Aviation of Word War II
Pe-8. Test by War.
In 1937, repressions hit not only many aircraft designers, but also the aircraft they created. After the arrests carried out in a number of design bureaus, officials did not dare to give the go-ahead to bringing the machines created there to mass production.
However, the Tupolev TB-7 was in a "suspended" state for a short time. Although they intended to “cover” him, test pilot Stefanovsky in 1939 sent a letter to Voroshilov in defense of the winged giant. I believe that the voice of one person, albeit a famous one, would hardly have been heard in the People's Commissariat of Defense if there had not been a response in a higher authority. One way or another, but fate abruptly turned the biography of TB-7. The rejection of the concept of a long-range heavy bomber for the employees of the People's Commissariat of the Aviation Industry turned out sideways - the People's Commissar for the Aviation Industry M. M. Kaganovich was removed from his post. It was to be assumed that all obstacles had been removed, and in the near future hundreds of new modern aircraft would fill the airfields of long-range bomber aviation, preparing to strike at the aggressors in the West and East...
Since the main design forces were "re-educated" on logging and other harvesting, work on the modernization of the TB-7 was led by an employee of the design bureau I. F. Nezval. The aircraft was put into production at the Kazan Aviation Plant No. 124. The activity of the factory design bureau with the highest permission was intensified, and it was decided to test one serial TB-7 during the war with Finland. In January 1940, he was sent to the Karelian Isthmus, but the ship, piloted by the pilot Datsko, did not reach the North-Western Front, having an accident on the way, as noted, due to the fault of the flight crew.
In the meantime, the production of the bomber unfolded. In the spring of 1940, the first three permanent TB-7 crews were formed (ship commanders - Lisachev, Gorbunov, Makarenko). In May 1940, at the Chkalovsky airfield, they began to study new materiel, and from the autumn of 1940, they were already distilling mass-produced bombers from Chkalovsky and Kazan to Borispol, for the 14th regiment (Air Force of the Kiev Special Military District), which was being re-equipped with TB-7 ). In the autumn of 1940, the flight crew of the 2nd Squadron of the 14th Regiment began to make familiarization flights on the TB-7th. By June 1941, the retraining of the squadron for the new materiel was completed. It was possible to start implementing the UBP plans. Everyone in the regiment, armed at that time with TB-3 bombers, looked with envy at the lucky ones from the 2nd AE. On June 11-12, the regiment departed for summer camps. The 2nd squadron, 8 TB-7 and 9 crews, remained at their base in Boryspil ...
The invasion of German troops on June 22 turned out to be sudden for many. Among them were 2 AEs of the 14th TBAP. Although the experienced flight crew was ready to carry out combat missions, it was first necessary to identify targets on enemy territory that could not be destroyed by aircraft other than TB-7. And such plans in case of war for the 2nd squadron, apparently, were not prepared.
On June 25, the Boryspil airfield was bombed by enemy aircraft. 2 TB-7s were destroyed. A few days later, the squadron was withdrawn to the rear, choosing Kazan as the new base. However, the reason for this decision was not so much the recent bombing as the decision to concentrate the most combat-ready air units in the Reserve of the High Command. On July 6, 1941, on the basis of 2 AE 14 TBAP, the formation of the 412 bomber regiment began. Soon the regiment received a new serial number - 432, and became part of the emerging 81st long-range bomber air division.
In the twentieth of July, German aircraft began to raid Moscow. The air defense system of the capital operated reliably, however, some aircraft penetrated through the “network” it had set up. A bomber that broke through to the Arbat dropped bombs along the street. Three houses were destroyed, and the Vakhtangov Theater, located in the immediate vicinity of the residence of the American ambassador, was turned into ruins.
The sight of destruction in the capital made a painful impression on foreigners. They were losing faith in the ability of the Soviet Union to resist aggression. Everyone competed in terms: how long will the USSR last - 6 months? 3 months? Or - no longer than 6 weeks?
The German raids prompted a retaliatory strike on Berlin, which by that time had become the rear city of Germany. Before the war, Soviet aviation had sufficient forces to carry out a massive bombing raid on the cities of the aggressor country.
But the situation on the fronts in June-July 1941 did not allow this to be done. The bulk of long-range bomber aviation these days was engaged in combat work in the interests of the fronts, carrying out daytime and, much less often, nighttime bombing of enemy mechanized columns, while incurring significant losses. There was no way to remove long-range bomber aviation from the "front line", since the front-line aviation of the border districts was largely out of action in the first month of the war, and there were practically no replenishments.
In these conditions, hope remained on the forces of the Reserve of the High Command. It is possible that Stalin was informed about the intensive preparation of the 1st MTAP of the BF Air Force for a raid on Berlin. Based on the airfields of the Moonsund Archipelago, the regiment was located quite close to the borders of Germany. However, a number of serious factors hindered its combat activity: the depreciation of materiel (because of which DB-thirds could not take on board more than 500 kg of bombs), the lack of fighter cover for island airfields, the activation of German agents in the archipelago with the capture of the Baltic states ... And although the raid on Berlin was carried out by naval pilots, the bombardment of the capital of the Reich by heavy aircraft would have looked more solid. Stalin's attention turned to 81 air divisions, which included air regiments of the latest TB-7 and Yer-2 bombers. At the beginning of August 1941, Stalin sent a note to the commander of the 81st air division, Vodopyanov, indicating: August 9-10, or one of the following days, to bomb Berlin.
