Lavochkin La-7

https://en.wikipedia.org/wiki/Lavochkin_La-7

The Lavochkin La-7 (Russian: ???????? ??-7) was a piston-engined Soviet fighter
developed during World War II by the Lavochkin Design Bureau (OKB). It was a
development and refinement of the Lavochkin La-5, and the last in a family of
aircraft that had begun with the LaGG-1 in 1938. Its first flight 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 the following year,
but it was otherwise not exported. Armed with two or three 20 mm (0.79 in)
cannon, it had a top speed of 661 kilometers per hour (411 mph). The La-7 was
felt by its pilots to be at least the equal of any German piston-engined
fighter. It was phased out in 1947 by the Soviet Air Force, but served until
1950 with the Czechoslovak Air Force.

By 1943, the La-5 had become a mainstay of the Soviet Air Forces, yet both its
head designer, Semyon Lavochkin, as well as the engineers at the Central
Aerohydrodynamics Institute (Russian: TsAGI), 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/n 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.

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 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,
when production ended in early 1946.


Role
Fighter

Manufacturer
Lavochkin OKB

First flight
February 1944

Introduction
1944

Retired
1950

Primary users
Soviet Air Forces
Czechoslovak Air Force

Number built
5,753

Developed from
Lavochkin La-5

The 63rd Guard Fighter Aviation Corps began combat trials of the La-7 in
mid-September 1944 in support of the 1st Baltic Front. Thirty aircraft were
provided for the trials, which lasted one month. During this time the new
fighters made 462 individual sorties 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.

The British test pilot, Eric "Winkle" Brown was given the chance to fly an La-7
at the former Erprobungsstelle Tarnewitz Luftwaffe aircraft test station on the
Baltic coast, shortly after the German surrender in May 1945. He described the
handling and performance as "quite superb", but the armament and sights were
"below par", the "wooden construction would have withstood little combat
punishment" and the instrumentation was "appallingly basic".

Production of the La-7 amounted to 5,753 aircraft, plus 584 La-7UTI trainers.
Those aircraft still in service after the end of the war were given the NATO
reporting name Fin. The follow-up model, the La-9, despite its outward
similarity, was a completely new design.

Tactical significance

The La-7 ended the superiority in vertical maneuverability that the
Messerschmitt Bf 109G 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 returned to German-controlled airspace at full
speed. The Yakovlev Yak-3 and the Yakovlev Yak-9U with the Klimov VK-107 engine
lacked a large enough margin of speed to overtake the German raiders. 115 La-7s
were lost in air combat, only half the number of Yak-3s.

Specifications (1945 production model)

General characteristics
Crew: 1
Length: 8.6 m (28 ft 3 in)
Wingspan: 9.8 m (32 ft 2 in)
Height: 2.54 m (8 ft 4 in)
Wing area: 17.59 m2 (189.3 sq ft)
Empty weight: 2,638 kg (5,816 lb)
Gross weight: 3,315 kg (7,308 lb)
Powerplant: 1 × Shvetsov ASh-82FN 14-cylinder, two-row, air-cooled radial, 1,380
kW (1,850 hp)
Propellers: 3-bladed VISh-105V-4

Performance
Maximum speed: 661 km/h (411 mph; 357 kn) at 6,000 meters (19,685 ft)
Range: 665 km (413 mi; 359 nmi) (1944 model)
Service ceiling: 10,450 m (34,280 ft)
Rate of climb: 15.72 m/s (3,095 ft/min)
Time to altitude: 5.3 minutes to 5,000 meters (16,404 ft)

Armament

Guns: 2 × cowl-mounted 20 mm ShVAK cannons with 200 rounds per gun or 3 ×
cowl-mounted 20 mm Berezin B-20 cannons with 100 rounds per gun
Bombs: 200 kg (440 lb) of bombs


*