Lavochkin La-150
Encyclopedia
The Lavochkin La-150 (also known as the Izdeliye 150 – Aircraft or Article 150,All Lavochkin's jet aircraft were referred to in-house, and at government level, as "Izdeliye 150", etc. USAF/DOD designation Type 3), was designed by the Lavochkin
design bureau (OKB
) in response to a 1945 order to build a single-seat jet fighter using a single German turbojet. By this time both the Americans and British, as well as the Germans, had already flown jet fighters and the single Soviet jet engine under development (the Lyulka TR-1) was not yet ready for production. The design was completed quickly, but the construction of the five flying prototypes was protracted by the factory's inexperience in building metal aircraft. The aircraft made its first flight in September 1946, but proved to require extensive modifications to meet the Soviet Air Forces' requirements. These took so long to make and test that the aircraft was essentially obsolete by the time that they were completed. Even one variant with a much more powerful engine was inferior to other aircraft that the OKB had under development and all work was terminated in 1947.
s and slotted flap
s. The cockpit was well forward, giving the pilot good visibility, and he was protected by an armored headrest. The windscreen of the teardrop-shaped canopy
was also armored. Two 23 millimetre (0.905511811023622 in) Nudelman-Suranov NS-23
autocannon
were mounted on the lower side of the fuselage with 75 rounds per gun. The tricycle landing gear retracted into the fuselage which gave the 150 a very narrow track. The Soviet derivative of the Jumo engine, the RD-10, was rated at 900 kgf (1,984 lbf) and was mounted behind the cockpit. A steel heat shield
protected the bottom of the rear fuselage from the engine's exhaust. Air was supplied by an intake in the aircraft nose that split around the cockpit before reaching the engine. Seven tanks, five in the fuselage and one in each wing, carried a total of 500 kilograms (1,102.3 lb) of fuel.
Construction of a full-scale mockup
was completed in June 1945 by Factory No. 81, but the order for five prototypes was given to Factory No. 381 as Factory No. 81 was already fully committed to other programs. Manufacturing drawings were delivered to Factory No. 381 by the end of August, but the prototypes were delayed because the plant had no experience building metal aircraft and lacked the necessary tooling. By the end of the year, the factory had only managed to complete a single airframe
for static load testing. This showed that the rear fuselage, wings and tail needed to be reinforced, and the opportunity was taken to enlarge the vertical stabilizer
as well. These tests and modifications required six months of work so that the first flying prototype was not completed until July 1946. Manufacturer's testing of the first prototype began on 27 August, after ground testing had required replacing the engine twice, and the first flight was made on 11 September.
The following day, the Council of Ministers ordered that a small batch of jets from each OKB were to participate in the 7 November parade commemorating the October Revolution
. Because of the tight deadline, the components for the two incomplete prototypes were turned over to Factory No. 301 at Khimki
, the new headquarters for the Lavochkin OKB, for assembly by Factory No. 381. Factory No. 21 in Gorky
joined the program with three more aircraft built in record time with support from Factory No. 301. Tooling was constructed in 5–10 days with the first aircraft completed in a week and a half.
was cancelled because of bad weather.
The tests conducted in preparation for the parade revealed a number of flaws in the design including poor directional stability, a cramped cockpit without heating or ventilation, poor access to the engine, inadequate fuel capacity, compounded by the lack of a fuel gauge, and poor elevator
control forces. Five aircraft were modified to correct these issues before resuming the factory's testing in late 1946. The modifications were not entirely successful and the lateral stability was now too great and the elevator forces remained too weak. Engine problems, however, plagued the tests as the first prototype alone required four engine changes.
After the conclusion of the manufacturer's trials in April 1947, one aircraft was returned to the factory for extensive modifications as the 150M. The wing tips were angled downward 35° to reduce the lateral stability, the wing was redesigned to detach from the fuselage, and the aerodynamic balancing of the elevators was reduced from 24% to 20%. The fuel capacity was increased to 660 kilograms (1,455.1 lb), the cockpit was widened by 80 centimetres (31.5 in) and fitted with an ejection seat. Fore and aft armor plates were fitted to protect the pilot and a new radio aerial mast was installed. All these changes added 365 kilograms (804.7 lb) of weight and increased drag
which reduced the aircraft's top speed by 73 kph, to 805 kph, and slowed its time to 5000 metres (16,404.2 ft) from 4.8 minutes to 7.2 minutes in comparison to the unmodified aircraft. Given that a higher-performance design, the Aircraft 156, had already been submitted for state acceptance trials, Semyon Lavochkin
decided not to continue the development of the 150M.
