Combat aircraft. ANT-31: Sukhoi, loser to Polikarpov

2024 Author: Matthew Elmers | [email protected]. Last modified: 2023-12-16 21:49

May 27, 1933 pilot K. A. Popov made the first flight on an I-14 (ANT-31) prototype fighter. The flight was successful, work on the aircraft continued.

What is behind this information? Basically, nothing special. But for those who do not know what kind of car it is, now there will be very informative material. The I-14 was not just an aircraft that was produced in a small series, it was a transition to a new principle of designing and creating aircraft.

The plane, which seems to have not remained in history, but nevertheless became a very noticeable milestone in the development of the design school of the USSR.

To begin with, the name ANT is not entirely correct (and, to be honest, it is completely incorrect). Patriarch Alexei Nikolaevich Tupolev did not design this aircraft, the work was carried out under his "general supervision". But everyone understands how it looked.

The aircraft was designed by Pavel Osipovich Sukhoi. At that time, he was the head of brigade No. 3 for the creation of fighters and record aircraft in the structure of the Design Department of the Experimental Construction Sector (KOSOS) at TsAGI.

Combat aircraft. ANT-31: Sukhoi, loser to Polikarpov

The story began in 1932, when Sukhoi, in parallel with Polikarpov, was given the task of developing the machine of the future: a single-seat all-metal fighter with reinforced weapons.

The aircraft had to meet international standards, and preferably exceed them. The technical requirements were as follows:

- maximum flight speed at an altitude of 5000 meters - 340-400 km / h;

- time of ascent to a height of 5000 m - 7 minutes;

- flight range - 500 km;

- armament - 2 guns.

And this was in 1932, when the I-5 fighter was in service with the Red Army Air Force, the maximum speed of which was below 300 km / h and the armament of which consisted of two PV-1 machine guns. And what is "Air machine gun" is known: the Maxim machine gun converted by Nadashkevich for air cooling.

Sukhoi did everything he could and even more. The project turned out to be not just innovative, at that time it was generally something futuristic.

Judge for yourself, here is a list of innovations (looking at it, remember that the case takes place in 1932):

- low-wing monoplane, the wing is located at the bottom of the fuselage;

- retractable landing gear (yes, this is exactly how it is, the I-14 was ahead of the I-16, which is mistakenly considered the first in this business);

- chassis on oil-pneumatic shock absorbers;

- wheels with brakes;

- a closed canopy and therefore a heated cabin.

The equipment of the pilot's cockpit was also at a very decent level: an optical sight, a walkie-talkie (conditionally, but the place was planned), an altimeter, a speed indicator, a slip indicator, a longitudinal inclinometer, a clock, a compass.

In the parallel project of NN Polikarpov, there were no such "excesses". The fighter, named I-14a, was a sesqu-glider of a mixed design with a Seagull wing, with a closed cockpit and fixed landing gear. We found out right away, it was later I-15.

Sukhoi and his comrades went their own way, and this path was thorny and difficult. What did the designers have to face and what became the main obstacle in the development?

That's right, no engine.

Yes, there was no engine (as always, however). That is, there was no new engine suitable in terms of power for the new aircraft. In the initial calculations, it was supposed to use the M-38 engine designed by F. V. Kontsevich, air-cooled and with a power of 560 hp. However, the engine did not go into production without passing the life tests, and the I-14 was left without an engine at all.

The British helped out by selling the Bristol-Mercury engine, which, although it produced a little less, only 500 hp, was considered a high-altitude one. During the tests of the I-14 with a British engine, the pilot K. A. Popov reached a record level flight speed for the USSR - 384 km / h. At this speed, the I-14 flew into state trials.

Factory tests of the I-14 were carried out from October 6 to December 13, 1933. During the tests, 16 flights were carried out with a total flight time of 11 hours 07 minutes.

The assessments given to the aircraft by test pilot Popov and lead engineer Kravtsov were generally positive, but ambiguous.

