Russian investigators have ruled out poor fuel quality as a contributor to the fatal Dagestan Airlines Tupolev Tu-154 crash at Moscow last December.
The trijet landed long on the runway and broke up when it diverted to Domodedovo Airport after encountering engine problems in flight.
Two of its engines shut down and Russia's Interstate Aviation Committee (MAK) says instrumentation had indicated fluctuations in the fuel supply.
But in its latest progress update MAK states that the investigation has determined that the accident "is not related to the quality of fuel".
Two of the occupants of the Tu-154, which had been en route to Makhachkala on 4 December, were killed in the break-up.