Lavochkin La-5 Vol. I

Lavochkin La-5 Vol. I

The history of the design and development of Lavochkin fighter aircraft powered by radial engines is inextricably linked with two factors: the more or less flawed decision-making by the authorities regarding the development of the new generation of fighters, and the development of high-powered radials, which itself wasn’t exactly plain sailing.

There were also intrigues, behind-the-scenes bickering and a ruthless struggle for influence, all part-and-parcel of the history of Soviet aviation of that period.
While in the early and mid-1930s, the Soviet aviation experienced a period of rapid development, on the eve of the war it was quickly descending into a crisis. One of the most important reasons for this was the fact that the Polikarpov I-16 aircraft, the backbone of the Soviet fighter force, had become obsolete and the single-row, nine-cylinder radial engines (M-25, M-62 and M-63), powering I-15, I-16 and I-153 fighters, offered no more room for further development or upgrades. At that time, water-cooled inline engines, such as the German DB-601 and many others, achieved a similar power output of 1,000-1,100 hp, but had a much smaller cross-section, which ensured better aerodynamics of the aircraft and, consequently, better performance. Although liquid-cooled engines were more susceptible to combat damage, by the end of the Spanish Civil War the advantage of the Messerschmitt Bf-109E powered by the DB-601 over the Polikarpov I-16 with the M-62 engine had become evident.
The great Soviet fighter designer Nikolai Nikolaevich Polikarpov understood perfectly well that a future war would require a new fighter type powered by an air-cooled twin-row radial engine. Unfortunately, the only indigenous, reliable powerplant of this type available at that time was the M -88 – the latest example of the M-85 / M-87 family, based on the French Gnome-Rhone Mistral Major design. The engine had been in production at Plant No. 29 in Zaporizhzhia since 1935. Unfortunately, at the end of the 1930s those engines were already considered obsolete and their power output (M-87 developed 950 hp and the M-88 – 1,100 hp) wasn’t exactly impressive. In addition, the prototype of the new I-180 fighter, developed by Polikarpov in 1938 and powered by the M-87 engine, crashed during its maiden flight, claiming the life of the national hero and one of Stalin’s protégés, Valery P. Chkalov. As it turned out, the crash had very serious and long-lasting consequences, affecting not only the fate of the I-185 project (probably the best Soviet fighter design of that period), but also the future of Polikarpov and his design bureau.

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In early 1939, the Soviet authorities called a meeting of all Soviet aircraft designers, at which they pitched a proposal for a fighter capable of competing with the Bf-109. It wasn’t long before the design bureaus came up with a variety of projects, most of which were built around the M-105 liquid-cooled inline engine. Many of those proposals were considered promising and worth implementing and there was no doubt that some would actually go into production. Ultimately, three designs were selected: the I-200 powered by the Mikulin AM-35 engine, built at Polikarpov’s OKB, but handed over to Mikoyan and Gurevich for final development (the future MiG-1/3), Yakovlev’s I-26 powered by the Klimov M-105 engine (the future Yak-1) and the I-301 designed by Lavochkin, Gorbunov and Gudkov, also powered the M-105 (the future LaGG-1/3).

In addition to fighters powered by inline engines, the 1930s also saw new fighter designs featuring radials. One of them was the Polikarpov I-180 with the M-88 engine. In terms of performance, it was just as good as or even slightly better than the LaGG-3 and Yak-1, and it certainly had a huge development potential. Unfortunately, following the death of Chkalov during the first flight of the I-180 prototype (December 15, 1938), Polikarpov fell out of favor with Stalin and his designs stood little chance of being selected for mass production. Ironically, Polikarpov’s team couldn’t really be blamed for the crash. Feeling enormous pressure to take the new fighter up as soon as possible, Chkalov himself decided to take his chances with an aircraft that hadn’t yet passed all the ground tests and was still in the process of being outfitted with vital pieces of equipment, such as the cowl flaps. After the death of Chkalov, work on the I-80 continued and in 1940 it was even approved for production at Plant No. 21 in Gorki, where I-16 was previously manufactured. However, at the end of 1940 the plans for the machine’s production were dropped and Plant No. 21 received orders to launch the production of the LaGG-3 instead. The official reason for such a decision was the fact that the NKAP (Narodnyi Komisariat Aviatsionnei Promyshlennosti) – National Commissariat of Aviation Industry considered the development of fighter planes with radial engines as pointless. The decision was based on the results of the 1939 large-scale wind tunnel tests conducted at TsAGI, which involved various inline and radial engine types. The official tests results showed that the radial engine, due to its large diameter and significant frontal drag, was not suitable to power the new generation of fighters. With the benefit of hindsight, that conclusion was clearly wrong. As a replacement for the I-16, the I-180 could go into production much more quickly than the Yak-1 or LaGG-3, not to mention the fact that Plant No. 21 could have taken the project on with only minimum preparations required, which wasn’t the case with the LaGG-3.
Among the heavy-weights racing to develop the next generation fighter, such as Yakovlev, Mikoyan, or Polikarpov, was an up-and-coming designer Vladimir Yatsenko with his I-28, which became a worthy competitor of the I-180.
Yatsenko had a good resume. In the 1930s he was one of Polikarpov’s assistants and he shared his mentor’s views on the use of a high-power radial engine as the best way to improve the performance of the I-16. He remained true to the idea when he began work on his own fighter design.

