Circumstances
On 4 August 1995, the pilot of a Piper PA-28R-200 (registration HB-OQF) departed from Birrfeld airport at 0959 hours local time, landing at Samedan after 52 minutes. At 1139 hours, he departed Samedan for Les Eplatures. Over St-Imier, he contacted the Les Eplatures tower but only understood the QNH. After switching both COM radios to the same frequency without improving communication, he noticed that both fuel gauges indicated zero.
Impressed by this observation, the pilot decided to land immediately without requesting runway information. He reduced power, manipulated the landing gear lever, and made an approach to runway 24 — although runway 06 was the active runway — at a speed of 120 MPH. With flaps extended to the landing position, he touched down at 90 MPH with the landing gear retracted. The aircraft slid on its belly and struck a glider that was ready for departure on the threshold of runway 06. The Piper came to rest in a field beyond runway 24.
Technical Findings
Technical examination of HB-OQF revealed that the battery was completely discharged due to an inoperative alternator caused by a defective regulator. When tested with a different regulator, the alternator functioned correctly. During the flight, after the total electrical failure, the landing gear could not be extended electrically, and the VHF transceivers and fuel quantity indicators were also inoperative. The aircraft had a valid certificate of airworthiness, and its mass and center of gravity were within limits.
Injuries and Damage
The pilot of the Piper and the two occupants of the glider suffered minor injuries. Both aircraft sustained heavy damage.
Cause
The accident was caused by a missed landing due to the pilot's panic following a total electrical failure resulting from an alternator failure.