What happened
A Fokker F-27, registration YN-BZF, was conducting a delivery flight from North Yemen to Nicaragua. To facilitate the long-distance journey, two 200 US gallon auxiliary ferry tanks had been installed within the cabin. Following several stops in Saudi Arabia, Egypt, and Greece, the aircraft flew from Prestwick, Scotland, to Reykjavik, Iceland, arriving on 15:48 hours on 20 April 1985.
While in Reykjavik, the crew inspected the auxiliary fuel system. Although Icelandic engineers noted that the installation appeared unprofessional and expressed concerns regarding the crew's familiarity with its operation, they provided instruction and assisted with a ground run. The aircraft departed Reykjavik at 17:21 hours for Kangerlussuaq-Søndre Strømfjord Airport. Shortly after takeoff, the pilot sent a message via Iceland radio to confirm the auxiliary system was functioning correctly.
During the flight toward Greenland, the crew encountered difficulties retrieving fuel from the ferry tanks. By 19:50 hours, approximately 50 NM west of Kulusuk, the crew reported that the auxiliary system had failed, resulting in a loss of roughly 400 US gallons of usable fuel. Due to the reduced reserves and a low ground speed of 180 knots, the crew attempted to return to Kulusuk. However, heavy weather prevented them from locating the airport. The aircraft diverted toward the "SOB STORY" radar station for an emergency landing on the icecap, but the aircraft collided with the terrain during its descent.
Findings
Investigations into the accident revealed that while the crew was properly certified and most standard aircraft systems were operational, the auxiliary ferry fuel system failed to function as intended. The exact reason for this mechanical failure remained unconfirmed.
Key contributing factors included:
- The crew failed to perform an adequate airborne functional test of the auxiliary system before it became critical.
- Potential deficiencies in the procedures used to operate the ferry tanks.
- Deteriorating weather conditions and low visibility during the approach to the emergency site.
- An error by an AFIS operator who provided an incorrect distance from the KK NDB, though this was not considered a primary cause of the impact.