Aviation of Word War II
Almost on all WWII aircraft with liquid-cooled engines attempted to install a radial engine. And if the installation of such an engine on the LaGG-3 aircraft led to the creation of an outstanding fighter of the Second World War, then in the case of the Pe-2, as in most others, some improvement in the aircraft's flight and technical qualities did not lead to the creation of a new aircraft.
In 1942, the M-105 engines installed on the Pe-2 were also installed on the Yakovlev and LaGG-3 fighters, were in great shortage, and the difficulties of their delivery forced the designers to look for the possibility of installing the M -82 Shvetsova, because in the first half of 1942, they were used only on the Su-2.
The expected speed increase due to the installation of a more powerful engine (1100 hp for the M-105RA and 1330 for the M-82) should have led to an improvement in the aircraft's flight performance.
Leonid Leonidovich Selyakov, who was already mentioned in our article on the creation of a turret installation for the Pe-2FT aircraft.
The aircraft was created by reworking one of the aircraft of the 31st series (No. 19/31), produced by the plant in 1931. In addition to replacing the motor unit (M-105R from VISH-61 was changed to M-82 with AV-5L-118A propellers, covered with large rounded spinners with starter ratchets protruding forward), the bow ShKAS and onboard machine gun were removed from the radio operator's gunner, an experimental turret was installed at the navigator installation VUB-2 with a machine gun BK.
The forward displacement of the centering of the aircraft due to the installation of new, heavier engines forced the landing gear wheels to be moved forward by 60 mm due to the lengthening of the struts. An empty plane turned out to be heavier by about 600 kg.
The first prototype was ready at plant number 22 in Kazan in the fall of 1942, but the plane, as they say, "did not go". Despite the fact that at all altitudes the speed increased, the practical ceiling increased and the takeoff run decreased, the still low reliability of the Shvetsov engine of the early series nullified all the advantages obtained. In factory tests, oil was knocked out of prompters, which ultimately led to engine seizure. The engine was unreliable in idle mode, stopping it for gliding during landing made it even more difficult and dangerous. Many problems were associated with the unsatisfactory operation of the oil cooler, its gusts created a threat of oil escape and engine jamming.
Long months of improvements and rework have delayed the release of the aircraft. Only in April 1943, the plant put the aircraft for testing at the Air Force Research Institute, the test results at the Air Force Research Institute confirmed the factory test data.
If at the ground the plane with the M-82 was only 7 km (458 km/h versus 451 km/h) ahead of the car with the M-105PF, released in February 1943, then already at medium altitudes the advantage increased significantly. Here the new version of the Pe-2 overtook not only domestic aircraft with water-cooled engines, but also the American Douglas "Boston" III (A-20C), which at that time was one of the fastest serial medium bombers in the world. The Pe-2 with the M-82 at an altitude of 6200 m developed a speed of 547 km / h, while the Boston III - 530 km / h at 4500 m. The new car also significantly surpassed the Boston III in climb rate and ceiling. During the combat turn, it was possible to reach 800 m instead of the previous 450-500 m. The high thrust of the engines sharply reduced the takeoff - from 620 m for a serial aircraft from the M-105RA to 490 m (when forcing the M-82). The longitudinal and directional stability of the aircraft has somewhat improved. The new version flew freely on one motor.
However, the disadvantages were noted, perhaps, no less than the advantages. Bulky engine hoods impaired the view from the side of the cockpit. But this was not the main thing: the reliability of the new motor installation turned out to be very low, in operation it was difficult, capricious and sometimes simply dangerous.
Here, the lack of knowledge of the M-82 itself, and errors in the design of the installation, and technological defects of a number of handicraft experimental units, for example, oil coolers, have come together. Formally, the resource of the M-82 produced by the plant No. 19 was 100 hours, but the VG-12 plugs constantly failed. Only during tests at the Air Force Research Institute, 110 candles were replaced on one machine! The candles broke down every 5-6 hours of operation.
The afterburner control worked unsatisfactorily - it simply refused to turn off, and the forced modes were very tightly limited in time. Otherwise, a quick engine failure is inevitable. The high-altitude corrector functioned poorly, oil coolers were torn, the mechanisms for opening and closin.
