Lavochkin La-7
Encyclopedia
The Lavochkin La-7 was a piston-engined Soviet
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....

 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...

 developed during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 by the Lavochkin Design Bureau
Lavochkin
NPO Lavochkin is a Russian aerospace company. It is a major player in the Russian space program, being the developer and manufacturer of the Fregat upper stage, as well as interplanetary probes such as Phobos Grunt...

 (OKB
OKB
OKB is a transliteration of the Russian acronym for "Опытное конструкторское бюро" - Opytnoe Konstructorskoe Byuro, meaning Experimental Design Bureau...

). It was a development and refinement of the Lavochkin La-5
Lavochkin La-5
|- See also :- References :NotesBibliography* Abanshin, Michael E. and Nina Gut. Fighting Lavochkin, Eagles of the East No.1. Lynnwood, WA: Aviation International, 1993. ISBN unknown....

, and the last in a family of aircraft that had begun with the LaGG-1 in 1938. Its first flight
Maiden flight
The maiden flight of an aircraft is the first occasion on which an aircraft leaves the ground of its own accord. This is similar to a ship's maiden voyage....

 was in early 1944 and it entered service with the Soviet Air Forces later in the year. A small batch of La-7s was given to the Czechoslovak Air Force
Czechoslovak Air Force
The Czechoslovak Air Force was the air force branch of the military of Czechoslovakia. It was known as the Czechoslovak Army Air Force from 1918–1939...

 the following year, but it was otherwise not exported. Armed with two or three 20 mm (0.78740157480315 in) cannon, it had a top speed of 661 kilometres per hour (410.7 mph). The La-7 was felt by its pilots to be at least the equal of any German piston-engined fighter and even shot down a Messerschmitt Me 262
Messerschmitt Me 262
The Messerschmitt Me 262 Schwalbe was the world's first operational jet-powered fighter aircraft. Design work started before World War II began, but engine problems prevented the aircraft from attaining operational status with the Luftwaffe until mid-1944...

 jet fighter. It was phased out in 1947 by the Soviets, but lasted until 1950 with the Czechoslovak Air Force.

Design and development

By 1943, the La-5 had become a mainstay of the Soviet Air Forces, yet both its head designer, Semyon Lavochkin
Semyon Lavochkin
Semyon Alekseyevich Lavochkin , a Soviet aerospace engineer, Soviet aircraft designer who founded the Lavochkin aircraft design bureau. Many of his fighter designs were produced in large numbers for Soviet forces during World War II.-Biography:...

, as well as the engineers at the Central Aerohydrodynamics Institute
TsAGI
TsAGI is a transliteration of the Russian abbreviation for Центра́льный аэрогидродинами́ческий институ́т or "Tsentralniy Aerogidrodinamicheskiy Institut", the Central Aerohydrodynamic Institute....

 , felt that it could be improved upon. TsAGI refined earlier studies of aerodynamic improvements to the La-5 airframe in mid-1943 and modified La-5FN c/nconstruction number 39210206 to evaluate the changes. These included complete sealing of the engine cowling, rearrangement of the wing center section to accommodate the oil cooler and the relocation of the engine air intake from the top of the cowling to the bottom to improve the pilot's view.

The aircraft was evaluated between December 1943 and February 1944 and proved to have exceptional performance. Using the same engine as the standard La-5FN c/n 39210206 had a top speed of 684 kilometres per hour (425 mph) at a height of 6150 metres (20,177.2 ft), some 64 kilometres per hour (39.8 mph) faster than the production La-5FN. It took 5.2 minutes to climb to 5000 metres (16,404 ft). It was faster at low to medium altitudes than the La-5 that used the more powerful prototype Shvetsov M-71
Shvetsov M-71
-Bibliography:...

 engine.

