What happened
On January 1, 1962, a Swissair SE-210 Caravelle (registration HB-ICY) was performing an instrument approach to runway 16 at Zurich-Kloten Airport. The flight, arriving from Düsseldorf, was part of a sequence of landings following a period where the runway had been closed for snow removal. Heavy snowfall throughout the day had left a layer of wet snow on the runway and created significant snowbanks on both sides, effectively narrowing the usable width of the pavement to approximately 50 meters.
The pilot was conducting the approach using the autopilot to instruct a trainee copilot. Upon gaining visual contact with the runway at approximately 1,800 feet, the autopilot was disengaged. During the transition to manual control, the pilot performed a correction to the right that was more pronounced than intended, necessitating a subsequent counter-correction to realign with the runway centerline.
The aircraft touched down approximately 550 meters past the threshold, slightly left of the centerline and with a slight leftward yaw. As the aircraft rolled, the pilot attempted to correct the deviation using steering and braking, but the slippery surface rendered these efforts ineffective. The left wing and main landing gear struck the left-side snowbank. While the crew managed to steer the aircraft back toward the center, the momentum caused the aircraft to veer right, eventually breaching the right-side snowbank. The aircraft came to a stop approximately 1,600 meters past the threshold, 10 meters outside the right edge of the runway.
The investigation
The investigation examined the aircraft's technical condition, the meteorological circumstances, and the runway environment. Investigators found no technical defects in the SE-210 Caravelle's braking or steering systems. The crew, including the pilot, copilot, and cabin staff, were found to be highly qualified, and the pilot's health was not a factor.
The investigation also noted that the airport's touchdown zone lighting was out of service and centerline lighting was unavailable. The presence of the snowbanks was a critical factor in the physical impact, though the investigation noted that the aircraft might have still drifted off the slippery runway even without the banks.
Findings
- The primary cause of the damage was the collision with the snowbanks located at the runway edges.
- The aircraft's deviation from the runway centerline was caused by a combination of the lateral movement component during touchdown, insufficient initial directional corrections, and the slippery condition of the runway.
- The pilot's ability to correct the aircraft's path was severely compromised by the reduced braking effectiveness due to the wet snow and the reduced lateral control caused by the low landing speed and the late engagement of the nose wheel.
- The safety margins normally present on the runway were significantly eroded by the weather conditions, leaving no room to compensate for the lack of precision during the landing phase.