TB-7s were concentrated in the 432nd and 433rd air regiments of the 81st air division.
By the end of July, the 433rd regiment had only 4 bombers, which, due to many malfunctions, could not be used for combat flight. Therefore, the choice fell on the 432 air regiment.
By the beginning of August, the regiment still had a lot of problems, both organizational and technical. It was impossible to fly over Berlin with the whole crew: the TB-7s of the first three series had uneconomical engines (AM-34FRNV and AM-35) and were clearly not suitable for long-range flight. The choice fell on cars of the fifth and sixth series, equipped with M-40F diesel engines. A preliminary calculation showed that with a bomb load of 4 tons (of which 2 were on an external sling), they would be able to cover a distance of 3038 km and thus reach their goal. Prepared for the mission, 8 airships flew to the Pushkin airfield on the morning of August 10, 1941, took off in the late evening of the same day and headed for Berlin ...
The results of that flight are well known: 5 out of 8 aircraft were lost. To investigate such an unprecedented case, a commission was created. Among other things, she had to determine the share of guilt in the incident M-40F diesel engines.
Here, I think, it is appropriate to turn to the background. Before the war, it was not clearly defined which engine should become the main one for a long-range heavy bomber. It is not surprising, therefore, that by June 22 a rather motley company of TB-sevenths was produced: four high-altitude vehicles with AM-34FRNV + M-100 engines (including the Doubler), two vehicles with 4 AM-35s, one with AM -35A, one with M-30 diesels. However, the M-40F aircraft diesel engine, developed by the CIAM design team led by V. Yakovlev, received the greatest advantages of all power plants. Having more power than similar gasoline engines, high efficiency, "softness" of work (which helped to reduce the vibration of the structure and the level of noise generated during flight), the M-40F diesel seemed to be a long-awaited find for heavy aviation.
At the end of 1940, he passed state tests, though not without sin. In the summer of 1940, when testing on the BOK-15 aircraft, it was noticed that at high altitudes, when the fuel pressure dropped, the M-40F began to “sneeze”, and at first one of the cylinder blocks remained operational, while the other turned off. After a short “fever”, the diesel engine stopped, and it was not possible to start it up to a height of about 3500 m. They could not immediately eliminate this phenomenon, since the fuel supply to the diesel engine was adjusted by a flight engineer who monitored the fuel level on a measuring scale, and much depended on human attention and the efficiency of actions, which at high altitude were still not the same as near the ground. The presence of a "human factor" in the fuel "automatic" introduced an element of uncertainty into the reliability of the new engine. Fuel automation needed to be seriously reworked, it would take a lot of time, but since the M-40F basically worked out the state test program without comment, it was decided to make a series of 60 copies. The order was transferred to the Kirov plant. The designers of the Chelyabinsk Tractor Plant, who had experience in creating diesel engines, were obliged to provide assistance to CIAM in the completion of automation in a short time.
In the spring of 1941, they began testing the M-40F on the TB-7. Less than three months later, the war began. Perhaps, if the engine specialists had more time, the modes of unstable operation of the diesel engine would have been precisely determined, and accordingly, the rules for its operation had been developed. But two or three months to carry out these works, as well as the retraining of minders and flight technicians for servicing diesel engines, was clearly not enough. The events of the first sortie of 432 BAL put an end to the fate of the M-40F. During the investigation of the reasons for the loss of combat vehicles, a control flight of TB-7-M-40F (ship commander - Peregudov) was made to check the operation of power plants in various modes. But even without this, the commission was inclined to recognize the further operation of the M-40F as dangerous. Aircraft equipped with them went under their own power to Kazan for re-equipment under AM-35A.
Ever since those sad August days, diesel powered aircraft have become synonymous with something unreliable. Leaving technical assessments for a while, it is worth paying attention to the circumstances that led to the loss of five giant cars at once in one August night, and determine how big the fault of diesel engines is:
1. Pe-8 # 42045, commander Tyagunin. The plane was shot down by anti-aircraft gunners of the Baltic Fleet.
2. Pe-8 # 42016, commander Kurban. The plane was fired upon over Berlin, was damaged, crashed during an emergency landing in the forest.
3. Pe-8 # 42026, commander Panfilov. The plane was shot down by anti-aircraft artillery Finland.
4. Pe-8 # 42036, commander Vodopyanov. The plane was fired upon over Berlin, was damaged, crashed during an emergency landing in the forest.
5. Pe-8 # 42046, commander Egorov. Takeoff accident due to failure of two diesels on one side.
As you can see, diesels are mentioned only in one out of five cases, it is the failure of two engines at once at once that indicates that diesel has nothing to do with it.
The command of the 81st Air Division took a little more than a day to prepare for the flight around Berlin. By the way, the 1st MTAP, the first of the Soviet air regiments to carry out two raids on Berlin, prepared for this task for two weeks, carefully studying the route, working out situations possible in a long-range flight ...
