What happened
A positioning flight was en route from Geneva to Mecca, with scheduled stops in Dakar, Niube, and Khartoum. The aircraft was operated with a crew of ten and included two Swiss journalists as passengers. While navigating through Sudanese airspace at night, the aircraft type (not specified) was flying at an altitude of 8,000 feet when it collided with the slope of a mountain within the Djebel Marra range. Following the impact, the wreckage was discovered several hours later. The accident resulted in 12 fatalities, with no survivors among the occupants.
Findings
Investigations into the crash identified several navigational discrepancies that contributed to the disaster. The crew operated under the impression that their ground speed was between 175 and 178 knots, whereas the actual average ground speed was significantly higher, at least 200-205 knots. Additionally, a minor directional deviation of approximately 2 to 3 degrees existed between the intended track and the real flight path.
Over the course of the 2.5-hour flight, these errors accumulated, leading to a positional error of roughly 70 nautical miles to the west and 30 nautical miles to the south. Although an astronomical fix was used for a position report at 1906Z, this report was inaccurate, preventing the crew from realizing they had drifted off course. Consequently, the aircraft struck the mountains four minutes before the crew anticipated reaching the El Fasher beacon, a point where they intended to begin climbing to 12,000 feet. At the time of impact, the crew believed they were still more than 60 nautical miles away from the mountain range.