Russian Jet Vanishes Mid-Flight It may have crashed or been hijacked: Indonesian officials By Kevin Spak, Newser Staff Posted May 9, 2012 7:00 AM CDT Updated May 9, 2012 7:53 AM CDT 20 comments Comments A Sukhoi Superjet 100 performs at an air show in Zhukovsky, Russia, Aug. 18, 2009. (AP Photo / Misha Japaridze, file) (Newser) – A Russian Sukhoi SuperJet-100 disappeared during a demonstration flight in Indonesia today, vanishing from radar screens while it was still at high altitudes and failing to land at its appointed time. The plane was last heard from when it requested, and was granted, permission to descend from 10,000 feet to 6,000 feet, Russia Today reports. Indonesian officials say it may have crashed—there's a 6,200-foot-tall mountain in the area—or it may have been hijacked. The plane must have come down somewhere, because by its scheduled landing time, its fuel supply should have been exhausted. There were 44 people onboard, most of them reps from major airline companies, and so far none of them can be reached by phone.