Yakovlev Yak-7
Unanswered Questions
Encyclopedia
The Soviet
Yakovlev Yak-7 was developed from the earlier Yak-1
fighter
, initially as a trainer
but converted into a "heavy" fighter. As both a fighter and later reverting to its original training role, the Yak-7 proved to be a capable aircraft and was well liked by air crews. The Yak-7 was simpler, tougher and generally better than the Yak-1.
s-in-training experience on a high-performance aircraft before transitioning to a fighter. With development work stated in 1940, the UTI-26 differed from its predecessor in its larger span wing being placed farther back for balance as well as having two cockpit
s with dual controls and a rudimentary communication system. It was armed with a single 7.62 mm ShKAS machine gun
in the cowling
, mainly for use in training, but Yakovlev envisioned a multi-purpose aircraft that could also undertake courier and light transport duties at the front.
The first production aircraft known as Yak-7UTIs retained a retractable main landing gear
, but beginning in the summer of 1941, a fixed landing gear variant, the Yak-7V (Vyvozoni for Familiarization) was substituted. The factory reasoned that production would be simplified and that reduced performance would not be detrimental for a trainer. Yak-7UTIs and Yak-7Vs were also equipped with skis for winter operations.
A factory team from N° 301, headed by K.A. Sinelshchikov, was detached from the Yakovlev OKB
to supervise production of Yak-7UTI. One of these aircraft (serial number 04-11) was fitted with an armored backrest plate over the rear position, selfsealing tanks which filled with inert gas as they emptied, three "RO" rocket launchers under each wing for as many RS-82 rockets, an axial 20 mm ShVAK cannon
firing through the Propeller
spinner, with 120 shells, and two 7.62 mm ShKAS machine gun
s under the cowling
, each with 750 rounds.
The rear cockpit
position was retained, allowing it to accommodate a second seat (without controls) for fast courier and transport duties or a fuel tank for extended range. The additional space could also house bombs or other gear. The engine was an M-105P and the model was designated Yak-7/M-105P.
Sinelshchikov did not inform Yakovlev about the conversion and when he learned about it, Yakovlev remained sceptical of the need for the changes. After brief factory trials, the aircraft turned out to be better than the single-seat Yak-1, thanks to the modifications already applied to the UTI as well as revised undercarriage
with bigger tyres and wheels, more efficient brakes and revised elevators, among other changes. Yakovlev submitted the Yak-7 to the authorities who approved it immediately. The firing tests at the scientific trials Polygon for aircraft armament (NIPAV) were a success and the armament was found to have no affect on the flight characteristics or the general performances of the new fighter. The aircraft's stability as a firing platform was judged far better than that of the Yak-1, the LaGG-3 and MiG-3.
The GKO
and the NKAP
issued decrees in August 1941 for the Yak-7 to be produced by Factories N°301 and N°153, but the Factory 301 had to be mo evacuated to Novosibirsk
where it merged with N° 153. So, just 62 aircraft were produced in 1941: 51 in September-October by Factory N° 301 and 11 by N°153 in December.
Test pilot A.N. Lazarev noted the good flight characteristics, how easy it was to get out of a spin, how well it behaved when diving, characteristics that he considered safer than those of the Yak-1. But the Yak-7 showed some defects: the M-105P engine piping, the landing gear locking system, the tyres and the tail wheel were identified.
The Yak-7 was introduced into the production line and the first batch of 60 reached operational squadrons by the end of 1941.
Another important variant was the Yak-7/M-105PA. On this model the two ShKAS on the cowling had been replaced by two UBS with 400 rounds (260 for the left and 160 for the right). It was powered by an M-105PA engine with a ShVAK axial cannon and 120 rounds. Oil and glycol radiators had been widened and refined and slightly tilted downwards. The insulation of the airframe was improved, tail wheel was totally retractable; joints and skin were more carefully made; panels on engine cowling fitted better; the propeller reduction gear worked better; an electro-pneumatic reloading system was installed; canopy frame was reinforced. The Yak-B made 27 tests flights in January and February 1942. The reports noted that while the aircraft "was not inferior to the LaGG-3 and MiG-3 and to foreign fighters in service in the USSR", it was more stable and had better flight characteristics. Subsequently the GKO authorised production at Factory N°153 in place of the Yak-7A, from April 1942 and 261 machines were built until July. After 20 May, the aircraft were equipped with a 18 gallons tank behind the pilot’s seat, but the pilots that used the Yak-7 on Stalingrad and on the Kuban removed it as it was not protected and affected the flight characteristics. Generally the Yak-7B pleased its pilots. They reported that it was easy to fly at all altitudes, stable and easy to maintain and although it did not climb as quickly as a Bf 109, it was as manoeuvrable and fast, except in the vertical plane. But defects were also noted: there was too much drag from the radiators, canopy glass was of bad quality; pilot was not protected enough, taking-off and landing distances were too long and, above all, it was underpowered.
