderjet already under construction promised 587 mph. On Nov 22, 1944, the company’s RD-1265 design study proposed a version of the XFJ-1 for the Air Force to meet this requirement. This design was known in company records as NA-140. The USAAF was sufficiently impressed that they issued a letter contract on May 18, 1945 which authorized the acquisition of three NA-140 aircraft under the designation XP-86.
The Navy’s XFJ-1 design had to incorporate some performance compromises in order to support low-speed carrier operations, but the land-based USAAF XP-86 was not so constrained and had a somewhat thinner wing and a slimmer fuselage with a high fineness ratio. However, the XP-86 retained the tail surfaces of the XFJ-1.
The XP-86 incorporated several features not previously used on fighter aircraft, including a fully-pressurized cockpit and hydraulically-boosted ailerons and elevators. Armament was the standard USAAF equipment of the era–six 0.50-inch Browning M3 machine guns that fired at 1100 rounds per minute, with 267 rounds per gun. The aircraft was to use the Sperry type A-1B gun/bomb/rocket sight, working in conjunction with an AN/APG-5 ranging radar. Rocket launchers could be added underneath the wings to carry up to 8 5-inch HVARs. Self-sealing fuel tanks were to be fitted, and the pilot was to be provided with some armor plating around the cockpit area.
In the XP-86, a ten percent ratio of wing thickness to chord was used to extend the critical Mach number to 0.9. Wingspan was to be 38 feet 2.5 inches, length was 35 feet 6 inches, and height was 13 feet 2.5 inches. Four speed brakes were to be attached above and below the wings. At a gross weight of 11,500 pounds, the XP-86 was estimated to be capable of achieving a top speed of 574 mph at sea level and 582 mph at 10,000 feet, still below the USAAF requirement. Initial climb rate was to be 5,850 feet per minute and service ceiling was to be 46,000 feet. Combat radius was 297 miles with 410 gallons of internal fuel, but could be increased to 750 miles by adding a 170 gallon drop tank to each wingtip. As it would turn out, these performance figures were greatly exaggerated.
A mock-up of the XP-86 was built and approved on June 20, 1945. However, early wind tunnel tests indicated that the airframe of the XP-86 would not be able to reach the desired speed of 600 mph. It is highly likely that the XP-86 project would have been cancelled at this time were it not for some unusual developments.
Saved by the Germans
After the surrender of Germany in May of 1945, the USAAF, along with a lot of other air forces, was keenly interested in obtaining information about the latest German jet fighters and in learning as much as they could about secret German wartime research on jet propulsion, rocket power, and ballistic missiles. American teams were selected from industry and research institutions and sent into occupied Germany to investigate captured weapons research data, microfilm it, and ship it back to the US.
The First XP-86 Prototype in Flight Testing [San Diego Air & Space Museum]By the summer of 1945, a great deal of German data was pouring in, much of it as yet untranslated into English. As it turned out, German aeronautical engineers had wind-tunnel tested just about every aerodynamic shape that the human mind could conceive of, even some ideas even only remotely promising. A particular German paper dated 1940 reported that wind tunnel tests showed that there were some significant advantages offered by swept wings at speeds of about Mach 0.9. A straight-winged aircraft was severely affected by compressibility effects as sonic speed was approached, but the use of a swept wing delayed the effects of shock waves and permitted better control at these higher speeds. Unfortunately, German research also indicated that the use of wing sweep introduced some undesirable wing tip stall and low-speed stability effects. American researchers had also encountered a similar problem with the swept-wing Curtiss XP-55 Ascender, which was so unstable that it flipped over on its back and stalled on one of its test flights.
In 1940, these German studies were of only theoretical interest, since no powerplants were available even remotely capable of reaching such speeds. However, such studies caught the attention of North American engineers trying to develop ways to improve the performance of their XP-86.
Going Supersonic
The first XP-86 prototype in what would be a temporary white paint scheme
The optimal design for an aircraft capable of high speeds produces a design that stalls easily at low speeds. The cure for the low-speed stability problem that was worked out by North American engineers was to attach automatic slats to the wing leading edges. The wing slats were entirely automatic, and opened and closed in response to aerodynamic forces. When the slats opened, the changed airflow over the upper wing surface increased the lift and produced lower stalling speeds. At high speeds, the slats automatically closed to minimize drag.
In August of 1945, project aerodynamicist L. P. Greene proposed to Raymond Rice that a swept-wing configuration for the P-86 be adopted. Wind tunnel tests carried out in September of 1945 confirmed the reduction in drag at high subsonic speeds as well as the beneficial effect of the slats on low speed stability. The limiting Mach number was raised to 0.875.
Based on these wind-tunnel studies, a new design for a swept-wing P-86 was submitted in the fall of 1945. The USAAF was impressed, and on November 1, 1945 it readily approved the proposal. This was one of the most important decisions ever made by the USAAF. Had they not agreed to this change, the history of the next forty years would undoubtedly have been quite different.
North American’s next step was to choose the aspect ratio of the swept wing. A larger aspect ratio would give better range, a narrower one better stability, and the correct choice would have to be a tradeoff between the two. Further tests carried out between late October and mid November indicated that a wing aspect ratio of 6 would be satisfactory, and such an aspect ratio had been planned for in the proposal accepted on November 1. However, early in 1946 additional wind tunnel tests indicated that stability with such a narrow wing would be too great a problem, and in March the design reverted to a shorter wingform. An aspect ratio of 4.79, a sweep-back of 35 degrees, and a thickness/chord ratio of 11% at the root and 10% at the tip was finally chosen.
All of these changes lengthened the time scale of the P-86 development in comparison to that of the Navy’s XFJ-1. The XFJ-1 took to the air for the first time on November 27, 1946, but the XP-86 still had almost another year of work ahead before it was ready for its first flight.
The first XP-86 prototype in flight during testing [North American Aviation]On February 28, 1946, the mockup of the swept-winged XP-86 was inspected and approved. In August of 1946, the basic engineering drawings were made available to the manufacturing shop of North American, and the first metal was cut. The USAAF was so confident of the future performance of the XP-86, that on December 20, 1946 another letter contract for 33 production P-86As was approved. No service test aircraft were ordered. Although the 4000 lb.s.t. J35 would power the three XP-86 prototypes, production P-86As would be powered by the General Electric TG-190 (J47) turbojet offering 5000 lb.s.t.
The first of three prototypes, 45-59597, was rolled out of the Inglewood factory on August 8, 1947. It was powered by a Chevrolet-built J35-C-3 turbojet rated at 4000 pounds of static thrust. The aircraft was unarmed. After a few ground taxiing and braking tests, it was disassembled and trucked out to Muroc Dry Lake Army Air Base, where it was reassembled.
Test pilot George “Wheaties” Welch took the XP-86 up into the air for the first time on October 1, 1947. The flight went well until it came time to lower the landing gear and come in for a landing. Welch found that the nosewheel wouldn’t come down all the way. After spending forty minutes in fruitless attempts to shake the nosewheel down into place, Welch finally brought the plane in for a nose-high landing. Fortunately, the impact of the main wheels jolted the nosewheel into place, and the aircraft rolled safely to a stop. The swept-wing XP-86 had made its first flight.
On October 16, 1947, the USAF gave final approval to the fixed price contract for 33 P-86As, with the additional authorization for 190 P-86Bs. The P-86B was to be a strengthened P-86A for rough-field operations.
XP-86 number 45-59597 was officially delivered to the USAF on November 30, 1948. By that time, its designation had been changed to XF-86. Phase II flight tests, those flown by USAF pilots, began in early December of 1947. An Allison-built J35-A-5 rated at 4000 lbs of static thrust was installed for USAF tests. The second and third XP-86 prototypes, 45-59598 and 45-59599 respectively, joined the test program in early 1948. These were different from the first prototype as well as being different from each other in several respects. Numbers 1 and 2 had different fuel gauges, a stall warning system built into the control stick, a bypass for emergency operation of the hydraulic boost system, and hydraulically-actuated leading-edge slat locks. The number 3 prototype was the only one of the three to have fully-automatic leading-edge slats that opened at 135 mph. Numbers 2 and 3 had SCR-695-B IFF beacons and carried the AN/ARN-6 radio compass set.
The original XP-86 prototype was used for evaluating the effects of nuclear blasts on military hardware at Frenchman Flats. It was later scrapped. [This Day in Aviation]In June of 1948, the new US Air Force redesignated all Pursuit aircraft as Fighter aircraft, changing the prefix from P to F. Thus the XP-86 became the XF-86. XP-86 number one was officially delivered to the USAF on November 30, 1948. The three prototypes remained in various test and evaluation roles well into the 1950s, and were unofficially referred to as YP-86s. All three prototypes were sold for scrap after being used in nuclear tests at Frenchman Flats in Nevada
Design
The three XP-86 prototypes flying in formation together in 1948 [National Archives]Evolving from the NA-134 project with wings borrowed from a P-51, the XP-86 would eventually end up with a low swept wing mounted to a tubular fuselage, with a large jet intake opening at the nose. The plexiglass bubble canopy gave the pilot great visibility, and afforded the pilot a pressurized cockpit. The tail featured a swept back rudder with tailplanes angled upwards, marking a departure from the largely perpendicular angles seen on most of the Sabre’s propeller driven predecessors. The landing gear was a tricycle configuration, which helped balance the weight of the jet engine at the rear.
The wing of the XP-86 was to be constructed of a double-skin structure with hat sections between layers extending from the center section to the outboard edges of the outer panel fuel tanks. This structure replaced the conventional rib and stringer construction in that area. This new construction method provided additional strength and allowed enough space in the wing for fuel tanks.
The wing-mounted speed brakes originally contemplated for the XP-86 were considered unsuitable for the wing design, so they were replaced by a hydraulic door-type brake mounted on each side of the rear fuselage and one brake mounted on the bottom of the fuselage in a dorsal position. The speed brakes opened frontwards, and had the advantage that they could be opened at any attitude and speed, including speeds above Mach One.
The maximum speed of the XP-86 was over 650 mph, 75 mph faster than anything else in service at the time. The noise and vibration levels were considerably lower than other jet-powered aircraft. However, the J35 engine did not produce enough thrust, and the XP-86 could only climb at 4,000 feet per minute. However, this was not considered an issue, since the production P-86As were to be powered by the 5000 lb.s.t. General Electric J47.
The XP-86 could go supersonic in a dive with only a moderate and manageable tendency to nose-up, although below 25,000 feet there was a tendency to roll which made it unwise to stay supersonic for very long. Production Sabres were limited to Mach 0.95 below 25,000 feet for safety reasons because of this roll tendency.
For the second and third prototypes, the ventral brake was eliminated, and the two rear-opening side fuselage brakes were replaced by brakes which had hinges at the front and opened out and down. These air brakes were adopted for production aircraft.
Prototype number 3 was the only one to be fitted with armament. The armament of six 0.50-inch M3 machine guns were mounted in blocks of three on either side of the cockpit. Ammunition bays were installed in the bottom of the fuselage underneath the gun bay, with as many as 300 rounds per gun. The guns were aimed by a Mk 18 gyroscopic gunsight with manual ranging.
Possibly the First Supersonic Aircraft
George Welch Circa 1947 – [San Diego Air & Space Museum]There is actually a possibility that the XP-86 rather than the Bell XS-1 might have been the first aircraft to achieve supersonic flight. During some of his early flight tests, George Welch reported that he had encountered some rather unusual fluctuations in his airspeed and altitude indicators during high speed dives, which might have meant that he had exceeded the speed of sound. However, at that time, North American had no way of calibrating airspeed indicators into the transonic range above Mach 1, so it is uncertain just how fast Welch had gone. On October 14, 1947, Chuck Yeager exceeded Mach 1 in the XS-1. Although the event was kept secret from the general public, North American test crews heard about this feat through rumors and persuaded NACA to use its equipment to track the XP-86 in a high-speed dive to see if there was a possibility that the XP-86 could also go supersonic. This test was done on October 19, five days after Yeager’s flight, in which George Welch was tracked at Mach 1.02. The tests were flown again on October 21 with the same results. Since Welch had been performing the very same flight patterns in tests before October 14, there is the possibility that he, not Chuck Yeager, might have been first to exceed the speed of sound.
In any case, the fact that the XP-86 had exceeded the speed of sound was immediately classified, and remained so for several months afterward. In May of 1948, the world was informed that George Welch had exceeded Mach 1.0 in the XP-86, becoming the first “aircraft” to do so, with an aircraft being defined as a vehicle that takes off and lands under its own power. The date was set as April 26, 1948. This flight did actually take place, but George Welch was not the pilot. In fact, it was a British pilot who was evaluating the XP-86 who inadvertently broadcasted that he had exceeded Mach 1 over an open radio channel. However, the facts soon became common knowledge throughout the aviation community. The June 14, 1948 issue of Aviation Week published an article revealing that the XP-86 had gone supersonic.
Variants
XP-86 45-59597 – The first prototype Sabre produced, was reconfigured many times with various test configurations. May have been the first aircraft to have gone supersonic in October 1947 with George Welch at the controls.
XP-86 45-59598 – The second prototype, had different production model speedbrake and flap configuration, various sensors and equipment installed for testing purposes.
