What happened
On the evening of January 30, 1964, a Swissair SE-210 Caravelle (registration HB-ICX) was completing a scheduled flight from London to Zurich. The aircraft, carrying 44 passengers and seven crew members, arrived at Zurich-Kloten during a period of light snowfall.
Upon landing on runway 16, which was covered in a thin layer of wet snow, the aircraft initially maintained its centerline. However, during the landing roll, the aircraft began to drift toward the left edge of the runway. Despite the crew applying maximum braking, full rudder deflection, and maximum nosewheel steering, the aircraft could not be stabilized. After rolling approximately 800 meters, the aircraft struck the left edge of the runway, destroying four runway lights and sustaining damage to the nosewheel steering and the right main landing gear. The aircraft eventually came to a halt at the intersection with the Bisen runway after a total roll of 1,915 meters. There were no injuries to the passengers or crew.
The investigation
The investigation examined the runway conditions, weather data, and the aircraft's flight recorder. At the time of the accident, the runway braking action had been reported as "medium," though subsequent data suggested the friction coefficient had dropped below 0.19. The investigation also reviewed the cockpit communications and the crew's response to the wind conditions. Investigators noted that a significant wind gust of 16 knots from 230 degrees was reported by air traffic control just seconds before the aircraft touched down, a message that was not clearly received by the pilots due to the timing of the Middle Marker signal and cockpit activity.
Findings
- The primary cause of the excursion was the aircraft encountering unexpectedly strong crosswind gusts while rolling on a runway surface made slippery by snowfall.
- The aircraft likely entered a zone of significantly higher crosswind components as it exited the wind shadow of a nearby forest located to the west of the runway.
- The braking action on the runway had likely degraded below the reported "medium" level by the time of landing.
- The crew did not receive or act upon the final wind update regarding the increased gust intensity due to interference from the Middle Marker signal and the focus required for the landing phase.