What happened
On the morning of January 26, 2021, a Mooney M20J aircraft, registered HB-DIC, was performing a private VFR flight from Birrfeld to Ecuvillens. During the initial approach to runway 27, the pilot maintained an approach speed that was slightly too high, resulting in the aircraft touching down in the first third of the runway. Following this touchdown, the pilot elected to execute a go-around and perform a second circuit.
During the subsequent approach, witnesses observed the aircraft with its landing gear retracted. The aircraft subsequently impacted the runway on its belly, sliding across the surface and coming to a halt in the snow near the threshold of runway 09. While the pilot escaped without injury, the aircraft sustained grave damage to the engine, propeller, landing gear, and the lower fuselage, while ground infrastructure including runway lights was also damaged.
The investigation
Investigators examined the aircraft and the flight circumstances to determine why the gear was not properly deployed. Technical analysis of HB-DIC revealed that the main landing gear struts were bent and the nose gear control rods were broken on both sides. The investigation also found that the gear warning horn was non-functional due to an incorrect switch setting.
Evidence from the fuselage underside, wheel fairings, and nose gear bay indicated significant scraping, suggesting the gear was likely fully retracted upon initial ground contact. The investigation also noted that the pilot's propeller pitch control was out of position by approximately 3 cm, which is a critical step in the landing gear extension and final check procedure.
Findings
Two primary scenarios were considered regarding the gear state. The first possibility was that snow accumulation on the runway during the first landing attempt interfered with the gear mechanism during the second attempt. The second possibility was that the pilot simply failed to extend the gear during the downwind leg of the second circuit.
Regardless of the mechanical or procedural cause, the investigation established that the final landing checks were not completed. The pilot's lack of recent flight experience on this specific type and the failure of the gear warning horn to alert the pilot to the retracted state were significant contributing factors. The investigation also noted that the pilot likely faced unusually high stress levels during the second approach.