https://en.wikipedia.org/wiki/Lavochkin_La-7
The Lavochkin La-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 and even shot down a
Messerschmitt Me 262 jet 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 British test pilot, Eric "Winkle" Brown was given the chance to fly an La-7
at the Tarnewitz test site 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.
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)
Gross weight: 3,315 kg (7,308 lb)
kW (1,650 hp)
Propellers: 3-bladed VISh-105V-4
Performance
Maximum speed: 661 km/h (411 mph; 357 kn) @ 6,000 meters (19,685 ft)
Range: 665 km (413 mi; 359 nmi) (1944 model)
Service ceiling: 10,450 m (34,285 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
cowl-mounted 20 mm Berezin B-20 cannons with 100 rounds per gun
Bombs: 200 kg (440 lb) of bombs
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