What happened
On May 25, 2004, at approximately 19:30 UTC, a Cessna T210N, registration EC-FSU, was performing a local flight at Alicante Airport for the purpose of flight training and license renewal. The crew consisted of a pilot and an instructor. During the approach to runway 10, the crew performed a long landing to avoid turbulence from preceding heavy traffic.
Upon touchdown, the landing was described as abrupt, primarily impacting the main landing gear. Following the impact, the main gear retracted, while the nose gear remained extended and locked. This caused the aircraft to settle onto its tail, dragging several meters along the runway before exiting the right side of the runway. The aircraft sustained damage to the right horizontal stabilizer and the lower rear fuselage.
The investigation
The CIAIAC examined the aircraft's landing gear mechanism, which is an electro-hydraulic system. Post-incident testing was conducted on jacks in a workshop. The investigation included 15 complete landing gear cycles using both the normal system and manual emergency procedures.
Testing confirmed that the hydraulic pump, actuators, and locking mechanisms were fully functional. The investigators found that the nose gear could descend and lock via gravity even without hydraulic pressure, whereas the main gear required positive hydraulic pressure to reach the over-center locking position. The investigation also reviewed the electrical system, including the circuit breakers and warning lights, finding no mechanical failures or hydraulic leaks that would explain an involuntary retraction.
Findings
- The landing gear mechanism, including the hydraulic pump and locking struts, was found to be in good working order during post-accident testing.
- The aircraft's nose gear remained extended and locked throughout the event, while the main gear retracted.
- The crew may have inadvertently manipulated the landing gear lever during the final moments of the landing sequence, causing the gear to cycle between up and down positions.
- There was no evidence of mechanical failure, hydraulic leaks, or electrical malfunctions in the landing gear system.