XP-86 45-59599 – The third prototype, and the only Sabre prototype to have been armed, fitted with the standard six M3 Browning guns
Operators
United States – The prototypes were extensively tested by North American Aviation before being handed over to the U.S. Air Force in 1948.
XP-86 – 1st Prototype 45-59597 circa 1947 note it bears the P for “Pursuit”XP-86 – 1st Prototype 45-59597 circa June 1948 in white paint scheme, note the wingtip pitot probesXP-86 – 1st Prototype 45-59597 circa 1948, note the additional test equipment behind the pilot’s seatXP-86 – 2nd Prototype 45-59598 circa 1948XP-86 – 3rd Prototype 45-59599 circa 1948
People’s Republic of China (1958)
Helicopter / Bus / Boat Hybrid – None Built
Perhaps the only known photo of the original Shangdeng No.1 model. (中国飞机全书: 第3卷)
Shangdeng No.1 was an overambitious design undertaken by the Chinese Shanghai Bulb Factory in 1958 to produce a multipurpose vehicle which could serve as a helicopter, a bus and a boat for the National Day celebrations. Vastly unknown both inside and outside of China, the Shangdeng No.1 can be considered one of the People’s Republic of China’s more obscure designs of the 1950s. Quietly canceled after the conclusion of National Day, the Shanghai Bulb Factory would never fulfill their promise of completing the design and preparing it for mass production. This could be attributed to a plethora of reasons, but information is scarce.
History
On October 1st 1958, the People’s Republic of China celebrated the ninth anniversary of the founding of the nation. As their personal way of celebrating this national holiday, representatives of the Shanghai Bulb Factory unveiled a model of a hybrid design as a gift to the government. Unorthodox and, some may rightfully argue, ridiculous in concept, this design (dubbed the “Shangdeng No.1” / “上灯” 1号) was meant to have served as a versatile multipurpose vehicle capable of acting as a helicopter, a boat and a small bus. Upon presenting this model to the government, they proclaimed that design and manufacturing work would be completed in 1959 thus allowing for mass production. However, this would never happen, as work on the project ceased shortly after the model was presented and the conclusion of National Day.
The reason for the cancellation is unknown, but one could speculate a number of reasons. First and foremost, the Shanghai Bulb Factory specialized in the production of lightbulbs, therefore they completely lacked any expertise, experience, qualified personnel and machinery required to design and in turn produce such a conceptually complicated vehicle. A second possible reason why the project was canceled was due to Mao Zedong’s “Great Leap Forward” campaign, which would have the entire country struggle to industrialize and collectivize. The Shangdeng No.1 could have been deemed as useless and thus canceled by the government so that the factory could focus its resources to fulfill government mandated quotas of lightbulb production. Lastly, the Shanghai Bulb Factory could have had no intention of developing the Shangdeng No.1 in the first place, and the model presented could have been just a demonstration to show off Chinese ingenuity and to boost the morale of the Chinese people in a small show of fanciful propaganda. These, however, are just theories to speculate on why the Shangdeng No.1 was canceled. Only one photo is known to exist of the Shangdeng No.1’s scale model presented during National Day.
In conclusion, the Shangdeng No.1 was an overambitious design concept explored by the Shanghai Bulb Factory which resulted in the presentation of a scale model on the ninth National Day of the People’s Republic of China. Absurd in concept, the Shanghai Bulb Factory would have had no possible way of delivering on their promise to produce such a vehicle as they certainly had little to no experience on vehicle design and machinery intended for light bulb production could only produce so little. The fact that a light bulb factory conceptualized this vehicle is quite interesting though, and, to their credit, an intended helicopter/bus/boat hybrid design would most certainly have raised a few eyebrows in the country and in the Western world, assuming that the design was feasible and successful.
As details on this project are so scarce, it has led to some debate on the legacy of the design. A popular claim by numerous online sources is that, after the project was canceled, documents on the Shangdeng No.1 was transferred to the American Boeing firm, and that the Shangdeng’s tandem rotor design served as the inspiration of the Boeing CH-47 Chinook helicopter. This claim is unrealistic and vacuous, as the People’s Republic of China and the United States of America had no formal relations until the late 1960s / early 1970s, nearly a decade after the Chinook was serviced. Therefore, the concept of a Chinese light bulb factory transferring documents to and influencing a world-renowned aviation corporation would be extremely illogical and, frankly, impossible. The United States of America was also no stranger to tandem bladed helicopters designs, as numerous helicopters (eg. Piasecki HRP Rescuer, Piasecki H-21, etc) formerly and currently in service had these designs prior to the conceptualization of the Shangdeng.
Design
The design of the Shangdeng No.1 resembles a rectangular box with rounded edges. A tandem rotor blade configuration was used, and the conceptual power plant of the Shangdeng would have been an unspecified radial engine model capable of producing up to 450 hp, connected to both the front and the rear rotors. The cockpit located at the front of the helicopter would have allowed space for two pilots. Four passengers (or the weight equivalent in cargo) could have been held in the compartment located behind the cockpit. Windows were planned to be installed in the fuselage as can seen in the scale model. Relatively speaking, the Shangdeng’s dimensions are quiet small for a tandem rotor helicopter design. The Shangdeng was only 6 ft 7 in (2.00 m) tall, which would have likely made the interior compartment quite cramped.
Four static wheels were mounted in pairs in the front and rear part of the fuselage which would have moved the Shangdeng in its bus configuration. It is unknown whether or not the design would have allowed the tandem helicopter rotors to be folded in this configuration. If not, the blades could potentially be damaged in urban areas or crowded spaces. It is unknown if a separate transmission would have been connected to the wheels, but this would have certainly greatly complicated the design. If the vehicle in its bus configuration was meant to be propelled by the rotors, that would have been not only unacceptably inefficient, but would have also limited the paths it could travel and would have been highly dangerous to be next to. Steering in the wheeled mode is also unclear.
In its naval configuration, the Shangdeng would have been propelled by an unspecified amount of 15 in / 40 cm propellers in the rear, possibly with assistance from the wheels which would have provided limited propulsion in the water. Again, this would have probably been highly fuel-inefficient. Also, why would a helicopter, which can easily get between any two points by flying, be used as a boat is hard to fathom. How steering was achieved in the boat mode is unclear.
In the helicopter configuration, the Shangdeng would have just been propulsed by the rotor blades and radial engine. The problem of having someone trained both as a pilot, driver and skipper at the same time seems to have gone unnoticed by the designers. As the project did not progress beyond the conceptual model stage, intricate details regarding the Shangdeng No.1 are unknown. However, basic dimensions and estimated performances are provided by 中国飞机全书: Volume III, a book written by People’s Liberation Army Air Force (PLAAF) general Wei Gang (魏钢), former PLAAF model maker and artist Chen Yingming (陈应明) and aviation magazine author Zhang Wei (张维).
Operator(s)
People’s Republic of China – The Shangdeng No.1 would most likely have been operated by the various military branches and likely some civilian institutes if it were to see mass production.
Shanghai Bulb Factory Shangdeng No.1*
* – Statistics taken from中国飞机全书 (Vol. 3)
Length
32 ft 10 in / 10.00 m
Height
6 ft 7 in / 2.00 m
Engine
1x Unspecified Multi-Cylinder Radial Engine Model (450 hp)
The Yer-2ON was a VIP passenger transport aircraft designed in 1944 by Vladimir Grigoryevich Yermolayev and his Yermolayev OKB (design bureau). Based off of the firm’s preexisting Yer-2 bomber, the Yer-2ON was meant to fulfill the role of a government VIP transport aircraft which would carry government members to and from meetings in or out of the Soviet Union. Shortly after Vladimir Yermolayev died on December 31st of 1944 from a typhoid infection, the Yermolayev OKB firm was integrated into Pavel Sukhoi’s Sukhoi OKB firm where the project continued. Despite showing relatively promising performance, the Yer-2ON would eventually be cancelled due to the conclusion of the Second World War and the Sukhoi OKB’s need to concentrate resources on other projects. Thus, the three produced Yer-2ON would never be used for their intended purpose and were presumably scrapped some time post-war.
History
Diplomacy between the Allied countries during the Second World War was an essential step in defeating the Axis powers. With the increasing successes of the Allies during the war, meetings between representatives from the United States, Soviet Union and United Kingdom were held to discuss the future of Europe along with battle plans. In order to attend these meetings, the Soviet government became aware of the need for a long-range VIP passenger transport aircraft capable of carrying 10 to 12 people while maintaining comfort, reliability, cruising abilities at 13,000 ft to 16,400 ft (4,000 m to 5,000 m) and range of 2,500 mi to 3,100 mi (4,000 km to 5,000 km). After Joseph Stalin himself made a request for an aircraft meeting these requirements in January of 1944, a meeting was held between government and Soviet Air Force officials discussing the feasibility of converting existing bomber aircraft to meet this need. Not only would this save time, but also had the benefit of sharing the same airframe as aircraft already in production. In the end, the Yermolayev OKB’s liquid-cooled Charomskiy ACh-30B V-12 diesel engine powered Yer-2 bomber was chosen for conversion. Curiously enough, Yer-2 being used as a transport aircraft is quite ironic, as it reflects on Roberto L. Bartini’s 1937 Stal-7 transport aircraft, from which the Yer-2 bomber was originally developed from.
A frontal view of the passenger compartment. (AviaDejaVu)
Shortly after the NKAP (People’s Commissariat for Aviation Industry) approved Order 351 on May 23, 1944, the head designer of the Yermolayev OKB firm, Vladimir Grigoryevich Yermolayev, began work on converting the Yer-2 into a VIP passenger transport aircraft. In his address to the NKAP on that day, he promised that a completed example would be converted by Factory No.39 and be ready for tests by November 15th. This new variant would be designated Yer-2ON (Osoboye Naznachenie – Special Purpose). With most of the groundwork already completed, Yermolayev was able to complete the conversion blueprints by August. An inspection was conducted on the Yer-2ON’s plans on August 28th and was approved for production. The difference between the Yer-2ON and the standard bomber variant was the removal of all armament and replacement of the bomb bay with a passenger compartment. The passenger compartment would have been able to hold 9 passengers, as well as a flight attendant. All relevant technical drawings were sent to Factory No.39 in the Irkutsk Oblast. A total of four Yer-2 bombers were ordered for conversion, but standard Yer-2 production would run into difficulties as the diesel powered Charomskiy ACh-30B engines manufactured at Factory No.500 were found to have defects and needed to be addressed. As such, the project was put on hold for a considerable amount of time.
A rear view of the Yer-2ON. (Одноклассники)
On December 31st, Vladimir Grigoryevich Yermolayev passed away due to a typhoid infection. As a result, the Yermolayev OKB and its assets were integrated into Pavlov Sukhoi’s Sukhoi OKB firm. It would appear that N.V. Sinelnikov took over as head designer once the project was integrated into Sukhoi OKB. Once the issue with the engines was resolved, three Yer-2 bombers were set aside and were prepared to be converted into the Yer-2ON. Due to the relatively poor documentation of the Yer-2ON’s development, it is unknown when precisely the first Yer-2ON was completed, but most sources allege it was completed at the end of December. The manufacturer’s flight tests and maiden flight appeared to have taken place sometime in February of 1945. Through these tests it was revealed that the Yer-2ON was capable of covering a distance of 3,230 mi / 5,200 km while maintaining a flight ceiling of 19,700 ft / 6,000 m and a top speed of 270 mph / 435 kmh.
On April 16th, the first Yer-2ON made a record non-stop flight from the Irkutsk Aviation Plant’s airfield in Eastern Siberia to Moscow. This flight was accomplished by Heroes of the Soviet Union M. Alekseev and Korostylev over a flight time of 15 hours and 30 minutes and covered a distance of approximately 2,611 mi / 4,202 km. It would appear that a second flight would be conducted sometime near the end of April with the second converted aircraft once it was ready. The second flight had identical circumstances as the first flight (same pilots, destination, fuel load, etc). Interestingly enough, both flights concluded with enough fuel for four more hours of flight, attesting to the Yer-2’s long-range capabilities. A third Yer-2ON was converted at an unspecified time, but details of its tests (if it performed any at all) are unknown. Some internet sources claim that a fourth example was completed on May 10th of 1945, but this cannot be confirmed and disagrees with most publications.
One of the passenger seats of the Yer-2ON. (AviaDejaVu)
Despite the Yer-2ON performing relatively well and passing the manufacturer’s flight tests, the aircraft was never used for its intended role of government VIP passenger transportation. This was likely the result of the project being deemed as low priority within the Sukhoi OKB firm. At the time, Sukhoi was invested in other more pressing projects which led to the Yer-2ON being eventually canceled. Joseph Stalin himself was reputed to have aviophobia (a fear of flying) and the Yer-2ON not entering service did not appear to have consequences for the Sukhoi OKB. Nonetheless, the Yer-2ON project was dropped some time post-war and the three manufactured prototypes were likely scrapped as a result.
