Ilyushin Il-62

The Ilyushin Il-62 (NATO reporting name Classic) is a Soviet long-range jet airliner conceived in 1960 by Ilyushin. As successor to the popular turbo-prop Il-18 and with capacity for almost 200 passengers, the Il-62 was the largest jet airliner when it first flew in 1963. It entered Aeroflot service on 15 September 1967 with an inaugural passenger flight from Moscow to Montreal. One of four pioneering designs (the others being Boeing 707, DC-8, and VC10), the Il-62 was the first such type to be operated by the Soviet Union and a number of other nations, becoming the standard long-range airliner for several decades. It was the first Russian pressurised aircraft with non-circular cross-section fuselage and ergonomic passenger doors, and the first Russian jet with six-abreast seating (the turbo-prop Tu-114 shared this arrangement) and international-standard navigation lights. Over 30 nations operated the Il-62 with more than 80 being exported and others leased by Russian-sphere and Western airlines. Special VIP (salon) and other conversions were also developed. The Il-62M became the longest-lasting model in its class with some being in civilian service for three decades. Expensive to operate compared to new generation airliners, the number in use was reduced after the 2008 recession. The Il-62's successors include the wide-bodied Il-86 and Il-96, both of which were made in smaller numbers and not widely exported. The Ilyushin OKB presented a proposal for a four-engined long-range jet airliner in February 1960, receiving the go-ahead from the Soviet Council of Ministers on 18 June 1960, with the Kuznetsov Design Bureau being instructed at the same time to develop the NK-8 turbofan to power the new airliner. The official specification required that the airliner, designated Il-62, must carry 165 economy-class passengers over a distance of 4,500 km (2,800 mi) or 100 first class passengers over 6,700 km (4,200 mi).[1] The Il-62 replaced the fast turboprop Tu-114 on long range routes. As the Tu-114 was just entering service when the Il-62 was on the drawing board, Ilyushin had time for

n unhurried design, test, and development programme. This was useful, since the Il-62 did call for significant development. The Il-62 and the British Vickers VC10 are the only commercial airliners with four engines fitted in twinned/paired nacelles by the sides of, and beneath, a "T" shaped empennage (T-tail), although the Lockheed JetStar business jet shares this configuration. In the case of Ilyushin, the configuration was dictated by TsAGI, the Soviet Union's aerospace agency, since Ilyushin's design bureau lacked the resources to engage in configuration studies.[citation needed] This layout allowed the wing design to be optimised for aerodynamic efficiency, without being cluttered by having to carry engines. In addition, the rear mounted engines reduced engine noise in the cabin and allowed smaller vertical tail surfaces (as the yawing moment in the event of an engine failure was reduced compared to wing mounted engines). These advantages are balanced by a number of drawbacks. The wing structure, without wing mounted engines to relieve the wing bending moment, need to be heavier, as did the rear fuselage structure, which had to carry the engines. In addition, aerodynamic wash (shadow) from the wing blankets the tail when the nose is pitched up (high angle of attack) leading the aircraft into a condition known as deep stall. This called for complex and (in the 1960s) unreliable automatic stall warning systems such as stick shakers and stick pushers to prevent the aircraft getting locked into the deep stall condition, although the Il-62's wing was designed to prevent deep stall.[1][2] Early aircraft (prototypes, pre-production and initial production aircraft) display an evolution from thin or thick kinked leading inboard edges to the ultimate thick and straight 1966 shape. The characteristic "dog tooth" also moved until fixed before production began. The engine installation also evolved, with the engines' longitudinal axes canted by 3 degrees from the horizontal; thrust reversers were added to the outer engines, and the entire installation was slimmed down as production began.