What happened
On October 10, 1965, a Piper J3C Cub, registration HB-OHO, departed from Reichenbach airfield for a private sightseeing flight through the Prealps. The aircraft was carrying a pilot and one passenger. During the second leg of the day's operations, the aircraft was observed flying at a very low altitude near the Firstbahn mountain railway.
Witnesses near the Faulhorn summit reported seeing the aircraft flying at a low altitude and slow speed. While following the mountain slope, the aircraft suddenly banked sharply to the left and entered a steep, spinning descent. The aircraft struck the ground approximately 50 and 200 meters southwest and below the Faulhorn peak. The impact destroyed the aircraft and resulted in two fatalities; the passenger died on the way to the hospital, and the pilot succumbed to his injuries six days later.
The investigation
Investigators examined the wreckage and the aircraft's maintenance history. The Piper J3C Cub had recently undergone a 100-hour inspection and a state inspection in September 1965. While the inspection notes mentioned a fluctuating airspeed indicator and low engine compression, the aircraft had been cleared for continued operation.
Post-crash analysis of the wreckage showed that the control surfaces were functional and all linkages were intact. The fuel tank was empty and leaking, but the fuel valve was open. The pilot's camera, which contained footage of the flight, showed the aircraft was still at a relatively safe altitude just moments before the final descent. There was no evidence of engine failure or mechanical obstruction of the flight controls.
Findings
- The primary cause of the accident was that the pilot failed to maintain the necessary altitude and airspeed reserves required for the flying conditions.
- The pilot may have been distracted by his efforts to take aerial photographs, focusing more on the scenery than on aircraft control.
- The sudden wing drop could have been triggered by a gust of wind, an intentional turn, or an accidental rudder input by the passenger.
- The aircraft was flying at an altitude that left no margin for error, particularly while operating on the lee side of the mountain.