It was not possible to resupply 433 BAPs in 1941 with materiel. The production of TB-7 was not deployed in the required volume; plus, there was an urgent need to quickly replenish the depleted fleet of day bombers. All the forces of the 22nd plant were thrown into increasing the production of Pe-2, and the production of TB-7 was slowed down. The 433rd air regiment, which was never supplemented with materiel to the state, was disbanded, and all the TB-7s released by 1942 were reduced to one air regiment, which received the serial number 746. The Pushkin airfield could no longer be the location of the unit - the Germans were approaching Leningrad. The main part of the regiment at that time was based at the Ivanovo air hub, in the deep rear, and used the LII airfield in Kratovo as an intermediate landing site during combat flights. Some time later (from the spring of 1942) it became the main base for 746 BAP.
By the time of relocation to the Kratov airfield, the regiment's combat strength included aircraft with AM-35A engines - engines in a little-studied combat situation, and, moreover, had unacceptably high fuel consumption. This circumstance, as well as the remoteness of the Kratovo airfield from the rear of the enemy, did not allow the regiment to fly out to bombard Berlin. Targets for TB-7 began to choose real ones, primarily the cities of East Prussia with large military production: Koenigsberg, Danzig, less well-known now Marienburg, Insterburg, Allenstein ...
In addition to distant targets, objects in the occupied Soviet territory were also bombed. In these bombardments carried out by single aircraft, the crews used the element of surprise and high-altitude characteristics of the TB-7, and the proximity of the targets made it possible to take on board a large number of bombs (up to 30 FAB-100!). The most striking example of such sorties was the daytime bombing of Vodopyanov's crew on Orel in October 1941.
In order to determine the most advantageous operating conditions for the TB-7, after each long-range flight, the regiment studied the dependence of kilometer and hourly fuel consumption on the flight profile and bomb load. The results obtained made it possible to identify economical modes of operation of the AM-35A and reduce their fuel consumption from more than 1000 kg/h to 800-810 kg/h. It is possible that lower fuel consumption would have been achieved, but the TB-7 crews, when flying over the front line, were ordered to descend to a height of 1000 meters (at which the AM-35A engines worked uneconomically) and follow at this echelon to the airfield. The most convincing arguments put forward by the command of the 746th regiment did not help, and it was necessary to comply with the requirements of the Moscow Air Defense Command until the summer of 1944, when the Pe-Eighth left the Moscow region.
Thanks to the work done by the engineering and flight crew of the 746th regiment, the "hidden reserves" of the TB-7 were revealed: the aircraft with the AM-35A with a bomb load of 2 tons began to cover a distance of more than 3400 km, could stay in the air up to 12 hours. This made it possible in August 1942 to carry out several sorties to Berlin. Thus, the previous indicators obtained on bombers with M-40F diesel engines were achieved. In addition, rational fuel consumption, coupled with strengthening the design of the TB-7 airframe, made it possible by mid-1942 to raise the bomber's bomb load from the initial 2.7-3.2 to 4.5 tons.
A qualitative leap occurred in 1943. The work carried out by the staff of the Nezval design bureau made it possible to increase the bomb load to 5 tons. A new modification of the Pe-8 with M-82 engines could take on board, in addition to the bombs already used, the main novelty of domestic gunsmiths - the FAB-5000.
In February 1943, before the appearance of the "five-ton" in the warehouses of the 45th air division, the commission, which checked the technical condition of the Pe-eighths, identified only two ships capable of lifting 5 tons of bomb load: No. 42057 and No. 42077. The situation was defused only in April 1943, when new aircraft with M-30B engines (2 machines) and M-82-112 arrived from Kazan. In April, the first FAB-5000 was delivered to the warehouses of the 746th regiment.
However, on the way to the realization of the combat qualities of this bomb stood ... its mass. None of the devices were designed to hang the FAB-5000 in the bomb bay. In the end, the armed forces of the 890th regiment developed and manufactured a special system of winches, and the suspension of a bomb on an aircraft became possible. Then they saw that its dimensions did not allow the bomb bay doors to close completely; the resistance of the Pe-8 increased, and this should be taken into account when planning sorties.
To determine the strength of the bomb explosion, they decided to drop it at a nearby training ground. And even those who could not see from the air how, after the flash, the blast wave cleared several hectares of forest from trees in a matter of seconds, felt at the moment of the explosion how the earth trembled. A funnel with a diameter of about one hundred meters made an impression, and the next FAB-5000 drop was planned for an enemy object.
On April 29, 1943, aircraft No. 42029 (Pe-8 M-30B), piloted by the commander of the ship Peregudov, navigator Tomkevich, headed for Koenigsberg. In this sortie, the crew of the Pe-8 increased due to the armed forces of the regiment and division and amounted to 15 people. Due to the special situation, the command of the 746th regiment set the altitude of the aircraft, the bomb was ordered to be dropped only on Koenigsberg.
In flight, the turbocharger of the left block of the 2nd diesel engine collapsed. However, the crew dropped the bomb on the intended target. "At an altitude of 5800 meters, the ship was illuminated by an explosion, a slight push was felt."