The first was built aircraft number 1/226, then they made one - two cars in series from 227 to 243, but the 244 series was almost entirely equipped with Shvetsov engines. On these aircraft, they introduced all the novelties that had appeared by that time on the serial Pe-2, including the canopy of the pilot's cockpit with the radio antenna mast moved forward and an improved turret at the navigator.
A little earlier than on the series with the M-105PF, an extended upper hatch appeared. The absence of ShKAS machine guns from the pilot and the shooter remained unchanged, which was subsequently criticized in combat units. The bow ShKAS, for example, was often used for sighting. In the series, the engine nacelle bomb compartments were restored. Myasishchev planned to continue work on improving the Pe-4 type by installing a new flashlight with a FZ turret and moving the battery and oxygen cylinders further to the tail.
Myasishchev, in his August 1943 program, planned to continue work on improving the Pe-4 type by installing a new lantern with an F3 turret, changing the design of the middle fuselage section as Pe-2F and increasing the internal bomb load. But this version of the car, called the Pe-4A, remained unrealized.
Of the 32 manufactured serial Pe-2s with radial engines, only 24 were handed over to military acceptance. Despite such a small number of these machines, they appeared at the front and took part in hostilities.
The main production aircraft Pe-2 with the M-82F was tested at the Air Force Research Institute only in February 1944, and it was not No. 1/226 (its connecting rod broke during factory tests and the aircraft went out of order), but the aircraft No. 1/332. Due to the unsatisfactory operation of the carburetors and altitude correctors, the engines at an altitude of more than 3000-4000 m were not used at full power, so the maximum speed of the aircraft at the second altitude limit was less than at the first (526 km / h). The main reasons that held back the serial production were two: the lack of M-82F engines and the very low quality of oil coolers. It is still not entirely clear how the GKO could have planned the mass production of "pawns" with Shvetsov engines, if they were not even enough for Lavochkin's planes.
Moreover, a powerful competitor has appeared - the Tupolev Tu-2 bomber. For the first time, several Tu-2s appeared at the front back in 1942 during military trials. On the Kursk Bulge there were only 18 Tu-2 in the 285th BAA of Colonel V.A. Sandalov, who were used mainly as scouts. And in May 1944, near Leningrad, the 334th bad of Colonel N.P. Dap consisted entirely of these aircraft. The Tu-2 was superior to the Pe-2 in flight data, armament, and bomb load.
In the spring of 1944, Pe-2M-82 began to be sent to combat units in small batches (3-5 aircraft each). Such aircraft had, for example, one of the squadrons of the 99th Guards Separate Reconnaissance Regiment. In the summer of 1944, the 39th ORAP received three vehicles. In these regiments, the brake grilles were removed from the aircraft.
There were Pe-2s with M-82s and in ordinary bomber regiments, but they were also used for the most part as scouts. At the end of the war, the commander of the 4th Guards BAD, Hero of the Soviet Union, Major General F. Kotlyar, a famous master of aerial reconnaissance, flew on such a machine.
I must say that these machines were disliked at the front. The reliability of the new motors has not reached the level of the old ones. There were complaints about the unstable operation of the motors, heavy starting. Engines stalled from hypothermia at altitude, especially in winter. The introduction of new motors has brought more hassle than good. Modifications of Pe-2 with M-105PF and M-82 differed quite significantly in their assemblies and assemblies, which created many difficulties in production and maintenance. The lack of knowledge of the new motor installation did not allow full use of its advantages. The original reason for the creation of the modification also disappeared: M-105 began to come in abundance from engine plants, and the M-82F found other mass "consumers" - the La-5 fighter and the Tu-2 bomber. There was no point in breaking the well-established Pe-2 production process. Therefore, after the manufacture of 32 serial machines with air-cooled motors, their production was stopped and returned completely to the old motor installation. Instead of the Pe-2 with the M-82, plant No. 22 received a new task - to restore the production of the Pe-3, but with the VK-105PF engines.
' After the first stage of improvements
'' After the second stage of improvements