3 fatalities

1991-07-10: De Havilland DHC-6 Twin Otter (RAN-26) — Nepalese Army — Surkhet, Nepal

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: The crew flew into a mountain due to an incorrect altimeter setting that provided a false sense of clearance. 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 1781211857Data APIEditorial standards

An aircraft crashed into a mountainside shortly after departing Surkhet Airport, resulting in the deaths of all three people on board.

What happened

Shortly after departing from Surkhet Airport, an aircraft began its climb toward an altitude of 5,800 feet. Approximately four minutes into the flight, the captain communicated with Air Traffic Control to report favorable flying conditions and indicated intentions to exit the valley. One minute later, while operating within cloud cover, the aircraft collided with a mountain slope situated at an elevation of 6,300 feet, located a short distance from the airport.

The wreckage was subsequently located 500 feet below the peak of the mountain. The accident resulted in three fatalities, with no survivors among the crew members.

Findings

Investigations into the crash determined that the flight was being conducted under Visual Flight Rules (VFR) when the aircraft entered clouds, which significantly reduced visibility. The primary factor in the collision was a discrepancy in altimeter readings. At the moment of impact, the captain's altimeter indicated an altitude of 7,350 feet, whereas the actual altitude of the aircraft was only 5,800 feet. This error led to controlled flight into terrain.

Probable cause

The crew flew into a mountain due to an incorrect altimeter setting that provided a false sense of clearance.