Lavochkin had been monitoring TsAGIs improvements and began construction in January 1944 of an improved version of the La-5 that incorporated them as well as lighter, but stronger, metal wing spar
Spar (aviation)
In a fixed-wing aircraft, the spar is often the main structural member of the wing, running spanwise at right angles to the fuselage. The spar carries flight loads and the weight of the wings whilst on the ground...

s to save weight. The La-5, as well as its predecessors, had been built mostly of wood to conserve strategic materials such as aircraft alloys. With Soviet strategists now confident that supplies of these alloys were unlikely to become a problem, Lavochkin was now able to replace some wooden parts with alloy components. In addition Lavochkin made a number of other changes that differed from c/n 39210206. The engine air intake was moved from the bottom of the engine cowling to the wing root
Wing root
The wing root is the part of the wing on a fixed-wing aircraft that is closest to the fuselage. On a simple monoplane configuration, this is usually easy to identify...

s, the wing/fuselage fillet
Fillet (mechanics)
In mechanical engineering, a fillet is a concave easing of an interior corner of a part design. A rounding of an exterior corner is called a "round" or a "chamfer".-Applications:...

s were streamlined, each engine cylinder was provided with its own exhaust pipe, the engine cowling covers were reduced in number, a rollbar was added to the cockpit, longer shock struts were fitted for the main landing gear while that for the tail wheel was shortened, an improved PB-1B(V) gunsight was installed, and a new VISh-105V-4 propeller with a Mach
Mach
Mach may refer to:* Mach , a lunar crater* Mach disk, diamond pattern seen in rocket exhaust* Mach number, a measure of speed* Gillette Mach3, a manual razor with three blades* Mach bands, an optical illusion...

-resistant airfoil
Airfoil
An airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....

 was fitted. Three prototype 20 mm (0.78740157480315 in) Berezin B-20
Berezin B-20
The Berezin B-20 was a 20 mm caliber autocannon used by Soviet aircraft in World War II.-Development:The B-20 was created by M.E. Berezin in 1944 by chambering his Berezin UB 12.7 mm machine gun for the 20 mm rounds used by the ShVAK cannon...

 autocannon
Autocannon
An autocannon or automatic cannon is a rapid-fire projectile weapon firing a shell as opposed to the bullet fired by a machine gun. Autocannons often have a larger caliber than a machine gun . Usually, autocannons are smaller than a field gun or other artillery, and are mechanically loaded for a...

 armed the 1944 standard-setter , as the modified aircraft was designated.

The etalon only made nine test-flights in February and March 1944 before testing had to be suspended after two engine failures, but quickly proved itself to be the near-equal of c/n 39210206. It was 180 kilograms (396.8 lb) lighter than the earlier aircraft, which allowed the etalon to outclimb the other aircraft (4.45 minutes against 5.2 minutes climb to 5,000 meters). However it was 33 kilometres per hour (20.5 mph) slower at sea-level, but only 4 kilometres per hour (2.5 mph) slower at 6000 metres (19,685 ft). The flight-tests validated Lavochkin's modifications and it was ordered into production under the designation of La-7, although the B-20 cannon were not yet ready for production and the production La-7 retained the two 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...

 armament of the La-5.

Five La-7s were built in March by Factory Nr. 381 in Moscow
Moscow
Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...

 and three of these were accepted by the Air Force that same month. The Moscow factory was the fastest to complete transition over to La-7 production and the last La-5FN was built there in May 1944. Zavod Nr. 21 in Gorky
Nizhny Novgorod
Nizhny Novgorod , colloquially shortened to Nizhny, is, with the population of 1,250,615, the fifth largest city in Russia, ranking after Moscow, St. Petersburg, Novosibirsk, and Yekaterinburg...

 was considerably slower to make the change as it did not exhaust its stock of wooden La-5 wings until October. The quality of the early production aircraft was significantly less than the etalon due to issues with the engine, incomplete sealing of the cowling and fuselage, and defective propellers. One such aircraft was tested, after these problems had been fixed, by the Flight Research Institute and proved to be only 6 kilometres per hour (3.7 mph) slower than the etalon at altitude. Aircraft from both factories were evaluated in September by the Air Force Scientific Test Institute and the problems persisted as the aircraft could only reach 658 kilometres per hour (408.9 mph) at a height of 5900 metres (19,357 ft) and had a time to altitude of 5.1 minutes to 5,000 meters.

