Incident Details
On 29 June 2019, a Piper PA31T Cheyenne, registered as N90FS, was preparing for a private flight from Raron (LSTA) to Montichiari (LIPO). The pilot, a Swiss national born in 1958 holding a commercial pilot licence (CPL(A)) issued by the Federal Office of Civil Aviation (FOCA), had accumulated 3095 total flight hours, including 400 hours on type. Four passengers were onboard.
According to the investigation, the aircraft had been pushed towards Hangar 1 after landing the previous day, with care taken to position the right elevator near the wind sock mast. On the day of the incident, the pilot completed a pre-flight outside check, then boarded the passengers, started the engines, and demonstrated the cabin air outlets. He then returned to the cockpit, moved his seat forward, and programmed the navigation system.
After making a blind transmission, the pilot taxied the aircraft and turned left towards the taxiway. During this turn, the right elevator swung outward, and its leading edge and balance tab struck the wind sock mast. The aircraft sustained light damage to these components; no injuries were reported.
Pilot Statements
The pilot later stated that although he had performed an outside check, he simply forgot about the wind sock mast. He also said he had not perceived the proximity of the elevator to the hangar wall as an immediate collision risk. All passengers had drawn the cabin curtains closed.
Investigation Findings
The Swiss Transportation Safety Investigation Board (STSB) noted that several minutes elapsed between the outside check and the start of taxi. The curtains prevented the pilot from seeing the mast over his right shoulder, which might have prompted a different taxi path. The investigation concluded that no further safety actions were necessary and closed the case with this summary report.