A Su-57 fighter jet exploded at a Russian airfield.

The press service of the Main Intelligence Directorate of the Ministry of Defense of Ukraine reported this.

According to the Main Intelligence Directorate (GUR), the cost of the combat aircraft is approximately $150 million. The Su-57 is equipped with an AL-41F1 turbofan engine. Intelligence reports suggest the use of substandard fuel as one of the possible causes of the engine explosion or critical failure.

The Main Intelligence Directorate notes that RN-Aero supplies aviation fuel to the United Aircraft Corporation (UAC) under a government contract for the production of Su-57 fighter jets. The latter is subject to sanctions by the US, Canada, Switzerland, the EU, the UK, Australia, New Zealand, Japan, and Ukraine.

The fuel in question is Jet A-1, a derivative of the Russian-Soviet TS-1 and RT aircraft fuels. According to the Main Intelligence Directorate, it is compatible with a number of Russian aircraft, including the MiG-29, Su-34, Su-35S, Su-30SM, Su-57, Su-24M, and Tu-95MS.

The Jet A-1 can also be used to refuel Geran-4 and Geran-5 attack drones equipped with Telefly TJ2000A turbojet engines or their Russian counterparts, the TRD-2000.