Introduction
On Sunday, 10 October 1965, at 1151 Central European Time, a Piper J3C Cub (registration HB-OHO) departed from Reichenbach airfield with a pilot and a passenger for a private flight in the pre-Alps region. Approximately half an hour later, the aircraft was observed on the south slope of Faulhorn, flying slowly in straight flight at about 100 meters above ground. It then stalled over the left wing and crashed at 1225, about 500 meters southwest and 200 meters below the Faulhorn summit (elevation 2680 m). The aircraft was destroyed, and both occupants died from injuries sustained in the crash.
Aircraft and Occupants
The aircraft was a Piper J3C Cub, built in 1944, with a Continental A-65 engine producing 65 horsepower. Its maximum takeoff weight was 550 kg; at the time of the accident, the weight was approximately 545 kg, with the center of gravity within limits. The stall speed was 35 mph. The aircraft was owned and operated by the Fluggruppe Reichenbach of the Bern section of the Aero-Club of Switzerland. The last 100-hour inspection was performed on 2 September 1965, which noted that the airspeed indicator oscillated and the engine had poor compression. After the inspection, the airspeed indicator was removed, cleaned, and tested with no defects found, then reinstalled and rechecked. The aircraft flew about 10 hours after that inspection.
The pilot, born in 1944, held a private pilot license issued on 1 June 1963, valid until 27 November 1965. His total flight experience was approximately 130 hours and 600 landings, with 41 hours 25 minutes and 204 landings on the accident type. In 1965, he flew exclusively the accident aircraft, totaling 71 minutes on the day of the accident prior to the flight. No accidents or violations were on record, and no health issues were found at the time. The passenger, born in 1937, had no aviation experience or licenses.
Flight Sequence
The pilot had initially reserved the aircraft for flights in the pre-Alps area. During pre-flight preparation, he removed the rear control stick and stated he would occupy the front seat due to poor visibility in lower layers. He took a first flight at 0957 with another passenger, flying to Interlaken, then through broken haze to the Schilthorn, Mürren, Wengen, and the Faulhorn area, returning to Reichenbach at 1116. The first passenger reported that the pilot made turns and loops at varying heights, used a camera frequently, and operated it with both hands, but the passenger did not feel the flight was dangerous.
After landing, the aircraft was refueled, and the first passenger was replaced by a new passenger. The second flight departed at 1151. Around 1215, a witness climbing from the Firstbahn mountain station toward Faulhorn observed the aircraft flying very low, passing 30-50 meters above them. Another witness southwest of the Faulhorn hotel reported seeing the aircraft flying slowly along the slope at about 100 meters distance, then suddenly banking steeply to the left and falling. Multiple witnesses noted the engine sound was normal, but the speed appeared slow, and the aircraft stalled from a left bank after straight flight along the slope.
Accident and Investigation
The aircraft crashed at 1225, spinning steeply. Both occupants were found with seat belts fastened and undamaged. The aircraft was destroyed. Examination of the wreckage revealed: the elevator was trimmed slightly nose-up; all controls were connected with no anomalies; the fuel tank was leaking and empty, fuel valve open, fuel injection pump locked, carburetor heat off; the airspeed indicator was destroyed; the rear control stick was properly secured. The pilot's camera contained a film with 24 exposures, all taken from the front seat on the accident day. The last two exposures were from the accident flight—one from the Interlaken area and the last showing the Bachsee with Simelihorn and Faulhorn, taken when the aircraft was about 150 meters above ground and about 3 km east of the crash site.
Weather at the time: Switzerland was under a high-pressure system. On the north side of the Alps, high fog had a ceiling of 1400 m. In the accident area, sky was cloudless, visibility over 50 km, winds weak to moderate from east to northeast, humidity about 40%, temperature +7°C.
Probable Cause
The crash was with high probability due to the pilot not maintaining the altitude and speed reserve required under the circumstances.