Experts noted high speed characteristics, impressive load per square meter of the wing, slightly worse maneuverability in comparison with the I-5, but a large payload. And (importantly) a small load on the control levers, which made the plane strict in piloting. The pilot was required to be precise and accurate in movements.

Naturally, it was not without childhood illnesses. The motor warmed up with terrible force, and when it overheated, detonation began. I had to redo the exhaust system, select a scheme of anti-knock additives for gasoline, and at the same time finalize the chassis retraction mechanism.

The car was handed over for state tests on January 2, 1934 without cannons, which Plant No. 8 simply did not have time to make, but they tested an aircraft with a ski landing gear.

A few words should be said about the guns separately. It was planned to strengthen the armament of the new aircraft by installing two 75-mm guns of the agro-industrial complex - Kurchevsky's aviation cannons. There was such a fetish at the time, dynamo-jet guns that had no recoil.

But since Kurchevsky was more of a charlatan than an engineer, overlaps always occurred with his creations. So this time, the I-14 was tested without guns.

Leading pilot Thomas Susi and Alexey Filin, who helped him, gave a conclusion based on the test results:

"The I-14 aircraft with the Bristol-Mercury engine, possessing flight data that, when the landing gear is retracted, is at the level of the best foreign high-speed fighters, at the same time it is not strong enough and has a number of major defects."

And it all started anew. We re-calculated and started building a backup aircraft.

In August 1933, construction of a backup for the I-14 fighter with the American Wright-Cyclone engine began. When designing, all the shortcomings of the previous car were taken into account - the chassis, planes and the moto installation were redone. The construction of the I-14 was completed on February 5, 1934, the next day the plane was taken to the airfield, and on February 13, it was handed over for testing. Both factory and government tests were passed with a rating of "good".

Everyone liked the car, and on May 1, 1934, the I-14 took part in the Air Force parade over Red Square. This is a kind of recognition of the corresponding quality of the machine. At the parade, I-14, I-15 and I-16 passed in three.

And on May 19, 1934, the head of the Red Army Air Force Alksnis signed the "Act on the results of state tests of the I-14 fighter with the Wright-Cyclone F-2 engine, conducted by the pilot AI Filin."

The document is large, however, like all that related to state tests, but it contains the following lines:

"In terms of speeds at 5000 m, the I-14" Wright-Cyclone "aircraft is at the level of the best foreign fighters, surpassing it in speed at an altitude of 1000-3000 m, significantly surpassing their weapons and somewhat inferior in ceiling and climb rate …"

Fighter flights within the framework of tests were made by such luminaries as K. Kokkinaki, A. Chernavsky, I. Belozerov, P. Stefanovsky. And in their opinion, the I-14 was a pretty decent machine.

By the way, it was thanks to Stefanovsky's work on testing weapons that they decided to abandon dynamo-reactive guns on airplanes altogether.

Initially, the aircraft's armament was supposed to consist of 1-2 PV-1 machine guns and two APC cannons under the wing. But after testing the agro-industrial complex, it was decided to abandon the dynamo-reactive cannons in favor of the new ShKAS machine guns, and a little later it turned to the installation of ShVAK cannons.

During 1935, a new wing with fenders was installed on the second prototype I-14, heated manifolds, an electric starter, a variable pitch propeller and AIC guns were replaced with ShKAS machine guns.

At the same time, the wing was calculated on the I-14bis of greater strength with enlarged flaps for an experimental installation in the wing of the ShVAK cannons, however, unfortunately, the matter did not advance beyond the initial calculations.

But the plane received external bomb racks with SI electric droppers and a 15SK radio station.

The serial production of the I-14 was originally planned to be established at the plant No. 21, which produced the I-5. The first batch of 50 vehicles was supposed to appear in Nizhny Novgorod, but alas, the matter was somewhat delayed at the stage of transferring the drawings and, as a result, the order for the I-14 was transferred to Irkutsk, to plant No. 125.

So the serial birth of the I-14 took place in Irkutsk in 1936. At the same time, there were problems with the aircraft during factory tests.

