Russian investigators have determined that the Tupolev Tu-204 that crashed on approach to Moscow Domodedovo in March had adequate fuel on board at the time of the accident.
But the Interstate Aviation Committee has found that the crew switched to manual control after encountering a problem with the flight-control system while attempting an instrument approach to Runway 14R.
The problem emerged as the twinjet descended through 13,100ft (4,000m), leaving the crew unable to use director indicators.
But the pilots did not inform air traffic controllers of the problem and did not request a change to the approach.
They opted instead to continue the approach - conducted in darkness and fog - with the navigation aids available. The aircraft struck trees about 1km (0.5nm) from the runway and was destroyed.
MAK has learned that the aircraft received 16t of fuel before departing from Hurghada, Egypt, on the return service to Moscow. With residual fuel in the tanks, MAK estimates that the Tu-204 was carrying 24t before take-off.
It says that analysis shows that the aircraft had "no less" than 9t of fuel remaining in the tanks at the time the crash. Investigators have already concluded that both Aviadvigatel PS-90 engines were functional before impact.
No passengers were on board the 22 March flight, operated by Aviastar-Tu, and all eight crew members survived.