Combat trials began in mid-September 1944 and were generally very positive. However four aircraft were lost to engine failures and the engines suffered from numerous lesser problems, despite its satisfactory service in the La-5FN. One cause was the lower position of the engine air intakes in the wing roots of the La-7 which caused the engine to ingest sand and dust. One batch of flawed wings was built and caused six accidents, four of them fatal, in October which caused the fighter to be grounded until the cause was determined to be a defect in the wing spar.

Production of the first aircraft fitted with three B-20 cannon began in January 1945 when 74 were delivered. These aircraft were 65 kilograms (143.3 lb) heavier than those aircraft with the two ShVAK guns, but the level speed was slightly improved over the original aircraft. However, the time to climb to 5000 meters increased by two-tenths of a second over the older model. More than 2000 aircraft were delivered before the war's end, most by Zavod Nr. 21. A total of 5753 aircraft had been built by Zavod Nr. 21, Nr. 381, and Nr. 99 in Ulan-Ude
Ulan-Ude
Ulan-Ude is the capital city of the Republic of Buryatia, Russia, located about southeast of Lake Baikal on the Uda River at its confluence with the Selenga...

, when production ended in early 1946.

Operational history

The 63rd Guard Fighter Aviation Corps began combat trials of the La-7 in mid-September 1944 in support of the 1st Baltic Front
1st Baltic Front
The First Baltic Front was a Front of the Soviet Army during the Second World War. The commanders of it were Army General Andrey Yeryomenko and succeeded by Army General Bagramyan. It was formed by re-naming the Kalinin Front in October 12, 1943 and took part in several important military...

. Thirty aircraft were provided for the trials, which lasted one month. During this time the new fighters made 462 individual sortie
Sortie
Sortie is a term for deployment or dispatch of one military unit, be it an aircraft, ship, or troops from a strongpoint. The sortie, whether by one or more aircraft or vessels, usually has a specific mission....

s and claimed 55 aerial victories while losing four aircraft in combat. Four other La-7s were lost to non-combat causes, mostly related to engine problems. A total of three pilots were killed during the trials to all causes.

One regimental commander, Colonel Ye. Gorbatyuk, a Hero of the Soviet Union
Hero of the Soviet Union
The title Hero of the Soviet Union was the highest distinction in the Soviet Union, awarded personally or collectively for heroic feats in service to the Soviet state and society.-Overview:...

, commented: "The La-7 exhibited unquestionable advantages over German aircraft in multiple air combats. In addition to fighter tasks, photo reconnaissance and bombing were undertaken with success. The aircraft surpasses the La-5FN in speed, manoeuverability, and, especially, in the landing characteristics. It requires changes in its armament, and urgent fixing of its engine." The twin ShVAK armament inherited from the La-5 was no longer powerful enough to bring down later, more heavily armored German fighters, especially the Focke-Wulf Fw 190
Focke-Wulf Fw 190
The Focke-Wulf Fw 190 Würger was a German Second World War single-seat, single-engine fighter aircraft designed by Kurt Tank in the late 1930s. Powered by a radial engine, the 190 had ample power and was able to lift larger loads than its well-known counterpart, the Messerschmitt Bf 109...

, in a single burst, even when Soviet pilots opened fire at ranges of only 50 metre.

The 156th Fighter Air Corps of the 4th Air Army was the next unit to receive the La-7 in October 1944. At one point during the month, they had fourteen aircraft simultaneously unserviceable with engine failures. By 1 January 1945 there were 398 La-7s in front-line service of which 107 were unserviceable. By 9 May 1945 this had increased to 967 aircraft, of which only 169 were unserviceable. For the invasion of Japanese Manchuria, 313 La-7s were assigned and only 28 of these were unserviceable on 9 August 1945.