 

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In 1937 Yatsenko became the head of the design bureau at Plant No. 81 in Tushino. The I-28 fighter he created shared many design features with Polikarpov’s I-180 – the same overall arrangement, the M-88 engine producing 1,000 hp, strong armament and a similar take-off weight of 2,700 kg. The performance was also similar (in 1939 the I-180 prototype reached a speed of 575 km/h, and in 1940 the second I-180 prototype flew at 566 km/h). In 1939 there were plans to equip the first prototype of the I-28 with the Urmin’s 1,700 hp M-90 engine and it was expected that the use of this power unit would allow the machine to reach the speed of 600 km/h. Unfortunately, since the M-90 was still under development and far from reaching its design power output, Yatsenko had no choice but to equip the first prototype with the 950 hp M-87A engine. In this configuration the aircraft was flown by P. Stefanovski and reached a speed of 545 km/h at 6,000 m. It was 100 km/h more than what the I-16 was capable of, but far from the expected leap in performance. Nevertheless, in the report of the commission evaluating the prototype, the following entry appeared: “The I-28 is currently the first fast fighter in the USSR.”
Yatsenko hoped to improve the performance of his fighter so that it would outclass the I-180, but soon the Polikarpov’s machine received the M-90 engine and reached a speed of 701 km/h! This development meant that the chances of the I-28 to ever go into mass production decreased and its future, similar to the fate of Polikarpov’s I-180 and I-185, was uncertain, to say the least. In the end, a total of two prototypes and five productions examples were built out of the 30 machines on order. Another 15 aircraft were at various stages of completion when all work was stopped in June 1940. At that time, the production of the LaGG-3, MiG-3 and Yak-1 fighters was already in full swing, and the I-28 project had lost much of its attractiveness.

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The history of the I-28 is in many ways instructive and symptomatic. Its design, construction and testing took an incredibly short time. Unfortunately, Saratobayn plant in Saratov was hardly suited for the purpose and its workforce lacked experience in woodworking to rise to the challenge posed by the all-wooden structure of the airframe. Another issue was the unavailability of suitable powerplants – a perennial weakness of Soviet aviation industry. Since the existing engine couldn’t be upgraded to deliver an additional 300 hp needed to eke out the desired performance from the I-28, the commission supervising the tests recommended that the aircraft’s weight should be reduced by 300 kg – a formidable task to achieve.
After the work on I-28 was abandoned, Yatsenko lost all hope in his design. In July 1941, he was transferred to a factory manufacturing MiG-3 fighters and later worked as one of A.I. Mikoyan’s and then S.V. Ilyushin’s deputies.
Both the I-180 and the I-28 were well-thought-out designs that never made it into mass production, mainly due to the unavailability of high-power radial engines. Another design that emerged during the push to modernize the Soviet fighter aviation in the late 1930s was Silvansky’s I-220, also known as the IS, which according to various sources translates as “Iosif Stalin” or “Istriebitiel Silvanskogo” –  “Silvansky’s fighter”. The history of that project is another example of how modernization programs should not be run.
In early January 1938, the People’s Commissar of Aviation Industry, Mikhail M. Kaganovich, was approached by his son-in-law, then twenty-two, Alexander Vasilyevich Silvansky, who decided to try his hand in aircraft design business. The young man’s idea was quickly blessed by Kaganovich and Silvansky received not only the green light to develop a single-seat fighter, but also starting capital and a full access to a design bureau staffed by former associates of recently deceased D.P. Grigorovich – all consummate professionals in their fields of expertise. According to the memoirs of V.B. Shavrov, this is how the Design Bureau No. 153 at the recently opened plant in Novosibirsk came to be.
Needless to say, none of the established Soviet designers could hope for such a lucky break and a lightning-fast decision-making when dealing with the authorities, but Silvansky’s “successes” didn’t end there. To spare the talented young man from the tedious and time-consuming task of actually designing an aircraft, Sylvansky received full technical documentation of Polikarpov’s I-16 fighter powered by the prototype of A.S. Nazarov’s M-58 engine with a take-off power of 680 hp.

