Did a Su-35S Fighter Shoot Down a Su-30 Jet in Russian Exercises?

The Su-30 fighter jet of the Russian Aerospace Forces (RuAF) that crashed during exercises on Tuesday could have been brought down by friendly fire from a Su-35S jet whose cannon had not been disarmed.

While the crash of the Su-30 was widely reported in the Russian media, what caused the crash in which the crew ejected was not explained.  Netizens speculated that if the crew had to eject then a catastrophic occurrence- such as both engines failing at the same time or an external impact may have taken place.

"On September 22, a Su-30 jet of the Western Military District crashed during a planned training flight in the Tver Region. The crew has safely ejected. After landing, the pilots made contact," the press service of the Western Military District informs. The crew members have been evacuated to their air base. The press service said that the jet had crashed in the forest area, there is no damage on the ground,” TASS reported Tuesday quoting the press service of the Western Military District as saying.

Asserting that the Su-30 was brought down by a Su-35’s cannon fired accidentally, a well-known Russian military blog reported on the sequence of events that led to the Su-30 crash (translated from Russian):

“After combat duty, the Su-35S fighter was sent to ordinary (training) flights, namely for "sparring" in aerial combat (with the Su-30SM). The missiles were removed from the Su-35 but due to someone's oversight, the fighter plane’s cannon’s were not disarmed.

The  Su-35S and Su-30 practiced aerial combat, the Su-35S was supposed to perform photographic shooting, but instead fired a real volley from a cannon at the Su-30 and demolished that little "plumage" (empennage) . The crew of the Su-30 successfully ejected, and the pilot of the Su-35S, after all that happened, was a little shocked as follows from the message.”