What happened
On April 19, 2006, at approximately 12:15 local time, a PIPER PA-34-200T, registration EC-ICH, was conducting a dual instruction flight departing from Cuatro Vientos Airport, Madrid. During the flight, the crew attempted to retract the landing gear, but the nose gear failed to provide an indication of being down and locked.
The crew exited the airport traffic pattern to attempt several gear extension procedures, including both normal and emergency procedures. During a subsequent pass, the control tower observed that the nose gear was still retracted and the nose gear doors were barely open. Following the declaration of an emergency, the crew performed a landing on the main gear on the unpired runway 28.
Both occupants of the aircraft, the instructor and the student, were uninjured. However, the aircraft sustained significant damage to both engines, the propellers, and the lower forward section of the fuselage, including the nose gear doors and the actuation mechanism.
The investigation
The CIAIAC investigation examined the aircraft's maintenance history and the mechanical operation of the landing gear. The aircraft had a valid certificate of airworthiness and was being maintained according to the authorized program. The last 50-hour inspection had been completed just two days prior to the accident, and the 100-hour inspection had been performed approximately one month earlier. No issues had been reported in the 29 flights conducted since the last 100-hour inspection.
Upon inspection of the aircraft at the accident site, investigators manually separated the nose gear doors, after which the nose gear descended and locked correctly. This confirmed that the emergency extension system and the gear strut mechanism itself were functional. The investigation found that the hydraulic system was operating correctly, with no evidence of leaks or pressure loss, and the main landing gear had extended and locked without issue.
Findings
- The nose gear doors were found to be nearly closed at the moment of impact, as observed by the tower and confirmed by the damage to the doors and actuation rods.
- The hydraulic pump, electric motor, and hydraulic circuit were all functioning correctly.
- The mechanism for the nose gear doors relies on a spring-loaded system that is charged during gear retraction; while the spring might have lacked sufficient strength, the weight of the gear should have been enough to open the doors if they were not physically obstructed.
- The physical impact of the landing altered the state of the door mechanism, making it impossible to determine the specific reason why the doors failed to open during the approach.
The nose gear doors became blocked due to undetermined causes.