| The Yakovlev Yak-1 was a World War II Soviet | | | | required adjusting their attachments to |
| fighter aircraft and the first among the | | | | ensure an even stance for the completed |
| war's many successful Yakovlev fighters. | | | | aircraft. Parts were often |
| | | | non-interchangeable between aircraft. |
| Design and development | | | | Production of Yak-1 ended in July 1944 with |
| | | | somewhere around 8,700 built. |
| Although prior to World War II Yakovlev was | | | | |
| best known for building light sports | | | | Operational history |
| aircraft, the Yak-4 light bomber impressed | | | | |
| the Soviet government enough to order the OKB | | | | At the onset of Great Patriotic War on 22 |
| to design a new fighter with a Klimov M-106 | | | | June 1941, 425 Yak-1 were built, although |
| V-12 liquid-cooled engine. Formal | | | | many of these were en route or still |
| specifications released on 29 July 1939, | | | | disassembled. It was soon discovered that |
| called for two prototypes - I-26-1 with a top | | | | most air combat took place below 4,000 m |
| speed of 620 km/h (385 mph) at 6,000 m | | | | (13,000 ft) which placed the new Soviet |
| (20,000 ft), combat range of 600 km (375 mi), | | | | fighters, designed for high-altitude |
| a climb to 10,000 m (32,800 ft) of under 11 | | | | performance at a disadvantage. Still, Yak-1s |
| minutes, and armament of 2x 7.62 mm ShKAS | | | | did prove to have a significant advantage |
| machine guns and 1x 12.7 mm Berezin BS heavy | | | | over its Soviet competitors. A full circle |
| machine gun, and I-26-2 with a turbocharged | | | | turn took just 17 seconds in the Yak-1M. The |
| M-106 engine with a top speed of 650 km/h | | | | MiG-3, which had the best high-altitude |
| (404 mph) at 10,000 m (33,000 ft) and | | | | performance, did poorly at low and medium |
| armament of 2x 7.62 mm ShKAS machine guns. | | | | altitudes and its light armament made it |
| The design took full advantage of Yakovlev | | | | unsuitable even for ground attack. The LaGG-3 |
| OKB's experience with sports aircraft and | | | | experienced a significant degradation in |
| promised agility as well as high top speed. | | | | performance (as much as 100 km/h (62 mph) on |
| Since M-106 was delayed, the design was | | | | some aircraft) compared to its prototypes due |
| changed to incorporate Klimov M-105P with a | | | | to the manufacturer's inexperience with its |
| 20 mm ShVAK cannon in the "vee" of the engine | | | | special wooden construction which suffered |
| block. | | | | from warping and rotting when exposed to the |
| | | | elements. The Yak-1's plywood covering also |
| I-26-I first flew on 13 January 1940. The | | | | suffered from the weather but the steel frame |
| prototype suffered from oil overheating | | | | kept the aircraft largely intact. |
| problems which were never completely resolved | | | | |
| resulting in 15 emergency landings during | | | | The aircraft's major problem early in |
| early testing. Then, on 27 April 1940, I-26-1 | | | | deployment was fuel leaks caused by |
| crashed, killing its test pilot Yu.I. | | | | disintegration of spot-welded fuel tanks from |
| Piontkovskiy. The investigation of the crash | | | | vibration. Also troublesome was the fact that |
| found that the pilot performed two | | | | the canopy could not be opened at high |
| consecutive barrel rolls at low altitude | | | | speeds, potentially trapping the pilot in a |
| which was in violation of test flight plan. | | | | falling aircraft. As the result, some pilots |
| It was believed that during the first roll, | | | | had the sliding portion of the canopy removed |
| the main landing gear became unlocked, | | | | altogether. The notoriously unreliable and |
| causing it to crash through the wing during | | | | short-ranged radio equipment was also |
| the second roll. It has been hypothesized | | | | frequently removed to save weight. Like most |
| that Piontkovskiy's deviation from the flight | | | | early carburetor-equipped engines, M-105 |
| plan was caused by frustration that his | | | | could not tolerate negative G forces which |
| aircraft was being used for engine testing | | | | starved it of fuel. |
| while I-26-2, built with the lessons of | | | | |
| I-26-1 in mind, was already performing | | | | Nonetheless, the Yak-1 was well-liked by its |
| aerobatics. | | | | pilots. Twenty-four of these aircraft were |
| | | | sent to the elite all-female 586 IAP whose |
| Poor quality of subassemblies provided by | | | | pilots included the world's only female aces |
| different suppliers raised the I-26-2's | | | | with 11 (Katya Budanova) and 12 (Lydia |
| weight 400 kg (880 lb) above projected | | | | Litvyak) victories. Yak-1s were also the |
| figues, which restricted the airframe to only | | | | first aircraft of the 1st Polish Fighter |
| 4.4 G while overheating oil was still a | | | | Regiment "Warsaw" (Polish: 1 Pulk Lotnictwa |
