What happened
On March 27, 2006, an Esqual VM-1P ultralight aircraft, registration CS-ULQ, was performing a local flight departing from Castro Verde. Approximately 15 minutes after takeoff, the pilot attempted to land on the same runway, approaching from a north-to-south direction.
The landing was heavy, resulting in all three wheels of the tricycle landing gear contacting the runway simultaneously. As the aircraft rolled approximately 10 and 100 meters along the runway, the pilot applied the brakes. At this moment, the nose gear strut collapsed, causing the nose of the aircraft to strike the ground. The impact caused the propeller blades to strike the runway surface and fracture, which subsequently caused the engine to stop.
The pilot, who was the sole occupant of the aircraft, was able to exit the aircraft uninjured. There were no injuries to third parties and no damage to property on the ground.
The investigation
The GPIAAF investigation focused on the landing technique and the structural failure of the nose gear. The investigation examined the aircraft's maintenance records, which showed the aircraft had a valid flight certificate and had followed the recommended maintenance program. The investigation also reviewed the aircraft's flight manual, which specifies landing procedures.
Findings
- The pilot performed a landing that did not adhere to the manufacturer's recommended principles, which suggest landing with the tail slightly low to ensure the main wheels touch the runway before the nose wheel.
- The simultaneous contact of all three wheels with the runway subjected the nose gear to lateral shear forces for which it was not designed.
- The nose gear collapsed due to the application of these transverse forces during braking, which shifted the center of gravity and concentrated stress on the nose strut.
- The aircraft sustained damage to the propeller tips and the lower engine cowlings.
Safety action
No safety recommendations were formulated as a result of this investigation.