At the end of May 1943, intelligence established the concentration of German troops in Mogilev. The 45th air division received an order to strike at the enemy troops with all serviceable ships. The division completed its first sortie for this mission on the night of May 22. And on May 27, 1943, among others, ships with "five-tons" in bomb bays, piloted by pilots of the 746th regiment Ishchenko and Zelensky, took off. That night, the division's bomb strike on Mogilev exceeded 74 tons.
On the night of June 4, 1943, the FAB-5000 was dropped by the crew of the 890th regiment (commander of the ship Shamrai) at the Orel railway junction.
In July 1943, 4 drops of the FAB-5000 were made. On the night of July 12, before the start of the offensive of the Soviet troops on the Kursk Bulge, two "five-tons" (from aircraft piloted by Shatrov and Kaminsky) were dropped on enemy fortified areas on the Western Front: one - on the village of Progress, the other - on a height of 254.9 (1.5 km north-east of the village of Leski). The results, apparently, turned out to be quite good, but in the future such (i.e., tactical) drops were not carried out due to the too large area of defeat, into which friendly troops could also fall.
On the night of July 19, 1943, two bombers of the 746th regiment headed for Oryol. The crew of Dodonov dropped the FAB-5000 on the railway junction, the crew of Shatrov on the area of the city where the concentration of German troops was noticed. The node was completely disabled. After the bombardment, trains to Orel could only go along a thin bypass line laid by the restoration brigade. This branch, of course, no longer had the capacity of a major railway junction. The supply of German troops was weakened, which undoubtedly contributed to the liberation of Orel on August 5, 1943.
The high power of the explosive created for the FAB-5000 prompted weapon designers to equip already existing types of bombs with it: FAB-500, -1000, -2000; this increased their power compared to their predecessors, and, accordingly, the strength of the bombing strikes inflicted by parts of the ADD.
In 1944, the 45th air division carried out 4 drops of the FAB-5000.
On the night of February 7, 1944, in order to withdraw Finland from the war and facilitate the de-siege of Leningrad, the ADD subjected Helsinki to a massive bombardment. Aircraft of the 45th Air Division (commanders of the ships Ishchenko, 25th Guards Regiment (formerly 746 AL DD), and Shamray, 890th Air Regiment) dropped five-ton guns on military facilities located in Helsinki. One bomb exploded in the area of the cable factory, the other in the area of the railway workshops. By February 28, four ships of the division were prepared for repeated bombing of the FAB-5000 on targets in Finland, but the flight was set aside by order of the commander of the ADD Golovanov - the expected result was achieved by the previous bombing of the ADD regiments (February 7, 17 and 26).
The last time the FAB-5000 was dropped on enemy targets was on March 9, 1944 - from ships piloted by Zelensky (25th Guards Regiment) and Oleinikov (890th Regiment). In total, out of the eighteen FAB-5000 divisions that arrived at the warehouses, 13 such bombs were used against enemy targets, one was used in tests.
The Aircraft is Being Improved
The carriers of the "five-tons", as already mentioned, were the Pe-8, equipped with the M-82 and ASh-82FN engines. The first experimental aircraft with the M-82 (serial number 42047) was built in the fall of 1942. Its flight along the combat profile gave good results: the range with 1 ton of bombs exceeded 4300 km, fuel consumption was 730 kg / h - lower than that of the AM-35A. After minor modifications, a new modification of the Pe-8 was put into production.
The first serial Pe-8 M-82 head. No. 42058 entered the 746th AP DD in January 1943, was tested in March, after which it entered the combat strength of the regiment. In April, other Pe-8 M-82s began to arrive at 45 TBAD. However, contrary to expectations, the combat path of the new modification began extremely unsuccessfully. From the very first days, massive malfunctions in the Pe-8 M-82 gyroscopic units were revealed: the rush of military production affected the quality. After filing a complaint with the plant, the shortcomings were eliminated in a short time. But the shaft went others. Due to the increased take-off weight, the tail wheel pyramid ceased to “hold”. It broke down at the most inopportune moment - when taxiing a car with bombs to the start. Cases of disruption of sorties have become more frequent. The plane turned out to be even less comfortable than the Pe-8 AM-35A: the roar of star-shaped engines created unimaginable noise in the internal compartments, worsening the working conditions of the crew. True, in wartime this problem was considered secondary. Something else was worse: it turned out that it was immeasurably more difficult to manage four M-82s than four AM-35As. The change in thrust after giving the ORE occurred with a significant delay. Reworking of the engine control system was required, which forced the Pe-8 to stop leaking. And, on top of all the troubles. the main drawback of the new modification made itself felt: the exhaust flame from the M-82 nozzles up to 1 meter long betrayed the position of the aircraft in the night sky.
In the division there were victims of enemy fighters: for nine days of July 1943 (from the 15th to the 23rd) they shot down 4 Pe-8 M-82 bombers. Those who managed to escape said that the fighters approached the bomber exactly from the side of the “dead zones” (this is at night! Focusing exclusively on the fiery exhaust tails!) And appeared in front of the shooters suddenly, so that they did not have time to return fire. There was only one explanation: the Germans somehow found out everything about the firing sectors of the Pe-8 airborne weapons. Only much later did the division learn that the Pe-8 AM-35A head. No. 42018 from the 890th regiment, shot down over Berlin on August 30, 1942 and making an emergency landing on the territory of East Prussia almost without a drop of fuel, was thoroughly studied by the enemy and, apparently, gave him valuable information.
