What happened
On February 23, 2015, a Cessna 172 RG, registration EC-HYT, operated by GAIR, was conducting a dual flight training mission departing from Madrid-Cuatro Vientos airport. The flight, which included an instructor and a student preparing for a commercial pilot license exam, was performing an engine failure simulation maneuver.
During the descent toward a field near Villamanta, the crew extended the landing gear. While flying at approximately 50 feet, the aircraft encountered a 132 kV high-voltage power line. In an attempt to maneuver under the lines, the aircraft passed through an area that triggered a high-intensity electrical arc. The discharge entered through the left wingtip and exited through the right main landing gear brake assembly.
Upon returning to Madrid-Cuatro Vientos, the crew communicated the situation to the tower. After flying a specific path to allow controllers to visually inspect the gear, the tower confirmed that the right main wheel was not in the correct position. During the landing on runway 28, the aircraft touched down on the left wheel and nose wheel first. As the right wheel made contact, the aircraft tilted, causing the left wingtip and horizontal stabilizer to strike the pavement. The aircraft rotated and came to a stop transverse to the runway. The two occupants were uninjured and evacuated the aircraft on their own.
The investigation
The CIAIAC investigation focused on the sequence of events leading to the gear malfunction and the subsequent landing instability. Investigators examined the damage to the aircraft and the impact on the local power grid, noting that the electrical discharge caused a temporary disconnection in the high-voltage line. The investigation also reviewed the operator's flight manuals, emergency procedures, and the crew's adherence to altitude limits during instructional maneuvers.
Findings
- The primary cause of the accident was landing with the right main landing gear partially retracted/not fully deployed.
- The underlying cause was the damage to the landing gear caused by a high-intensity electrical arc when the aircraft flew too close to high-voltage power lines.
- The crew's attention was likely divided due to preparations for an upcoming flight exam, leading to a failure to maintain adequate clearance from obstacles.
- The operator's manual lacked specific guidance regarding minimum altitudes for VFR maneuvers and did not sufficiently detail the procedures for declaring an emergency.