Incident
On July 15, 2000, at 14:35 local time, a Mooney M-20J aircraft, registration F-GKPA, was landing at Cuatro Vientos Airport in Madrid after a flight from Córdoba. The pilot was warned by the tower that the landing gear was not down. Despite the warning, the aircraft touched down with the gear only partially extended. The aircraft sustained significant damage to its underside, including antennas, a step, and the left main landing gear door. Both occupants—a pilot and one passenger—were uninjured.
Investigation
The pilot reported that on the previous flight, the aircraft had experienced a complete electrical failure. To land at Córdoba, the landing gear was extended manually using the emergency procedure. A voltage regulator was replaced by an authorized shop at Córdoba. The subsequent flight to Cuatro Vientos was normal, and all systems functioned correctly. Before departure from Córdoba, the pilot checked and locked the emergency gear mechanism, armed the circuit breakers, and verified that the gear retracted normally with correct indicators.
During approach to Cuatro Vientos, the pilot performed standard procedures, including lowering the gear. Upon touchdown, he felt the gear contact the runway and believed it retracted after contact. He maintained a straight landing path, closed the fuel selector before the aircraft stopped, and turned off the magnetos after stopping. After the aircraft was removed from the runway, the pilot found the landing gear unlocked and extended approximately 30 centimeters, and the gear circuit breaker had tripped.
Review of air traffic control recordings revealed that another aircraft (likely on the same frequency) transmitted in Spanish that the traffic on final had no gear. The tower then twice informed the aircraft in English that its gear was up. Subsequently, the tower advised following traffic of a possible landing delay due to an accident and contacted airport firefighters.
The landing gear actuation system is a screw mechanism driven by an electric motor, making it practically irreversible. The tripped circuit breaker was likely caused by an overload as the motor attempted to extend the gear further while it was already in contact with the ground.
Probable Cause
The probable cause of the incident was the pilot's failure to extend the landing gear during the approach. When warned by the tower, the pilot activated the gear extension, but insufficient time remained for full deployment. The pilot chose not to execute a go-around due to the airport's high elevation, high temperature, surrounding obstacles, and the amount of runway required for takeoff under similar conditions.