Yakovlev suggested Klimov, the engine builder, some modifications that resulted in the M-105PF which was 130 bhp more powerful. With this modified engine the Yak-7B top speed was of 372 mph, it climbed much faster up to 16,500 feet and it was more manoeuvrable both in the horizontal and the vertical planes. But because the rear tank was removed, its range was reduced and the CG was moved too forward, while M-105 defects (glycol and oil overheating, oil leaks etc.) persisted.
After the war, some Yak-7V trainers were provided to the Poles and a single Yak-7V was delivered to the Hungarians for familiarization with the Yak-9 fighter.
Ya-27: two-seat prototype converted from a pre-serial I-26
Yak-7: two-seat training, liaison aircraft. The Yak-1 was built in small numbers.
Yak-7UTI: initial two-seat communication/trainer version
Yak-7V: (UTI-26, vyvoznoy) production version of two-seater; about 1,500 were built.
Yak-7A: production single-seat fighter version with M-105P piston engine
Yak-7B: upgraded version of Yak-7A (reduced wingspan, simplified landing gear, better equipment), about 5,000 were built.
Yak-7D: long range prototype.
Yak-7K courier: VIP transport version. converted from Yak-7B, 1944.
Yak-7U Mark:
Yak-7PVRD: experimental - had two DM-4 ramjet
under wings. Two were built.
Yak-7DI: direct predecessor of Yak-9
.
Yak-7 M-82: - new (M-82) engine version. tested in 1941.
Yak-7R: Jet project with one liquid fuel jet and two ramjet
s. 1942.
Yak-7R: purported jet version of Yak-7 with Jumo 004
engine. Said to have been built in Tbilisi to fly over Red Square at the parade in 1947.
Yak-7R: Yak-3 with Jumo 004
turbojet. Development started not later than 1945
. First flown in 1946?
Yak-7T: two aircraft for testing engine mounted heavy cannons (NS-37 and NS-45—37 mm and 45 mm caliber respectively).
Early Modern France
Bulgaria
Hungary
Mongolia
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
Yakovlev Yak-7 was developed from the earlier Yak-1
Yakovlev Yak-1
The Yakovlev Yak-1 was a World War II Soviet fighter aircraft. Produced from early 1940, it was a single-seat monoplane with a composite structure and wooden wings....
fighter
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...
, initially as a trainer
Trainer (aircraft)
A trainer is a class of aircraft designed specifically to facilitate in-flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristics and a simplified cockpit arrangement—allows...
but converted into a "heavy" fighter. As both a fighter and later reverting to its original training role, the Yak-7 proved to be a capable aircraft and was well liked by air crews. The Yak-7 was simpler, tougher and generally better than the Yak-1.
Design and development
In 1939, Alexander Yakovlev designed a tandem-seat advanced trainer, originally designated "I-27" and then "UTI-26", offered along with the original I-26 proposal that became the Yak-1. The "UTI" (Uchebno Trenirovochnyi Istrebitel, translated as: Training Fighter) was intended to give pilotAviator
An aviator is a person who flies an aircraft. The first recorded use of the term was in 1887, as a variation of 'aviation', from the Latin avis , coined in 1863 by G. de la Landelle in Aviation Ou Navigation Aérienne...
s-in-training experience on a high-performance aircraft before transitioning to a fighter. With development work stated in 1940, the UTI-26 differed from its predecessor in its larger span wing being placed farther back for balance as well as having two cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
s with dual controls and a rudimentary communication system. It was armed with a single 7.62 mm ShKAS machine gun
ShKAS machine gun
The ShKAS is a 7.62 mm machine gun widely used by Soviet aircraft in the 1930s and during World War II...
in the cowling
Cowling
A cowling is the covering of a vehicle's engine, most often found on automobiles and aircraft.A cowling may be used:* for drag reduction* for engine cooling by directing airflow* as an air intake for jet engines* for decorative purposes...
