33 years ago, on April 15th, 1991, at 17:02, the world's first and currently the only aircraft Tu-155 on alternative fuel took off.

The Tupolev Tu-155 is a modified Tupolev Tu-154 (СССР-85035) which was used as an alternative fuel testbed, and was the first experimental aircraft in the world operating on hydrogen and later on liquid natural gas. The similar Tu-156 was never built.

The Tu-155 first flew on 15th April 1988 by the crew of test pilot V.A.Sevankaev. The first test flight on liquefied gas took place on January 18, 1989. It used first liquid hydrogen and later liquified natural gas (LNG). It flew until the fall of the Soviet Union and it is currently stored at Ramenskoye Airport near Zhukovskiy. 

The aircraft used cryogenics to store fuel. The fuel tank was located in the air-blown (or nitrogen) rear compartment. A distinctive feature of the aircraft is that the protrusion of the ventilation system is visible on the tail (near the no. 2 engine). 

The Tu-155 used Kuznetsov NK-88 engines. The Tu-156 was intended to use Kuznetsov NK-89 engines. The Tu-155 flew around 100 flights until it was placed in storage.