Design
A cutout drawing of the Yer-2ON’s interior. (AviaDejaVu)
The Yermolayev Yer-2ON was a two engine VIP passenger transport aircraft based on the Yermolayev Yer-2 bomber aircraft, powered by two liquid-cooled Charomskiy ACh-30B V-12 diesel engines capable of producing 1,500 hp each. The Yer-2ON was identical to the standard Yer-2 bomber in most respects, though armaments and turrets were removed and the bomb bay was converted to a passenger compartment with seats for 9 passengers and 1 flight attendant. The crew would have consisted of a commander pilot, a co-pilot, a navigator, a radio operator, and a flight attendant. In the passenger compartment, the left side (aircraft facing forward) had 5 seats while the right side had 4. The flight attendant’s seat was located behind the last seat on the right side, and was retractable. A luggage compartment was also provided. Another notable feature was the addition of a toilet compartment, as the aircraft’s long-distance travel routes required such a feature. Several windows were installed on the side of the fuselage for the passengers.
Operators
Soviet Union – The Yer-2ON was intended to be used as a passenger transport aircraft for government VIPs traveling in and out of the country to attend meetings.
Yermolayev Yer-2ON*
* – Statistics taken from “OKB Sukhoi: A History of the Design Bureau and its Aircraft” by Dmitriy Komissarov, Sergey Komissarov, and Yefim Gordon
Yermolayev Yer-2ON Side View IllustrationA side view of the Yer-2ON. (AviaDejaVu)The entrance to the passenger section. (AviaDejaVu)This photo shows what appears to be a retractable seat in the rear of the passenger compartment. This seat most certainly would be for the flight attendant. (AviaDejaVu)Toilet compartment of the Yer-2ON. (AviaDejaVu)
USSR (1936)
Experimental Light Bomber – One Prototype Built
Bolkhovitinov’s light bomber was a truly unusual design, with two engines mounted in the same fuselage.
Prior to the German invasion, the Soviet air industry was in the process of developing a series of new experimental ideas and concepts. While generally unknown around the world, some of these were interesting designs, such as the Bolkhovitinov “S” experimental twin-engine fast attack bomber. Due to the German advance and the need for immediately operational planes, the development of this model was terminated.
An Unusual Idea
The leader of the whole S-2M-103 project, aircraft engineer Viktor Federovich Bolkhovitinov.
The S-2M-103 was designed and developed by a Soviet aircraft engineer team led by Viktor Federovich Bolkhovitinov (Ви́ктор Фёдорович Болхови́тинов). Bolkhovitinov (February 1899 – 29 January 1970) was a Soviet professor at the Zhukovsky Air Force Academy in Moscow, and also an aircraft engineer. One of his best known designs was the four-engined Bolkhovitinov DB-A bomber that was intended to replace to aging TB-3 bomber.
During 1936, Bolkhovitinov and his team were looking for a solution for the lack of a high-speed light bomber in the Soviet Air Force. Their answer would be an unusual twin-engine aircraft with a peculiar wing configuration. Instead of a conventional wing placement, the wings were mounted very low on the fuselage, and the tail was a twin fin design.
When they began working on the first calculations and drawings, their greatest concern was how to reduce drag. Usual bomber designs with wing-mounted engines slowed down the plane due to excessive drag. Fighters, on the other hand, had much better aerodynamic properties as they were designed to achieve the highest possible speeds. Bolkhovitinov and his team decided that, for their purposes, they would reuse elements from other bombers (two engines, bomb-carrying capacities, defensive armament) and a one-part fuselage.
The problem was how to position the two engines in order to reduce the drag as much as possible. They quickly came up with the idea of putting them both on the same line (one behind the other) and in the same fighter-like fuselage. While this configuration would make the new plane longer, it could be designed with much better aerodynamic properties.
The development and design of the unusual twin-engine system began in 1936, while work on the aircraft design itself began the next year. By 1938, the design was completed and preparations for the construction of a fully operational prototype began in July that year. The prototype was completed in 1939 and flight tests were scheduled to begin in July 1939 (or in early 1940 according to some sources).
Designation
This was the single-engined version tested during the winter of 1940/41.
The aircraft’s original designation was simply “Bolkhovitinov S” or “Sparka/Cпаренный”, which means twin. Today it is generally known under the “S-2M-103” designation, where the “2” stands for twin-engine configuration and “M-103” is the name of the engine. There were other designations used for this plane, such as “BBS-1” (Ближний бомбардировщик скоростной, fast short-range bomber), “LB-S“ (легкий бомбардировщик спаренный, light twin-engined bomber) оr “BB“ (Болхови́тинов Бомбардировщик, Bolkhovitinov Bomber). As the plane is best known as the the S-2M-103, this article will use this designation.
Technical Characteristics
The S-2M-103 was designed as a low wing, all-metal construction, two-seater, two-engined fast attack bomber. The S-2M-103’s main fuselage had an elliptical cross-section. The fuselage consisted of four (bottom, top and left and right side) panels that were held in place by using four strong angled-section longerons. The S-2M-103’s structure was covered with a modern light alloy stressed-skin.
The wings were constructed using a structural box with flanged lightening holes (to save weight). The wings’ interior sheet ribs were covered on both sides (upper and lower) by metal skin and held in place by flush riveting.
The two three-bladed propellers turned in the opposite directions in order to provide better stability during flight.
The rear twin-finned tail was covered with duralumin skin. For better stability, the rudders were equipped with inset balanced hinges. For the tailplanes’ movement, an irreversible trimming motor was used. The elevator had trim tabs with a variable geared drive.
The S-2M-103 had a completely retractable landing gear that was operated electrically. The front wheels and the smaller rear tail wheel was able to retract backward 90 degrees. During the winter of 1940/41, the wheeled landing gear was replaced with fixed skis.
Drawing of the twin-engined configuration.
This aircraft had an unusual two tandem engine arrangement, placed in the same mounting in the fuselage. The rear-mounted engine’s shaft passed through the front engine’s cylinder blocks. Both engines were connected to the two propellers (with six blades in total) which, when powered, turned in opposite directions, which provided better stability during flight (at least in theory). The S-2M-103 was powered by two 960 hp (716 kW) Klimov M-103’s V-12 liquid cooled engines. This engine was based on the French Hispano-Suiza 12Y which was produced under license by the Soviet Union as the M-100.
The water radiators were placed under the fuselage and had controllable exit flaps. Two oil coolers were located on the ducts on both sides of the two engines. The fuel was stored in four fuel tanks that were placed in the wings (between the wing spars). Unfortunately, there is no information available about the capacity of these tanks.
The two crew members were positioned in an unusually large cockpit fully enclosed with a plexiglass canopy. The crew consisted of the pilot and the navigator. The navigator was also provided with a bombsight. The navigator’s position was covered with plexiglas on all sides, which provided him with an excellent all-around view, including under the plane. His additional role was to operate the rear-mounted machine gun.
The S-2M-103 lacked any forward-firing offensive armament. While it was planned to equip it with weapons mounted in the wings, this was never accomplished. For self-defense, one 0.3 in (7.62 mm) ShKAS machine gun was provided for the navigator/gunner. Due to its tail design, the rear machine gun had a wide firing arc. Later, it was planned to replace the single 7.62 mm rear gun with heavier twin 0.5 in (12.7 mm) UBT machine guns. There were also alleged plans to equip the S-2M-103 with a rear-mounted remotely controlled ShKAS machine gun. Whether this was ever implemented is unknown, as there no photographs or precise information are available. The bomb bay, which could carry 880 lb (400 kg) of bombs, was located under the pilot cockpit. The bomb bay opening doors were opened electrically.
Operational Tests
Side view of the S-2M-103.
The S-2M-103, piloted by D.N. Kudrin, made its first test flight in late 1939. More tests were carried out by the Army from March to July 1940, the plane being piloted by D.N. Kudrin and A.I. Kabanov. During these flight tests, the S-2M-103 proved to be able to achieve a maximum speed of 354 mph (570 km/h) at 15,400 ft (4,700 m). The tests also proved that the concept of installing two engines in the same fuselage had some advantages over the wing-mounted configuration. The most obvious was the reduced drag, which lead to increased speed and improved flight performance.
There were also some problems with the design. Immediately noticeable were the poor take-off and landing performance during these tests trials. Due to its high weight of 12,460 lb (5,650 kg), the S-2M-103 needed a 3,430 ft (1,045 m) long airfield. More tests were carried out by removing any extra weight. With the weight being reduced by some 1,100 lb (500 kg), the S-2M-103 now only needed a 2,800 ft (860 m) long airfield. During landing at speeds of 103 mph (165 km/h) the aircraft needed a 2,130 ft (650 m) long airfield. Some problems with the twin propellers were also noted. The rear-mounted propeller drive shaft was damaged due to strong vibrations. Unfortunately, there are no records of cruising speed, climbing speed, or maximum service ceiling.
The Single-Engine Version
For testing during the winter of 1940/41, instead of the standard landing gear, fixed skies were provided.
In the following months of 1940 and 1941, the S-2M-103 received a number of modifications in the hope of solving the issues observed during preliminary testing. The twin-engine configuration was replaced with a single M-105P engine with a power of 960 hp (or 1,050 hp depending on the source). The area where the second engine was previously located was filled in order to maintain the stability of the aircraft. Due to the removal the second engine, the second contra-rotating propeller was no longer needed. The new engine’s oil coolers were placed in the main radiator duct. The designers had a dilemma about what to do with the extra interior space left by the removal of the second engine, but this was never solved completely. With these modifications, the weight was reduced from 12,460 lb (5,650 kg) to 8,820 lb (4,000 kg).
The wing design was also changed to one done by Z.I. Iskovich by increasing its size and using a new aerofoil shape. The previous wing design had an area of 246.5 ft² (22.9 m²), while the new one had 252 ft² (23.4 m²). The last change was made to ease testing during winter, replacing the landing gear with fixed skis.
It appears that no official designation for this version existed but, using the same logic as for the two-engine version, it could be called S-M-105, but this is only speculation at best. According to some sources, the single-engined variant was marked as the S-1.
There were plans to improve the performance of the projected fighter version by mounting two M-107 engines. The new fighter was to be designated simply as the “I” or “I-1”. Due to the later cancellation of the S-2M-103 project, the I-1 was also abandoned.
The Fate of the S-2M-103 Project
More flight tests were carried out during the first half of 1941. While there is no precise information, the newly modified single-engined version of the S-2M-103 allegedly had poor performance. Despite the modifications, the new single-engined version managed to achieve a much lower top speed of 248 mph (400 km/h) at 14,440 ft (4,400 m). The poor performance, preparation for Pe-2 production at the factory where it was built, and the German Invasion of the Soviet Union led to the cancellation of the S-2M-103 project.
Operators
TheSoviet Union – A single prototype was tested in 1940/41, but was not adopted for production.
Variants
S-2M-103 – Twin engine fast bomber
S-2M-103 (possibly S-M-105) – Single-engine version
I-1 – Improved fighter version equipped with two M-107 engines, due to cancelation of the S-2M-103 none were built.
Conclusion
The concept of installing two engines in the same fuselage had some advantages over the wing mounted configuration. It reduced drag, which lead to increased speed and flight performance. The S-2M-103 proved this by achieving speeds of up to 350 mph (570 km/h). However, its design had issues that were never resolved. Given enough time, those might have been solved. Alas, in 1941, the German Invasion and the need to increase production of already existing aircraft stopped all unimportant projects.
Drawing of the S-2M-103.View of the engine compartment interior.Rear view of the S-2M-103.
Credits
Gordon, E. & Khazanov, D. (1998). Soviet combat aircraft of the Second World War. Leicester Osceola, WI: Midland Pub. North American trade distribution by Motorbooks International.
Yefim G. and Bill G (2000), Soviet X-Planes, Midland Publishing
Kingdom of Hungary (1944)
Fictitious Jet Attacker / Dive Bomber – 1 Scale Model Built
The original photo published on the XNI-02. (Repülés Magazine)
The Manfréd-Weiss XNI-02 Kaméleon (Chameleon) is a fictitious Second World War Hungarian jet-powered attacker aircraft written about in the April 1980 edition of the Hungarian aviation magazine Repülés (Flight) as an April Fools joke. The brainchild of Hungarian author György Punka, the XNI-02, though meant as a harmless April Fools joke, unfortunately fooled unsuspecting readers and caused controversy within the military aviation fanbase. As a result, numerous websites, magazine authors, armchair historians and casual readers are still convinced to this day that the XNI-02 Kaméleon was an authentic project undertaken during the war and believes it existed.
Alleged History
According to the April 1980 edition of the Hungarian aviation magazine “Repülés”, while working for the Hungarian Manfréd Weiss Steel and Metal Works, (Weiss Manfréd Acél- és Fémművek, also known as “Csepel Works”) engineer Pál Nemisch designed a jet attacker aircraft in 1944. Due to the frequent Allied bombing and Hungary’s shortage of supplies, Nemisch presumably decided to base his design off pre existing components taken from other aircraft. Christened the “XNI-02”, the aircraft gained the nickname of Kaméleon (Chameleon) due to the number of parts incorporated from foreign designs. The XNI-02’s construction consists of a concoction of German, American and indigenously manufactured parts. Further details of the XNI-02’s design process are unknown, as Punka did not expand on them.
