The aircraft with designation Tu-155 was used as a testbed for alternative fuels. It was built in 1972 as Tu-154B. The right engine is type NK-88, a modification of original NK-8-2. Liquified gas, formerly hydrogen, lately natural gas was stored in a Dewar in the aft. The tank takes one quarter of the fuselage which is indicated by plugged windows behind the second emergency exit. The amount of fuel allows for 1,5 hours of engine operation. On top of the tail structure is a valve of the fuel system drain. First flight with hydrogen fuel was on 15th April 1988. Aircraft operations stopped in 1993.
This Tupolev 134 was acting as a photographic chase aircraft to a Tupolev 22M3-LL aerodynamics research aircraft ("32 Red") when both aircraft collided in flight on 9.9.1994. The Tu-134 crashed into a forest, while the Tu-22 managed to land safely. The Tu-134 was operated by the Gromov Flight Research Institute (LII) of the Ministry of Aviation Industry (MAP).