Until the shortcomings were eliminated and the reasons for the losses were clarified, combat flights on the Pe-8 M-82 were prohibited by Golovanov's order. Various organizations have made orders for the development of flame arresters. The first to be tested was the NII GVF, then the design was received from the NII VVS KA. Along the way, the engineers of the 45 AD decided to investigate the effectiveness of the flame arresters that were on the engines of the FW 200 bomber, which made an emergency landing in the Kalmyk steppes.
All three developments were tested in September 1943 in night flights on the aircraft head. No. 42210 over the airfield of the 45th air division in Kratovo. Flame arresters were installed on one of the engines. The smallest exhaust (flame less than 10 cm) was given by the flame arrester of the Air Force Research Institute. but it was nevertheless decided to install fishtail flame arresters similar to the German ones on the nozzles of the M-82 engines.
Pe-8 M-82 again began to fly on missions only from October 1, 1943. However, even during the forced downtime, the improvement of this modification continued. Representatives of the division received at the plant L ° 22, manufactured in August 1943, the aircraft head. No. 42410 with ASh-82FN engines, designed for a bomb load of 7 tons. In view of the clear improvement in the combat and operational qualities of the Pe-8, the commander of 45 AD V. I. Lebedev put forward a proposal to celebrate the efforts of the Chief Designer Nezval, giving the new modification his name.
The work done by KB Nezval was really impressive. The plane has changed a lot compared to its original version, and first of all, externally. The modification with the ASh-82FN engines bore little resemblance to the TB-7 "Understudy", which was also part of the combat composition of the division.
First of all, we got rid of the fifth M-100 supercharger. It was not possible to bring it to a working state, but even if this happened ... The benefits of supercharger motors were imaginary, but they created problems that were unacceptable in combat conditions. The M-100s were mounted in the fuselage in such a way that in order to repair them, the bomber itself had to be taken out of service. A working supercharger "devoured" the fuel urgently needed in a long-range flight; its mass was "taken away" from the bomb load. It was expected that the supercharger motors would protect the TB-7 from fighter attacks, allowing it to fly at altitudes of 9-11 km. But for flights at these altitudes, the human body must be thoroughly prepared, which is achievable in the conditions of the flight center, but not in the air unit that made daily combat missions. In addition, bombing from heights greater than 8000 m was ineffective; this was shown by pre-war experiments - the spacing of bombs reached 1.5 km. Before bombing, TB-7 would still have to go at lower altitudes (about 3500-7000 m), at which the value of superchargers became equal to zero. Because of all these reasons, the "five-engine" TB-7s were not used in combat operations. In the summer of 1941, they were all sent to Kazan, where the AM-34FRNV engines and M-100 superchargers were removed and replaced by AM-35A engines. The altitude of the latter already provided the bomber with acceptable performance at altitudes up to 8 km.
Starting with the aircraft head. No. 42049 Pe-8s were produced with a new navigational cockpit. * The nose of the new design had better contours than the previous machines, which affected fuel consumption in flight. The working conditions of the crew were also facilitated. Previously, the “forward looking” ** of the airship (gunner-scorer), due to the slots in the bow gun turret, along which the ShKAS moved, was under the continuous influence of the oncoming air flow. In order to avoid drafts during the flight, the entrance to the tower was closed with double-leaf metal doors.
In the new navigator's cabin, the place of the gunner-scorer moved to the starboard side: In its upper part, a hemispherical astronomical dome was installed, which, however, increased the requirements for the quality of the glass surface, since the smallest deviations from a perfectly spherical shape would lead to errors in the execution astromeasurement navigator. and this would lead to the deviation of the bomber from the route.
Having introduced a new navigational cockpit into production, the engineers solved many problems. Replacing the electric gun turret with a ball mount with a UBT machine gun of a simple design. firstly, it facilitated the maintenance of aircraft weapons. Secondly, the extra consumer of electricity has disappeared. Thirdly, the aircraft got rid of strong drafts in flight, blowing into the fuselage when flying through clouds and snow, and mist. From the old design of the cockpit, only the metal roof was preserved, which was necessary for the navigator in his work: standing on it, he could carry out astro-measurements through the astro-hatch located on the ceiling of the cockpit.
The changes also affected the cockpits. Again, starting with the aircraft head. No. 42049, the steering columns began to be curved - like the DC-3. Were changed, in accordance with the recommendations of the flight crew of the 45th Air Division, the design of the pilot's seat and the arrangement of instruments on the dashboard. The flight crew expressed the wish that the designers develop a new version of the pilot's cabin - with the pilots side-by-side (theoretically, there were opportunities for such a rearrangement), which, however, was not implemented.