, mainly for use in training, but Yakovlev envisioned a multi-purpose aircraft that could also undertake courier and light transport duties at the front.
The first production aircraft known as Yak-7UTIs retained a retractable main landing gear
Landing Gear
Landing Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...
, but beginning in the summer of 1941, a fixed landing gear variant, the Yak-7V (Vyvozoni for Familiarization) was substituted. The factory reasoned that production would be simplified and that reduced performance would not be detrimental for a trainer. Yak-7UTIs and Yak-7Vs were also equipped with skis for winter operations.
A factory team from N° 301, headed by K.A. Sinelshchikov, was detached from the Yakovlev OKB
OKB
OKB is a transliteration of the Russian acronym for "Опытное конструкторское бюро" - Opytnoe Konstructorskoe Byuro, meaning Experimental Design Bureau...
to supervise production of Yak-7UTI. One of these aircraft (serial number 04-11) was fitted with an armored backrest plate over the rear position, selfsealing tanks which filled with inert gas as they emptied, three "RO" rocket launchers under each wing for as many RS-82 rockets, an axial 20 mm ShVAK cannon
ShVAK cannon
The ShVAK was a 20 mm autocannon used by the Soviet Union during World War II. It was designed by Boris Shpitalniy and Semyon Vladimirov and entered production in 1936...
firing through the Propeller
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...
spinner, with 120 shells, and two 7.62 mm ShKAS machine gun
ShKAS machine gun
The ShKAS is a 7.62 mm machine gun widely used by Soviet aircraft in the 1930s and during World War II...
s under the cowling
Cowling
A cowling is the covering of a vehicle's engine, most often found on automobiles and aircraft.A cowling may be used:* for drag reduction* for engine cooling by directing airflow* as an air intake for jet engines* for decorative purposes...
, each with 750 rounds.
The rear cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...
position was retained, allowing it to accommodate a second seat (without controls) for fast courier and transport duties or a fuel tank for extended range. The additional space could also house bombs or other gear. The engine was an M-105P and the model was designated Yak-7/M-105P.
Sinelshchikov did not inform Yakovlev about the conversion and when he learned about it, Yakovlev remained sceptical of the need for the changes. After brief factory trials, the aircraft turned out to be better than the single-seat Yak-1, thanks to the modifications already applied to the UTI as well as revised undercarriage
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...
with bigger tyres and wheels, more efficient brakes and revised elevators, among other changes. Yakovlev submitted the Yak-7 to the authorities who approved it immediately. The firing tests at the scientific trials Polygon for aircraft armament (NIPAV) were a success and the armament was found to have no affect on the flight characteristics or the general performances of the new fighter. The aircraft's stability as a firing platform was judged far better than that of the Yak-1, the LaGG-3 and MiG-3.
The GKO
GKO
GKO , OFZ are abbreviations for and , respectively. They are government bonds issued by the state of Russia.GKOs are short-term zero-coupon Russian Government Treasury Bills. OFZs are coupon-bearing Federal Loan Bonds...
and the NKAP
NKAP
NF-kappa-B-activating protein is a protein that in humans is encoded by the NKAP gene.-Further reading:...
issued decrees in August 1941 for the Yak-7 to be produced by Factories N°301 and N°153, but the Factory 301 had to be mo evacuated to Novosibirsk
Novosibirsk
Novosibirsk is the third-largest city in Russia, after Moscow and Saint Petersburg, and the largest city of Siberia, with a population of 1,473,737 . It is the administrative center of Novosibirsk Oblast as well as of the Siberian Federal District...
where it merged with N° 153. So, just 62 aircraft were produced in 1941: 51 in September-October by Factory N° 301 and 11 by N°153 in December.
