What happened
On September 22, 2021, an An-26, registration RA-26673, operated by ZAO Letnye proverki i sistemy, was scheduled to perform flight inspections of the radio navigation equipment at Khabarovsk (Novy) Airport. The crew had arrived at the airport via separate flights from other airlines. The aircraft had been ferried from Chita to Khabarovsk by a different crew on September 21, 2021.
The flight plan was filed for instrument flight rules (IFR) to inspect the SP-200 instrument approach system and the RMD-90NP distance measuring equipment for Runway 05R. The inspection was to be conducted without interrupting airport operations, as active takeoffs and landings were being handled on Runway 05L.
The first inspection flight commenced at 23:30 on September 21 and concluded with a landing at 03:46 on September 22, with no technical issues reported. The second flight phase began with a takeoff at 04:59. During this second flight, at 07:57, the flight mechanic notified the crew that they had been flying for three hours and had 2,200 units of fuel remaining.