Yakovlev Yak-4


Yak-4 a Soviet intelligence light bomber.

"Product No. 23" with M-105 engines is very similar to the similar "product No. 22". Specialists from Yakovlev Design Bureau believed that the aircraft with the presence of a more powerful engine is able to develop a speed over 625 km / h. A little later found out more real speed, but interest in high speeds was not lost. In March of the year 40, the work on the revision of the serial aircraft in a new version of BB-1bis (later renamed to Yak-22) was completed at the factory No.4. On external grounds, it was practically no different from the BB-22 bomber. He had only a few differences. Engineers lengthened the exhaust pipes and appeared overlapping metal lining, which protected the plywood sheathing.

It should be noted and other features of the air unit. For example, on it for the first time we tried the additional eight-oil cooler mounted on the inside of the nacelle and the variable pitch screws VISH-22E.


In May this year, the factory tests were completed. The results, though not spectacular, but they were very close. The flight speed of the aircraft near the ground was 460 km / h, the second high-altitude border - 574 km / h. In contrast to the basic model of the time taken to climb in 5000 m, declined to 5 45 minutes seconds. It should be noted that the domestic car is slightly larger than a German fighter Bf-109E in terms of speed in the calculated altitude.

Serial production of reconnaissance bomber BB-22bis started in October of the same year the factory №81. Serial devices pretty much different from the prototype. Each nacelle were equipped with one-fired, oil cooler segment, placed in the "beard". When you exit the tunnel radiator BB-22bis installed sash, which allows the temperature of the oil during the flight. Another interesting fact is that the installation of the navigator of movable type TSS-1 ShKAS with a machine gun was the same type.

Also, this model is equipped with a bomber variable pitch propellers, 22E, not as the BB-22, dvuhshazhnymi propellers-2K. It's good for fuel economy. As planned to create a long-range bomber, initially thought about how to extend his time for the flight to the target and back. To do this, the only solution revealed hanging stolitrovyh tanks. Total capacity was 960 l. Accordingly, increased and range - 1100 km. Serial airplane BB-22bis at maximum speed reached a point 533 km / h.

NCAP ordered to rename the bomber BB-22bis in Yak-4. It was almost one period to the first flight Pe-2. In the same year 1940 began public testing. That they like the Yak-4, and Yakovlev have problems started. Pe-2 far superior to the bomber, and almost all the important parameters.


January 31 1941, the plant №81 was built more than fifty copies of the series, but only three overflew. Most of them had some defects with-rotor, which in turn made it impossible to raise the aircraft into the sky.

By order of the government in February 11 41, the mass production of Yak-4 stopped. By the time the plant had №81 construct machines Yak 28-2 and 57 machines Yak-4. Yak-4 because of the large number decided to bring up the flight status and sent to the flight of the Soviet Air Force. And thanks to the joint order of the Head of State and People's Commissar of the Air Force has built Yak 33-4. When the Second World War, these planes were divided between two shelves ATM and sent to the front. Almost immediately it was replaced by a more promising Pe-2.

Yak-4 characteristics:

Modification   Yak-4
Wingspan, m   14.00
Length m   10.18
Height, m  
Wing area, m2   29.40
Weight, kg  
  empty aircraft   4000
  normal takeoff   5845
engine's type   2 PD M-105
Power, hp   X 2 1100
Maximum speed km / h   574
Cruising speed, km / h   545
Practical range, km   960-1200
Rate of climb, m / min   920
Practical ceiling, m   9500-10000
Crew   2
Armament:   two-three 7.62-mm ShKAS machine gun
  400-800 kg bombs



I fully support the view that the plane did not particularly successful. Yet this machine was created by Yakovlev, and it means a lot. Designers simply just not thought through to the end of construction as the fuselage and tyagovooruzhonnosti. Especially at a rather difficult time, it was difficult, in the absence of normal financing and short deadlines machine.

The creation of a two-engine bomber OKB A. Yakovlev engaged in 1938, when military experts came to the conclusion about the inevitability of the upcoming military operations. Making the starting point in the design of the BB (near bomber) minimization of size and weight, completely uncharacteristic for this type of aircraft, the engineers made a fatal mistake, which could not be further corrected either by design or technological improvements. It was planned that the new aircraft would replace the slow-moving and obsolete mass bomber SB. But due to the small size of Yak-4, the possibility of rearrangement was extremely limited. The features of the accommodation of the crew and the bomb compartment caused an unacceptable offset of the alignment to the tail of the aircraft, which significantly worsened stability. Insufficient fuel supply did not allow reaching the acceptable range for the bomber. Despite such shortcomings, the production of the aircraft began. There were two modifications, from the end of the year 1940 received their own names - Yak-2 and Yak-4. "Quartet" in comparison with "deuce" had an engine of increased power (M-105) and, accordingly, higher speed and mass characteristics, as well as increased range. Extension of the fuselage made it possible to double the bomb load. However, the Yakovlev idea itself did not save it: the Yak aircraft with the indices "2" and "4" remained unsuccessful "breakthrough" of the famous designer.

I believe that the aircraft Yakovlev success bad enough. But he flew, but virtually all the benefits and end. If the prototype still had a better performance, the production models were not always of good quality. Even despite the fact that he had two egos engine load and speed were low, and it is known is not the last parameters for the aircraft of this class. Is not it strange that this model produced a short period of time, and their combat employment did not last long due to the fact that they were easy targets for the enemy.