Lavochkin La-15

https://en.wikipedia.org/wiki/Lavochkin_La-15

The Lavochkin La-15 (Plant 21 product code Izdeliye 52, USAF reporting name Type
21, NATO reporting name Fantail), was an early Soviet jet fighter and a
contemporary of the Mikoyan-Gurevich MiG-15.

Lavochkin had produced a line of prop powered fighters in World War II. The
Lavochkin La-150 was its first response to a 1945 order to build a single-seat
jet fighter using a single German Junkers Jumo 004 turbojet from the Me 262. The
Lavochkin La-152 which flew in December 1946 moved the engine to the front of
the nose, which reduced thrust loss. The Lavochkin La-160 was the first Soviet
fighter to apply swept wings, and flew in June 1947.

The Lavochkin La-168 first flew on April 22, 1948. It was designed to use the
new turbojet based on the Rolls-Royce Nene in response to a 1946 request for an
advanced swept-wing jet fighter capable of transonic performance. The engine was
placed behind the pilot, but with a high-mounted wing and T-tail compared to the
similar MiG-15.

The La-15 which reached mass production was the outcome of a series of
development aircraft that began with the Aircraft 150 bomber in 1945 and
culminated in Aircraft 176, later in 1948. These aircraft were designed for
British engines, Rolls-Royce Derwent V and Rolls-Royce Nene, acquired by the
Soviets in 1947 and then copied as the Klimov RD-500 and Klimov RD-45
respectively. The Derwent-powered Aircraft 174 was designed as a backup for the
main program, the Nene-powered Aircraft 168, in case the British failed to
deliver more powerful Nene engines with afterburners (which they did fail to
deliver). The first prototype of Aircraft 174 was flown just 9 days after its
counterpart the Mikoyan-Gurevich I-310, on January 8, 1948. The first prototype
was however lost on May 11, 1948 due to vibrations. Trials were continued with
an improved second prototype, designated Aircraft 174D, which underwent State
Acceptance Tests from August to September 25, 1948. In comparison with the
Nene-powered MiG-15 it had almost the same maximum speed and better
maneuverability, with somewhat reduced rate of climb. The type was ordered into
production in September 1948, even while Aircraft 174D was undergoing flight
trials, and given the official designation La-15 in April 1949.

The La-15 had a barrel-like fuselage, shoulder-mounted swept wings with 6
degrees anhedral, and stabilizers mounted high on the fin, almost a T-tail. It
was popular with pilots because of its easy handling and reliability, and its
pressurized cockpit was an advantage at high altitude. Nevertheless, official
enthusiasm for the La-15 was mild, largely because it was a complex design that
required complicated and expensive production tooling. Only 235 La-15s were
built, serving with the Soviet Air Force until 1953.


Role
Fighter

Manufacturer
Lavochkin / Plant 21 "Sokol"

First flight
January 8, 1948 (Aircraft 174)

Introduction
1949

Retired
1953

Primary user
Soviet Air Force

Number built
235

The La-15 was tested operationally by the 192nd Fighter Wing, based at Kubinka
from 19 March 1949, and began appearing in front-line combat units later the
same year. Introduction was accompanied by numerous accidents, but the competing
MiG-15 design fared little better. However, although the La-15 had a number of
technical advantages over the MiG-15, a combination of easier manufacture and
lower costs led to the MiG-15 being favoured. The Soviet authorities decided to
produce only one fighter, and they chose the MiG-15bis. The remaining La-15s in
service were disarmed by 1953, and their engines reused on the KS-1 Komet
air-to-surface missile. The aircraft were expended as targets at various nuclear
bomb tests.

Variants

Aircraft 174
Rolls-Royce Derwent powered first prototype of La-15. Crashed due to structural
vibrations caused by sympathetic resonant frequencies of tailplane and rear
fuselage.

Aircraft 174D
(Dooblyor-second)- Second prototype with modifications shown to be required from
Aircraft 174's flight tests.

Aircraft 180
A two-seat trainer version was also developed as Aircraft 180 and was to be put
into production as the UTI La-15 or La-15UTI, but as official interest in the
La-15 waned, the trainer was cancelled before mass production began and only two
were made.

Specifications (La-15)

General characteristics
Crew: 1
Length: 9.563 m (31 ft 4 in)
Wingspan: 8.83 m (29 ft 0 in)
Height: 3.8 m (12 ft 6 in)
Wing area: 16.167 m2 (174.02 sq ft)
Empty weight: 2,575 kg (5,677 lb)
Gross weight: 3,850 kg (8,488 lb)
Fuel capacity: 1,060l (233.2Imp Gal)
Powerplant: 1 × Klimov RD-500 centrifugal compressor turbojet, 15.59 kN (3,500
lbf) thrust

Performance
Maximum speed: 1,007 km/h (626 mph; 544 kn) at 8,000m (26,350ft)
Range: 1,145 km (711 mi; 618 nmi) at 10,000m (32,810ft)
Service ceiling: 13,500 m (44,300 ft) at nominal power - prone to surge at
military power above 8,000m (26,250ft)
Rate of climb: 31.7 m/s (6,240 ft/min)
Time to altitude:

5,000m (16,400ft) in 3.1min
10,000m (32,180ft) in 9min
Wing loading: 238 kg/m2 (49 lb/sq ft)
Thrust/weight: 0.42

Armament

Guns: 3 * 23mm Nudelman-Suranov NS-23 cannon with 100 rounds per gun



*