The Ilyushin Il-76 cargo plane departed Ulyanovsk on a training/cargo flight to Leninakan. The aircraft carried a cargo of 37200 kg. Approaching Leninakan the flight was cleared to descend to 3300 metres. During the descent the approach controller reported the airport pressure being 637 mm Hg. After issuing a further clearance down to 1100 metres, the controller corrected the airport pressure to 637 mm Hg. Erroneously the crew programmed their barometric altimeters using 736 instead of 636 mm Hg, causing a difference in altitude indication of about 1100 metres. Descent was continued at a vertical speed of 10 m/sec. At a height of 270 metres the GPWS alarm began to sound and continued to 19 seconds. Then the flight engineer suddenly informed the captain of the mistake, but no corrective action was taken. Ten seconds later the aircraft struck terrain and crashed. PROBABLE CAUSE: – error by the crew in programming both barometric altimeters using the 736 mm Hg pressure instead of the actual 636 mm Hg causing a descent below MDA; – failure to use the radio altimeters, which deprived the crew of additional information about their descent below MDA; – failure of the crew to respond to the recommendation by the flight engineer to climb; Factors were: – the fact that it was the instructor captain’s first flight into Leninakan and the student pilot’s (in the right hand seat) first flight on an Il-76; – insufficient crew resource management; – insufficient training of pilots regarding the actions to be taken in case of a GPWS warning