Though a jet, the Yak 42M was required to operate from primitive airports without paved runways or any other facilities in the world's severest climates ranging from southern republics to the arctic conditions of northern Siberia. The Yak-42M was designed to takeoff on any two engines and continue level flight on one. The prototypes had twin-wheel main landing gears but these were changed to four-wheel bogies in the production version to improve behaviour on soft surfaces. Updates were also being introduced to the avionics to improve navigation and the ability to land in bad weather.