Introduction
On 5 September 1982, at 1513 local time, a Piper PA-28-181, registration HB-PGH, crashed at Langenthal airfield. The aircraft was destroyed, and the pilot and three passengers sustained serious injuries (erheblich verletzt). The accident occurred during a public air show organized by the Segelfluggruppe Oberaargau, while the Motorfluggruppe Langenthal concurrently operated paid sightseeing flights.
Flight History
HB-PGH returned from a sightseeing flight and reported to the airfield radio at the Dornegg-Gütsch reporting point. The flight service leader assigned landing runway 23 and informed the pilot about the display program. During the final approach to runway 23, the pilot saw the Dewoitine HB-RAI (which had no radio) performing low passes over the airfield. He last observed it departing northwest.
When the aircraft was at about 1.5 meters above ground level (AGL), approximately 50 meters past the threshold of runway 23, the pilot suddenly noticed the Dewoitine approaching from the opposite direction at the same altitude. The Dewoitine was flying at 230–240 km/h, about 20 meters AGL, and was about 250 meters away on a collision course. The Dewoitine pilot initiated a left evasive turn.
Collision Avoidance Maneuvers
The HB-PGH pilot responded by applying full power and initiating a right turn, but then saw the Dewoitine turning into the same sector and instead turned left. With landing flaps fully extended and at landing speed, the aircraft stalled during the climbing left turn after about 90 degrees of rotation. It crashed east of runway 05/23, approximately 30 meters behind a workshop building.
Cause
According to the investigation, the accident was due to exceeding the minimum sustaining speed near the ground and, simultaneously, a reflex due to fear of a collision between two aircraft, a risk resulting from a lack of organization and coordination on the part of the organizers of the air show.