3 fatalities

Aircraft Collision with Mountain Near Surkhet Airport (RAN-26)

Surkhet, NepalTakeoff (climb)

On July 10, 1991, a De Havilland DHC-6 Twin Otter (registration RAN-26) operated by Nepalese Army was involved in an aviation accident near Surkhet, Nepal during takeoff. 3 people were killed. Investigators recorded the probable cause as: Controlled flight into terrain following a wrong altimeter setting. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 5 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 2026-06-11Data APIEditorial standards

An aircraft struck a mountain slope near Surkhet Airport after takeoff, killing all three occupants. The official investigation attributed the accident to controlled flight into terrain caused by an incorrect altimeter setting.

Incident Overview and Timeline Four minutes after departing from Surkhet Airport, the aircraft was climbing to an altitude of 5,800 feet. At that point, the captain reported to air traffic control that flight conditions were good and that the aircraft would soon leave the valley. One minute later, while flying in clouds, the aircraft collided with the slope of a mountain located a few kilometers from the airport. The mountain had a height of 6,300 feet. The wreckage was discovered 500 feet below the summit, and all three people on board were killed. ## Official Investigation Findings The official investigation determined that the probable cause was controlled flight into terrain following a wrong altimeter setting. The crew had departed Surkhet Airport under visual flight rules (VFR). During the climb, the captain encountered limited visibility because the mountain that was struck was shrouded in clouds. At the time of impact, the captain's altimeter indicated 7,350 feet, while the aircraft's actual altitude was 5,800 feet.