Date & Time: Aug 16, 1991 at 1246 LT
Type of aircraft:
Landing (descent or approach)
Scheduled Revenue Flight
Calcutta - Imphal
Crew on board:
Pax on board:
The aircraft departed Calcutta-Dum Dum Airport at 1154 on a regular schedule service to Imphal, Manipur. On descent, the crew encountered poor weather conditions and the visibility was low. After being cleared to descend to 10,000 feet, the crew obtain the permission to make a direct outbound course in view of an ILS approach to runway 04. While completing a turn to join the approach path, the crew failed to realize his altitude was insufficient when the GPWS alarm sounded in the cockpit during 6,3 seconds. The aircraft struck the slope of Mt Thangjing located 39 km southwest of runway 04 threshold and disintegrated on impact. All 69 occupants were killed.
The accident occurred by reason of a grave error on the part of the Pilot-in-Command in not adhering to the operational flight plan and ILS let down chart and not realizing that his early descent to 10,000 feet and turning right for outbound leg without reporting overhead VOR would result in loss of time reference and as such misplace him in the hilly terrain. The Pilot-in-Command's action may have been influenced by his extreme familiarity with the terrain.