In the meantime, the OKB had been developing two afterburning versions of the RD-10 in an effort to increase the engine's power. The more successful model was only 100 millimetres (3.9 in) longer and weighed an additional 31 kilograms (68.3 lb) more than the original engine. Its power, however, was increased by an additional 340 kilogram-forces (749.6 lbf), over 30% more thrust. This engine was designated the izdeliye YuF by the bureauConfusingly, some sources refer to both this engine and Yakovlev's afterburning version of the RD-10 as RD-10Fs, although they had two different afterburner designs. and was fitted into an aircraft 150 prototype in July 1947, designated as the 150F. The additional power increased the aircraft's top speed to 950 kph at sea level and 915 kph at an altitude of 4320 metres (14,173.2 ft). This made the 150F the second-fastest Soviet fighter of the period, after the MiG-9 powered by two afterburning RD-21 engines. Nevertheless, Lavochkin decided not to submit the 150F for state acceptance trials as the fundamental design flaws of the airframe still had not been resolved.
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...
design bureau (OKB
OKB
OKB is a transliteration of the Russian acronym for "Опытное конструкторское бюро" - Opytnoe Konstructorskoe Byuro, meaning Experimental Design Bureau...
) in response to a 1945 order to build a single-seat jet fighter using a single German turbojet. By this time both the Americans and British, as well as the Germans, had already flown jet fighters and the single Soviet jet engine under development (the Lyulka TR-1) was not yet ready for production. The design was completed quickly, but the construction of the five flying prototypes was protracted by the factory's inexperience in building metal aircraft. The aircraft made its first flight in September 1946, but proved to require extensive modifications to meet the Soviet Air Forces' requirements. These took so long to make and test that the aircraft was essentially obsolete by the time that they were completed. Even one variant with a much more powerful engine was inferior to other aircraft that the OKB had under development and all work was terminated in 1947.
Design and development
The Lavochkin OKB was ordered to design a fighter using a single Junkers Jumo 004B axial-flow turbojet in February 1945. Much like their rivals at the Mikoyan-Gurevich OKB with their MiG-9, the OKB chose a "pod-and-boom" layout for their new fighter, based on advice from the Central Aerohydrodynamic Institute (TsAGI), although their design had a shoulder-mounted wing. The wings of the all-metal aircraft had fixed leading edgeLeading edge
The leading edge is the part of the wing that first contacts the air; alternatively it is the foremost edge of an airfoil section. The first is an aerodynamic definition, the second a structural one....
s and slotted flap
Flap (aircraft)
Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...
s. The cockpit was well forward, giving the pilot good visibility, and he was protected by an armored headrest. The windscreen of the teardrop-shaped canopy
Canopy (aircraft)
An aircraft canopy is the transparent enclosure over the cockpit of some types of aircraft. The function of the canopy is to provide a weatherproof and reasonably quiet environment for the aircraft's occupants. The canopy will be as aerodynamically shaped as possible to minimize drag.-History:Very...
was also armored. Two 23 millimetre (0.905511811023622 in) Nudelman-Suranov NS-23
Nudelman-Suranov NS-23
The NS-23 was a aircraft cannon designed by A. E. Nudelman, A. Suranov, G. Zhirnykh, V. Nemenov, S. Lunin, and M. Bundin during World War II as a replacement for the Volkov-Yartsev VYa-23 cannon. It entered service in 1944...
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...
were mounted on the lower side of the fuselage with 75 rounds per gun. The tricycle landing gear retracted into the fuselage which gave the 150 a very narrow track. The Soviet derivative of the Jumo engine, the RD-10, was rated at 900 kgf (1,984 lbf) and was mounted behind the cockpit. A steel heat shield
Heat shield
A heat shield is designed to shield a substance from absorbing excessive heat from an outside source by either dissipating, reflecting or simply absorbing the heat...
protected the bottom of the rear fuselage from the engine's exhaust. Air was supplied by an intake in the aircraft nose that split around the cockpit before reaching the engine. Seven tanks, five in the fuselage and one in each wing, carried a total of 500 kilograms (1,102.3 lb) of fuel.
Construction of a full-scale mockup
Mockup
In manufacturing and design, a mockup, or mock-up, is a scale or full-size model of a design or device, used for teaching, demonstration, design evaluation, promotion, and other purposes...
was completed in June 1945 by Factory No. 81, but the order for five prototypes was given to Factory No. 381 as Factory No. 81 was already fully committed to other programs. Manufacturing drawings were delivered to Factory No. 381 by the end of August, but the prototypes were delayed because the plant had no experience building metal aircraft and lacked the necessary tooling. By the end of the year, the factory had only managed to complete a single airframe
Airframe
The airframe of an aircraft is its mechanical structure. It is typically considered to include fuselage, wings and undercarriage and exclude the propulsion system...
for static load testing. This showed that the rear fuselage, wings and tail needed to be reinforced, and the opportunity was taken to enlarge the vertical stabilizer
Vertical stabilizer
The vertical stabilizers, vertical stabilisers, or fins, of aircraft, missiles or bombs are typically found on the aft end of the fuselage or body, and are intended to reduce aerodynamic side slip. It is analogical to a skeg on boats and ships.On aircraft, vertical stabilizers generally point upwards...
as well. These tests and modifications required six months of work so that the first flying prototype was not completed until July 1946. Manufacturer's testing of the first prototype began on 27 August, after ground testing had required replacing the engine twice, and the first flight was made on 11 September.
