Yakovlev Yak-36
| Yakovlev Yak-36 | |
|---|---|
.jpg) The second prototype during the presentation in Moscow in 1967 |
|
| Type: | Prototype of a VTOL - combat aircraft |
| Design country: | |
| Manufacturer: | |
| First flight: |
January 9, 1963 |
| Number of pieces: |
2 prototypes |
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The Jakowlew Jak-36 ( Russian Яковлев Як-36 , NATO code name "Freehand" ) was a technology carrier of the Soviet Union for the development of a VTOL combat aircraft. The machine forms the basis for the later Jakowlew Jak-38 .
description
After some studies on vertical takeoffs (e.g. with the Turboljot flying table ) in the Soviet Union had been successful in the 1950s , the government authorities placed an order in February 1961 for the development of a single-seat fighter-bomber, which was originally powered by two R21M-300 engines should be to the OKB Jakowlew. Yakovlev had already worked out the VTOL project Jak-104, which was to receive three R19-300 engines, a year earlier. It stayed with the draft. Instead, work began on the Jak-W (W for Wertikalny, also: Isdelije W), the later Jak-36, under the direction of Stanislaw G. Mordovin.
The aircraft is an all-metal mid - decker in half-shell construction. The trapezoidal wings have only a low aspect ratio of 2.7 and a leading edge sweep of 40 °. They are a single spar construction and have no slats but one-piece ailerons and flaps on the trailing edge. The four-part landing gear consists of a central, double-tyred, retractable main landing gear, a single-tyred nose gear that can be retracted forwards and two landing gear that can be retracted to the rear in the cigar-shaped wing end container. The landing gear construction was determined by the arrangement of the engines, which left no space for a conventional three-legged landing gear. The two engines were supplied with air through a large elliptical two-part inlet in the bow, at the vertical division of which a landing light was also attached. To increase the performance during vertical take-off, a methanol / water mixture was injected into the compressor of the engines. So that the pilot could safely leave the aircraft in an emergency, even when it was hovering, the OKB Jakowlew developed the ejection seat KJa-1 (Kreslo Jakowlewa, Jakowlew's seat) as well as the SKM system, which was able to independently recognize critical flight conditions and automatically triggered the ejection seat. A critical flight condition could occur especially due to an engine failure while hovering, which would cause the aircraft to roll violently and the pilot would hardly have been able to react within the 0.4 seconds after which the on-board computer triggered the rescue from a roll angle of 60 degrees. The system had to be activated manually for takeoff and landing from an altitude of five meters.
Similar to the British Harrier, the vertical take-off design was based on vector thrust control . The machine was powered by two engines that were installed behind and under the cockpit . The exhaust gas jet was passed through air slot nozzles, which were mounted rotatable by 90 ° in the center of gravity. The mechanism for rotating the two thrusters was designed to be mechanically coupled to one another for safety reasons (to avoid asymmetrical thrust even in the event of a fault). At both ends of the wing, in the tail cone and in a boom at the aircraft nose, there were control nozzles that were operated with engine bleed air . The steering itself was carried out for tilt and roll control by a double redundant autopilot and the control lever; The direction control was carried out via the rudder pedals, whereby a total of up to 10% of the air throughput of the engines was used for the control nozzles. At a speed of more than 400 km / h, the steering jets were automatically switched off.
The first tethered hover took place on January 9, 1963 with Yuri A. Garnajew at the helm, which revealed the complexity of a vertical take-off. In the beginning there were problems with the intake of exhaust gas from the engines (which caused their failure or uneven combustion), intake effects from the exhaust gas on the ground (which required a higher engine power) and some problems with the control system. This made some design changes necessary. On June 23, 1963, the first untethered flight took place, followed by the first full transition to level flight on September 16, 1963. On March 24, 1966, the first complete VTOL flight (vertical take-off and landing) took place with Valentin G. Muchin at the wheel. The first public presentation of the machine took place on July 9, 1967 at the air show in Moscow- Domodedovo on the 50th anniversary of the October Revolution, but it broke down. Originally both prototypes were supposed to start for demonstration , but shortly before that the 37 was damaged in a hard landing at Domodedovo Airport, so that only the 38 could fly its program.
The Jak-36 had two sub-wing stations for bombs, automatic cannons and missiles; however, the range of the machine was too short to be able to use it effectively with full combat load. A total of a break cell (number 36 ) and two flying copies ( 37 and 38 ) were built; These were experimentally equipped with two containers for unguided rockets, but no firing tests were carried out with them. The break cell went to the Aircraft Museum in Monino, a prototype was used in 1972 to test the loads emanating from VTOL aircraft on a mockup of the flight deck of the later Type 1143 flight deck cruiser Moskwa , the second prototype served as a training aircraft for test pilot training and was released in February 1971 destroyed in a very hard landing by Leonid Rybikov. Yakovlev planned to build about ten to 15 more Yak-36s, but received no permission.
From the Jak-36 the Jak-38 was developed, which flew as the Jak-36MP for the first time in 1971.
Technical specifications
| Parameter | Data |
|---|---|
| length | 17.00 m |
| span | 10.0 m |
| height | 4.50 m |
| Wing area | 17 m² |
| Empty mass | 5,300 kg |
| Takeoff mass | 8,900 kg (11,700 for a conventional start) |
| Fuel capacity | 2,600 kg |
| Service ceiling | 12,000 m |
| Hover altitude | 1,900 m |
| Top speed | 1,000 km / h |
| Rate of climb | 140 m / s |
| Range | 370 km |
| crew | 1 |
| Engines | Two Soyuz Tumanski / Katschaturow R-27-300 |
| power | each 5,300 kgp thrust |
See also
Individual evidence
- ↑ Nikolai Jakubowitsch: The first Soviet whiz kid - up and away! In: Aviation Classics 2/12. Pp. 30-33.
- ↑ a b Jefim Gordon : Yakovlev Yak-36, Yak-38 & Yak-41 . 2008, ISBN 978-1-85780-287-0 .
- ↑ Nikolai Jakubowitsch: The first Soviet whiz kid - up and away! In: Aviation Classics 2/12. Pp. 30-33.
Remarks
- ↑ Garnajew died on August 7, 1967 in the crash of an Mi-6 fire fighting helicopter near Marseille, whereupon Valentin G. Muchin took over his duties as a test pilot.