Flight MS844: Nighttime ADF Approach Accident at Tripoli (SU-ALC)

Flight Operations and Pre-Departure Issues Flight MS844 was a scheduled international service operating from Algiers to Cairo with an intermediate stop at Tripoli. The outbound segment from Cairo to Tripoli and then Algiers had been delayed by 29 hours because of adverse weather along the route. At Algiers, after systems testing, the fire warning light for Zone I of engine number 3 remained illuminated. Local personnel, who were not familiar with the Comet aircraft, attempted to correct the discrepancy, causing an additional delay of nearly two and a half hours. The light eventually extinguished, and the pilot-in-command, who had considered canceling the flight and returning to Cairo without passengers, decided to continue the service. ## Approach and Accident There was no evidence that the crew requested or received a weather forecast before departing Algiers for Tripoli, although a verbal forecast may have been obtained. The QNH at Algiers was 1011 mb. As the aircraft entered the Tripoli Control Area, the crew received a weather report indicating horizontal visibility of 1,000 meters due to sand haze. This was below the airline's authorized minimum, though vertical visibility was unlimited. The pilot-in-command checked Benina weather and decided to attempt a landing at Tripoli, with Malta as the alternative, stating an endurance of 3 hours 50 minutes. Both Tripoli Control and Tripoli Tower provided a QNH of 1008 mb. Tripoli Control indicated that visibility was better than 1,000 meters, and Tripoli Tower stated that the pilot could see 3 kilometers. The airport's VOR was unavailable for calibration, leaving the ADF as the only ground aid. The approach to Runway 18 from Algiers required joining the holding pattern in the opposite direction to the circuit, necessitating a teardrop turn to re-approach the beacon on the outbound leg using an ADF procedure turn. The beacon was located 0.6 NM north of Runway 18. Shortly after passing the beacon for the first time, the pilot-in-command reported at 3,000 ft. The last message was received when the aircraft was passing the beacon outbound for the ADF approach procedure turn. No altitude was stated after entering the holding pattern. The flight path to Runway 18 crossed sand dunes 160 ft AMSL that rose steeply to 425 ft AMSL before falling to the runway threshold elevation of 240 ft. The aircraft struck sand dunes at an elevation of 395 ft approximately 7 km before the runway threshold. The accident occurred at 01:25 GMT. The aircraft was destroyed, and all 16 occupants were killed.