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