RogerBW's Blog: Yakovlev Yak-38

The Yak-38 (NATO reporting name "Forger") was the Soviet carrier-borne fixed-wing aircraft of the Cold War.

Its story actually begins in 1960, when the Yakovlev design bureau first proposed the use of two small lift engines coupled with a thrust-vectored conventional main engine. Other engine layouts were tried (including something like a Harrier, a single engine with rotating nozzles, and the Yak-36 demonstrator, with two engines each driving a vectored nozzle on one side of the aircraft), but eventually Yakovlev came back to the idea of separate lift jets.

Enthusiasm for a full order wasn't high until the Kiev-class ships were being planned. To a Western eye these look quite odd: they are externally similar to helicopter carriers, but the foredeck is filled with a heavy surface-to-surface missile armament. Western doctrine says that the carriers should be kept out of harm's way and send their aircraft forward to do the fighting, so their own weapons fit would be minimal and defensive; the Soviet approach was that the carrier should be a major surface combatant which happened also to have an aviation capability. (Even their full-deck carrier design, the Admiral Kuznetsov, carries twelve supersonic P-700 Granit missiles with a range of over 300 miles.)

However, while it had originally been hoped that the Kiev would be fitted with catapults and able to conduct full carrier operations, it rapidly became clear that this could not be afforded; the need for some more capable form of air wing than could be provided by helicopters rekindled interest in the Yakovlev VTOL designs.

The aircraft eventually built, first as the Yak-36M in pre-production form and then with modifications as the Yak-38, had three engines: two small Rybinsk jets mounted (almost) vertically within the fuselage, and one larger Tumansky jet with a pair of rotating nozzles at the rear. Supersonic capability was considered, but deferred to a possible later improved model. Indeed, the Yak-38 was a pretty basic aircraft: no radar (it was to be guided to its target by ground controllers, in keeping with standard Soviet doctrine), no internal gun, and the only air-to-air missiles it could carry were short-range IR-homers. An airborne radar, and radar-guided missile capability, were also deferred to a later version.

Its primary role was to be as an attacker going against surface targets, but the need for VTOL capability kept payloads very light. Indeed, when Minsk sailed off the coast of West Africa and in the Indian Ocean, high temperatures reduced performance to the point that the aircraft couldn't carry any external stores at all. Rolling takeoffs were possible, and helped the payload capacity a bit, but this was always the aircraft's major problem; the need to carry the dead weight of the two lift engines even when not flying vertically cut directly into the payload. High fuel consumption and the need to keep a large landing reserve gave it short ranges and loiter times.

All three engines were needed in order to land, and this introduced a reliability problem compared with the Harrier, especially since the lift engines had a reliable life between maintenance of around twenty hours. The designers realised this, and included an automatic system which would fire the pilot's ejection seat if any one of the engines failed while in vertical flight mode. (On at least one occasion this fired without an engine failure, with consequent loss of aircraft.) The system also monitored other parameters, such as aircraft attitude and descent rate, and would fire if it sensed that a landing attempt was going wrong. As one would expect, this was vastly unpopular with the pilots, who liked to make their own decisions about when to abandon the aircraft.

They flew very briefly over Afghanistan in 1980 in a fifty-day "near-operational" evaluation, possibly dropping small numbers of bombs in combat (it's still not clear), but with very limited capability in the hot thin air; this was the closest they ever got to war.

The Yak-38M variant upgraded all the engines and increased payload capacity, though it didn't add any new capabilities; it entered service in 1987. But the aircraft was never terribly effective, nor was it popular, and the collapse of the USSR led to its rapid retirement. Unlike many other Soviet aircraft, no attempt was ever made to sell it to overseas customers, even when India bought the Kiev-class Baku (later Admiral Gorshkov, now Vikramaditya).

The Yak-141 (Yak-41M) was a development of the Yak-38, finally giving the supersonic capability that had eluded other VTOL aircraft designers, and adding back in features like radar and guns. Prototypes first flew in 1987, but it did not enter service before the end of the USSR and in spite of efforts by Lockheed the project seems to have been completely abandoned.

Comments on this post are now closed. If you have particular grounds for adding a late comment, comment on a more recent post quoting the URL of this one.