Aggregate improvement has also given a lot. The replacement of the sighting equipment TB-7 affected the increase in the effectiveness of bombing. The calculation for the daytime use of the bomber fell away with the outbreak of hostilities: in the conditions of air supremacy of enemy aviation, any daytime flight of the TB-7 was accompanied by a too high probability of being shot down. The PS-1 synchronous bombsight, as unsuitable for night bombing, was replaced at the request of the engineering leadership of the 746th regiment with a NKPB-4 night collimator sight and an OPB-2MU optical sight. The latter, however, did not last long on the TB-7, giving way to the OPB-1p: aircraft began to complete them from 1943. The OPB-1p, a sight of a relatively simple design, was not planned to be used as the main one - only as a navigation sight for the navigator. It was impossible to use OPB sights during bombing at night for a number of reasons. If the navigator on the combat course had been observing through the OPB, then when the aircraft hit the searchlights, he would be blinded by a powerful beam of light and, due to the long period of adaptation of the eyes, after that he would not be able to carry out bombing. In addition, the OPB sights had a limited field of view. Working with the NKPB, which had an illuminated reticle, the navigator at the time of putting the aircraft on a combat course could simultaneously see the target, bring the ship to it even before it hit the crosshairs of the sight; he could follow the air situation, see the direction of the beams of searchlights, managing to do his job before they captured the plane and fell into the optics of the sight.
Other improvements were also carried out, which had little effect on the appearance, but meant a lot in everyday combat work. In connection with the increased take-off weight of the aircraft, the structure of the tail wheel pyramid was strengthened, the size of the tail pneumatic was increased (from 700x300 to 770x330). The new pneumatic first appeared on aircraft No. 42047; it was planned to install it on serial Pe-8s, starting with aircraft of the 9th series.
Again, from aircraft of the 9th series, it became possible to suspend two FAB-2000s in the bomb bay, which reduced the "forehead" of the bomber and, accordingly, affected fuel consumption in combat missions.
To compare the effectiveness of various types of stern gun mounts, several Pe-8s were launched with a stern turret designed by Mozharovsky and Venevidov.
In order to confidently determine by anti-aircraft gunners the belonging of an aircraft that entered the air corridor in the Moscow air defense system, and to prevent the possibility of German bombers breaking through to the Kratov airfield, the Pe-8, starting from the 7th series, became the owner of the "friend or foe" identification system: a small transmitter broadcast coded signals. The ground receiver of the system received signals only from the Pe-8. The transmitter turned on when the crew, returning from a mission, crossed the front line and entered the air corridor leading to their airfield. A small transmitter antenna was located at the bottom of the Pe-8 fuselage.
On the plane head. No. 42088, the hydraulic mechanism for feathering VISH-61V propellers was checked. The tests gave positive results, but feathered propellers were not installed on them until the end of the serial production of the Pe-8.
However, not all technical problems were resolved during the serial production of TB-7-Pe-8.
Back in 1942, the designers began to develop a thermal heating system for the leading edge of the wing, which was supposed to supplement the anti-icing systems on the aircraft - propellers, with the supply of an alcohol-glycerin mixture to the blades (stock on board - 20 liters), and the cockpit canopy pilot, with the supply of alcohol to him (stock - 4 liters). The work carried out did not give positive results for a long time. At first, the aircraft did not have a device that regulated the flow of hot gases to the leading edge of the wing, and it was heated continuously, starting from the moment the engines were leaking. Pipes, corroding under the influence of hot gases, quickly lost their strength. Due to their location next to the fuel tanks, it turned out to be unsafe in terms of fire. They found a simple way out: on the Pe-8, which had a thermal anti-icing system, it was recommended not to include it in the work. True, starting with the aircraft head. No. 421010, the insulation of hot air supply pipes began to be made of a double layer of asbestos, the thickness of the material used for the manufacture of heaters was increased from 0.8 to 1.2 mm. The damper system, with the help of which it was possible to transfer hot air from the heaters to the atmosphere, if there was no need to warm up the leading edge of the krya, they began to mount it on the Pe-8, starting from the aircraft manufacturer. No. 42611.
The explosion safety of the fuel tanks was increased by filling them as they were exhausted with exhaust gases that were taken from 1 and 4 engines, cleaned, cooled in radiators and entered the fuel tanks, the connection of which with the atmosphere was turned off. In the course of combat work, it turned out that when one of the above-mentioned engines stopped, the volume of exhaust gases entering the pressurization became less than the amount of fuel consumed, and fuel was leaked, which led to unstable operation of the remaining serviceable engines even with full tanks. The first such incident occurred on September 7, 1941 on plane No. 4221 after a successful bombing of the Orsha railway junction. The crew had to make an intermediate landing in Efremov to fix the problem. On Sumtsov's plane (serial number 42039), all four engines stopped in flight due to a fuel leak. Only the energetic actions of the flight engineer M. Dogov and his assistant K. Pochkurny, who restored the connection between the tanks and the atmosphere and eliminated fuel leakage, prevented the accident.
The developers of the tank pressurization system were asked to reserve it from 2 and 3 engines in order to exclude the situations described above, but these works were not carried out until the end of Pe-8 production.
The reliability of the AM-35A engines caused concern. Due to frequent failures, their warranty life, which was brought to 100 hours, had to be reduced again to 50. The most characteristic defect of engines of this type was a sudden and intense release of oil through the venting system when flying at high altitude. Even if this did not lead to the disruption of the combat mission, it caused a lot of trouble for the crew. It was possible to somewhat smooth out the “course of the disease” on the AM-35A engines of the 8th series, but they were able to completely cope with this defect only on the AM-35A engines assembled under pilot production conditions.
