Yakovlev Yak-42 Yak-42

The production standard was settled by flying the two wings against each other: the 11-degree surface of the first prototype and the 23-degree wing of the aircraft that followed. The more swept wing won, and with it went a fully swept T-tail and twin-wheel main gear legs, replacing the single wheels used on the test aircraft.

The Yak-42 is an all-metal low-wing monoplane driven by three Lotarev D-36 high-bypass turbofans: two in pods flanking the rear fuselage and the third buried inside it, fed through an S-duct. The cabin was laid out for 120 seats six abreast and a two-pilot flight deck, and the aircraft carries its own airstairs — one under the rear fuselage, inherited from the Yak-40, and one on the forward port side — so that it can work airfields with little ground equipment. The airframe was designed for 30,000 one-hour flights.

The first production airframe was completed on 28 April 1978, and the first scheduled service, Moscow to Krasnodar, flew on 22 December 1980. Deliveries built up slowly: only about ten aircraft were flying by mid-1981. The original 120-seat, three-plus-three cabin soon gave way to a mixed layout with a two-plus-two first class and 96 economy seats, 104 in all. During its first year in service Aeroflot's Yak-42s carried around 200,000 passengers, mostly out of Moscow but also on international runs from Leningrad to Helsinki and Donetsk to Prague.

On 28 June 1982 the tailplane of a Yak-42 came away in flight after its actuator jackscrew failed, and the aircraft crashed near Mazyr. The fleet was grounded and did not fly again until October 1984, once the mechanism had been redesigned. Production resumed afterwards, and in 1988 the Yak-42D — more fuel, more weight — took over on the assembly line.

The original version set the pattern the whole family kept: three high-bypass engines, self-contained boarding stairs and room for a hundred-odd passengers over medium stages. It was also the first Soviet airliner with modern turbofans, and its production was eventually shared between the Smolensk and Saratov plants.