The design bureau of the Deputy People's Commissar for the Aircraft Industry Yakovlev was among those involved in creating a new generation of combat aircraft in the USSR, working on the I-26 project. The specialization of the design bureau, which had previously created sport aircraft, had a positive impact on the project. The fighter was to have high speed and maneuverability thanks to efficient aerodynamic design and a rational layout with all large masses near the center of gravity.

The prototype flew for the first time on January 13, 1940 and turned out to be "crude": the tests were accompanied by continuous failures, accidents, and even disasters. If Yakovlev had not been a deputy people's commissar, the story of this fighter would probably have ended at the factory testing stage, but due to the use of administrative resources, the aircraft, which was given the name Yak-1, not only entered state tests, but in 1940 was put into mass production even before they were carried out. As a result, it had several major defects, which, however, did not change its overall high rating. During production, the design was constantly changed, sometimes quite fundamentally: for example, the wing design was completely changed and the oil system was redesigned several times.

The Yak-1 was a single-seat front-line fighter monoplane with a low wing of wooden construction and a retractable two-strut landing gear with a tail support. The fuselage was mounted on a welded metal frame that was integral with the engine mount. To give the fuselage a streamlined shape, bulkheads were installed at the top and bottom of the frame: the upper one, which was a continuation of the cockpit canopy, was lined with bakelite plywood and had 2 windows to improve rearward visibility.

The water-cooled M-105PF engine developed 1240 hp at takeoff and 1200 hp at an altitude of 4000 m and drove a VISH-61P three-bladed propeller.

The armament consisted of a 20 mm cannon mounted in the camber of the engine cylinder block and firing through the hollow shaft and propeller transmission, and two synchronized rifle-caliber machine guns above the engine. Racks for two 50 kg or 100 kg bombs or launch rails for six unguided rockets could be fitted to the underside of the wings.

The Yak-1 of the 69th series appeared at the front in the summer of 1942 and was able to engage in combat with all types of German aircraft, especially in turns, but was inferior to the Bf 109 in climb rate and the Bf 109 F in speed, which did not allow the type to effectively counter Bf 109 in vertical maneuvers.

The Yak-1 also had several design flaws: the main ones were fuel tank leaks and oil leaks from the propeller transmission, especially in aircraft with the M-105PF engine, which caused oil to splash onto the transparent part of the canopy, impairing visibility. There was also no canopy emergency release, which created the risk of its sliding part jamming in case of damage in combat, so pilots often preferred to fly with the cockpit open, believing that the loss of 10-15 km of speed was compensated by better visibility and safety in combat. The M-105PF engine also suffered from the same overheating problems that had occurred during testing, so it was necessary to carefully monitor the water temperature when climbing and to make horizontal turns every 2.5-3 km of altitude gained.

Nevertheless, pilots and technicians loved it: it was simple and easy to control in flight, accessible to pilots with little training and straightforward, and easy to repair in the field.

Used sources:

1. V. Shavrov “History of aircraft designs in the USSR 1938-1950.” 1988

2. M. Nikolsky “Yak-fighter” Aviation and Cosmonautics magazine No. 5-5 1999

3. Materials from the site airwar.ru