| problem. The many defects caused I-26-2 to | | | | Mysliwskiego "Warszawa") and French |
| fail government testing in 1940. Fortunately | | | | Normandie-Niemen squadron. |
| for Yakovlev, its competitors I-200 (future | | | | |
| Mikoyan-Gurevich MiG-3) and I-301 (future | | | | Variants |
| LaGG-3) also failed testing. Requested | | | | |
| improvements were incorporated into I-26-3 | | | | Yak-1b - ("b" was an unofficial designation, |
| which was delivered for testing on 13 October | | | | after October 1942, all Yak-1s were built to |
| 1940. Although it passed on 9 December 1940, | | | | this standard). New bubble canopy with |
| the aircraft was still very much unfinished | | | | lowered rear fuselage, increased armor, ShKAS |
| with unresolved engine problems. | | | | machine guns replaced with a single 12.7 mm |
| | | | Berezin UBS, electrical and pneumatic firing |
| Troublesome and slow testing and development | | | | of the weapons instead of the mechanical |
| must have been quite worrisome for Soviet | | | | system, new control stick based on the |
| officials considering the fact that I-26 was | | | | Messerschmitt Bf 109 design, new gunsight, |
| ordered into production under the name Yak-1 | | | | airtight fuselage, retractable tailwheel, |
| on 19 February 1940 - a mere month after | | | | improved engine cooling, Klimov M-105PF |
| I-26-1 made its maiden flight! The goal of | | | | engine with better low-altitude performance. |
| this gamble was to reduce lag time between | | | | The first flight (aircraft No.3560) took |
| prototype and production aircraft. [1] As a | | | | place in June 1942, with aircraft entering |
| backup, I-200 and I-301 were also ordered | | | | production in August. A total of 4,188 were |
| into production. Although Yak-1 was slower | | | | built. |
| than I-200 and less heavily armed than I-301, | | | | |
| it enjoyed the advantage of having been | | | | Yak-1M - Yak-3 prototype with a smaller wing, |
| started earlier which gave it a consistent | | | | revised cooling intakes, reduced overall |
| lead in testing and development over its | | | | weight and upgraded engine. Two were built. |
| competitors. Beginning of the Great Patriotic | | | | |
| War on 22 June 1941 made development and | | | | Several other Yak-1 variants did not receive |
| implementation of several other upcoming | | | | special designations. These include |
| promising designs like Polikarpov I-185 | | | | prototypes with Klimov VK-106 and Klimov |
| unfeasible. The fact that Yakovlev was | | | | VK-107 engines, production aircraft capable |
| Stalin's personal favorite likely also played | | | | of carrying external fuel tanks, production |
| in the Yak-1's favor. | | | | aircraft with the ability to carry 6x RS-82 |
| | | | rockets or 2x 100 kg (220 lb) bombs, and |
| Simultaneous manufacturing and testing of a | | | | lightened versions for air defense. |
| design that required as many improvements as | | | | |
| I-26 wreaked havoc on the production lines. | | | | I-28 (Yak-5) - High-altitude interceptor |
| Almost 8,000 changes were made to the | | | | prototype with Klimov M-105PD engine |
| aircraft's blueprints by 1941 with an | | | | developed from I-26-2. Differed from I-26 in |
| additional 7,000 implemented the following | | | | having an all-metal fuselage and tail and |
| year with 5,000 more changes coming in 1942. | | | | automatic, leading-edge slats on slightly |
| Production was further slowed by shortages of | | | | smaller and reshaped wings. One aircraft was |
| engines, propellers, radiators, wheels and | | | | built, first flying on 1 December 1940. It |
| cannons. Shortages of quality materials | | | | did not enter production due to many |
| resulted in plywood being torn off the wings | | | | deficiencies of the engine but served as the |
| on several aircraft. To make the matters | | | | basis for high-altitude versions of Yak-7 and |
| worse, Factory No.292 which was the main | | | | Yak-9. |
| manufacturer of Yak-1s was bombed on 23 June | | | | |
| 1943 and burned to the ground. Amazingly, | | | | I-30 (Yak-3) - Development of I-26 with an |
| production resumed among the ruins on 29 | | | | all-metal wing with leading-edge slats, |
| June. Due to loose tolerances, each aircraft | | | | weight and space savings were utilized for |
| was essentially unique with workers | | | | additional armament and greater fuel |
| performing the final assembly having the | | | | capacity. Two prototypes built - I-30-1 armed |
| unenviable task of mating what often proved | | | | with 3x 20 mm ShVAK cannons and 2x 7.62 mm |
| to be very dissimilar components. For | | | | ShKAS machine guns, and I-30-2 with two |
| example, left and right main landing gear | | | | additional ShKAS. It did not enter |
| could be of different lengths and different | | | | production. The name Yak-3 was re-used for a |
| angles relative to the aircraft which | | | | different fighter. |