What happened
On June 25, 1965, a Piper PA-28-180 Cherokee, registration HB-OVX, departed Beromünster carrying a pilot and three passengers. The group intended to fly to Wangen-Lachen for a midday excursion. Prior to departure, the pilot contacted a local number found on an outdated directory to inquire about runway conditions; the conversation with a resident of the airfield resulted in a misunderating regarding the current status of the field.
Upon arriving at Wangen-Lachen, the pilot performed two low-altitude flypasts. During this time, a "no landing" signal (a red field with yellow diagonal stripes) was displayed on the field. The pilot landed the aircraft at approximately 12:00, after which he inspected the grass runway and determined that the first 300 meters appeared usable.
At 13:15, the pilot attempted a takeoff from runway 09. During the takeoff roll, the pilot deployed 10 degrees of flaps. He reported that the aircraft lifted off at approximately 60 mph, which was below the minimum required flight speed. After briefly reaching an altitude of about one meter, the aircraft failed to climb and began to sink, eventually striking reeds. In an attempt to avoid a ditch at the end of the runway, the pilot applied full power, but the landing gear struck the edge of a ditch, causing the aircraft to veer right and come to a stop.
The investigation
The investigation examined the aircraft's maintenance records, the runway conditions, and the pilot's actions. It was noted that the aircraft's 50-hour inspection was significantly overdue. The investigation also reviewed the communications regarding the airfield's status, finding that the pilot had relied on an outdated telephone list rather than the official aeronautical information manual. While the pilot had been previously fined by the Federal Office of Civil Aviation for landing despite a landing prohibition, the investigation focused on the mechanics of the takeoff attempt.
Findings
- The primary cause of the accident was the pilot attempting to lift the aircraft off the ground before it had reached a safe, flyable speed.
- The takeoff speed of 60 mph was below the minimum required speed and significantly lower than the best rate of climb speed.
- The pilot may have misjudged the distance to the takeoff point or the location of the runway markers.
- The presence of a light tailwind during the takeoff roll may have contributed to the difficulty in maintaining altitude.
- The aircraft's maintenance interval for its 50-hour check had been exceeded.
All four occupants of the HB-OVX remained uninjured, though the aircraft suffered heavy damage, including a broken right landing gear and damage to the right wing.