The following day, the Council of Ministers ordered that a small batch of jets from each OKB were to participate in the 7 November parade commemorating the October Revolution
October Revolution
The October Revolution , also known as the Great October Socialist Revolution , Red October, the October Uprising or the Bolshevik Revolution, was a political revolution and a part of the Russian Revolution of 1917...
. Because of the tight deadline, the components for the two incomplete prototypes were turned over to Factory No. 301 at Khimki
Khimki
Khimki is a city in Moscow Oblast, Russia, situated just northwest of Moscow, at the west bank of the Moscow Canal. Population: 207,125 ; 141,000 ; 106,000 ; 23,000 .-History:...
, the new headquarters for the Lavochkin OKB, for assembly by Factory No. 381. Factory No. 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...
joined the program with three more aircraft built in record time with support from Factory No. 301. Tooling was constructed in 5–10 days with the first aircraft completed in a week and a half.
Testing and evaluation
All eight aircraft were complete by 1 November and had been tested to ensure their readiness to participate in the parade. They were later given the unofficial service designation of La-13. It was considered too risky to fly the aircraft from Gorky to Moscow and their wings could not be dismounted which meant that they could not be railed to Moscow either. Special three-wheeled trailers were built and the aircraft were driven to Moscow, but the flypastFlypast
Flypast is a term used in the United Kingdom, the Commonwealth, and other countries to denote ceremonial or honorific flights by groups of aircraft and, rarely, by a single aircraft...
was cancelled because of bad weather.
The tests conducted in preparation for the parade revealed a number of flaws in the design including poor directional stability, a cramped cockpit without heating or ventilation, poor access to the engine, inadequate fuel capacity, compounded by the lack of a fuel gauge, and poor elevator
Elevator (aircraft)
Elevators are flight control surfaces, usually at the rear of an aircraft, which control the aircraft's orientation by changing the pitch of the aircraft, and so also the angle of attack of the wing. In simplified terms, they make the aircraft nose-up or nose-down...
control forces. Five aircraft were modified to correct these issues before resuming the factory's testing in late 1946. The modifications were not entirely successful and the lateral stability was now too great and the elevator forces remained too weak. Engine problems, however, plagued the tests as the first prototype alone required four engine changes.
After the conclusion of the manufacturer's trials in April 1947, one aircraft was returned to the factory for extensive modifications as the 150M. The wing tips were angled downward 35° to reduce the lateral stability, the wing was redesigned to detach from the fuselage, and the aerodynamic balancing of the elevators was reduced from 24% to 20%. The fuel capacity was increased to 660 kilograms (1,455.1 lb), the cockpit was widened by 80 centimetres (31.5 in) and fitted with an ejection seat. Fore and aft armor plates were fitted to protect the pilot and a new radio aerial mast was installed. All these changes added 365 kilograms (804.7 lb) of weight and increased 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...
which reduced the aircraft's top speed by 73 kph, to 805 kph, and slowed its time to 5000 metres (16,404.2 ft) from 4.8 minutes to 7.2 minutes in comparison to the unmodified aircraft. Given that a higher-performance design, the Aircraft 156, had already been submitted for state acceptance trials, 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:...
decided not to continue the development of the 150M.
In the meantime, the OKB had been developing two afterburning versions of the RD-10 in an effort to increase the engine's power. The more successful model was only 100 millimetres (3.9 in) longer and weighed an additional 31 kilograms (68.3 lb) more than the original engine. Its power, however, was increased by an additional 340 kilogram-forces (749.6 lbf), over 30% more thrust. This engine was designated the izdeliye YuF by the bureauConfusingly, some sources refer to both this engine and Yakovlev's afterburning version of the RD-10 as RD-10Fs, although they had two different afterburner designs. and was fitted into an aircraft 150 prototype in July 1947, designated as the 150F. The additional power increased the aircraft's top speed to 950 kph at sea level and 915 kph at an altitude of 4320 metres (14,173.2 ft). This made the 150F the second-fastest Soviet fighter of the period, after the MiG-9 powered by two afterburning RD-21 engines. Nevertheless, Lavochkin decided not to submit the 150F for state acceptance trials as the fundamental design flaws of the airframe still had not been resolved.
Variants
- 150M – One 150 prototype was modified with drooped wingtips, a wider cockpit and extra fuel.
- 150F – One 150 prototype was modified with a Izdeliye YuF engine, an afterburning RD-10.
Specifications (Aircraft 150)
See also
External links
- http://avia.russian.ee/pictures/russia/la-150.jpg