What happened
On August 6, 1962, a private flight departing from the Lommis airfield in Switzerland resulted in an aircraft accident. The pilot, operating an Auster Mk.5, registration HB-EOW, was accompanied by two passengers for a flight intended to travel from Lommis to Wangen-Lachen.
Prior to the accident, the pilot had performed a landing at the same airfield that was somewhat unstable, hitting a metal drum during the rollout and briefly veering onto a nearby road. Following a brief inspection of the propeller and landing gear, the pilot prepared for takeoff.
During the takeoff roll on the 425-meter grass runway, the pilot applied full power. After approximately 250 to 270 meters, the aircraft lifted off the ground. However, the aircraft failed to maintain flight and descended, striking a ground undulation located near the end of the runway. About 70 meters past the runway threshold, the aircraft made secondary contact with the ground in a grain field. Realizing the loss of control, the pilot reduced throttle, but the aircraft subsequently overturned, coming to rest on its back approximately 200 meters beyond the runway end.
The investigation
The investigation examined the aircraft's weight, the runway conditions, and the pilot's performance. The Auster Mk.5 was at its maximum allowable takeoff weight of approximately 840 kilograms. The airfield at Lommis featured a short, uneven grass strip with a notable one-meter-high rise at the end of the runway.
Investigators found no mechanical defects in the aircraft or the engine. The pilot's flying credentials were found to be in good standing, and no health issues were identified as contributing factors. The investigation also noted that the pilot had no prior experience using the Lommis airfield.
Findings
- The pilot attempted to rotate the fully loaded aircraft too early in the takeoff roll.
- The aircraft had not reached the minimum required airspeed for a safe takeoff at that point in the roll.
- The high ambient temperature (26°C) and the weight of the two passengers necessitated a longer takeoff roll than was available on the short runway.
- The pilot's previous landing error at the same airfield should have prompted a more cautious approach, such as a test takeoff with reduced weight.
Safety action
No specific safety recommendations were recorded in the final report.