Test pilot A.N. Lazarev noted the good flight characteristics, how easy it was to get out of a spin, how well it behaved when diving, characteristics that he considered safer than those of the Yak-1. But the Yak-7 showed some defects: the M-105P engine piping, the landing gear locking system, the tyres and the tail wheel were identified.
The Yak-7 was introduced into the production line and the first batch of 60 reached operational squadrons by the end of 1941.
Another important variant was the Yak-7/M-105PA. On this model the two ShKAS on the cowling had been replaced by two UBS with 400 rounds (260 for the left and 160 for the right). It was powered by an M-105PA engine with a ShVAK axial cannon and 120 rounds. Oil and glycol radiators had been widened and refined and slightly tilted downwards. The insulation of the airframe was improved, tail wheel was totally retractable; joints and skin were more carefully made; panels on engine cowling fitted better; the propeller reduction gear worked better; an electro-pneumatic reloading system was installed; canopy frame was reinforced. The Yak-B made 27 tests flights in January and February 1942. The reports noted that while the aircraft "was not inferior to the LaGG-3 and MiG-3 and to foreign fighters in service in the USSR", it was more stable and had better flight characteristics. Subsequently the GKO authorised production at Factory N°153 in place of the Yak-7A, from April 1942 and 261 machines were built until July. After 20 May, the aircraft were equipped with a 18 gallons tank behind the pilot’s seat, but the pilots that used the Yak-7 on Stalingrad and on the Kuban removed it as it was not protected and affected the flight characteristics. Generally the Yak-7B pleased its pilots. They reported that it was easy to fly at all altitudes, stable and easy to maintain and although it did not climb as quickly as a Bf 109, it was as manoeuvrable and fast, except in the vertical plane. But defects were also noted: there was too much drag from the radiators, canopy glass was of bad quality; pilot was not protected enough, taking-off and landing distances were too long and, above all, it was underpowered.
Yakovlev suggested Klimov, the engine builder, some modifications that resulted in the M-105PF which was 130 bhp more powerful. With this modified engine the Yak-7B top speed was of 372 mph, it climbed much faster up to 16,500 feet and it was more manoeuvrable both in the horizontal and the vertical planes. But because the rear tank was removed, its range was reduced and the CG was moved too forward, while M-105 defects (glycol and oil overheating, oil leaks etc.) persisted.
Operational history
The Yak-7 proved to be an effective close support fighter although the first two-seaters were considered nose-heavy, consequently, the factory introduced a rear cockpit fuel tank. Pilots complained about the fuel tank's vulnerability since it was unarmoured, and it was usually removed in the field. There were constant changes to the design based on combat observations including a definitive single-seat variant, the Yak-7B which was produced in large numbers.After the war, some Yak-7V trainers were provided to the Poles and a single Yak-7V was delivered to the Hungarians for familiarization with the Yak-9 fighter.
Variants
Yak-7: two-seat training, liaison aircraft. The Yak-1 was built in small numbers.
Yak-7UTI: initial two-seat communication/trainer version
Yak-7V: (UTI-26, vyvoznoy) production version of two-seater; about 1,500 were built.
Yak-7A: production single-seat fighter version with M-105P piston engine
Yak-7B: upgraded version of Yak-7A (reduced wingspan, simplified landing gear, better equipment), about 5,000 were built.
Yak-7D: long range prototype.
Yak-7K courier: VIP transport version. converted from Yak-7B, 1944.
Yak-7U Mark:
Yak-7PVRD: experimental - had two DM-4 ramjet
Ramjet
A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of airbreathing jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot produce thrust at zero airspeed and thus cannot move an aircraft from a standstill...
under wings. Two were built.
Yak-7DI: direct predecessor of Yak-9
Yakovlev Yak-9
The Yakovlev Yak-9 was a single-engine fighter aircraft used by the Soviet Union in World War II and after. Fundamentally a lighter development of the Yak-7 with the same armament, it arrived at the front at the end of 1942. The Yak-9 had a lowered rear fuselage decking and all-around vision canopy...
.
Yak-7 M-82: - new (M-82) engine version. tested in 1941.
Yak-7R: Jet project with one liquid fuel jet and two ramjet
Ramjet
A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of airbreathing jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot produce thrust at zero airspeed and thus cannot move an aircraft from a standstill...
s. 1942.
