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