Flightline: 71

"user314" (user314) 11/04/2020 at 11:00 • Filed to: flightline, Planelopnik, planelopnik history

5

0

Yakovlev Yak-38M VTOL attack aircraft at MAKS-1993 airshow

The Yakovlev OKB began design work on a VTOL fighter for the Soviet Air Force in the early 1960s, with the Yak-104 being designed to incorporate both lift and cruise engines, though this effort was abandoned in favor of a more simple set up of a single engine with rotating nozzles, similar to the Hawker P.1127. This revised design was designated the Yak-36 and given the NATO code name “Freehand”. The Yak-36 mounted two Tumansky R-27 -300 engines in the nose, with pivoting nozzles mounted amidships. The aircraft had a cropped delta wing, and as with the P.1127, bleed air nozzles were included in the wings, tail, and on the extended nose probe to maneuver while in hover.

The second prototype of Yak-36 Freehand at the training flights before Domodedovo airshow July 1967

Orthograph of the Yak-36

Four “ Freehand” prototypes were built, though the first was a static test article and did not fly. The second prototype took its first tethered hover flight on 9 January 1963, followed swiftly by a free hover on 23 June and a transition flight from vertical to horizontal on 16 September. Initial tests demonstrated that the concept worked, but that the design created an issue with reingestion of exhaust gases, which robbed the engine of power at critical moments in hovering flight. Modifications were made, and on 24 March 1966 the first complete flight was made from vertical takeoff, transition to horizontal flight, deceleration to vertical flight, and vertical landing. The third prototype incorporated further improvements, including an autopilot which automatically set the engine and nozzles for optimal airflow during hover. The Yak-36 still proved to be a difficult airplane to fly, and the third and fourth prototypes both crashed. The second Yak-36 is on display at the !!!error: Indecipherable SUB-paragraph formatting!!! at !!!error: Indecipherable SUB-paragraph formatting!!! , outside Moscow, Russia.

The second Yak-36, marked as Yellow 36, on display

Yak began design work on a supersonic VTOL follow-up for the Soviet Navy , but the actual Yak-36M pre-production aircraft were simplified subsonic aircraft. In order to bring performance up, the new design incorporated two dedicated lift engines in the forward fuselage along with the main vectored engine. The design was more streamlined than its predecessor, allowing the Yak-36M/Yak-38 to carry 4,400lbs of stores, including one or two gun pods, GP, incendiary or nuclear free-fall bombs, R-60/M (AA-8 Aphid) air-to-air missiles, Kh-23 (AS-7 Kerry) anti-ship missiles, or drop tanks. The Yak-38 was unique among VTOL aircraft in that it had an automatic ejection seat that would fire if the engine ingested exhaust gas and lost power.

Schematic of the Yak-38 showing the main and lift engines, as well as the maneuvering jets for hover

The Yak-36M, NATO reporting name “ Forger” , first flew in 1970-71, with deliveries to the 279 OKShAP ( Otdelny Korabelny Shturmovoy Aviatsionny Polk) , “ Independent Shipboard Attack Air Regiment” , the Russian Navy’s training centre based at Saki, in the !!!error: Indecipherable SUB-paragraph formatting!!! . The improved Yak-38 (NATO reporting name “ Forger-A” ) entered service in 1976, flying from the !!!error: Indecipherable SUB-paragraph formatting!!!   !!!error: Indecipherable SUB-paragraph formatting!!! s. In 1978 the Yak-38U “Forger-B” two-seat trainer entered service. In 1982, Forger-As from the cruiser !!!error: Indecipherable SUB-paragraph formatting!!! intercepted aircraft from the USS Enterprise operating over the Arabian Sea, the first time Soviet VTOLs intercepted American aircraft. In 1983, Yak-38s were operated from two civilian roll-on, roll-off ships, the Agostinho Neto and Nikolai Cherkasov , similar to RAF Harriers operating from the !!!error: Indecipherable SUB-paragraph formatting!!! and !!!error: Indecipherable SUB-paragraph formatting!!! during the Falklands Islands campaign . Beginning in 1985, production began on the Yak-38M, which featured upgraded engines, allowing an increase in VTOL takeoff weight from 22,700lbs to 24,900lbs.

A Yak-38 operating from the heavy aircraft cruiser Novorossiysk

Air-to-air shot of a Yak-38U from an American aircraft

In 1983 Yakovlev began design work on a fighter/attack variant of the “Forger” designated the Yak-39, which would have featured more powerful engines, a larger wing, multimode radar, increased fuel capacity and expanded weapons options. This variant was abandoned, however. The Yak-38 was retired in 1991 with the dissolution of the Soviet Union.