Yak-7R: purported jet version of Yak-7 with Jumo 004
Junkers Jumo 004
The Jumo 004 was the world's first turbojet engine in production and operational use, and the first successful axial compressor jet engine ever built. Some 8,000 units were manufactured by Junkers in Germany during late World War II and powered the operational Messerschmitt Me 262 jet fighter,...
engine. Said to have been built in Tbilisi to fly over Red Square at the parade in 1947.
Yak-7R: Yak-3 with Jumo 004
Junkers Jumo 004
The Jumo 004 was the world's first turbojet engine in production and operational use, and the first successful axial compressor jet engine ever built. Some 8,000 units were manufactured by Junkers in Germany during late World War II and powered the operational Messerschmitt Me 262 jet fighter,...
turbojet. Development started not later than 1945
1945 in aviation
This is a list of aviation-related events from 1945:- Events :* The probe-and-drogue aerial refueling system, in which the tanker aircraft trails a hose with a stabilizing conical drogue at its end which mates to a fixed probe mounted on the receiving aircraft, is perfected...
. First flown in 1946?
Yak-7T: two aircraft for testing engine mounted heavy cannons (NS-37 and NS-45—37 mm and 45 mm caliber respectively).
Operators
Early Modern France
- Free French Air ForceFree French Air ForceThe Free French Air Force was the air arm of the Free French Forces during the Second World War.-Fighting for Free France — the FAFL in French North Africa :...
operated some in the Normandie-NiemenNormandie-NiemenThe Normandie-Niemen Regiment was a fighter squadron, later regiment of the French Air Force. It served on the Eastern Front of the European Theatre of World War II with the 1st Air Army...
squadron
Bulgaria
- Bulgarian Air ForceBulgarian Air ForceThe Bulgarian Air Force is a branch of the Military of Bulgaria, the other two being the Bulgarian Navy and Bulgarian land forces. Its mission is to guard and protect the sovereignty of Bulgarian airspace, to provide aerial support and to assist the Land Forces in case of war. The Bulgarian Air...
operated three Yak-7V.
Hungary
- Hungarian Air ForceHungarian Air ForceThe Hungarian Air Force is the air force branch of the Hungarian Army.- 1918 to Pre–World War II :Following the dissolution of the Austro-Hungarian Monarchy in 1918, a small air arm was established operating surviving aircraft from Hungarian factories and training schools...
operated one Yak-7V for familiarization with the Yak-9 fighter.
Mongolia
- Mongolian People's Air ForceMongolian People's ArmyThe Mongolian People's Army or Mongolian People's Revolutionary Army was established on 18 March 1921 as a secondary army under Soviet Red Army command during the 1920s and during World War II.-Creation of the army:One of the first actions of the new Mongolian People's Revolutionary Party...
operated some aircraft as trainers
- The Polish Air Force in Soviet UnionPolish Air ForceThe Polish Air Force is the military Air Force wing of the Polish Armed Forces. Until July 2004 it was officially known as Wojska Lotnicze i Obrony Powietrznej...
operated a few Yak-7Bs for training in the 1st Fighter Regiment "Warszawa". Several Yak-7Vs were used for training and courier duties. Yak-7s were operated by the Polish Air Force between September 1943 till September 23, 1946.
- Soviet Air ForceSoviet Air ForceThe Soviet Air Force, officially known in Russian as Военно-воздушные силы or Voenno-Vozdushnye Sily and often abbreviated VVS was the official designation of one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces...
- SFR Yugoslav Air ForceSFR Yugoslav Air ForceThe Socialist Federal Republic of Yugoslavia Yugoslav Air Force , was the air force of the Socialist Federal Republic of Yugoslavia . Formed in 1945, it was preceded by the Yugoslav Royal Air Force which was disbanded in 1941, following the German occupation of Yugoslavia...
operated two Yak-7V.
Specifications (Yak-7)
Cultural references
The Yakovlev Yak-7 was the attack plane for Soviet Forces in the computer game Command & Conquer: Red AlertCommand & Conquer: Red Alert
Command & Conquer: Red Alert is a real-time strategy computer game of the Command & Conquer franchise, produced by Westwood Studios and released by Virgin Interactive in...