From 1960, the Yakovlev Design Bureau began work on a VTOL system, using the compact and lightweight Tumansky RU-19-300 turbojet engine, drafting a proposal for the Yak-104, a converted Yak-30 jet trainer with two vertically mounted Ru-19 engines between the inlet ducts of the standard Yak-30 powerplant. Work on the Yak-104 was terminated in favour of an aircraft with a single lift/cruise engine with rotating nozzles, similar to the Hawker Siddeley P.1127, which was nearing completion in England. Unable to find a suitable engine or convince the government to order the development of one, the Yakovlev bureau was forced to follow a different course.[2]
In response to a contract for the development of a single-seat V/STOL fighter in 1961, Yakovlev proposed a twin-engined aircraft with a large nose air intake, engines in the forward fuselage and swivelling exhaust nozzles, one for each engine on either side of the lower fuselage near the centre of gravity of the aircraft. The fighter version was not proceeded with but four technology demonstrators, (initially designated Izdeliye V) based on the fighter studies were ordered.[2]
Four prototypes were completed, one of which was used only for static testing. The second was used for takeoff and landing tests, including free hovering. The third incorporated improvements found in testing, including an improved autopilot which automatically selected optimal air flow for hover stability. This prototype crashed, but was later rebuilt. The fourth prototype crashed in February 1971 and was not rebuilt.[2]
Construction
The airframe had a semi-monocoque fuselage with bicycle-type landing gear, short cropped delta wings of 37° leading edge sweep, with 5° anhedral, attached to the fuselage in a mid position. The fuselage was substantial forward of the wing trailing edges, due to accommodating the engines, cockpit, fuel tanks and equipment bays as close to the centre of gravity as possible, tapering sharply to the swept tail surfaces with a high-set tailplane. Control of the aircraft was by conventional rudder, ailerons and elevators in normal flight and by compressed engine bleed air blown from control nozzles at the wingtips, rear fuselage tip and at the end of a long boom extending forwards from the top lip of the air intakes.[2]
Two underwing hard points could carry bombs, podded machine guns or rocket pods, but the Yak-36 had insufficient excess thrust and range for effective use as a combat aircraft.
Operational history
The first tethered hover flight took place on 9 January 1963. There were initial problems with hot gas reingestion where hot exhaust gasses are sucked back into the intakes causing poor airflow through the engines and loss of thrust. The suction effect of the exhaust on the ground (which made a higher engine power needed) and problems with control systems caused further difficulties. After modifications, the first untethered vertical flight was made on 23 June 1963, followed by the first full transition to horizontal flight on 16 September 1963.[1]
On 24 March 1966, the first complete flight was made from vertical takeoff transition to horizontal flight deceleration to vertical flight and vertical landing. After much testing and practice the first public presentation of the Yak-36 was made on 9 July 1967 at an air show at Moscow-Domodedovo airport, marking the 50th Anniversary of the October Revolution. After the promising results obtained from the flight test programme of the Yak-36, the next development step was the Yakovlev Yak-36M which flew for the first time on 27 September 1970.[1]
Wikimedia Commons has media related to Yakovlev Yak-36.
The surviving Yak-36 at Monino
January 06, 2023
yakovlev, also, known, izdeliye, nato, reporting, name, freehand, soviet, technology, demonstrator, vtol, combat, aircraft, 36yak, undergoing, demonstration, flight, before, domodedovo, show, 1967role, experimental, vstol, aircraftnational, origin, soviet, uni. The Yakovlev Yak 36 also known as Izdeliye V NATO reporting name Freehand is a Soviet technology demonstrator for a VTOL combat aircraft 2 Yak 36Yak 36 undergoing a demonstration flight before the Domodedovo Air Show in 1967Role Experimental VSTOL aircraftNational origin Soviet UnionManufacturer OKB YakovlevFirst flight 9 January 1963 1 Number built 4 2 Contents 1 Design and development 1 1 Construction 2 Operational history 3 Operators 4 Aircraft on display 5 Specifications Yak 36 6 See also 7 References 8 External linksDesign and development EditFrom 1960 the Yakovlev Design Bureau began work on a VTOL system using the compact and lightweight Tumansky RU 19 300 turbojet engine drafting a proposal for the Yak 104 a converted Yak 30 jet trainer with two vertically mounted Ru 19 engines between the inlet ducts of the standard Yak 30 powerplant Work on the Yak 104 was terminated in favour of an aircraft with a single lift cruise engine with rotating nozzles similar to the Hawker Siddeley P 1127 which was nearing completion in England Unable to find a