What happened
On February 23, 2013, a Piper PA-34-200T, registration EC-HUY, was conducting a flight verification for multi-engine and instrument ratings. The flight originated from Cuatro Vientos, Madrid, and proceeded to the Casarrubios Aerodrome in Toledo. After performing several take-off and landing maneuvers on runway 26, the crew decided to land on runway 08.
During the landing roll, immediately after touchdown, the aircraft began to drift progressively toward the left. Despite corrective actions taken by the pilot and subsequently by the examiner, who took control of the aircraft, the plane continued to deviate. The aircraft traveled approximately 4 and 50 meters on the ground before exiting the left edge of the runway into the grass strip. The impact caused the left main landing gear to collapse and the left engine propeller to strike the ground. The crew escaped the aircraft without injuries.
The investigation
The investigation examined the aircraft's flight path using onboard GPS data, which revealed that the aircraft had overshot the runway heading during the transition from the base leg to final, necessitating a late correction. Investigators also analyzed the physical evidence on the runway, noting distinct tire marks that showed a discontinuous trajectory toward the left.
Technical inspection of the landing gear revealed that the left main gear's attachment supports to the wing spar had fractured, along with the outer race of the pivot bearing. This damage caused the left wheel to become misaligned with the aircraft's longitudinal axis. Additionally, the investigation found that the brake pads and discs were at the limit of their service life due to intensive use.
Findings
- The landing approach was destabilized by the lateral displacement of the aircraft relative to the runway centerline.
- The primary cause of the excursion was the structural failure of the left main landing gear supports during touchdown, which caused the left wheel to skid sideways rather than roll.
- This misalignment created significantly higher friction on the left side compared to the right, pulling the aircraft off the runway despite control inputs and braking.
- The aircraft's landing distance requirements were tight relative to the available runway length at Casarrubios, necessitating high precision.