What happened
On a scheduled service traveling from Algiers to Cairo via Tripoli, the de Havilland Comet experienced several delays prior to its departure. The outbound leg had been delayed by 29 hours because of poor weather along the flight path. During pre-flight checks in Algiers, a fire warning light for the number 3 engine's Zone I remained illuminated. Maintenance staff, who lacked specific experience with this aircraft type, attempted repairs, which added another two and a half hours to the delay. Although the pilot considered canceling the flight, the light eventually turned off, and the decision was made to continue.
Upon entering the Tripoli Control Area, the crew received a weather report indicating horizontal visibility of 1000 meters due to sand haze. While this visibility was below the airline's established minimums, vertical visibility remained unlimited. The pilot decided to attempt a landing at Tripoli with Malta as an alternative, noting a remaining endurance of 3 hours and 50 minutes. Air traffic controllers provided a QNH of 1008 mb and suggested that visibility might be better than 1000 meters.
At the time, the airport's VOR was out of service for calibration, leaving only the ADF as an available ground aid. The approach to Runway 18 required a teardrop turn via an ADF procedure turn after passing a beacon located 0.6 NM north of the runway. After initially reporting at 3,000 feet, the aircraft's last communication occurred while passing the beacon on the outbound leg of the procedure turn. The aircraft subsequently struck sand dunes at an elevation of 395 ft, roughly 7 km from the runway threshold. The impact destroyed the de Havilland Comet, and there were 16 fatalities.
Findings
- The pilot decided to proceed with a landing attempt despite visibility being below the airline's required minimums for that location at night.
- The aircraft was flying at an altitude lower than necessary for the prescribed ADF approach procedure.
- Adverse weather conditions, specifically sand haze, acted as a contributing factor to the accident.