What happened
On August 16, 1994, a Piper J3C aircraft registered as HB-OXZ departed from Porrentruy airfield in Switzerland for an unplanned local flight. The pilot, accompanied by a female acquaintance in the front seat, flew at exceptionally low altitude over his hometown of Rossemaison. Multiple witnesses observed the aircraft moving unusually slowly and maneuvering erratically near residential rooftops. After completing a sharp left turn, the plane pitched right and crashed nose-first into a hedge bordering a private orchard. Both occupants were killed instantly, and the aircraft was destroyed.
The investigation
Swiss authorities investigated the crash, examining the wreckage, conducting medical autopsies, and analyzing engine components. Technical inspections revealed no mechanical failures; the carburetor, magnetos, and spark plugs were functional, and the aircraft had passed its 50-hour inspection just days prior. Toxicology tests confirmed neither occupant had alcohol in their systems. The investigation focused on operational factors, noting that the pilot was experienced but had improvised the flight without a formal schedule.
Findings
The accident was caused by a stall at low altitude due to excessive angle of attack during slow flight, compounded by pilot distraction. Witnesses reported the aircraft was flying significantly slower than normal and very close to the ground. The pilot likely became distracted by his passenger, who was signaling to people below and partially obstructing his view of the instruments. When the pilot attempted to accelerate rapidly to correct the low speed, the Piper J3C’s lack of high-lift devices caused an abrupt stall. With insufficient altitude to recover, the aircraft crashed.
Safety action
The report highlighted the dangers of unscheduled low-level flying and the specific handling characteristics of light aircraft like the Piper Cub, which can stall without significant warning buffet. No further regulatory safety actions were recorded in this final report beyond the establishment of these causal factors.