The La-7 was flown by the top Soviet ace of the war, Ivan Nikitovich Kozhedub
Ivan Nikitovich Kozhedub
Marshal of Aviation Ivan Mykytovych Kozhedub was a Soviet Ukrainian military aviator and a World War II fighter ace. Arguably Kozhedub, as he revealed in his memoires, took a part in the Korean War as fighter pilot, whilst being a commander of Soviet aviation Corps. in Korea. He is credited with...

. The Ukrainian-born Kozhedub, nicknamed "Ivan the Terrible", a three-time Hero of Soviet Union, scored his last 17 air victories in 1945 in the La-7 numbered 27, which is now preserved in the Central Air Force Museum
Central Air Force Museum
The Central Air Force Museum in Monino at the site of Monino Airfield 40km east of Moscow, Russia, is one of the world's largest aviation museums, and the largest for Russian aircraft...

 at Monino
Monino
Monino is an urban locality in Shchyolkovsky District of Moscow Oblast, Russia, situated east of Moscow. Population:...

 on the outskirts of Moscow. The last German aircraft that he shot down was the Messerschmitt Me-262, of Sergeant Kurt Lange from 1./KG(J)54, over Frankfurt an der Oder on 15 February 1945.

One fighter regiment of the 1st Czech Composite Aviation Division was equipped with the La-7 and participated in the Slovak National Uprising
Slovak National Uprising
The Slovak National Uprising or 1944 Uprising was an armed insurrection organized by the Slovak resistance movement during World War II. It was launched on August 29 1944 from Banská Bystrica in an attempt to overthrow the collaborationist Slovak State of Jozef Tiso...

 of August–October 1944. A total of 56 aircraft were delivered and equipped the 1st and 2nd Fighter Regiments. The bulk of the aircraft, however, were delivered in 1945 and saw no combat during the war. It remained in service with the Czechs until 1950 and was designated postwar by them as the S-97. One of these aircraft survives in the Prague Aviation Museum, Kbely
Prague Aviation Museum, Kbely
Prague Aviation Museum, Kbely is a major aviation museum located at Prague's original airport at Kbely, north-east of the town centre near Route 10 .-History of Kbely Airfield:...

.

Production of the La-7 amounted to 5,753 aircraft, plus 584 La-7UTI 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...

s.It is uncertain if these La-7UTIs are included in the overall production total. Those aircraft still in service after the end of the war were given the NATO reporting name
NATO reporting name
NATO reporting names are classified code names for military equipment of the Eastern Bloc...

 Fin.

The follow-up model, the La-9
Lavochkin La-9
|-See also:-Bibliography:* Gordon, Yefim. Lavochkin's Piston-Engined Fighters . Earl Shilton, Leicester, UK: Midland Publishing Ltd., 2003. ISBN 1-85780-151-2....

, despite its outward similarity, was a completely new design.

Tactical significance

The La-7 ended the superiority in vertical maneuverability that the Messerschmitt Bf 109
Messerschmitt Bf 109
The Messerschmitt Bf 109, often called Me 109, was a German World War II fighter aircraft designed by Willy Messerschmitt and Robert Lusser during the early to mid 1930s...

G had previously enjoyed over other Soviet fighters. Furthermore, it was fast enough at low altitudes to catch, albeit with some difficulties, Focke Wulf Fw 190 fighter-bombers that attacked Soviet units on the frontlines and immediately headed for German-controlled airspace at full speed. The Yakovlev Yak-3
Yakovlev Yak-3
The Yakovlev Yak-3 was a World War II Soviet fighter aircraft.Robust and easy to maintain, it was much liked by pilots and ground crew alike....

 and the Yakovlev 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...

U with the Klimov VK-107
Klimov VK-107
|-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...

 engine lacked a large enough margin of speed to overtake the German raiders. Only 115 La-7s were lost in air combat, only half the number of Yak-3s.

La-7TK

One aircraft used to evaluate the TK-3 turbosupercharger in July 1944 in the hopes of improving high-altitude performance. It was destroyed when the TK-3 disintegrated in flight.

La-7R

Testbed
Testbed
A testbed is a platform for experimentation of large development projects. Testbeds allow for rigorous, transparent, and replicable testing of scientific theories, computational tools, and new technologies.The term is used across many disciplines to describe a development environment that is...

 for a tail-mounted liquid-fuelled RD-1KhZ rocket engine
Rocket engine
A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...

