Details
On 12 July 1956, an aircraft departed San Diego, California, at 0407 local time on a delivery flight to Swissair, destined for Zurich Airport, Switzerland. Two American pilots were at the controls. Intermediate stops included New York, Gander, and Shannon.
Sequence of Events
After departing New York at 1240 GMT on 14 July, the aircraft landed at Gander at 1659 GMT. Following a 57-minute stop, it departed Gander for Shannon at 1748 GMT with the same crew of four members. The ocean crossing was uneventful. At 0008 hours on 15 July, the aircraft received initial descent clearance to Shannon and was subsequently cleared into the Shannon Holding Pattern, where four other aircraft were holding.
At 0125 hours, the aircraft commenced a Ground Controlled Approach (GCA) to runway 23. After establishing visual reference to the ground, the crew broke off the approach for a left-hand visual circuit to runway 05. During the turn onto final approach to runway 05, the aircraft was observed to drop while banking steeply. The aircraft was destroyed on impact with the ground at approximately 0135 local time, and the four occupants were killed. There was no fire.
Probable Cause
The probable cause of the accident was an error of judgment by the pilot, resulting in the execution of an abnormally steep turn onto final approach during which the aircraft slipped into the ground. Possible contributory factors were:
- Insufficient visual guidance from the terrain for the successful execution of an approach involving a steep turn near the ground on a very dark night,
- Impairment of the pilots' proficiency due to the length of the period on duty.