Ilyushin Il-62 Il-62

The Ilyushin OKB presented a proposal for a four-engined long-range jet airliner in February 1960 and received the go-ahead from the Soviet Council of Ministers on 18 June 1960; at the same time the Kuznetsov bureau was instructed to develop the NK-8 turbofan to power it. The official specification required carrying 165 economy passengers over 4,500 km or 100 first-class passengers over 6,700 km. The Il-62 was to replace the fast Tu-114 turboprop on long routes, and since the Tu-114 was only just entering service while the Il-62 was on the drawing board, Ilyushin had an unhurried design and test programme: it needed one.

The Il-62 and the British Vickers VC10 are the only two commercial airliners with four engines in paired nacelles at the sides of the rear fuselage, beneath a T-tail. In Ilyushin's case the configuration was dictated by TsAGI, since the design bureau lacked the resources for configuration studies. The layout let the wing be optimised without carrying engines, cut cabin noise and allowed smaller vertical tail surfaces. In exchange the wing and rear fuselage had to be heavier and the arrangement was prone to deep stall, though the Il-62's wing was designed specifically to prevent it.

The wing's most characteristic feature is the leading-edge «dog-tooth», acting as a vortex generator and as a fixed leading-edge device: it ensures vice-free behaviour at high angles of attack and removes the need for hydraulic controls, stick shakers and stick pushers. The Il-62 is the only airliner in its class with entirely unpowered, all-manual flight controls, using steel cables, rods, pulleys, aerodynamic and weight balances and trim tabs. It also carries a forward water ballast tank for flying empty or lightly loaded, and an extendable tail strut that stops the aircraft sitting on its tail when parked.

Early NK-8-4-powered Il-62s suffered engine fatigue and overheating, with false fire alarms that could lead crews to shut down both engines on one side and leave the aircraft unbalanced. There were two fatal losses involving engine failure, both with LOT: Flight 007, an unmodified NK-8-4 Il-62, on 14 March 1980 with 87 fatalities, and Flight 5055, an Il-62M, on 9 May 1987 with 183. Aeroflot progressively replaced its NK-8-powered Il-62s with Soloviev D-30KU-powered Il-62Ms: by mid-1973 it operated 60 aircraft, and by 1989 as many as 165 of both versions.

Continuous production ended in 1993, although it is said to have continued until 1995, and the last airframe was built in 2004 for the Sudanese government. Total output is surmised at 289 aircraft including prototypes, but the factory states 292: 5 prototypes, 94 Il-62s and 193 Il-62Ms. Both figures are recorded without choosing between them.