The pursuit of better performance continued until all the possibilities for improvement were literally squeezed out of the Yak-1’s mixed design characterized by an all-wooden wing.
In the process, alterations to the basic design gave birth to new, more advanced types – the Yak-9 in 1942 and Yak-3 in 1944. Still, given the high degree of manufacturing optimization achieved at Saratov factory, it was decided to keep the fighter that was rapidly becoming obsolete in production. Its latest version – the Yak-1b – contributed significantly to the wartime effort of the Soviet Union. These developments as well as some interesting facts from the Yak-1/1b history are covered in the current volume.
Combat history and comparative data
The first months of hostilities on the Eastern front demonstrated (see Appendix 1) that most air combat occurred at altitudes between 1,500-4,000 m, mainly because of the way bombers were used there. Bombers focused mostly on close air support, performing dive bombing runs and low level strikes to hit small size targets on the battlefield. As the fighters provided support for the bombers, they had to operate at these lower altitudes as well. Naturally, the performance of the MiG-3, LaGG-3, and Yak-1 – the fighters that were designed in response to the requirement for a high altitude fighter – deteriorated. The high-altitude MiG-3 suffered the most, becoming unresponsive and inert at low altitudes and falling significantly behind the German Bf 109 in terms of maneuverability. Even though some pilots achieved successes in this type, the MiG’s poor performance together with its lack of cannon meant that it did not meet the requirements for a frontline fighter plane. Late in 1941, the decision had been taken to stop manufacturing the MiG-3.
It is difficult to know the reasons behind such a radical decision to discontinue the fighter that was favored the most before the war rather than attempt to modify it. Most likely it was a combination of factors that among others included large losses of this type in the first days of the war, the evacuation of production to the east with resulting decline in manufacturing volumes, the Red Army’s need for the Il-2 attack aircraft powered by similar engines, and the shortage of aluminum caused by the capture of Volkhov and Dneprovsk factories providing up to 60% of all aluminum before the war. Meanwhile, surviving MiGs were being transferred to the air defense units.
The LaGG-3, like the MiG-3, was not without its own set of issues. The production launch of the LaGG-3 was slowed down by a number of objective and subjective factors, so it was late for war. In the first half of 1941, four (!) factories – Nos. 21, 23, 31, and 153 – together manufactured only 181 LaGGs compared to 387 Yak-1s and 1,363 MiG-3s. Performance characteristics of this fighter turned out to be worse than those of the Yak-1 despite being powered by the same engine: this was a result of the higher drag and weight of the LaGG-3. Furthermore, series fighters manufactured at Factory No.21 suffered from poor workmanship; their speeds would be 30 to 102 km/h lower in comparison to the prototype. According to the results of control evaluation of the LaGG-3 No. 3121422 of the 4th production series, it could only reach 503 km/h at 5000 m when equipped with eight RS-82 launchers under the wing. An aircraft from the 7th production series without rockets accelerated to 549 km/h at the same altitude. To some degree, the military could be blamed for such loss of performance: it was at their insistence that the LaGG-3 was equipped with eight rocket launchers plus two drop tanks. The young Lavochkin’s bureau did not yet encounter the bitter experience of dealing with the military’s requests to “improve” designs, something that Yakovlev’s bureau already learned about with the AIR-8 and BB-22. In combat, it became evident that the overweight LaGG-3 severely lacked climb rate, lost altitude rapidly during turns and banks, and stalled too easily. Moreover, the main undercarriage legs often failed during landings because poorly manufactured struts from Factory No.31 were prone to seize. While the hydraulic system and the powerful armament of the LaGG-3 were definitely advantageous, they required additional tools, more maintenance, and increased the mission preparation time. On top of that, it turned out that it was impossible to overhaul the LaGG’s hydraulic system in the field.
Additionally, the all-wooden design of the LaGG-3 fuselage was poorly suited for field operations. After 10-15 days in the open air at 20-30°C, the filler, especially at the fuselage tail part, started to crack. Plywood skin warped and cracked, and the moisture getting through cracks caused wooden structural elements to rot, which substantially reduced the fuselage strength. For the Yak-1 this was less of a problem as the strength of its steel truss did not depend on the condition of the skin to such an extent. LaGGs whose plywood skin was compromised in that way had to be written off. Overhauling and repairing the LaGG-3 was complicated as spares manufactured at the Factory No. 21 did not fit the aircraft manufactured at the Factory No. 31 and vice versa – again, less of a problem for Yak-1’s, which starting with the second quarter of 1941, were manufactured at a single location.
Finally, the Lavochkin design bureau was significantly late in responding to the Government’s request for ski undercarriage in the winter of 1941-42. Not only that, but their design was below any criticism: the skis would deploy spontaneously in flight, it was impossible to retract them at speeds above 280 km/h. However, Factory No. 21 had no wheels available and had to deliver all its fighters with skis, further reducing their combat value. All this cultivated negative attitudes toward the LaGG-3 among frontline personnel who characterized it as being heavy and even incapable of standing up to enemy fighters (TsVMA st. 12 inv. 1 file 60 p. 94).
The Yak-1, on the other hand, enjoyed more positive assessment from Soviet pilots in 1941-42. It was considered capable of fighting with all German fighters on more or less equal terms. The type still had a worse climb rate compared to the Bf 109E and was slower than the Bf 109F. The Yak-1 was also at a disadvantage in vertical maneuvers, required special flight and gunnery skills from its pilot, and needed reserves of speed or altitude before the engagement. Equipped with leading edge slats, the Bf 109 could climb higher than the Yak-1 before stalling. Furthermore, the Messerschmitt’s direct fuel injection engine operated reliably at zero or negative g’s, whereas the carburetor-equipped M-105 could easily stall. German pilots learned to use this feature to their advantage. They also avoided frontal attacks considering that both opponents had equal chances in this type of engagement (in fact, the Yak’s salvo weight was 2.138 kg per second vs. 1.562 kg/s of the Bf 109F-4). Aware of their aircraft’s shortcomings, Soviet pilots preferred horizontal maneuvers, where the Yak had a small advantage. Widespread reliance of Soviet pilots on horizontal maneuvers also stemmed from their lack of experience with new types of fighters, which replaced slow but maneuverable I-16’s and I-15/15bis/153. To make vertical maneuvers difficult for their opponents, Soviet pilots tried to fight just below cloud layers or to spread their forces by altitude. Experienced Soviet aces were able to successfully use vertical maneuvers to their advantage in the Yak-1.
German aviators also noted the advantage of the Yak-1 over other Soviet fighter types. In the report on the JG54 combat experience it was noted:
“The Yak model was considered the best Soviet fighter plane. It had even better climbing performance and was faster than the I-18 (MiG-3 – authors), and approached the performance of the Bf 109F although it was not as fast. It was more difficult to set on fire when attacking from the rear than the Mig-3. Up to 19,100 feet it still climbed well but showed poor maneuverability”.
Some Luftwaffe pilots even considered the new Soviet fighters not inferior to their mounts:
“Major Rall confirms the above statements on the properties of the more modern Soviet fighter aircraft and also mentions their water-cooled engines and their closed cockpits. He also considers the German fighter models superior. Major Jaehne, however, admits that the new Soviet models were superior to the German Ju-88, and Colonel von Heimann supplements the picture with the statement that the new Soviet fighter models were of simple construction, fast, and maneuverable, and overall not much inferior to the German Bf 109F” (quoted from Schwabedissen W. The Russian Air Force in the Eyes of German Commanders. USAF Historical Studies №.175. Air University, 1960, p.103).