The mock guncam footage of the XNI-02 getting shot down. (Repülés Magazine)
Construction of the XNI-02 is presented as having began in mid to late 1944, after parts for the aircraft were collected. The prototype began assembly in Kőbánya, Hungary, but construction was relocated to an underground aircraft production facility near Augsburg, Germany. This can possibly be accredited to Operation Margarethe, the German occupation of Hungary to ensure their loyalty to the Axis. The XNI-02’s development team would once again be relocated to Austria, near Wiener Neustadt prior to November. The XNI-02 prototype was presumably completed by the Wiener Neustädter Flugzeugwerke factory and made its maiden flight on November 6th.
On April 1st of 1945, Lieutenant R. Taylor from the USAAF 385th Fighter Group was patrolling Austrian airspace in search of Axis fighters with his North American P-51 Mustang. While flying near the town of Linz, he spotted a rather peculiar looking aircraft flying to his starboard side at an altitude of approximately 9,840 ft / 3,000 m. While trying to get behind the mysterious fighter, Lt. Taylor inadvertently revealed his presence to the aircraft which led to it speed away. Determined to chase down this mysterious aircraft, Lt. Taylor proceeded with the chase. For some odd reason, the aircraft Lt. Taylor was chasing began to slow down and extended its landing gears. Now in a position to engage the aircraft, Lt. Taylor fired towards the unidentified aircraft. Failing to shoot it down in the initial pass, Lt. Taylor pulled off and reengaged it. This time, the burst of gunfire from his Mustang seemingly crippled the unidentified aircraft and thus forced the pilot to bail out. The aircraft crashed shortly thereafter. After returning to the 385th Fighter Group’s homebase in Foggia, Italy, the guncam on Lt. Taylor’s Mustang was examined and the film revealed that the mysterious aircraft Taylor shot down was the sole XNI-02 (the guncam still frame in the magazine was created using Punka’s model). This, however, was unknown to them at the time. This information would be revealed later on from an unnamed technician who provided pictures and some information regarding the XNI-02 after the war. On that day, the XNI-02 was supposed to be performing a weapon firing flight test, but this would never occur as Lt. Taylor was able to successfully shoot down the prototype. In Lt. Taylor’s private log book, he recorded the victory as: “Unidentified jet over Linz. 10:35, 1945 April 1st”. The reasons why the XNI-02 test pilot decided to slow down and extend his landing gear are up for personal interpretation, as the story is fictitious in itself. The test pilot may have believed he lost Lt. Taylor and decided to prepare for landing, or this was an indication that the XNI-02 was experiencing mechanical problems and needed to perform an emergency landing. Realistically though, the story was written in this way to cover up Punka’s XNI-02 model’s inability to retract its landing gears. It is unknown whether or not the radioman was present onboard the aircraft at the time of its shootdown.
The Wiener Neustädter Flugzeugwerke factory was also in the process of building the reconnaissance variant of the XNI-02 in 1945. The incomplete fuselage of this variant was destroyed by advancing Soviet troops when they overran the factory. Other than the attacker / dive bomber and reconnaissance variant, there was also plans to produce a night fighter and trainer variant for the XNI-02. These plans, however, were never acted upon due to the advancing Allied troops. Details of these variants are unknown as Punka did not write about them.
Supposed Design
As mentioned before, the XNI-02 Kaméleon is a fictitious jet fighter created by Hungarian author György Punka. All known photos of the XNI-02 are sourced from a model Punka created. Using components from several model kits, Punka was able to create a fairly realistic and convincing model. The XNI-02 model uses a North American P-51B Mustang’s fuselage, a set of the iconic gull wings from the Junkers Ju 87 Stuka (the model also uses the Ju 87’s horizontal stabilizer as an anhedral outer section of the regular wings), the Lockheed P-38 Lightning’s nose, and the BMW 003’s two engine cowls were taken from a Sud Aviation Caravelle passenger jet model. The combination of parts used for this aircraft is attributed to the fact that Hungary was unable to manufacture its own aircraft components. However, parts of the tail and nose were constructed using plastic and wood. In the original article written by Punka, only Stuka parts were mentioned. This could mean that the P-51 fuselage was either taken from captured models or the Hungarians reverse engineered it and indigenously produced them with modifications. The fuselage would have been reinforced with steel plates for protection, though every other part of the aircraft was constructed using wood and plastic.
The XNI-02 would have had space for two crew members, a pilot in the plexiglass cabin and a gunner / radio operator which would be housed in the nose (likely in a prone position). The gunner would be able to remotely control two 12.7x81mm Gebauer GKM 1940.M machine guns located under the nose help from a monitor. (The machine guns are not believed to have been installed on the prototypes.)
The XNI-02 was powered by two BMW 003 turbojet engines given to the Hungarians by the Germans. They are mounted on the rear fuselage on either side accompanied by a slight bulge in the fuselage which would have held the fuel tanks. It would appear that the fuel weight impacted the performance of the XNI-02 but guaranteed an increase in endurance and distance. The exact variant of the engines is unknown. The armaments consisted of two 30x184mm Rheinmetall-Borsig MK 103 autocannons and two remote-controlled 12.7x81mm Gebauer GKM 1940.M machine guns. The MK 103 cannons were mounted in the nose while two Gebauer GKM 1940.M machine guns were envisioned to be mounted under the nose. As an attacker, the XNI-02 prototype theoretically would have been able to mount two 550 lb / 250 kg bombs or four 8.26 in / 21 cm Werfer-Granate 21 rockets under the fuselage or wings.
The production variant of the XNI-02 would have had ejection seats for both crewmen, but this feature was not installed on the prototype. Curiously enough, the original prototype concept would have had a propeller-driven engine, but due to time constraints this experimental concept was not tested and jet engines were mounted right away.
Conclusion
Though the XNI-02 Kaméleon is a fictitious aircraft, the design of it would have been quite modern and advanced, but also unusual and with plenty of quirks that signal it as a fake design. The monitor assisted remote gunner system is an example of this. Though Punka was able to sell a convincing story of the XNI-02 Kaméleon, there are some questionable details which impact the veracity. For one, the fact that the Hungarians would have received BMW 003 turbojet engines in 1944 is quite unrealistic. At that time, German would have likely reserved their resources for use against the Allied forces. The basis of the design, although creative, would have imposed an issue for production facilities. The basis of the design resides on the availability of spare parts from existing aircraft, and if such parts were not available, the XNI-02 would have needed extensive modification to accommodate different parts.
Despite these flaws, Punka’s creation most certainly made an interesting and, to some degree, convincing story which made a great April Fools article. However, not everyone realized that this was, in fact, an April Fools joke and some took this as a real aircraft. This caused many other magazines and websites to write their own articles on the XNI-02, stating that it was a real project. The XNI-02 was even able to convince some Hungarian veterans, which led them to contact each other to see if anyone knew if this was a real project.
Variants
XNI-02 Attacker / Dive Bomber – Attacker variant powered by two BMW 003 turbojet engines. One prototype was built and was destroyed on April 1st of 1945 when Lieutenant R. Taylor of the 385th Fighter Group shot it down during a test flight.
XNI-02 Reconnaissance – Reconnaissance variant of the XNI-02. One incomplete prototype was in construction presumably at the Wiener Neustädter Flugzeugwerke factory in Austria. The prototype was destroyed by the Soviet troops.
XNI-02 Night Fighter – Intended night fighter variant. Details unknown.
XNI-02 Night Bomber – Intended night bomber variant. An IR (Infrared Radiation) bombsight would have been installed in the nose for use by the radio operator / gunner (bombardier in this context).
Operators
Kingdom of Hungary – The XNI-02 Kaméleon was intended for use by the Royal Hungarian Air Force.
Gallery
Credits
Punka, G. (1980, April). XNI-02 “Kaméleon”. Repülés, 17-18.
Austro-Hungarian Empire (1916)
Triplane Bomber Prototype – 1 built
Front view of the Luftkreuzer colorized by Michael Jucan
The Lloyd 40.08 was a prototype triplane bomber built for Austria-Hungary under an order for a new bomber by the Luftfahrtruppen (LFT, Aviation Troops) in 1915. The 40.08 “Luftkreuzer” (Air Cruiser) was a twin boom design that would have carried 200 kg of bombs into battle. The aircraft had frequent problems with its design, such as being front-heavy and the center of gravity being too high. Attempts to fix the issues were minimal and it would never fly. The aircraft was sent to a scrapyard in the end, but it was an interesting venture of a now-defunct empire.
History
World War I showcased the first widespread use of combat airplanes and the subsequent specialization of aircraft to fit certain roles. Bombers proved their effectiveness and most countries involved developed some sort of bomber for their early air forces. One shining example is the Gotha series of bombers, which were able to bomb London and eventually replace Zeppelin raids entirely. The Austro-Hungarian Empire was no exception to building their own bombers. At the time, in 1915, Austria-Hungary was fighting on several fronts, with the ongoing Russian front dragging on and by May, Italy had joined and had begun fighting its neighbor. A new bomber would be a helpful addition to Austria-Hungary’s military.
Direct frontal view of the Luftkreuzer [armedconflict.com]In 1915, the Luftfahrtruppen sent out an order for a 3-engine bomber design. The exact date the order was given in 1915 is unknown, but it is very likely the order was a reaction to Italy joining the war, as similarly, Austria-Hungary attempted to buy Hansa-Brandenburg G.1 bombers to bolster their aircraft complement. The requirement specified that two engines would be mounted inside fuselages and the main engine in a central hull. The bomb payload would be 440 Ibs (200 kg) and defenses would be six machine guns mounted around the aircraft. Expected flying time was up to 6 hours. Given the long flying time, strategic bombing might have been in mind but the bomb load is much smaller compared to other bombers in the role. Tactical bombing would be more practical in the long run for the aircraft. Three companies would submit their designs and would be awarded funding: Oeffag, Phönix, and Lloyd.
Lloyd was one of several aircraft manufacturers in Austria-Hungary. Most of their aircraft that entered production were reconnaissance planes, but they had designed and built several experimental designs as well, some of which had unique and unorthodox designs, such as their FJ 40.05 Reconnaissance/Fighter hybrid. Their bomber design would also verge on to the strange. This would be the only bomber the company would produce. Lloyd came forward with two designs in January of 1916, the Luftkreuzer I and the Luftkreuzer II. The first would eventually be redesignated the 40.08 and the second would be redesignated the 40.10. A complete 40.08 was constructed by June 20th, 1916 and was ready for testing. Given there is no further evidence of work on production examples of the 40.10, it can be assumed the 40.08 was chosen over this design.
Engine testing would shortly begin with the 40.08 at the Aszod Airport. Early testing showed the design was severely flawed. The center of gravity was too high and the aircraft was too front heavy. During ground testing, this problem became clear with the aircraft tipping forward, resulting in damage to the front. A frontal wheel was added to fix this problem, as well as other minor changes. With the modifications completed in Aspern (a section of Vienna), the aircraft was slated to finally take off, with a pilot being assigned to the aircraft. The aircraft would attemp a take off in October of 1916, with Oberleutnant Antal Lányi-Lanczendorfer at the controls. Attempts at flight proved the aircraft was too heavy as well and it would never get truly airborne. A solution came with reducing the bomb load to decrease the takeoff-weight, but at the cost of ordnance.
Little work was done on the aircraft between October and November. In December, large rails were fixed to the bottom of the aircraft, replacing the tailings on the aircraft in February of 1917. With the number of problems the Luftkreuzer faced, it was obvious it would not be possible to improve the plane fast enough for it to have any value on the battlefields of Europe. In March of 1917, all work had stopped on the Luftkreuzer after an attempt to revise the aircraft was denied. The sole Luftkreuzer was sent to storage where it would remain for almost a year. In January of 1918, what was left of the aircraft was taken to an aircraft boneyard and destroyed in Cheb (located in soon to be Czechoslovakia). Thus concludes the story of Austria-Hungary’s attempted triplane bomber.
Austria-Hungary itself wouldn’t survive by the end of the year and would dissolve into Austria and Hungary and new national states such as Czechoslovakia. This wouldn’t be the only bomber built nor used in Austria-Hungary. Several other companies had designed large bombers, but none of these would enter production either. The only bombers that would be operated by the Luftfahrtruppen and see combat would be German and license-built Hansa-Brandenburg G.1s. These were bought in 1916 and would go on a single sortie before being sent to training duty, as they were found to be heavily outdated by the time they arrived on the battlefield. In the end, Austria-Hungary wouldn’t see itself using a mass-produced bomber.
Design
Side view of the Luftkreuzer, notice the absence of a frontal wheel and the side window of the cockpit. [armedconflict.com]The Luftkreuzer was a large triplane, twin-boom design. On the end of each boom, an Austro-Daimler 6-cylinder engine was mounted in tractor configuration (engine faced forward) and ended with a wooden propeller. These propellers did not counter rotate. Each boom itself was a reused fuselage taken from the Lloyd C.II aircraft. Each wing on the aircraft was actually a different length; with the top wing having a 76.3 ft (23.26 m) wingspan, the middle wing with a 73.42 ft (22.38 m) wingspan and the lower wing being 55.2 ft (16.84 m) wingspan. The central wing would be connected to the main fuselage and booms while the upper and lower wings would be connected via struts.
