Incredibly, the Russian air force has lost another one of its rare Beriev A-50M/U Mainstay radar early-warning planes. Video that circulated online on Friday reportedly depicts the A-50’s burning wreckage in Krasnodar Krai, in Russia just east of the Sea of Azov.

The location of the crash, at least 120 miles from the front line in southern Ukraine, could indicate the four-engine, 15-person radar plane either suffered a mechanical failure—or took a hit while operating closer to the front and tried to make it back to its base in Krasnodar before exploding.

For what it’s worth, the Ukrainian air force claimed it shot down the A-50 with assistance from the intelligence directorate in Kyiv.

Either way, it’s a devastating blow for the battered Russian air force. The air arm has lost, mostly to Ukrainian long-range surface-to-air missiles—American-made Patriot PAC-2s, in particular—nine of its best planes in just a month. Including an A-50 that the Ukrainians hit over the Sea of Azov in January.