But not everything depended on constructors either. The acute shortage of skilled workers in the aviation industry had a painful effect on the quality of such high-tech products as airplanes.
Already in the fall of 1941, immediately after the facilities of the Moscow plant No. 22 were evacuated to the base of the Kazan aircraft plant No. 124, the engineering leadership of the 432nd regiment began to investigate the causes of mass failures of the TB-7 hydraulic autopilots. When dismantling the hydraulic units, it turned out that the filters and spools were clogged with metal chips, and metal dust was present in abundance in the hydraulic fluid. After reviewing the technological process, we found out that before assembly, the hydraulic and air pipelines of the autopilot were not washed, and after installing them on the aircraft, the system was not tested for operability. In 1944, another problem: on the planes of the head. No. 42510. 42710, 42810, 42211, 42411, 42711, as well as on the aircraft 4221, which had been repaired and finalized, when performing a flight (it was in late autumn; the air temperature dropped to -10 ° C), the landing gear was extended and retracted for about an hour, the flaps were not fully extended. Analyzes carried out in the laboratory revealed a significant excess of the percentage of water in the hydraulic fluid, as a result of which crystallization of the mixture began during frost ...
It was not possible to fully use the positive qualities of Charomsky's diesel engines. Their fate was more successful than that of the M-40F. M-30 diesels were installed on three TB-7s, of which aircraft 42055 and 42025 bombed Berlin in 1941 (the first on August 10, the second on October 29). As a result of the improvement of the M-30, the M-30B diesel engines were born, which in 1943 were installed on the Pe-8 by the head. No. 42038. According to the results of front-line tests, the aircraft and its diesel engines were given a positive assessment: both in terms of fuel consumption (580 kg / h), and in terms of simpler fuel automatics. In addition, due to the lower level of noise generated by them, crew fatigue in long-range flight was reduced, and the effectiveness of noise masking was increased. The diesel-powered bomber was recommended for series production. Plant No. 22 produced two vehicles with serial M-30Bs. But they did not cause the former enthusiasm. Breakdown followed breakdown, and the nature of the malfunctions indicated that diesel engines did not suffer from chronic design defects, but from poor manufacturing quality and their assembly in series. Again, the lack of production capacity and highly skilled workers affected. It was also significant that during the war the range of smelted steel grades used for the production of high-precision aircraft units narrowed. So, the warranty life of diesel engine superchargers was not maintained due to the high fluidity of the metal used to manufacture the supercharger blades - at maximum speed, the blades were pulled out ...
* - Pe-8-M-82 aircraft No. 22511 was issued with the old style nose. The reasons for this may be the following: the 22nd aircraft factory, apparently, created some backlog of the old-type navigation cockpits, which became unnecessary after the modernization of the bomber. However, there was a "breakthrough" in production, they took advantage of the old backlog.
** - Only on TB-7 (Pe-8) this crew member was saved. The shooter-scorer assisted the navigator in conducting orientation.
Pe-8 combat operation peaked in 1943 and the first half of 1944. Aircraft operate on the main directions of the Red Army's strikes: they bombard railway junctions, airfields, places of concentration of enemy troops, destroy artillery positions that shelled Leningrad. They carry out raids on the military and political centers of the Axis countries. The ever-increasing Pe-8 towers since the autumn of 1942 made it possible not only to replenish both regiments of 45 AD with new airships, but also to begin creating a “full-blooded”, three-regiment division. At the beginning of 1944, 4 Pe-8 ships (plant No. 221, 42099, 42310, 42610), together with the crews, were withdrawn from the 25 Guards and 890 regiments. They were equipped with the 362 bomber aviation regiment formed as part of the division.
However, the production of Pe-8 slowed down at the level of 3-4 ships per month. Defects periodically revealed by the military delayed the acceptance of ready-made bombers, and, consequently, the pace of production of the Pe-8. Intervened and "external" factors. With the approach of Soviet troops to the borders of Germany, the opposition of the German air defense system equipped with radar installations became more and more pronounced. And although those radars were far from perfect, although in 45 TBAD they developed instructions for overcoming radar fields, for repelling fighter attacks with radars, the Air Force leadership, apparently, decided to entrust the tasks that were once entrusted to the Pe-8 to less "noticeable" for radars B-25. In the spring of 1944, B-25D-30 bombers began to enter the division. The idea of arming the air force with a single type of aircraft was abandoned, and the 362nd regiment began to receive the Mitchells, returning the 4 Pe-8 bombers that were listed behind it.
In February 1944, a defect suddenly manifested itself, “dormant” for a long time. During the anti-aircraft maneuver after the bombing of Helsinki, the crew of the Pe-8 of the 25th Guards Regiment (aircraft serial number 42611) felt a strong blow. What happened? "Everyone look around!" But no traces of damage to the aircraft by anti-aircraft shells were found.
