What happened
On July 15, 2000, a Mooney M-20-J, registration F-GKPA, was performing a non-commercial general aviation flight from Córdoba to Madrid. During the landing phase at Cuatro Vientos Airport, the aircraft approached the runway with the landing gear in a partially retracted position. Although air traffic control issued two warnings in English notifying the pilot that the gear was up, the aircraft made contact with the runway with the gear only partially extended.
Upon touchdown, the aircraft sustained significant damage to its underside, specifically affecting the antennas, the step, and the left main gear door. The occupants of the aircraft, consisting of the pilot and one passenger, were uninjured.
The investigation
The investigation established that during the previous flight, the aircraft had experienced a general electrical failure, necessitating the manual extension of the landing gear in Córdoba. Following that flight, a voltage regulator was replaced at an authorized workshop. Prior to the flight to Madrid, the pilot had verified and engaged the emergency gear extension mechanism, and the landing gear indicators appeared to function correctly during the flight.
During the approach to Cuagtro Vientos, the pilot performed standard maneuvers, including the command to lower the gear. However, the investigation found that the gear did not fully deploy. After the aircraft came to a stop, the pilot observed that the landing gear was extended only about 30 centimeters and noted that the landing gear circuit breaker had tripped. The pilot decided to proceed with the landing despite the gear status to avoid a potential go-around, citing high airport elevation, high temperatures, and surrounding obstacles as factors that would have required significant runway length.
Radio transcripts confirmed that an unidentified third party (likely another aircraft on the same frequency) initially reported the gear issue, after which the tower issued the warnings to the pilot.
Findings
- The primary cause of the incident was that the pilot failed to actuate the landing gear during the approach.
- The landing gear circuit breaker tripped, likely due to an electrical overload caused by the electric motor attempting to continue the extension process while the gear was already in contact with the ground.
- The landing gear mechanism, which utilizes an electric motor and a screw jack, is practically irreversible, making it difficult for the gear to retract solely due to ground contact.
- The pilot's decision to avoid a go-around was influenced by environmental conditions, including high density altitude and the presence of obstacles.