What happened
On September 4, 1963, a Swissair SE-210 Caravelle III, registration HB-ICV, was prepared for a flight from Zurich to Geneva and Rome. Due to dense fog at Zurich-Kloten Airport, the pilot performed a reconnaissance roll along the runway to assess visibility. During this maneuver, the aircraft was operated with significant engine power while taxiing along the runway.
Shortly after takeoff at 06:13 GMT, ground observers noticed flames appearing on the underside of the left fuselage. Approximately six and a well-half minutes into the flight, as the aircraft reached an altitude of roughly 2,700 meters, it began to descend rapidly. The aircraft entered a steep dive and a wide left turn, shedding debris throughout the descent. The HB-ICV ultimately crashed near the village of Dürrenäsch, approximately 35 kilometers from the airport, resulting in 80 fatalities, including the entire crew and all 74 passengers.
The investigation
The investigation examined the aircraft's structural integrity, the landing gear, and the specific procedures used by the crew. Investigators analyzed the distribution of wreckage at the runway and the crash site, as well as the condition of the wheels and braking system. Technical tests were conducted on the brake system, including temperature development calculations during rolling and braking trials. The commission also reviewed the "fog dispersal" procedure used by Swissair, which involved high engine power during taxiing to clear fog, and evaluated whether this procedure exceeded the operational limits of the aircraft's braking system.