Only when examining the Pe-8 on the ground did they find out: there was a break in the lower belt of the front spar. Going back a few years, it should be noted that even in the first sorties of the TB-7 1-3 series, this already happened. Having decided that it was all about the insufficient strength of the spar belt, they limited themselves to strengthening the structure and reducing the bomb load to 3.2 tons - for bombers that had not been finalized. The cases of rupture of the spars at the time of the anti-aircraft maneuver stopped, the disease seemed to be cured, and they forgot about it ...
And now the emergency has happened again. The plane was laid up for a long time, and a specially created commission began to investigate the incident.
The version of the chief designer Nezval about exceeding the design stresses in flight after consultation with TsAGI specialists was rejected: the stresses were lower than the design ones. The answer was found when at plant No. 22 they examined pipe blanks that came there as material for the manufacture of Pe-8 spars. A large number of tiny hairline cracks were found in the pipes...
The incident did not put an end to the Pe-8's flight biography, but his life was declining. On June 21, 1944, the representatives of the 45th Air Division accepted the last combat Pe-8 (factory No. 42512) at the plant No. 22. But in the regiments, the development of the B-25 modifications D-30, D-35, J was already in full swing. Since 1944, not only the 362nd, but also the 890th DBAP began to receive them. Those of the pilots who mastered the Mitchells found themselves in a better position compared to fellow soldiers who “did not get” Lend-Lease equipment: the break in flights for the latter sometimes exceeded six months. By the end of the war, from November 1944, only the 25th Guards Regiment flew the Pe-8 - exclusively for training, to maintain the qualifications of the flight crew, which made it possible to perform combat missions as part of the ADD. Almost all Pe-8s in 890 DBAP were chained to the ground due to various malfunctions. As it is not surprising, but the most serviceable in the 890th regiment turned out to be ... TB-7 No. 385 "Understudy", released by Tupolev back in 1938.
The end of the war did not bring certainty to the fate of the Pe-8: the aircraft continued to be laid up, but they were not decommissioned and were not withdrawn from combat strength (with the exception of one transferred to the Civil Aviation Research Institute of the Air Force). The entire load of training and flight work in the 45th air division was carried by "non-standard" B-17 and B-24. The leadership of the Air Force KA seemed to be expecting something in order to finally determine the fate of the bomber.
In the summer of 1945, 12 Pe-8 ships departed for the Moscow region; 11 of them took part in the Air Victory Parade over Red Square. At the end of the holiday, the planes settled down at the Bykovo airfield, not far from their former air base.
On September 12, 1945, two Pe-eighths of the 203rd (former 25th) Guards Orlovsky Regiment were preparing to fly from Bykovo to Orsha, to the permanent base of the 45th Air Division. The leading bomber, commander Ishchenko, did not start the 3rd engine. Time dragged on with no results, and the second crew, having received permission, flew to Orsha. Finally, after many attempts, the engine on the commander's plane was able to start. The crew and technical staff, who were waiting for the departure - only 14 people, took their places on board. Ishchenko raised the Pe-8, at an altitude of 400 meters he circled over the airfield, and after the fourth turn, passing over the airfield, "pressed" the plane to the runway - before making a farewell "slide".
Those who remained on the ground saw how the bomber swayed slightly on the climb - it seemed that the crew was greeting the comrades gathered on the field. And the next moment the right wing collapsed. Pe-8 crashed to the ground.
As it was established during the investigation, the disaster occurred due to the fact that the front belt of the spar burst, and after it all the wing spars. The crashed plane had the number 42811...
After that, the technical condition of all the remaining aircraft was checked, and it turned out that most of them were threatened with the fate of aircraft 42811. By the beginning of 1946, out of 31 Pe-8s belonging to the 45th air division, nineteen could no longer fly.
The age of the Pe-eighth is over. The most serviceable ships were sent to civilian service. Three aircraft were transferred to the Polar Aviation. They were repainted in orange, inflicted with signs and numbers of the Polar Aviation. Aircraft No. 4218 and 42412 were transferred to the Civil Aviation Research Institute of the Air Force. The fate of most cars is sad. They began to be destroyed. “At first they tried to crush them with a light tank, such as a BT,” recalled K. P. Ikonnikov, at that time the navigator of the 203rd Guards Regiment. - one of the main landing gear was removed by car, the plane rolled over, the tank drove onto the wing, drove along it to the center section, climbed onto the fuselage and ... failed. He can’t get out on his own - he had to cut it out with an autogenous, free the tank. ” The designer of recoilless guns, Professor Lunts, arrived at the division with artillery systems developed under his leadership. Shooting from recoilless at the most vulnerable places of the aircraft, they checked the accuracy and penetrating ability of new guns ...
The "civilian" Pe-8s served well in the new field. However, even in a peaceful sky, dangers lay in wait for them. July 7, 1947 was a fateful day for the Pe-8 H-395 (former No. 18 of the 25th Guards Regiment). Due to the stop of the engines, he fell into the tundra. The damage turned out to be significant, and it was decided not to repair the aircraft, leaving it at the scene of the accident. Nevertheless, it was this Pe-8 that turned out to be the most "lucky" of all its brethren. In 1979, it was found and, disassembled into parts, was taken by An-12 aircraft to the Moninsky Aviation Museum, where it is currently located, waiting for restorations.
March 18, 2016.
March 18, 2016.