It is a bit sketchy but what is known so far - the passengers were not the owners of this aircraft, it was chartered commercially for medivac. The aircraft is not under AOC therefore it is illegal for them to operate commercially. The crew have flown positioning from Moscow to Utapao (2 pilots) on 18 hours duty. They had about 6-7 hours rest/stop in Thailand before departing back with a tech stops in Gaya and next one was supposed to be Tashkent (TAS). I have no idea of Falcon 10 range/performance but it is believed they ran out of fuel due to headwinds. With accidents like this one it is unlikely that something else will pop up which will change the picture considerably.