. The rocket was rated at 300 kilogram-forces (661.4 lbf) of thrust and its fuel (90 litres (190 US pt) of kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...

 and 180 litres (380 US pt) of red fuming nitric acid
Red fuming nitric acid
Red fuming nitric acid is a storable oxidizer used as a rocket propellant. It consists mainly of nitric acid , also containing 13% dinitrogen tetroxide and 3% water. The dissolved nitrogen dioxide is very concentrated and can be found at room temperature...

) was expected to last between three and three and a half minutes. While the rocket was firing it increased the fighter's speed by 80 kilometres per hour (50 mph), but the aircraft's other flying qualities deteriorated. Fifteen flights were made in the first quarter of 1945, although the rocket exploded on the ground on 12 May. The aircraft was repaired, but later had an explosion in flight although the pilot managed to land it safely. Details of any later flights are unknown, but the La-7R was displayed at the August 1946 Tushino Airshow with the rocket firing.

La-7PVRD

Testbed
Testbed
A testbed is a platform for experimentation of large development projects. Testbeds allow for rigorous, transparent, and replicable testing of scientific theories, computational tools, and new technologies.The term is used across many disciplines to describe a development environment that is...

 for two underwing 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...

 engines. The aircraft was expected to reach a speed of 800 kilometres per hour (497 mph) at a height of 6000 metres (19,685 ft), but could not exceed 670 kilometres per hour (416 mph) due to the high drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...

 of the ramjets.

La-7/M-71

One aircraft was fitted with the Shvetsov M-71
Shvetsov M-71
-Bibliography:...

 for trials in 1944. However the engine was not yet ready for service and the program was cancelled.

La-7UTI

Two-seat trainer version. Armament reduced to a single 20 mm gun and the oil cooler was relocated underneath the engine cowling. Fitted with a radio compass and gun camera. Considerably heavier than the fighter at 3500 kilograms (7,716 lb), but it retained the flying characteristics of the single-seat aircraft. 584 built, the last two delivered in 1947.

Operators

  • Czech Air Force
    Czech Air Force
    The Czech Air Force is the air force branch of the Armed Forces of the Czech Republic. The Air Force, with the Land Forces, comprises the Joint Forces, the main combat power of the Armed Forces of the Czech Republic...


  • Soviet Air Forces

Specifications (1945 production model)

See also

Further reading

  • Abanshin, Michael E. and Nina Gut. Fighting Lavochkin, Eagles of the East No. 1. Lynnwood, WA: Aviation International, 1993.
  • Gordon, Yefim and Dmitri Khazanov. Soviet Combat Aircraft of the Second World War, Volume One: Single-Engined Fighters. Earl Shilton, Leicester, UK: Midland Publishing Ltd., 1998. ISBN 1-85780-083-4.
  • Green, William. Warplanes of the Second World War, Volume Three: Fighters. London: Macdonald & Co. (Publishers) Ltd., 1961 (seventh impression 1973). ISBN 0-356-01447-9.
  • Green, William and Gordon Swanborough. WW2 Aircraft Fact Files: Soviet Air Force Fighters, Part 1. London: Macdonald and Jane's Publishers Ltd., 1977. ISBN 0-354-01026-3.
  • Gunston, Bill. Aircraft of World War Two. London: Octopus Books Limited, 1980. ISBN 0-7064-1287-7.
  • Jane, Fred T. “The La-7.” Jane’s Fighting Aircraft of World War II. London: Studio, 1946. ISBN 1-85170-493-0.
  • Liss, Witold. The Lavochkin La 5 & 7 (Aircraft in Profile number 149). Leatherhead, Surrey, UK: Profile Publications Ltd., 1967.
  • Veštšík, Miloš. Lavočkin La-7 (in Czech/English). Prague, Czech Republic: MBI-Miroslav BÍLÝ Books, 2000. ISBN 80-902238-7-7.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK