What happened
On January 23, 1968, a Swissair Douglas DC-8-53, registration HB-IDD, was taxiing at Geneva Airport prior to a scheduled flight to New York. After departing its parking position, the pilot initially intended to follow a path toward taxiway 1. However, upon encountering construction zones and obstacles, the pilot determined the passage was too narrow for the large jet and requested a change in routing to runway 05.
During this maneuver, the aircraft's main landing gear was positioned within a drainage ditch, and the nose wheels were pressed against a mound of hardened snow. To overcome this resistance and complete a left turn, the pilot had to increase engine thrust to approximately 80% of maximum power. The resulting jet blast from the four engines caught a nearby parked Luscombe HB-DUS, lifting the light aircraft and propelling it into a parked Piper Twin Comanche, registration N-8548-Y. The impact caused damage to the wings, fuselage, and engine components of both light aircraft. Neither the crew of the DC-8 nor the air traffic controllers observed the collision as it occurred.
The investigation
The investigation established that the aircraft involved were all airworthy and the pilot of the DC-8 held a valid airline pilot license. While the parked light aircraft were positioned according to airport regulations and the Luscombe was chocked, the investigation noted that the parking area in front of the "Grand Hangar" lacked mooring facilities. Furthermore, the investigation highlighted that the pilot's decision to change course brought the heavy jet into closer proximity to the light aircraft than originally intended.
Findings
- The primary cause was the pilot's decision to alter the taxi route while in close proximity to unmoored light aircraft.
- High engine thrust was required to restart the movement of the DC-8-53 because the nose wheels were obstructed by snow and the main gear was stuck in a ditch.
- The lack of mooring installations for aircraft parked near the hangar contributed to the vulnerability of the light planes to jet blast.
- The incident was part of a pattern of similar ground accidents involving jet blast at Geneva Airport recorded in the preceding five years.