The main hull was rather tall and was one of the causes for why the aircraft was so front heavy and had such a high center of gravity. The cockpit was located beneath the upper wing and had several windows on both sides. The lower extended area was where the bombardier would sit, and was between the middle and lower wings. The central hull also contained the main engine, an Austro-Daimler 12-cylinder water-cooled engine in a pusher configuration. This engine was linked to a wooden two-bladed propeller. The hull was designed in a way so that the gunners would have a clear field of vision. Despite its prototype status, the aircraft was fully marked with the Luftfahrtruppen’s insignia, including one very large symbol painted directly in the front of this aircraft. The Luftkreuzer originally only had two main landing gear legs, with 4 wheels being mounted to each leg. When it was realized the aircraft was front heavy, a 3rd landing gear leg was directly in front of the central hull. No photos exist that show this third landing gear leg.
The armament would consist of 4 machine guns and 440 Ibs (200 kg) of bombs. The bombs would be mounted in the main central hull. The machine guns would most likely be Schwarzloses. These guns would be placed around the airframe, with two being in the central hull and the other two being located in the side hulls. Certain gunner stations would be equipped with a searchlight to aid in night missions. The aircraft was never fully armed before being scrapped, but it is likely it was loaded with bombs or ballast, given that the aircraft had weight issues before taking off and the solution given was to lower the bomb load.
Variants
Lloyd 40.08 – The only version of the aircraft built. Never truly flew.
Operators
Austro-Hungarian Empire– The Lloyd 40.08 was built in and for the Austro-Hungarian Empire’s Lufthahrtruppen, but did not see action.
*Given that the aircraft never truly flew, speed and similar flight statistics were never found.
Lloyd 40.08 Specifications
Wingspan
76 ft 3 in / 23.26 m
Length
31 ft 3 in / 9.6 m
Height
16ft 5 in / 5 m
Wing Area
110.0 ft² / 10.2 m²
Engine
1 × Pusher Austro-Daimler 12-cylinder water cooled engine 300 hp (224 kW)
2 × Tractor Austro-Daimler 6-cylinder inline water-cooled engines 160 hp (120 kW)
Weight
10,670 Ibs / 4840 kg
Endurance
Maximum 6 hours of flight
Crew
4-5
Armament
440 Ibs (200kg) of bombs
4 × 0.315 in (8 mm) Schwarzlose machine guns
Gallery
Lloyd-40.08 Side Profile View by Ed JacksonFrontal shot [dieselpunks.com]
Kingdom of Italy (1935)
Fighter Plane – 774 to 791 Built
Freccia in Italian service. Colorization by Michael Jucan [monochrome-watches.com]During the thirties, Fiat Aviazione was one of the most advanced aircraft manufacturers in Europe. With the advent of new technology at the time, it was obvious that the next stage in the development of the aircraft industry, especially in military aviation, would be centered around all-metal monoplanes. Fiat’s Chief Designer, Ing. C. Rosatelli, had been designing mixed-construction biplanes and even an all-metal bomber. As the demand for a modern, all-metal fighter plane was high, Fiat officials made a decision to hire a young aircraft engineer named Giuseppe Gabrielli, who would later design the Freccia, the first operational Italian all-metal fighter.
Giuseppe Gabrielli’s Work
The history of the Fiat G.50 began in 1931, when Fiat formed a new Aircraft Technical Bureau – Department 2 (Ufficio Tecnico Aviazione – Divisione II). The main purpose of this bureau was designing and building brand new types of modern all-metal planes. The same year, a young Italian engineer, Giuseppe Gabrielli, was hired by Fiat Chairman Senator Angelli to work for the Technical Bureau. Giuseppe Gabrielli had gained some experience in aircraft design while working for Piaggio. When he moved to Fiat, he immediately began working on several non-military aircraft projects. All of his projects were marked by the capital letter ‘G’, his initial. First was the G.2, an all-metal, three-engined plane, then the G.8 biplane trainer, and later the twin-engine passenger plane G.18.
During the thirties, the Italian Ministry of Aviation (Ministero dell Aeronautica) was interested in adopting a new, all-metal monoplane fighter and ground attack aircraft for the Italian Air Force. Some specifications for their request were: to use one radial engine, armed with at least two 0.5 in (12.7 mm) heavy machine guns with at least 300 rounds of ammunition and one 0.7 in (20 mm) gun or 1.45 in (37 mm) gun, and provisions for bombs on the ground attacker. A request was sent out to all domestic aircraft manufacturers. There were several proposals in response, but only the G.50 and the Macchi C.200 would be chosen for production. The others were either rejected (Ro.51 and A.U.T. 18) or built in limited numbers, like the Caproni F.5.
In order to solve the problem of the lack of an adequate fighter design, Fiat officials even considered the acquisition of a license to produce the American Seversky SEV-3, but nothing came of this. In April of 1935, Giuseppe Gabrielli began working on a new low-wing, all-metal plane named G.50. According to his first plans and drawings, it was to be armed with two machine guns, powered by a 550 hp radial engine (with a diameter of 39 in/1 m), weigh around 3,395 lbs (1,540 kg), and equipped with a retractable landing gear. At the same time, Fiat was testing a new FIAT A 74 RC 38 14-cylinder radial piston engine, so it was logical that Giuseppe Gabrielli decided to use it for his work. The A 74, in principle, was a direct copy of the American Pratt & Whitney R-1830 Twin Wasp which powered a large number of US planes, including the Douglas C-47, Consolidated PBY Catalina, Douglas TBD Devastator and Grumman F4F Wildcat. The expected speed of the G.50 with this new engine was around 285 mph (460 km/h) at 11,500 ft (3,500 m).
G.50 prototype (MM.334) during its first test flights. [airwar.ru]On 28th September, 1935, Gabrielli submitted his project to the Ministry of Aviation. Military officials were impressed by the design, but ask for some modifications. These included a wingspan of 36 ft 1 in (11 m), a weight of 4,870 lbs (2,210 kg) and a maximum speed of 280 mph (452 km/h). The offensive armament was changed to two 0.5 in (12.7 mm) heavy machine guns located in the fuselage with an additional two 0.3 in (7.7 mm) machine guns placed in the wings. In addition, the G.50 was designed to carrying a bomb load of 220 lbs (100 kg) or, if needed, extra fuel tanks with 23.5 gal (90 l) capacity.
In January 1936, the Ministry of Aviation changed its original request, choosing instead to focus only on the fighter role. The Ministry of Aviation wanted to accelerate the development of the new fighter, and the proposed ground attack role was rejected. Because of this, the bomb load was deemed no longer necessary, and the main armament was reduced to only two 0.5 in (12.7 mm) machine guns with 150 rounds each. The most important requirement was that the new fighter should have the best possible flying performance.
Despite these changes, the Fiat officials decided to proceed with the G.50 project. As Fiat’s production capacities were overburdened, work on this new project was instead moved to the CMASA works at Marina di Pisa, part of Fiat since 1931. Giuseppe Gabrielli was finishing his last drawings and the list of needed materials and equipment in June 1936. In his final drawings, the armament was reduced to two heavy machine guns without the bomb load, and the plane would be powered by the new A 74 c/n engine.
The production of the first operational prototype was scheduled to begin in late summer of 1936. The prototype was finally ready at the beginning of 1937 and was transported to the city of Turin for further testing. This prototype, under registration number MM 334, made its first test flight on 26th February, 1937. The pilot was Giovanniego De Briganti, the CMASA test pilot. During initial testing, the pilot noted several faults and possible problems with the G.50. He especially pointed out the strong vibrations during flight and the aircraft’s tendency to spin.
On 22nd June, 1937, the G.50 prototype was moved to Marina di Pisa for more testing and modifications. After these modifications were completed, the prototype was sent to the Regia Aeronautica (Italian Air Force) experimental flight center near Rome. There, the G.50 prototype was tested by several army pilots. They noted that the controls were hard to work with at high speeds and a lack of climbing ability. Before the final order for mass production, Giuseppe Gabrielli was asked to solve these problems. For this reason, another prototype was made, designated MM 335.
The second prototype made its first flight on 20th October, 1937. After a series of successful flying tests, an accident occurred. On the 11th (or 8th, depending on the source) November, 1937, while flying the second prototype at high speed, the test pilot Briganti lost control of his aircraft and crashed to the ground. He did not survive the crash. His place was taken by the new chief test pilot, Enzio Guerra.
A G.50 from the 20th Group, front-side view. [wwiivehicles.com]A combination of the accident and inferior performance that did not meet expectations, along with better overall performance of the Macchi C.200 threatened to shut down the G.50 project. But as the CMASA works were already in process of producing a series of 45 G.50’s, it was deemed a waste of resources to abandon or scrap the tooling equipment needed to produced the G.50 that had already been produced. A second reason for keeping the project running was the fact that it would take too much time for Fiat to prepare for the production of the Macchi C.200. The Air Ministry decided to go on with G.50 production, but insisted that the company correct the shortcomings of the plane by the time of production. Of the 45 ordered, the first 11 were used for many more trials. Two planes, MM 3357 and 335, the salvaged and rebuilt prototype, were sent to the experimental centre in Rome. Seven were stationed at the Pisa S.Giusto airfield and tested there. Two more ,MM 3570 and 3571, were tested by pilots Guerra, Rolandi and Cus. These trials were held in Turin and the main purpose was to investigate possible changes to the design of the G.50. The preliminary tests showed that the fully enclosed cockpit had to be changed before production, and a new design was necessary. This enclosed cockpit had several drawbacks which pilots often complained about. The closed cockpit was hard to open (especially in emergency situations), was made of poor quality plexiglass which was prone to cracking, offered poor visibility and sometimes exhaust fumes accumulated in the cockpit so the pilots were forced to fly with an open cockpit. After some testing and modifications, it was decided to used a partially enclosed cockpit. This solution was not perfect and was uncomfortable for pilots. Despite this, it was decided that all future planes would be built with an open cockpit only. More modification that were deemed necessary were the installation of a new start-up system, a better undercarriage locking system and adding a new oxygen mask for piloting at high altitude.
The G.50 was first showed to the public in October of 1937 at the International Aeronautical Show held in Milan. From 1937 to 1940, when the production was changed to the improved version, some 224 G.50 were built.
Technical Characteristics
A G.50 flying alongside a German Bf-110, possibly during the Battle of Britain [Wiki]The G.50 Freccia, Italian for Arrow, was a single-seat, low-wing, all-metal fighter plane. The main fuselage was made from four angular shaped longerons with 17 metal frames. The wing construction consisted of a center section which was made of a steel tube connected to the lower fuselage and two metal spars connected with ribs. The four flaps were hydraulically actuated and at certain speeds they would automatically retract to their closed position. The fuselage, wing, and tail were covered with duralumin sheets. The only fabric-covered parts were the movable control surfaces in the wings and the tail.
This G.50 belonged to the 20th Group, transferred from Belgium to North Africa. [ea51.org]The engine was placed in a tubular shaped mount made of chrome-molybdenum steel that was connected to the fuselage by four bolts. The engine and the cockpit were separated by a fireproof screen in order to protect the pilot from any possible fire outbreak, either due to engine malfunction or damage. The plane was powered by the 840 hp (626 kW) Fiat A 74 RC 38, 14 cylinder radial piston engine. With this engine, the G.50 could reach a maximum speed of 293 mph (470 km/h), with an effective range of 276 mi (445 km) and a service ceiling of 35,000 ft (10,700 m). An all-metal three-blade propeller produced by Fiat was used. One of major disadvantages of using a radial type of engine was the massive drag due to its large cross-section. In order for ground repair crews to have easy access to the engine and the fuselage interior, several access doors were added. The maximum fuel capacity was 83.5 gal (316 l.) There were two fuel tanks located in the wings 11.9 gal each (45 l) and two more in the fuselage, one larger with 26.4 gal (100 l) and a smaller one with 18 gal (68 l) with an additional auxiliary tank 13.75 gal (52 l) also located in the fuselage.
The first G.50 series had an enclosed cockpit design but as this created many issues, it was later changed to an open cockpit. Despite its disadvantages, the enclosed cockpit had an excellent rear view. Many different open cockpit designs were tested before the final design was chosen. The later version with the open cockpit had two smalls door installed to help entering or exiting the plane. The seat was adjustable, so it could be adapted to the pilot’s needs.
In front of the pilot, the dashboard was divided into three sections. On the upper section were the navigation instruments, reflector sight, fuel indicators and engine instruments. The middle section had the ammunition counter, warning lights, the position of the landing gear, compass and oxygen control panel. The lower section had the engine starter, cowling controls and compressed-air system indicator. The radio in the pilot’s cabin was the ARC 1, but the quality of the batteries was poor. A fire extinguisher system was also provided. There was also the possibility of installing one OMI FM62 camera gun.
