Aviation of World War II
The work on I-200 drawings began on 25 November 1939. It differed from Project X because it had to be equipped with the Mikulin AM-35 engine; this was because the AM-37 was not yet ready for production. The AM-35A had the same dimensions, but its power was 200 hp lower. The drawings were completed and were submitted to the authorities on 8 December 1939, and on 25 December a mock-up was completed and approved. It was used for tests in the TsAGI fuselage: the control surfaces were an aluminium alloy frame covered with fabric.
Thanks to a great effort from his bureau, the I-200 prototype was completed on March 31, 1940. Then it was critically examined by A.G.Brunov, senior test pilot of Zavod I and leading engineer for the tests, and by Colonel M.I. Martseliuk and Major M.N. Yakushin of the VVS.
The I-200 No. 01 was first flown on April 5th, 1940, by test pilot A.N. Ekatov of Zavod 1. On the whole, the tests were satisfactory, though there was a fire in the inlet pipe due to a engine backfire on the 3rd flight, and some other difficulties: engine overheating, the canopy that was side hinged and impossible to open in flight, and there was insufficient braking power. On 1st May 1940 Ekatov flew the I-200 n.01 over Moscow's Red Square. On May 24 it reached a speed of 648 km/h at a height of 6,900 m, an exceptional performance not just in the Soviet Union. The only faster production built aircraft of the time was the Heinkel Hel 00.
The I-200 No.02 was completed for tests on April 25, and it was first flown by M.N. Yaskushin on May 9. It was externally distinguishable from the Nr. 1 by the oil coolers on both sides and the by the presence of slots in front of the windshield. The I-200 no.03 began ground tests of the armament on May 13, 1940. The prototype was completed on June 1, and was flown on June 6 by M.I. Martselyuk. This prototype had metal outer panels on the wings, but this modification wasn't used on later aircraft. It was also equipped with radio.
The performance demonstrated during the tests was highly satisfactory, particularly concerning speed. The I-200 no. 1, flown by Ekatov, reached 648.5 km/h at 6900 m in the nominal operating range of the engine on May 24. I-200 n.02 flown by Yakushin reached 651 km/h at 700 m, at nominal power as well. It reached 579 km/h at 2220 m and 605 km/h at 3630 m. The fighter reached an altitude of 5,000 m in 5.1 min, and 7.000 m in 7.15 min.
On May 25, 1940, even before the tests were completed, the Committee for Defence and the NKAP ordered the I-200 into production at Zavod 1, where it replaced the BB-22. It was expected than 125 I-200s would be built by the end of 1940. Such hurry was influenced by the enthusiasm of Stalin for the display in Red Square on May 1, and from the results of the tests, but the design team knew it was an error. In fact, tests also showed that the aircraft was demanding to fly, as it was longitudinally unstable and had neutral lateral stability. A list of 112 defects and corrections was made, including:
• improve stability;
• protection for the centre section fuel tanks;
• install wing slats;
• enlarge the wheels to provide for an increase in weight;
• install 2 further removable machine guns;
• increase the fuel tank capacity to reach a range of 1000 km.
The I-200 was first shown to the public at the Tushino Air Show on August 18,1940, where the I-200 no.03 flown by Yakushin made a demonstration flight. On September 13, 1940, at a meeting between the ОКО and Nil-VVS to discuss the results of tests, the chief test pilot Suprun commented NII-VVS to discuss the results of tests, the chief test pilot Suprim commented that "... the I-200 was the only prototype to pass the state tests at the first attempt": by comparison, the I-26 (later Yak-1) and I-301 (later LaGG-1) had to repeat the state tests several times.
* - by results of state official tests in AF Scientific Research Institute
** - more precisely after recalculation: maximum speed was 636 km/h at the altitude 7600 m.
IP-201 - cannon fighter, a modification of the I-200 high-speed fighter with two 23-mm PTB-23 cannons. The IP-201 aircraft was a further development of the I-200 fighter in the direction of increasing firepower without significant changes in the design of the prototype. Its armament was to consist of two MP-3 (PTB-23) 23 mm cannons (60 rounds magazines) and two 7.62 mm ShKAS machine guns (750 rounds of ammunition). The BS machine gun had to be sacrificed in favor of installing a larger capacity fuselage tank (195 liters) in order to increase the flight range. MP-3 guns designed by Ya.G. Taubin and M.N. Baburin (OKB-16 NKV) was installed in fairings under each wing console (in the area not swept by the propeller) on special metal carriages in the region of the 1st and 4th ribs between the main spar and the front stringer. In the reloading version, the IP-201 could take two 100-kg bombs. According to preliminary calculations, its maximum speed in relation to the I-200 should have decreased by 10-15 km / h and amounted to 635 km / h. However, the AM-37 engine made it possible to keep it at the level of 650 km/h.
