What happened
On July 15, 2001, a Jodel D 140 E, registration F-PLJP, departed from the Itxassou airfield in the French Basque Country, en route to Bilbao. While flying over Spanish airspace near San Sebastián, the pilot observed engine irregularities. After notifying the San Sebastián control tower of the engine malfunction and his intention to divert, the aircraft approached the town of Deba. During this phase of flight, the propeller became detached from the engine. The pilot performed an emergency landing in a grassy field near the Arraga farmhouse. All three occupants—the pilot and two passengers—sustained no injuries, and the aircraft remained undamaged.
The investigation
Investigators examined the wreckage at the landing site and recovered the propeller, along with two fastening screws and the disk used to secure the assembly to the rotating axis. Four additional screws could not be located. A visual inspection of the propeller's fastening points revealed wear and tear distributed around the rim of the six holes, with more significant wear noted in two specific holes, suggesting they were the final components to maintain the assembly's position.
Regarding maintenance, the propeller's assembly and maintenance manual requires torque checks at specific intervals, including between 10 and 30 flight hours. The pilot, who was authorized to perform his own maintenance, had conducted the last inspection. While the maintenance center had previously advised a torque check after 25 flight hours, the investigation focused on the assembly process itself.