What happened
On December 27, 1961, an United Arab Airlines flight from London, operated by a De Havilland Comet IV DH-106, registration SU-ALL, arrived at Geneva-Cointrin airport for landing on runway 23. The aircraft, carrying 9 crew members and 7 passengers, was performing a standard ILS approach. Prior to touchdown, air traffic control informed the crew that the runway was partially covered with 1.5 cm of hard snow and noted a snow wall of 80 cm on the right side of the runway, while indicating that braking action was normal.
Upon landing at approximately 11:12, the aircraft drifted from the centerline. At roughly 650 meters from the runway threshold, the left wing flap made intermittent contact with a snow wall on the left side of the runway. The aircraft then struck a snow wall at an angle approximately 350 meters from the threshold, causing damage to the nose gear. The aircraft continued to travel, exiting the runway at the 900-meter mark and traversing a section of taxiway 7 before the pilot managed to steer the aircraft back onto the runway. The aircraft finally came to a halt 1200 meters from the threshold with heavy damage to the engines, wings, fuselage, and landing gear.
The investigation
The investigation was hampered by delays in reporting the accident and the inability to interview the flight crew or obtain necessary information from the aircraft owner. Investigators examined the runway conditions, which included 1-2 cm of snow and snow walls on both sides of the runway, effectively narrowing the usable width to 40 meters. The investigation also reviewed the meteorological conditions, noting high humidity and recent heavy snowfall and rain.
Findings
- The primary cause of the excursion was that the aircraft escaped pilot control following touchdown due to adverse weather conditions.
- The information provided by the tower was imprecise; while the controller reported a snow wall only on the right side, a wall actually existed on both sides of the runway.
- The safety margin was significantly reduced by the combination of heavy snow accumulation, the presence of snow walls, and the lack of precise runway status information.
- It remains uncertain whether the lateral deviation was caused by an initial side-slip or an unidentified braking effect.