The G.50 was equipped, like most modern aircraft of the time, with inward retracting landing gear, but the rear tail wheel was fixed. In the G.50 bis version, the rear tail wheel was changed to a retractable type. The landing gear could, if necessary, be manually operated. At first, it was of a Messier type, but it was later replaced with a Magnaghi design. The retracting landing gear was hydraulically operated, and pneumatically during lowering. In case both systems did not work for any reason, it could be manually operated. For easier and more pleasant landing, hydraulic shock absorbers were provided for both telescoping legs.
The main armament consisted of two forward-firing 0.5 in (12.7mm) Breda-SAFAT heavy machine guns, with some 150 rounds of ammunition for each machine gun. The guns were placed behind the engine top and both were synchronised in order not to damage the propeller. It is interesting to note that this gun used oil lubricant for faster firing and thus a lubricant tank was added on top of the engine. Some G.50 planes were armed with bomb racks and used in North Africa.
An Italian armourer rearming a Regia Aeronautica Fiat G.50 with ammunition gun belts at an airfield in Sardinia in June 1942. Source: reddit.com
Modifications and Prototypes
As the war progressed, the Italians realized that they were lacking planes to fulfill the different necessary roles such as fast ground attack or training. In order to save time, the most obvious solution was to try to modify existing models instead of developing new ones. The G.50 would be modified in several ways, some of which demanded major changes to the plane’s design, while others were just minor variations, like the added sand filter for the G.50 S.A.
Trainer G.50 B
The Fiat G.50 B version with the longer cockpit design for the instructor and the student. [alieuomini.it]As the G.50 was entering production and the first operational units were formed, a trainer was needed for new pilots. As most army pilots were accustomed to flying older biplanes, retraining them for flying the monoplanes was required. For this purpose, in late 1936 the Italian Air Ministry placed an order for Fiat to developed a two seat dual control plane based on the G.50. After the mock-up was built and inspected in March 1938, it was deemed sufficient for production. By April, an order for the first prototype was placed. But due to the constant changes to the design, the production of the first prototype was frequently delayed. It was not until June 1939 when the final design with an enclosed cockpit was chosen. The plane was named G.50 B. The capital ‘B’ stands for ‘bipost,’ the Italian word for two-seater. This version was recognizable by its long glazed canopy with the rear cockpit being open from the top. The first prototype, marked 3615, would be ready in late April 1940 when it was tested by Enzio Guerra.
After only a few test flights, it was deemed adequate and was put into production. The first ten were built in 1940, with the last one built in 1943. In total, some 108 (or 100, depending on the source) G.50 B trainers were built during the war. Production by years was: 10 in 1940, 82 in 1941, 11 in 1942 and 5 in 1943.
The first series of G.50 planes produced had an enclosed cockpit design, but this was later replaced with a semi-open design. [warbirdphotographs]The G.50 B was, in essence, a modified single-seat version with a new cockpit and dual controls. The front part of the cockpit was fully enclosed in contrast with the rear which was open. The main armament was removed on the G.50 B. This version was very successful, as it was easy to build and offered almost the same flying performance as the single-seat version.
These were used mostly by the Regia Aeronautica Fighter Schools. Smaller numbers were operated as liaison planes or even in some front based fighter units. After the Italian capitulation, small numbers, possible 20 or more, were used by the National Republican Air Force. At least one was given to the Croatian puppet state in the Balkans. The last G.50 B were used by the Flying School in Lecce for a few years after the war, up to 1948.
The Improved G.50 bis
The final decision for the mass production of the G.50 fighter was not based on its performance, but instead on the fact that CMASA had already begun producing it. The performance of the G.50 was poor compared to the Macchi C.200. In order to justify the production, the Italian Air Force requested that Fiat to improve the G.50’s overall performance. The sought modifications were adding extra fuel tanks, increasing capacity from 83.5 gal (316 l) to around 108.3 gal (410 l), redesigning the rear fuselage and the vertical tail surfaces, better glazing of the cockpit to protect the pilot from air turbulence, the addition of armor plates behind the pilot seat, and the tailwheel to be made retractable. The original ARC 1 radio, with its poor quality batteries, was only changed in October 1941 with the R.B.30.
The new improved version was designated the G.50 bis. According to Italian original plans, the first planes should have been ready by late 1938, but this was never achieved. The whole process was slow and the first aircraft was tested on 13th (or 9th) of September 1940 at Turin. As the main engine was not changed, despite the other modifications, the general flying performance was almost the same. The only improvements were easier maintenance and increased operational range. As these tests were completed, an order for production was given. From 1940 to 1943, around 439 of these versions were built by CMASA and Fiat.
G.50 S.A Ground Attacker
A G.50 somewhere in Africa, where it saw extensive combat action, in many cases as a improvised ground attack plane. [asisbiz]A certain number of planes that were serving in North Africa were modified by adding sand filters and a bomb rack. The landing gear was also modified for easier landing.
G.50 A Ground Attacker
The G.50 A was designed to be used as a fighter-bomber on the “Aquila” aircraft-carrier which was under construction. For this modification, the G.50 B two seater version was reused. The main offensive armament was to be increased to four 0.5 in (12.7 mm) machine guns. The problem was that the wing design did not allow the installation of the new weapons directly in the wings. The solution was to increase a part of the central section of the wings in order to accommodate these guns. Additional bomb racks were also to be added. One prototype, serial number MM 8595, was built and tested in October 1942. The whole concept proved to be problematic and the project was abandoned. The prototype would be used up to 1943 in testing new wing designs. In some sources, this model is designated as G.50 A/N.
G.50 bis “Tuffo” Dive Bomber
This was a dive bomber version designed in 1941 and 42, possibly inspired by the famous German Ju-87 “Stuka.” A bomb load of up to 990 lbs (450 kg) was planned, with two 200 lbs (100 kg) bombs placed under the wings and one 550 lbs (250 kg) under the main fuselage. For this modification, the addition of dive brakes were necessary. There is no information about prototype construction, but there is a great chance that it was never made.
G.50 B Naval Observer
One plane (MM 6548) was rebuilt for a naval observation role in 1943. It had a larger tail, different wing sections, a camera and an arrestor hook for use on an aircraft carrier. It was also equipped with a B 30T transmitter, B.G.42 direction finder and a A.R.18 receiver. Only one was built, possibly because of the impending Italian capitulation.
G.50 O/R
This version was based on the G.50 bis and the only difference was the installation of a arrestor hook for aircraft carrier use. Around 16 planes were modified for this role and were in use by the 155th Group Autonomo, mostly for training, in 1943.
Other Projects
Beside these, there were some minor projects that were proposed, but the majority if not all of them were not implemented. On the base of the G.50 B some project were proposed like the: night fighter, land reconnaissance or even a floatplane fighter (G.50 Idro).
Prototypes based on the G.50
During the war, in order to improve the flying performance of the G.50, many new designs and weapon loads and engines were tested.
G.50 ter
This was a further development of the canceled G.52 project. The new project, designated the ‘G.50 ter,’ was to be equipped with the same 1000 hp (746 kW) Fiat A 76 engine as the G.52. Even before production of a prototype, the new engine was found to have a number of flaws. The first prototype powered by the new engine was ready by late July 1941. First flying tests were carried out at the Aeritalia airfield, with the plane being piloted by Agostini. During these flight tests, the engine proved to be mechanically unreliable and it could not reach expected performance. More test were held in November 1941, but in the end the project was canceled and only one plane was built.
G.50 V
The G.50 V prototype, powered by a new German engine. Even though this design solved the aerodynamic problems, it was never put into production. [Pinterest]In late 1939, the Italian Ministry of Aviation made a decision to begin negotiations with the German Daimler-Benz company for a production license of the newest liquid cooled DB 601A engine (1035 hp). It had a much lower frontal area and had much better aerodynamics than the larger Italian radial engines. The license was eventually obtained and Alfa Romeo was put in charge of the production of this engine, but it was never built in any great numbers.
In early 1940, the Italian Ministry of Aviation asked Fiat to build a modified version of the G.50 using this new engine. Two prototypes were to be built by CMASA, and these were marked as G.50 V (the ‘V’ stand for Veloce, which means fast). The first prototype, serial number MM 479, was built and tested in late August 1941 by the test pilot Ezio Guerra. Immediately, the new design proved to have some issues, such as an inefficient engine cooling system and the controls being difficult to operate. By the end of 1941, most these problems were solved and a new series of tests was scheduled.
In December 1941, more extensive flight tests were carried out by test pilot Valentino Cus in order to determine the precise flight performance, in particular the maximum speeds at various heights and the climbing rate. Maximum speed achieved was some 360 mph (580 km/h), and a maximum altitude of 16,400 ft (5,000 m) was reached in 5 minutes and 30 seconds. Mostly due to the introduction of the new FIAT G.55 and the lack of DB 601 engines, the G.50 V project abandoned.
G.51
In 1940, it was proposed to equip one G.50 with the new A 75 R engine. Nothing came of this project.
G.52
Information about this version differs significantly depending on the source.
According to Piero Vergnano, Fiat worked on improving the performance of the A 74 engine used on the G.50 for quite some time. This lead to the development of the new 1000 hp (746 kW) Fiat A 76 engine. In 1938, Fiat suggested the installation of this engine in the G.50 to the Air Ministry. At first, the request was accepted and an order for two prototypes was placed. By late 1939, the project was canceled due to the acquisition of new German DB 601A engines, and no prototypes were ever built. According to Gianni Cattaneo, the G.52 was in fact just a further development of the G.50 V. Due to the appearance of the new G.55 fighter, this project was abandoned.
G.53
This proposal was a combination of the G.50 B powered by the DB 601A engine. It was developed in 1941. It was intended to be used as a fast reconnaissance plane, but the Air Ministry never showed any interest in this proposal and nothing came of it.
First Operational Units
As CMASA began producing the first G.50 planes in late 1938, an experimental military fighter unit was formed for further testing and training. This unit was located at the Ciampino airfield near Rome. The unit was named Gruppo Sperimentale da Caccia (Experimental Fighter Unit/Group). Command of this new unit was given to Major Mario Bonzano, at that time a famous pilot ace from the Spanish Civil War (flying the CR.32 biplane). Pilot training on this new plane lasted until January 1939, when the Italian Air Force High Command decided to send a unit of 12 planes to Spain for real combat testing.
In Spain
A group of 12 new G.50 fighters arrived in January 1939 in Spain, having been transported by sea. This unit was based at Escalona Airport, some 43.5 mi (70 km) from the capital of Madrid. Starting in March, this unit carried out flight patrols and fighter cover missions for bombers at altitudes between 24,600 to 26,240 ft (7,500 to 8,000 m). By that time, the opposing air force had been almost destroyed and air to air combat was rare. The only combat action that was recorded happened when a lone Soviet-built I-16, possibly flown by a Canadian pilot by the name of Dickinson, was intercepted by a G.50. The Italian aircraft was damaged and the pilot was forced to land. None of the 12 G.50 that were sent were lost in combat during the Spanish Civil War. At the end of this war, 11 operational G.50 fighters were given to the new Spanish fascist regime. These planes were used by the 27 Gruppo Caza (Fighter Group). After 1943, they were sent to Spanish Morocco, to be used by the 2. Regimento Mixto (mixed regiment) together with several German supplied He-112B.
A small number of G.50 fighters were used in the Spanish Civil War. Their combat operations were minimal and all were gifted to the new Spanish state. [Wiki]After his return to Italy, Major Bonzano made his report of the effectiveness of the G.50. According to him, the G.50 had good maneuverability, effective armament and was easy to operate at altitude. On the other hand, he pointed out that the visibility was poor and the landing gear construction was weak and prone to malfunctioning. His conclusion about the effectiveness of the main armament would prove to have a great negative impact for the G.50 in the future.
In Finnish Service
Finnish G.50 on the airfield. [ww2aircraft.net]Because of the likelihood of a Soviet attack in 1939, the Finnish government and Army wanted to equip their forces with modern equipment and weapons. As a result, a Finnish military delegation visited Turin in 1939, where the new G.50 fighters were being tested. The delegation was impressed with the aircraft’s performance, so they placed an order for 35 brand new G.50. Most of the planes sold were of the first series produced by CMASA, with serial numbers 3599 to 3614. These were supplemented by planes from the second productions series (serial numbers 4722 to 4750).
A very interesting fact is the maximum speed achieved by Finnish pilot Tapani Harmaja. As he was testing the flying performance of the G.50 at an airfield near Latina, he managed to reach a speed of 515 mph (830 km/h). He achieved this by diving from a high altitude of 11,480 ft (3,500 m) down to 1,310 ft (400 m). This was the fastest speed reached by any aircraft in Italy at that time.
Due to the outbreak of the Second World War in Europe, the transportation of the purchased aircraft was slow and complicated. The planes were disassembled and then transported by train through Italy to the north of Germany and then by ship to Sweden, and from there to Finland. As they were transported in parts, the assembly was done at Gothenburg. When they were completed, the pilots were instructed to fly them to their new stations. The first 14 G.50’s were received in February 1940 and the last in June 1940. While flying en route to their designated airfields, two planes were lost in accidents in February 1940.
