Yakovlev - Yak-40
The program for the Yak 42 began in the mid sixties and was designed to fill the role of short range regional transport aircraft for both passengers and cargo. Up to this point aircraft that were operating in this market were the aging, LI-2 (being the licence built DC3’s) and Ilyushin IL-14. The aircraft design was required to operate from small air fields with minimal support as well as being capable in remote locations. The solution to this led to a triple engine design based on the need for greater redundancy and take off and runway lengths could be calculated with the loss of only a third of power in the event of engine failure. The aircraft has a cantilevered low-mounted wing giving the aircraft overall a high power to weight ratio, which was greatly needed for high altitude airfields that were in abundance in the remote areas of the Soviet Union
The first trial flight for the aircraft was 21st October 1965 and was then introduced operationally by Aeroflot on 30th September 1968. Production at the Saratov factory ran from 1967 up until 1983 where over 1000 aircraft were built. The aircraft incidentally was the first Jet aircraft in Russia designed for passenger and cargo use and was also the first Russian aircraft issued an airworthiness certificate by other european countries; no less than 125 were exported to over 18 countries in a state program led by Avia-Export the soviet state marketing scheme.
Construction of the aircraft remained essentially the same except for the addition of a clamshell thrust reverser and the removal of a fairing at the fin / tail plane leading edge junction.
Variants of the Yak 42 are mainly interior layout changes and some research aircraft.
Notably the 40D which is part of an upgrade program of some 80 aircraft. The main change of this program is the addition of two torsion-fuel boxes to increase the fuel load to 6000kg increasing the effective range from 1800Km to 2500Km. The Yak 40K is the Cargo variant of the 40
To date the model designations are: Yak-40, 40D, 40DTS (Troop carrier with a paramedic modification), 40K, 40-25, 40TL (Modified with TL LF507-1N engines).
