What happened
On August 22, 1979, a pilot departed from Grenchen airport in a Bravo AS 202, registration HB-HEN, for a private VFR flight through the Alps. At approximately 10:50 AM, the aircraft struck the north face of the Eimger at an altitude of roughly 3,600 meters. The impact resulted in the death of the pilot and the total destruction of the aircraft. No third-party damage or injuries were reported.
During the final minutes of the flight, the pilot transmitted a distress call via the Grenchen Tower frequency. In the transmission, the pilot claimed that the ailerons were jammed and that the aircraft was unable to steer. Despite instructions from the air traffic controller to attempt corrective maneuvers using the rudder, the aircraft continued on its path until the collision.
The investigation
Investigators examined the wreckage and the control systems of the Bravo AS 202. While the pilot reported aileron failure, the technical examination found that all control cables, including those for the elevators and rudder, were intact. Although the impact was severe enough to cause fractures in the control rods connecting the ailerons, there was no evidence of a mechanical failure or foreign object interference. The aircraft had previously undergone modifications to prevent a known aileron jamming issue that had occurred in 1976.
Beyond the technical aspects, the investigation looked into the pilot's personal circumstances. The pilot had been involved in a disciplinary dispute at his workplace involving a subordinate, which had occurred the previous night. On the morning of the flight, the pilot appeared to be in a depressed state and had reportedly had very little sleep.
Findings
Several factors led investigators to conclude that the crash was highly likely a suicide. Key findings include:
- The pilot specifically insisted on using the Bravo AS 202 for the flight, despite a more familiar Beagle Pup being immediately available.
- The pilot's claim of aileron failure was inconsistent with the flight path; the pilot was capable of using the rudder to steer, yet failed to respond to instructions to do so.
- The pilot's use of the radio to simulate a panic situation may have been an attempt to make a self-inflicted accident appear to be caused by a technical malfunction.
- The choice of the Eiger North Face provided an ideal location for such an event, as the extreme terrain would likely prevent the recovery of usable evidence from the wreckage.