1968 Piper PA-18-125 accident at Beromünster airfield (HB-OYB)

Overview and aircraft details On 18 June 1968, a Piper PA-18-125 (Super Cub) with registration HB-OYB was involved in an accident at the new Beromünster airfield. The aircraft, built in 1930, was operated by Flubag Flugbetriebs AG Neudorf and was in technically satisfactory condition. It was a braced single-engine high-wing aircraft with a Lycoming O-290-D engine and a Sensenich N76AM-2 propeller. ## Flight and accident sequence The student pilot, born in 1930, had begun training on 5 April 1968 and had accumulated 13:32 hours in 151 dual-control flights by 21 May, with the exception of 12 flights totaling 71 minutes, all in the PA-18-125. After a four-week interruption, training resumed on 18 June 1968. The student first flew seven circuits in 35 minutes on dual controls, then made three solo circuits between 1000 and 1015 hours. After a 75-minute pause, a further series of solo flights began. The accident flight started at 1130 hours on runway 36. The student completed two unremarkable circuits. On the third landing at 1145 hours, the aircraft bounced, likely because the student had not fully pulled the elevator control; the runway also had some shallow undulations. Without reapplying power, the student landed again in a normal three-point attitude about 120 meters after the initial touchdown. The aircraft initially rolled about 180 meters along the runway centerline, then progressively veered left. After a turn of approximately 60–70 degrees, it rolled at walking pace into the Wina stream, which formed the western boundary of the airfield. The student stated he did not brake during rollout and did not realize the narrow, grass-covered stream was there, instead assuming he could continue rolling left and then turn right in a wide arc to return to the runway. Had he seen or remembered the stream, he could have stopped the aircraft in a short distance given the low remaining speed. ## Findings and damage Post-accident inspection found the wheel brakes in satisfactory condition. The student pilot was uninjured. The aircraft sustained bent landing gear and fuselage floor, a bent propeller, a crushed engine intake duct, a cracked crankshaft, and a bent engine mount, with repair costs estimated at 20,000–25,000 Swiss francs. No third-party damage occurred. ## Conclusion The investigation concluded that the accident was caused by the student pilot's lack of reaction during rollout. The report noted that the student, although familiar with both the aircraft and the airfield, appeared to have become physically and psychologically passive during rollout, allowing the aircraft to roll where it would. The report speculated that the resumption of training after a four-week break, combined with the experience of first solo flights, may have placed excessive stress on the student.