The G.50 arrived too late to have any large impact on the Winter War (30 Nov. 1939 to 13 Mar. 1940) but they saw some combat during this period. The first G.50 planes were equipped with the 26th Fighter Wing (Lentolaivue 26 or just simply LeLv or HLeLv) located at Haukkajarvi. They were used to replace the older Gloster Gladiators used by this unit. By 13 March, the Finnish pilots flying the G.50 claimed to have shot down 11 Soviet planes. There is some disagreement between the sources, authors Gianni C. and David M. states that this unit did not participate in the Winter War.
Finland operated 35 G.50s during the war. Most saw extensive service during the Continuation War when, despite their obsolescence, they proved to be effective in the hands of Finnish pilots. [Wiki]Until the German and Finnish attack on the Soviet Union in June 1941, known in Finland as The Continuation War, Finnish technicians and engineers tried to improve the performance of the G.50 fighters. Most Finnish G.50s were from the first series, equipped with the enclosed cockpit. This design was not popular with the Finnish pilots and was replaced with an open cockpit. The vertical stabilizer and rudders were replaced with improved ones. Also, the Finnish tested snow skis taken from Fokker D.XXI’s, for the G.50 allowing them to better land on on frozen airstrips.
At the start of the German invasion of the Soviet Union in 1941, Finland joined the war with a much larger air force than it had in the previous conflict. LeLv 26 was stationed at an airfield near Utti, and was charged with the protection of the area around Lake Ladoga where they saw most of the action they were involved in. The G.50 proved to be an effective fighter in the hands of Finnish pilots. On 25th June 1941, six Finnish G.50 fighters managed to shoot down 10 Soviet bombers with no losses. Later in August, pilots from LeLv 26 managed to shoot down nine Soviet fighters. The most famous Finnish pilot was Oiva Tuominen, who had a total of 23 (33 or 43 according to different sources) air victories, with around 15 while flying the G.50. For his service, he was awarded the Mannerheim Cross, the highest Finnish military medal at the time. By the war’s end, LeLv 26 had around 88 air victories with the loss of 11 G.50s. Only two were shot down by Soviet planes, one was lost to AA fire, and eight more were lost either to accidents or mechanical failures. The Finnish G.50s remained in use up to June 1944, when they were moved to the rear for second-line duties. By the end of the war, there were still some 22 (the exact numbers are not known) operational G.50 fighters and they were used up to 1947.
In Italian Service
Fiat G-50 “1-3” of the 1 Experimental Group in Escalona, in March 1939
According to the Italian military program codenamed “R” (Programme R), the Italian Air Force was to be heavily reinforced with many new units and more modern aircraft designs. With the existing G.50 fighter, it was planned to form and equip one Stormo (Stormo-regiment) and one Fighter Wing/Group (Gruppo).
The first unit to receive the new G.50s was 51° Stormo located at the Ciampino airport near Rome, in November 1939. This regiment consisted of the 20th Group, with 351st, 352nd and 353rd Squadrons, and the 21st Group, with 354th, 355th and 356th Squadrons. Almost all of the squadrons were equipped with the newer G.50 with the open cockpit, and only the 351st Squadron was equipped with the first series with the enclosed cockpits. To more effectively train both experienced and new pilots, military war game exercises were often held by the Italian Army. During one of these games the 51° Stormo would earn its military emblem, a black cat with a green mouse. During one exercises, a group of different fighter planes were tasked with intercepting a group of S.M.79 bombers, marked with the green mouse emblem. The older CR.32 biplane could not fulfill this task, but the new G.50 from the 352nd Squadron accomplished this without any problem. From that point on, the pilots from 51° Stormo began painting the emblem on their planes.
Quite soon, the order was given to form a second unit, 52° Stormo. It consisted of the 22nd Group (357th, 358th and 359th Squadrons) and the 24th Group (360th, 361st and 362nd Squadrons). The 24th Group was equipped with older FIAT CR.32 planes that were soon to be replaced with G.50’s. 52° Stormo operated from two airports, Pontendera and Sarzana. Both of these groups had around 100 brand new G.50s.
Western Front
By the time Italy entered the War in the West, there were some 118 G.50 planes on hand, with 97 operational, and some 21 were ready for delivery to designated units. In an attempt to profit from the fast Allied defeat in Western Europe, Italy declared war on France on the 10th of June 1940. Most G.50s saw some limited action, mostly covering SM.79 bombers during their attack on Corsica on 15th and 16th June. Subsequent attacks followed on 17th and 19th June. The center of operations then moved to the north, in the French Alps on 21st June. Due to a lack of proper training, the G.50 pilots had problems adapting to this type of aircraft, as most of them had flown only on the older biplanes. The G.50 proved to have good flying performance at low speeds, but was hard to control at high altitudes and higher speeds.
Battle for Britain
In order to support the German air raids on Great Britain, a special unit (Corpo Aereo Italiano C.A.I) was formed in late 1940 and was sent to Belgium. For this operation, the 20th Group, with 45-48 G.50’s, was selected under the command of Col. Bonzano. Despite the original planes being planned to reach their base of operations in Belgium by September 1940, this was delayed until October 1940. This delay occurred mostly due to bad weather. During the transfer from Italy to Belgium, two G.50’s were lost to accidents. The first combat actions were carried out in late October 1940, and were mostly bomber support missions. Similar missions were planned for 11th November against Great Yarmount, but they were canceled due to bad weather. From November 1940 to January 1941, the G.50 flew on many surveillance missions but there was no contact with enemy planes. By the end of January 1941, most Italian Air Force units returned home, with the exception of the 20th Group.
The C.A.I had great technical problems during this operation. The G.50 was designed for the Mediterranean rather than the cold climate of the North, and there were problems with freezing and defective instruments, unreliable batteries and fuel problems.
By April 1941, the remaining units were ordered to return to Italy. Missions conducted against Britain were unsuccessful and they did not go well for the Italian pilots, as they did not win any air victories. Italy had lost more than six aircraft with two dead pilots. This operation was a strategic failure for the Italian Air Force, mostly due to poor planning, adverse weather conditions and inefficiency of the planes used.
In the Balkans
Mussolini ordered an invasion of Greece in October 1940. For that purpose, fewer than 80 G.50 fighters based in Southern Italy (33) and occupied Albania (43) were used. Initially, because of the lack Greek air resistance, the G.50 were used as ground attack planes. But, after the arrival of the British forces in November, the first air battles started. Due to the fact that the Italian pilots had some experience during the Spanish Civil War, they managed to achieve some successes against the British. The G.50’s main opponent was the Gloster Gladiator, which had poorer flying performance in comparison. Later, however, more modern Hurricanes appeared, which were much more advanced than the G.50.
During the war in Greece, there were a number of engagements between the British and the Italian Air Forces. During one dogfight on 20th February 1941, some 10, possibly even 12, British planes were shot down in a single engagement by a group of 22 G.50s. The Italians only lost one plane. However, during the same day, British Hurricanes managed to shoot down four G.50s in a different engagement. On the 28th of February 1941, some 12 British planes were shot down at the loss of 27 Italian aircraft. In one unusual case, a collision took place between a G.50 and a Gladiator. Because of the heavy damage, the Gladiator crashed to the ground, while the pilot of the G.50, despite the damage received, managed to fly about 123 mi (200 km) back to his home base and safely land. Due to significant disagreements among sources, there is no accurate data on the losses of both sides. As the G.50 proved to be inferior to the Hurricane, they were gradually replaced with the more advanced Macchi C.200 planes.
During the attack on Yugoslavia, the so-called “April War” in April 1941, the G.50 were used in escort missions. There were very few air battles and, by 17th April, the war was over.
In the Mediterranean and North Africa
During the North African campaign, the first G.50s were stationed near Tripoli by the end of 1940 and early 1941. The first units to operate in Africa were the 151st, 152nd and 358th Squadrons with around 76 to 80 planes. Even before these units saw any action, there were great problems with the maintenance of these planes due to sand. Taking into account that North Africa is dominated by the Sahara desert, it is very strange that the Italian military leaders did not take into account the fact that the desert sand could affect the plane’s engine. Since a certain number of planes were taken out of action by this, the demand for special sand filters was high. There were also problems with the sand getting into the landing gear which caused issues. To solve these problems, the Air Ministry urged CMASA and Aeritalia to provide adequate sand filters and modify the landing gear. The G.50 planes modified in such a way were marked as G.50 A.S (A.S standing for Africa Sahariana).
The G.50 saw heavy fighting in North Africa. Depending on the combat situation, it was used in a standard fighter role, for ground attack, defence missions, or for bomber escort. As the war progressed, the G.50 was mostly used in a ground attack role by equipping them with a 220 lbs (100 kg) bomb load to increase its offensive armament. For this purpose, 50° Stormo was formed. 50° Stormo mostly operated around the Sidi Barrani sector, where it attained some success against the British P-40 and Hurricanes. The pilot Bovoli (from 50° Stormo) shot down six British Blenheim bombers in July 1941.
During 1941 and early 1942, despite reinforcements, G.50 losses were increasing. At the beginning of 1941 there were only 20 planes operational, but with reinforcements the number increased to 80 in October and then fell down to 35 in December 1941. Most planes were lost not in air combat but instead during enemy ground and air attacks on airfields, as well as accidents. For example, the 20th group suffered heavy losses when 18 G.50 were destroyed as British armored forces attacked the airfield at Martubi on 19th November 1941. By the end of 1941, the only unit operating the G.50 was the 12th Group stationed at Tripoli. By 1942, most G.50 fighters were either lost or replaced with more modern Macchi C.200 and C.202. The surviving G.50s were relocated to second line airfields in Sardinia (24th Group), Greece (151 Group) and in the Aegean (154th Group). By the time of the Axis defeat in Africa (1943), only the 358th Squadron was still using the G.50.
Despite having poorer flying performance than its main opponents, the P-40 and the Hurricane, the G.50 proved to be a formidable plane in the right hands. The G.50 also proved capable in its new role as a ground attack plane, in which it destroyed a large number of enemy planes on the ground.
The Last Stand
The 20th Group’s emblem, a black cat hunting green mice. [ea51.org]After late 1942, the remaining G.50 fighters that were stationed in Italy serving as trainers and for second line operations. After the defeat in Northern Africa, the Italian army was in disarray and the rapid Allied landing in Sicily in July of 1943 worsened the situation. Many surviving G.50s were used to equip the 158th and 159th Groups. These two groups suffered heavy losses attacking strong Allied positions in Sicily. In a period of only a few days, the two groups ceased to exist.
After Sicily, the Allies landed on the Italian mainland and, on 8th September 1943, Italy capitulated. By that time, there were only around 40 to 48 G.50 airplanes still in service, of which only 17 were operational. A small number of G.50 were used by the new National Republican Air Force (Aeronautica Nazionale Repubblicana/ANR) in Northern Italy until the end of WW2 as second line and training planes. A few were even used by the Italian Co-Belligerent Air Force (Aviazione Cobelligerante Italiana, or ACI) in the southern part of Italy, which had switched over to the Allied side.
In NDH Service
In the middle of 1942, in exchange for raw resources and materials, Italy delivered 10 G.50 (9 single seat and one two-seat trainer) airplanes to the NDH, the independent state of Croatia Air Force (reg. number 3501-3510). These were not newly produced planes, but instead G.50s that returned from the front and were repaired. The planes that were supplied were used alongside French-built MS.406 fighters supplied by the Germans. In 1944, six more airplanes were obtained from Italy, now under German control (reg. number 5686, 5965 and 06186, the rest are unknown) bringing the total number used to around 16 planes, possibly more as the exact numbers are not known. According to Tihomir T. and Darko Č. NDH forces acquired three G.50, after the withdrawal of Italian forces in 1943.
Their participation in the war was negligible and they saw little if any action. On 15th September 1944, only 7 were reported, with none fully operational for service. There were several cases of desertion among Croatian pilots while flying the G.50. On 2nd September 1944, pilot Andrija Arapović escaped to the island of Vis, under the control of the Yugoslav communist Partisans. A second pilot flying a G.50 fled to the Allies stationed in Italy.
Partisan forces put the captured G.50 to use during the war and it would remain in service up to 1946. An interesting fact about Andrija Arapović’s G.50 aircraft (reg. number 3505) is that it still exists today and can be seen in the Belgrade Military Aviation museum near the airport “Nikola Tesla” in Serbia. This is the only surviving example of a G.50 in the whole world, but it is in very bad condition and has been under restoration for years. By the end of the war, the Yugoslav Partisans had captured almost all of the surviving G.50s in Croatian service, but their use was limited due to a lack of spare parts.
G.50 production attempts in China
Italians were for some time trying to negotiate with Chinese authorities about opening an aviation production factory in China. After initial negotiations in June 1934, the Chinese signed a contract with the Aeronautico Italiano per la China (Aerocina). This company was owned by the Italian Government in conjunction with Caproni, Breda, Fiat and SIAI. According to this contract, the Italians were to build the SINAW (Sino-Italian National Aircraft Works) factory in Nanchang. With this agreement, the Italians were to provide tools and machines necessary for the factory to work. The head of the soon-to-be factory was the Italian Luigi Acampora and the Director was General Chu Lin. The production of the first operational aircraft was to begin from July 1937 on and all Italian personnel were to return to Italy after five years of cooperation.
