What happened
On March 19, 1999, a private pilot was operating a Mooney M20R, registration HB-DID, on a multi-leg flight through Switzerland and Italy. After a business lunch in Padova, the pilot began the return flight toward Mollis. During the journey, the pilot encountered heavy cloud cover near Merano and elected to climb to altitudes between 10,000 and 15,000 feet to bypass the weather. Due to deteriorating conditions, the flight path was diverted through the Maloja Pass and eventually toward Lugano and Locarno.
While approaching Locarno, the pilot encountered significant turbulence. After two unsuccessful landing attempts, a third attempt was initiated. During this final approach, the aircraft touched down at approximately the middle of the runway, bounced, and touched down again. In an attempt to execute a go-around, the pilot applied full power and pulled back sharply on the control column. However, the aircraft entered a heavily pitched-up attitude, lost airspeed, and subsequently lost control. The aircraft struck the ground with its right wing, sliding approximately 150 meters from the runway centerline, resulting in the destruction of the aircraft and serious injuries to the pilot.
The investigation
SUST examined the aircraft's mechanical state and the pilot's operational decisions. Investigators found that the engine was at full power and the propeller was at high RPM at the moment of impact. While the landing gear was extended, the investigation noted that the pilot had attempted to retract the gear during a previous maneuver; however, the aircraft's airspeed safety switch would have prevented retraction below 60 knots unless the manual bypass was used.
Technical analysis also revealed that the elevator and rudder trim were not in the appropriate takeoff positions. Furthermore, the pilot had been flying at altitudes exceeding 10,000 feet for approximately 40 minutes without supplemental oxygen, a factor that likely contributed to fatigue. The investigation also noted that the fuel selector was set to the left tank, which contained only 8 US gallons, whereas the aircraft's manual notes that takeoff maneuvers have not been demonstrated with less than 12 gallons in the selected tank.
Findings
- The primary cause of the accident was the loss of control during a go-around, triggered by windshear and turbulent conditions caused by north winds interacting with the local topography.
- The pilot's flight preparation was inadequate, as there was no formal review of updated weather forecasts for the afternoon legs of the flight.
- The pilot's physiological state was likely compromised by flying at high altitudes without oxygen equipment, leading to increased fatigue and reduced decision-making capacity.
- The pilot demonstrated poor aircraft handling during an abnormal situation, specifically regarding the management of trim settings and airspeed during the missed approach.