2 fatalities

Canyon Flight Ends in Collision with Terrain, Two Fatalities (N4787C)

Ketchikan, United States of AmericaLanding (descent or approach)

On July 26, 1984, a De Havilland DHC-2 Beaver (registration N4787C) operated by Promech Air was involved in an aviation accident near Ketchikan, United States of America during landing or approach. 2 people were killed. Investigators recorded the probable cause as: In-flight collision with terrain/water due to mountainous/hilly terrain, improper in-flight planning/decision by the pilot in command, exceeded aircraft climb capability, inadequate clearance by the pilot in command, and impossible proper climb rate by the… This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 4 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 collided with upsloping terrain after flying into a canyon with a climb gradient exceeding its capability. Passengers reported no turbulence before impact.

Accident Summary

The accident occurred when the pilot flew into a canyon and attempted a climb-out gradient that was beyond the aircraft's performance capabilities. The aircraft subsequently collided with the rising terrain. The pilot reported experiencing a downdraft at the accident site and stated that he turned away from the terrain just before the collision. However, surviving passengers did not recall any turbulence or sinking sensation prior to the crash. The pilot did not report any turbulence or downdrafts at any other location.

Two passengers were killed in the accident.

Investigation Findings

An investigation into the accident identified several factors contributing to the event. The terrain was mountainous and hilly. The pilot's in-flight planning and decision-making were deemed improper. Additionally, the aircraft's climb capability was exceeded by the required gradient. The pilot failed to maintain adequate clearance from the terrain, and a proper climb rate was not achievable given the conditions.

Official Probable Cause

The official probable cause, as determined by the investigation, includes the following findings:

  • Terrain condition: mountainous/hilly
  • In-flight planning/decision: improper (pilot in command)
  • Aircraft performance, climb capability: exceeded
  • Clearance: inadequate (pilot in command)
  • Proper climb rate: not possible (pilot in command)