suitable engine or convince the government to order the development of one the Yakovlev bureau was forced to follow a different course 2 In response to a contract for the development of a single seat V STOL fighter in 1961 Yakovlev proposed a twin engined aircraft with a large nose air intake engines in the forward fuselage and swivelling exhaust nozzles one for each engine on either side of the lower fuselage near the centre of gravity of the aircraft The fighter version was not proceeded with but four technology demonstrators initially designated Izdeliye V based on the fighter studies were ordered 2 Four prototypes were completed one of which was used only for static testing The second was used for takeoff and landing tests including free hovering The third incorporated improvements found in testing including an improved autopilot which automatically selected optimal air flow for hover stability This prototype crashed but was later rebuilt The fourth prototype crashed in February 1971 and was not rebuilt 2 Construction Edit The airframe had a semi monocoque fuselage with bicycle type landing gear short cropped delta wings of 37 leading edge sweep with 5 anhedral attached to the fuselage in a mid position The fuselage was substantial forward of the wing trailing edges due to accommodating the engines cockpit fuel tanks and equipment bays as close to the centre of gravity as possible tapering sharply to the swept tail surfaces with a high set tailplane Control of the aircraft was by conventional rudder ailerons and elevators in normal flight and by compressed engine bleed air blown from control nozzles at the wingtips rear fuselage tip and at the end of a long boom extending forwards from the top lip of the air intakes 2 Two underwing hard points could carry bombs podded machine guns or rocket pods but the Yak 36 had insufficient excess thrust and range for effective use as a combat aircraft Operational history EditThe first tethered hover flight took place on 9 January 1963 There were initial problems with hot gas reingestion where hot exhaust gasses are sucked back into the intakes causing poor airflow through the engines and loss of thrust The suction effect of the exhaust on the ground which made a higher engine power needed and problems with control systems caused further difficulties After modifications the first untethered vertical flight was made on 23 June 1963 followed by the first full transition to horizontal flight on 16 September 1963 1 On 24 March 1966 the first complete flight was made from vertical takeoff transition to horizontal flight deceleration to vertical flight and vertical landing After much testing and practice the first public presentation of the Yak 36 was made on 9 July 1967 at an air show at Moscow Domodedovo airport marking the 50th Anniversary of the October Revolution After the promising results obtained from the flight test programme of the Yak 36 the next development step was the Yakovlev Yak 36M which flew for the first time on 27 September 1970 1 Operators Edit Soviet UnionSoviet Air ForceAircraft on display EditThe second Yak 36 prototype b n 35 is now on display at the Central Air Force Museum at Monino outside Moscow Russia 3 Specifications Yak 36 Edit Data from Yakovlev Yak 36 Yak 38 amp Yak 41 1 General characteristicsCrew one Length 17 m 55 ft 9 in Wingspan 10 m 32 ft 10 in Height 4 5 m 14 ft 9 in Wing area 17 m2 180 sq ft Empty weight 5 300 kg 11 684 lb Max takeoff weight 8 900 kg 19 621 lb Fuel capacity 2 600 kg 5 732 02 lb Powerplant 2 Tumansky R 27 300 Vectored thrust axial flow turbojets 51 993 kN 11 688 lbf thrust eachPerformance Maximum speed 900 km h 560 mph 490 kn Range 370 km 230 mi 200 nmi Service ceiling 12 000 m 39 000 ft Hovering ceiling 1 900 m 6 233 60 ft Rate of climb 140 m s 28 000 ft min Armament Guns 2 x 23 mm 0 91 in GSh 23L cannon UPK 23 250 gunpods Hardpoints 2 with a capacity of 100kg with provisions to carry combinations of Rockets S 5K Missiles R 3S air to air missiles Bombs FAB 100 and FAB 250 Rockets 2 x UB 16 57UM FFAR rocketpods 16 rockets each See also EditRelated development Yakovlev Yak 38Aircraft of comparable role configuration and era Hawker Siddeley P 1127References Edit a b c d Gordon Yefim 2008 Yakovlev Yak 36 Yak 38 amp Yak 41 Red Star Vol 36 Midland publishing pp 9 30 ISBN 978 1 85780 287 0 a b c d e f Gordon Yefim Dmitry Komissarov Sergey Komissarov 2005 OKB Yakovlev 1st ed Hinkley Midland publishing ISBN 1 85780 203 9 Yakovlev Yak 36 Freehand Moscow www moninoaviation com Retrieved 7 January 2012 Gordon Yefim 2008 Yakovlev Yak 36 Yak 38 amp Yak 41 Red Star Vol 36 Midland publishing pp 9 30 ISBN 978 1 85780 287 0 Gordon Yefim Dmitry Komissarov Sergey Komissarov 2005 OKB Yakovlev 1st ed Hinkley Midland publishing ISBN 1 85780 203 9 External links Edit Wikimedia Commons has media related to Yakovlev Yak 36 The surviving Yak 36 at Monino Retrieved from https en wikipedia org w index php title Yakovlev Yak 36 amp oldid 1101313540, wikipedia, wiki, book, books, library,