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In Novosibirsk, both the chief designer of the new OKB-153 and his associates were accommodated in comfortable conditions (at least by the Soviet standards of the day), but it wasn’t long before things began to go south. Although Silvansky was in fact a complete ignorant in the field of aircraft design, he seemed to be convinced of his omniscience and superior skills. The perfect storm was brewing on the horizon.
When Nazarov was arrested, the work on his M-58 engine was discontinued. Apparently this wasn’t much of an issue for Sylvansky, who promptly decided to equip his fighter with a much more powerful M-88 engine rated at 1,100 hp. The problem was that the M-58 drove a three-bladed propeller with a diameter of 2.85 m, while the M-88 was designed to use a 3 m propeller. Polikarpov designed the entire airframe taking into account the diameter of the propeller and the need to maintain an adequate clearance between the propeller tips and the ground. This included the dimensions of the wing’s center box, which in turn determined the track and length of the main landing gear legs. By using a more powerful engine and a larger diameter propeller without changes to the airframe structure, Sylvansky ignored the fact that the tips of the propeller blades would end up dangerously close to the ground. This resulted in damage to the propeller when the prototype was first fired up on October 6, 1939. Sylvansky’s reaction was typical of “party pets.” He didn’t want to hear about the need to extend the wing’s center section and insisted instead on lengthening landing gear struts. This would have brought the gear wells closer to the fuselage longitudinal axis, and towards engine components that couldn’t be moved. At some point Sylvansky went so far as to send a telegram to S.K. Tumanski, requesting the relocation of these components, because “the fighter is more important than the engine.” Not surprisingly, the telegram was ignored and so other solutions had to be found. According to some sources, Sylvansky himself, or perhaps a practical joker on his team, had put forward the idea of ​​digging a trench along the runway, which would protect the propeller from damage. Thankfully, no such steps were ever taken. Instead, the chief designer decided to cut off the tips of the propeller blades using an ordinary saw!

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In early October 1939, test pilot I.S. Baranov attempted to take off in the I-220 for the first time. The machine rolled up and down the runway, its engine roaring furiously, but failed to get airborne. After this test, the mercilessly mimed propeller was removed and destroyed, while the overheated engine was covered with a tarpaulin. In January 1940, the I-220 prototype was delivered to Moscow to undergo wind tunnel tests at TsAGI. As a new M-88 engine was unavailable, the machine was equipped with a less powerful M-87A motor driving a 3 m propeller. During the overhaul, the aft part of the fuselage was strengthened and a number of other improvements were made, which resulted in a significant increase in the weight of the aircraft. Sylvansky managed to persuade Polikarpov’s chief test pilot, Ye.G. Uliachin, to attempt the first flight of the rebuilt prototype. However, it went just as badly as the first try. After a number of unsuccessful attempts, Uliachin finally managed to get the machine off the ground, but landed quickly and stated bluntly that “this piece of **** will never fly!”. The I-220 turned out to be very unstable in flight, badly designed and seriously overweight.
On January 11, 1940 M.M. Kaganovich was dismissed from the post of People’s Commissar of the Aviation Industry, which also brought Sylvansky’s brief career as an aircraft designer to an end. The first prototype of the I-220 was handed over to MAI as a training aid, while the second machine was abandoned at the Novosibirsk plant, where it remained until mid-1944. The history of the I-220 is an interesting example of how the political intrigues and support of influential patrons shaped the development of aviation programs in the Soviet Russia.

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