To check the fastening of the gun and its operation under the wing of the I-200, a working model was made and on June 16, 1940, a shooting was carried out in the shooting range of the plant (108 shells were fired). On July 27, 1940, the permanent commission of the NKAP for the consideration of initiative projects and proposals for aircraft, headed by B.N. Yuryev, approved the draft design of the IP-201 cannon fighter and considered its construction expedient. At the same time, it was noted that the maximum speed of the aircraft was somewhat overestimated and actually 615 km / h should have been expected. However, the Air Force Research Institute, in its opinion on the IP-201 draft design, approved on August 14, noted that the proposed armament scheme was unacceptable due to the insufficient rate of fire of the MP-3 guns (300 rounds / min.). In this connection, it was proposed, on the basis of the armament system of existing aircraft adopted by the Head of the Air Force of the Spacecraft, instead of MP-3 cannons, to develop the installation of two BS machine guns with 300 rounds of ammunition on the I-200 aircraft.
Nevertheless, the construction of the IP-201 aircraft began at the end of September 1940 on the basis of a prototype of the I-200 No. 03 fighter, which, after state tests, arrived from the Air Force Research Institute at Plant No. 1 to refine and eliminate the identified defects.
On October 12, 1940, the NKAP issued an order to the NKV for experimental work to study the possibility of installing a 23-mm MP-3 cannon on the I-200 instead of ShKAS machine guns. For this, OKB-16 submitted a full-size mock-up of the fighter, due to the unavailability of the prototype aircraft.
The conducted studies found that the new gun could be installed instead of two ShKAS machine guns only with the condition of significant changes in its design, which in turn could affect its performance. To do this, it was necessary to change the compensation mechanism, the mechanism for feeding cartridges and the reloading mechanism. In addition, the synchronizer provided at the disposal of OKB-16 did not allow us to hope for its reliable operation with the new gun.
However, Ya.G. Taubin was ready to develop a special gun design for installation in the over-engine part of the IP-201 fighter, but calculations showed that for its normal operation it is necessary to significantly strengthen the aircraft structure. The installation of the gun in the wing did not present any particular difficulties and could be carried out without changing its design. It was only necessary to strengthen the set of the wing, which was not designed for large recoil forces. On October 28, 1940, a model aircraft with a cannon installed in its left wing was handed over to the NKAP along with a research report.
Soon OKB-16 brought the cannon's rate of fire up to 600 rds/min. (the gun was named MP-6) and the military showed interest in it. After testing by Decree KO under the Council of People's Commissars of the USSR No. 423 of November 16, 1940, the gun was put into service. In this regard, on November 23, 1940, the NKAP and the Air Force, by joint order No. 657/0293, ordered the Chief Designers Mikoyan, Lavochkin, Ilyushin and Sukhoi to ensure, within two months, the development and manufacture of standard installations for the MP-6 cannon and the AP-12.7 machine gun of design Taubin and Baburin. The team, headed by A.I. Mikoyan, was to develop the fuselage and wing installations for the gun and machine gun, as well as the installation of the gun in the engine.
In the meantime, work on the I-200 No. 03 was nearing completion. New wing panels were installed on it, modified to accommodate the MP-6 guns, and the ShKASs were replaced with AP-12.7 machine guns. However, it was not possible to transfer the aircraft for armament testing at NIPAV in a timely manner due to the deformation of the consoles that emerged after the installation of the guns, which changed the transverse V wing. In addition, the delay in the re-equipment was caused by the participation of the aircraft, along with the I-200 No. 01 and I-200 No. 02, in the air parade on November 7 over Red Square, after which work on the re-equipment of the I-200 No. 03 resumed, ending by the end of November. On December 1, 1940, pilot V.N. Gursky performed the first test flight, during which the engine stopped due to the exhaustion of fuel from the fuselage tank. The pilot made an emergency landing, during which the plane crashed and was sent for repairs. Repair of I-200 No. 03 continued until February 1941. In March, preliminary factory tests were carried out, but work soon stopped. The MP-6 cannon and the AP-12.7 machine gun never entered service with the Air Force due to the fact that in May 1941 Ya.G. Taubin and M.N. Baburin were repressed, and work was curtailed.