The SINAW officially started production in November 1936 with six Savoia-Marchetti SM.81B bombers. Future plans included production of 30 Breda Ba.65s and 50 Fiat G.50s. The factory was slightly damaged during the Japanese bombing of Nanchang on the 20th October 1937. By November the Italian Government made a decision to discontinue any further cooperation and stopped all future deliveries of equipment and materials. This was done mostly due to Japanese military actions and the poor cooperation of the Chinese. By early December 1937, all Italian personnel returned home, and the deal with the Chinese was abandoned without a single G.50 being built.
Production and Variants
Besides the few prototype planes, a total of 791 (source Piero V.) G.50 and its variants were built during the war. Other authors give different numbers, according to Chris B. some 774 were produced and author Gianni C. quotes the figure of 778 planes. Author Duško N. give a figure of 788 planes.
The production of the G.50 fighter began in 1937 and ended in 1940, with a total 244 planes. The production totals by years were: two prototypes in 1937, 14 planes in 1938, 75 in 1939 and 153 in 1940. The improved G.50 bis was produced from 1940 to 1943 with a total of 439 planes built (421 according to some sources). 71 planes were built in 1940, some 253 in 1941, 113 in 1942 and the last 2 were built in 1943. If we compare these production numbers with other modern fighters of the time, the G.50 was built in relatively small numbers. The G.50 and its modifications and prototypes were produced by CMASA and Fiat during the war.
Conclusion
The Fiat G.50 was the first Italian all-metal fighter plane to enter operational service in significant numbers. In the early stages of the war, it proved to be an effective fighter, but as the war progressed, it became obvious that it was outdated in comparison with other modern fighters like the Hurricane. The G.50 was easy to control at lower speeds and had good maneuverability. The negative side was the lack of engine power and the overall design of the radial engine which affected the aerodynamics of the G.50. There were problems with cockpit visibility, but the most notorious issue was the lack of effective offensive armament, which consisted of only two heavy machine guns. Despite all this, with a good pilot the G.50 proved that it could be an effective fighter and it was responsible of downing of a significant number of Allied planes during the war.
G.50 prototype – Two prototypes built, the second was lost in an accident.
G.50 – Production aircraft.
G.50 bis – Improved version.
G.50 A.S – A number of G.50 planes that were used in North Africa were modified with sand filters and improved landing gear.
G.50 A – One plane was modified with an increased offensive armament of four 12.7 mm machine guns in October 1942. Only one was constructed and used up to 1943 for testing different wing designs.
G.50 B – Two-seat trainer version, around 100 to 108 built.
G.50 bis “Tuffo”– Dive bomber version, none built.
G.50 B naval observation – One G.50 was modified to be used by the Italian Navy in 1943.
G.50 O/R – Based on the G.50 bis, some 16 were built and used for training in 1943.
Prototypes:
G.50 ter – Equipped with a stronger 1000 hp (746 kW) FIAT A.76 engine, only one built.
G.51– In 1940, it was proposed to equip one G.50 with the new A 75 R.C.53 engine, none built.
G.52 – Proposed project, none built.
G.50 V– Equipped with a German Daimler-Benz DB 601 engine, one built.
G.53 – Proposed project based on the G.50 B and powered by the DB 601, none built.
Operators
Kingdom of Italy – Operated around 720 G.50 aircraft, starting from the Spanish Civil War until the Italian Armistice.
Croatia (NDH) – Used at least 16 G.50 aircraft during the war (supplied by the Italians and Germans).
Finland – Operated 35 G.50’s during the Winter War and the Continuation War.
FascistSpain – Used some aircraft given to them by the Italians at the end of the Spanish Civil War and after.
SFR Yugoslavia – Captured some G.50 fighters from NDH during the war. Their use was very limited.
National Republican Air Force (Aeronautica Nazionale Repubblicana/ANR) – Operated a small number of G.50s, mostly as trainers.
Co-Belligerent Air Force (Aviazione Cobelligerante Italiana, or ACI) – Operated limited numbers.
Nazi Germany – A few were captured and saw limited use with the Luftwaffe.
China – There were plans to produce 50 G.50 aircraft in China but nothing came of this.
G.50 Freccia Specifications
Wingspan
35 ft 11 in / 10.9 m
Length
26 ft 3 in / 8 m
Height
10 ft 7 in / 3.28 m
Wing Area
196.5 ft² / 18.25 m²
Engine
One 840 hp (626 kW) Fiat A.74 RC.38, 14 cylinder radial piston
Empty Weight
4,353 lbs / 1,975 kg
Maximum Takeoff Weight
5,324 lbs / 2,415 kg
Fuel Capacity
316 l
Maximum Speed
292 mph / 470 km/h
Range
267 mi / 445 km
Maximum Service Ceiling
35,100 ft (10,700 m)
Climb speed
Climb to 19,700 ft (6,000 m) in 7 minutes and 30 seconds
Fiat G.50 PrototypeFiat G.50 “1-1” belonging to Mario Bonzano in SpainG.50 MM4743 in Finnish ServiceG.50 bis in Croatian Service circa 1941G.50 B MM6137 in Luftwaffe Service
A G.50 from the 351st squadron in flight somewhere in Italy in January of 1941. [alieuomini.it]Freccia in Italian service [monochrome-watches.com]Side view of two G.50s, probably in Africa. [warbirdphotographs]
The Germans managed to capture a small numbers of surviving G.50s, but their use was limited. [warbirdphotographs]The NDH received around 16 G.50 (with one G.50 B) planes during the war, but their use was very limited. [Asisbiz]
Credits
Nešić, D. (2008). Naoružanje Drugog Svetsko Rata-Italija. Beograd.
Gianni Cattaneo, The Fiat G.50, Profile Publications number 188
Piero Verganano (1997), Fiat G.50,, La Bancarella Aeronautica – Torino.
Nazi Germany (1945)
Rocket Interceptor Trainer – 1 Built
A rear 3/4 view of the Soviet captured “White 94” Me 163S. Colorization by Michael Jucan [Yefim Gordon]The Messerschmitt Me 163S (Schulflugzeug / Training Aircraft) Habicht (Hawk) was an unarmed two-seat training glider based off of the famous Messerschmitt Me 163 Komet. Originally designed for the purpose of training novice pilots for landing, the Habicht ultimately never saw active service with the Germans and only a single example was produced through the conversion of a serial Me 163B-1. With the sole example captured by the Russians after the war, the Habicht underwent extensive testing by the Soviet Air Force which helped them understand the flying characteristics of the Komet and prepared Soviet pilots for flying the powered Komets. The Habicht undoubtedly played a part in helping Soviet engineers understand the Komet and thus played a part in the future development of Soviet rocket aircraft.
History
A closeup view of the Me 163S showing the right wing. [Yefim Gordon]The Messerschmitt Me 163 Komet was one of Nazi Germany’s most famous aircraft produced during the Second World War. Although bearing the title of the world’s first mass-produced rocket-powered interceptor, the Komet did have its fair share of flaws, such as the volatile and sometimes dangerous Walter HWK 109-509 rocket engine, which prevented it from becoming an effective weapon against the Allies.
As the Komet was designed to have a limited amount of fuel to engage Allied bombers, pilots were expected to glide the Komet back to friendly airfields once they disengaged from combat. With gliding landings as a potential problem for the less experienced pilots, one of the ideas proposed by Messerschmitt designers in 1944 was to introduce a dedicated trainer variant of the Komet which would have a student pilot accompanied by an instructor pilot. Designated as the Messerschmitt Me 163S (Schulflugzeug / Training Aircraft) Habicht, the trainer glider differed from the production model with the addition of an instructor’s cockpit behind the forward cockpit. This addition was accompanied by the removal of the Walter HWK 109-509 rocket engine and the Habicht would have to be towed by another aircraft in order to get airborne. Another interesting addition to the Habicht was a second liquid tank behind the instructor’s cockpit for counterbalancing. All the liquid tanks would be filled with water for weight simulation and ballast. A total of twelve examples were planned for production, but only one was produced due to wartime production constraints.
The sole example of the Habicht was built by converting an earlier Me 163B-1 production model. Due to the scarcity of information regarding the Me 163S, it is unknown exactly when the Habicht was produced and what sort of testing it may have undergone during German possession. However, it is known that the Soviet Union was able to capture the only example during the final stages of the World War II’s Eastern Front. The sole Habicht was sent to the Soviet Union along with three Me 163B Komets during the Summer of 1945 for thorough inspection and testing. In historian Yefim Gordon’s book “Soviet Rocket Fighters – Red Star Volume 30”, he claims that in addition to the three Komets, seven Habicht trainer models were also captured. This, however, remains quite dubious as there is no evidence that more than one Habicht existed, and all current photographic material, research materials, and books all suggest that only a single example was produced.
The Me 163S in simulated flight configuration aided by struts. [Yefim Gordon]As the Soviets were particularly interested in rocket propulsion aircraft, the State Defence Committee issued a resolution which called for the thorough examination of the Walter 109-509 jet engine and the Me 163 Komet along with captured German documents on rocket propulsion. The three Me 163B Komets, of which only one was airworthy, and the Me 163S Habicht were sent to the Flight Research Institute (LII), the Valeriy P. Chkalov Soviet Air Force State Research Institute (GK NII VSS), and the Central Aerohydrodynamic Institute (TsAGI). The Habicht and Komets saw extensive testing in Soviet hands, undergoing several structural, static and wind tunnel tests. During the initial flight testing period, the Komet only flew as a glider as Soviet pilots and engineers were unsure of whether or not the Walter rocket engine was ready for use since bench tests were not completed. Securing the T-Stoff and C-Stoff propellants for the rocket engine was also a problem. In order to understand the handling characteristics of the Komet, the Habicht was flown numerous times at different altitudes, as was the unpowered Komet. A Tupolev Tu-2 bomber was responsible for towing the Habicht to these altitudes. Under Soviet ownership, the Habicht was given the nickname of “Карась” (Karas / Crucian Carp) due to the glider’s distinct silhouette. The test pilot responsible for flying the Habicht was Mark Lazarevich Gallaj. In general, the Habicht was considered relatively easy to handle by the Soviet test pilots. It is unknown how many test flights the Habicht underwent, but the aircraft certainly aided Soviet pilots in understanding the handling characteristics of the Komet. The Habicht’s service came to an end once the Soviet state trials of the Komet concluded. The sole example was scrapped sometime in 1946, along with seemingly all the other Komets.
If the Me 163S was able to be mass produced and flown with the Luftwaffe, the aircraft would have been a valuable tool to train German pilots. Landing the Komet was a problem for some pilots and in some cases resulted in fatalities but, with the use of the Habicht, the number of accidents would have certainly decreased.
Design
The Me 163S hung upside down in an unspecified TsAGI workshop for static testing. [Yefim Gordon]The Messerschmitt Me 163S Habicht was a semi-monocoque aluminum based two-seat training glider developed off the standard tailless Messerschmitt Me 163B-1 Komet. The sole example was converted from a production Komet, which meant dramatic modifications had to be made to the aircraft. The Walther HWK 109-509 rocket engine was removed and in its place was a cockpit for an instructor. The fuel tanks in the airframe were all filled with water to simulate fuel weight while another water tank was added behind the instructor’s cockpit for ballast purposes. There was no armament fitted to the glider. There was a small transparent section between the student pilot’s cockpit and the instructor pilot’s cockpit, presumably for the purpose of communication. As there are no known German documents on the Habicht and Russian documents are scarce, not much is known on the other differences the Habicht may have had. Detailed specifications of the Habicht are unknown, but theoretically it should have been identical to the standard Me 163B-1 Komet except for possibly weight, air drag and center of gravity.
Operators
Nazi Germany – The intended operator and producer of the Me 163S Habicht.
Soviet Union – The main operator of the Me 163S Habicht. A single Habicht was captured and tested by the Soviets after the war. The Habicht was scrapped in 1946.
*Editor’s note: As noted above, the exact specifications of the Me 163S Habicht are unknown. However they are presumed to be similar to that of the Me 163B-1 Komet.
Me 163S Habicht “White 94” in Russian Service [Haryo Panji]Me 163S Habicht in German Service [Haryo Panji]
Now known as the “White 94”, the Me 163S sits idly by. [Yefim Gordon]A closeup view of the Me 163S showing the transparent section between the two cockpits. [Yefim Gordon]The Me 163S in simulated flight configuration aided by struts. [Yefim Gordon]A top down view of the “White 94” Me 163S. [Yefim Gordon]A photo of the “White 94” Me 163S in flight being towed by a presumed Tupolev Tu-2. The pilot in the photo is likely Mark L. Gallaj. [Yefim Gordon]The Me 163S inside TsAGI’s T-101 wind tunnel for testing. The struts support the Habicht and simulate its flight configuration. [Yefim Gordon]An alternate closeup view of the Me 163S during static tests. [Yefim Gordon]
Yet another inverted static test, but this time the tail wheel strut and tire were removed from the Me 163S. [Yefim Gordon]
USSR (1946)
United Kingdom (1944)
United States of America (1945)
People’s Republic of China (1958)
Kingdom of Hungary (1944)
Austro-Hungarian Empire (1916)
Kingdom of Italy (1935)
Nazi Germany (1945)
