1997 Piper PA-28-161 Warrior accident at Lausanne Airport (HB-PEY)

Overview and flight details On 8 April 1997, a Piper PA-28-161 Warrior, registration HB-PEY, was involved in an accident at Lausanne Airport. The aircraft was privately owned and operated, and the flight was a training exercise. The instructor, a Swiss national born in 1956, held valid pilot and instructor licences and had a total of 8,300 flight hours, including 200 hours on the type. The aircraft had accumulated 5,826 flight hours and 13,850 landings, with its last 100-hour inspection completed on 19 March 1997. ## Sequence of events The instructor and student departed Lausanne at 1120 local time to practise local landings. During the fifth touch-and-go, the upper attachment of the left landing-gear compass broke during take-off. The aircraft landed on runway 01 with the left gear leg hanging from the brake hose. After travelling about 120 metres, it left the runway, turned 90 degrees to the left, and came to rest in the grass. The crew was uninjured, and the aircraft sustained light damage to the left landing gear and left flap. ## Investigation findings The investigation found that the upper joint of the cast light-metal pantograph was broken. Metallographic examination by the Federal Laboratory for Materials Testing and Research in Dübendorf concluded that the failure was due to fatigue, independent of crystal structure, and that the crack size indicated a relatively low nominal stress. The maintenance plan did not include specific crack inspections of the landing gear. Weather conditions were probably clear with good visibility and light winds, and were not considered a determining factor in the accident.