On September 29, 1936, a test flight of the first production copy of the I-14 was carried out. According to the results of factory tests, the specialists of the Air Force Research Institute issued the following conclusion:

“The I-14 RC aircraft is of undoubted value in terms of its flight data and relative simplicity of takeoff, landing and aerobatics, but due to the dangerous nature of the“spin”it cannot be recommended for introduction into the supply of the Red Army Air Force until this defect, which is dangerous for flights, is eliminated. Suggest TsAGI, together with plant No. 125, to carry out the necessary research and alterations of the aircraft to eliminate the dangerous nature of the "spin", and then again present the aircraft for testing at the Research Institute of the Red Army Air Force …"

The design bureau and the plant reacted, and during 1936-1937 a new tail was developed, which completely removed the problem with the "corkscrew". However, there were still claims to the aircraft from the military, caused by the poor build quality.

Since the Siberian plant lacked highly qualified specialists, production aircraft had a low quality of external surfaces, processing of rivets, and seams. All this caused both a loss of speed and fair criticism from the military.

In total, 55 I-14 aircraft were in the process of construction at the plant. In the aviation unit in 1936-1937. 18 were delivered. The rest of the fighters were never completed.

Here the "king of fighters" Polikarpov and his I-16 played their role.

The I-16, which appeared later than the I-14, was a seemingly more advanced machine. It was of a mixed design, which means it was simpler and cheaper. But most importantly, the I-16 was faster. Yes, unlike its competitor, the I-14 was easier to fly, had better maneuverability and simple takeoff and landing.

However, the simplicity of the design and the use of inexpensive and affordable materials did their job. Plus, with the same Wright-Cyclone engine, aka M-25V, the I-16 actually showed higher flight characteristics, despite the fact that Polikarpov's fighter was very difficult to fly.

Nevertheless, having weighed all the pros and cons, they decided to abandon the plane of the talented, but very young (second plane) designer P. O. Sukhoi.

The reasons for this decision are simple and understandable. The main one is the shortage and high cost of aluminum produced in the USSR, the technological complexity and high cost of the new all-metal fighter.

No matter how breakthrough the I-14 was, its cost was prohibitive, and the USSR could afford to build all-metal fighters only after 10 years.

Plus, for the Polikarpov fighter, military pilots, who were already accustomed to the technique of the "king", voted with both hands. This is also an important aspect.

The Polikarpov fighter was of a mixed wood-metal design, and even allowed the use of a canvas, it was cheaper and more technologically advanced in construction with approximately the same flight data as the Sukhoi fighter.

Yes, the I-14 was indeed somewhat ahead of its time. Polikarpov created a more familiar and cheaper car, but there is a nuance here. Sukhoi worked under the patronage of Tupolev himself, who was allowed to do everything, including work on all-metal aircraft. Therefore, no one forbade Sukhoi to develop and build such an aircraft, but all other designers were gently and unobtrusively “recommended” to use a mixed design scheme.

Well, what can you do if in reality the country at that time could not produce so much aluminum to satisfy the requests of ALL designers.

But it turned out that Polikarpov's cheap scheme defeated Sukhoi's expensive and innovative scheme. Yes, that often happened.

I-14 became the second (after I-4) aircraft of Pavel Osipovich Sukhoi. But far from the last. In any case, the designer was noticed, he was among the best. And he did not leave the design Olympus until his death in 1975.

And in December 1933, Pavel Osipovich Sukhoi was awarded the Order of the Red Star for the successful creation of serial I-4 and I-14 fighter aircraft. The first, but far from the last award.

The history of the outbreak of World War II confirmed that Sukhoi was absolutely right: the future belongs to all-metal aircraft. In the same way, he turned out to be right when, at the end of the war, he dropped everything and began working on jet planes.

But this, in many respects, the first, albeit not a very beautiful aircraft, became the beginning of a new and long path that Soviet aviation passed with honor and dignity.