Comparative Analysis of Designs and FTD of Soviet and German Fighters that Took Part in the WWII
Flight Technical Data - FTD
The I-200 fighter (hereinafter referred to as the MiG-1 and MiG-3) can be called a distant descendant of the I-16, which in many respects differed from it, but nevertheless retained certain "generic features". First of all, this is the design of the fuselage, inherited from the "donkey", but redesigned for a water-cooled engine. The rear of the fuselage was formed by a semi-monocoque, glued from veneer and reinforced with wooden frames and stringers. The frame of the central and bow parts, including the removable engine mount, is welded from thin-walled steel pipes and covered with duralumin sheets and removable hoods. The wing center section and stabilizer are all-metal. This similarity with the I-16 is no coincidence: Polikarpov, when developing the draft design, believed that the aircraft would be produced at the same plant and the same equipment as the I-16.
However, there was also a difference, and an important one. As already mentioned, according to the instructions "from above", Soviet aircraft designers had to increase the proportion of wood in the machines they created. In accordance with this, the wing consoles of the new fighter turned out to be wooden. Now it is already difficult to say whether this was the decision of Polikarpov himself or the initiative of the designers A.I. Mikoyan and M.I. The important thing is that the tree has increased the mass of the machine.
An additional aggravating factor was the installation of a rather powerful but heavy two-row AM-35A engine weighing 830 kg (for comparison, the M-105P engine, which was on the Yak-1 and LaGG-3, weighed 570 kg, that is, it was almost 35 % easier). AM-35A was considered high-altitude in our country. The highest rated power - 1200 hp. with. he "gave out" at five kilometers, and the power at low and medium (up to 4 km) heights was approximately 1100 - 1150 liters. with. Based on this, in the Soviet aviation history literature, one can find the statement that the I-200 was created as a high-altitude fighter. However, in the KB documents there is no mention of such a designated purpose. The plane is called there a high-speed fighter, and the maximum speed values (of course, if the engine allows it) is easier to achieve at high altitudes, that is, where the rarefied air has less resistance. For the I-200, such an optimal height, provided by the engine, was 7500 - 8000 m, and on these he demonstrated his highest "agility". On tests, the prototype was able to accelerate to 640 km / h at an altitude of 7800 meters. But, the closer to the ground, the worse its characteristics became.
I-200 (aka MiG-1) had two fuel tanks in the wing center section. Only 100 of these aircraft were built, and they did not play a significant role in the war. The MiG-3 differed from them in an additional gas tank located under the cockpit and installed at the request of the military to increase the flight range. This tank increased the already considerable takeoff weight of the fighter.
To make the machine lighter, we had to sacrifice firepower. The MiG-3 was originally equipped with only one large-caliber UB machine gun and two ShKAS, that is, its armament was as weak as that of the I-16 type 29. For 1941, such a set of weapons was already considered clearly insufficient, especially against bombers, therefore fighters began to place two additional BC machine guns in underwing containers. Its wooden structure with very voluminous load-bearing elements did not allow to mount machine guns with ammunition directly in the wing. And the containers hanging under the wings increased not only the mass of the machine, but also its drag, which significantly reduced flight data.
In addition, there were simply not enough large-caliber ammunition tanks in 1941, so at the beginning of the war an order was issued to dismantle ammo-ship containers from all "MIGs" and send machine guns back to the factory for installation on new machines.
At the end of 1941, shortly before the termination of serial production, the armament of the MiG-3 was nevertheless decided to be strengthened. 315 vehicles were built with two UBS synchronous machine guns, and 52 were built even with two ShVAK cannons. However, such quantities, as they say, did not make the weather anymore.
Serial MiG-3s, produced in the first half of 1941, had a takeoff weight of 3355 kg (in a three-machine gun version). The specific load on the bearing surface area was 192 kg, that is, much more than that of the Messerschmitts Bf 109E and F. The specific load on the power - almost 2.8 kg, which is also much higher than that of both of his opponents. It is not surprising that at altitudes up to five kilometers, the MiG-3 lost in speed to both the Bf-109F-2 and the older Bf 109E-4. The difference in the rate of climb was even more dramatic. According to this indicator, the MiG-3 at low and medium altitudes lagged behind the "Emil" by one and a half times, and from the "Friedrich" - almost twice! Then, when the engine power of the "Germans" began to decrease, the gap gradually narrowed, but did not completely disappear until the practical ceiling was reached.
In horizontal maneuverability, the MiG-3 also lost a lot, especially in the early series of machines that did not have slats. Depending on the height, the Messerschmitt, even without deflecting the flaps, made turns for a few seconds faster and with a smaller radius, and the MiG-3 pilot, making a turn, had to constantly monitor so as not to fall into a tailspin. Tests at the Air Force Research Institute, which took place in 1942, showed that at an altitude of 1000 meters, the MiG-3 cannot complete a steady bank (that is, a bank with a fixed roll) in less than 28 seconds.