What happened
On November 5, 2021, at approximately 17:30 local time, a Bücker 1131-E, registration EC-GIO, experienced an engine failure shortly after departing from La Axarquía-Leoni Benabú aerodrome in Málaga, Spain. The aircraft was operating a private flight with two occupants on board.
During the initial climb, at an altitude between 50 and 60 meters, the engine began to sputter. The pilot in the front seat suspected a vapor lock and instructed the pilot in the rear seat to operate the manual priming pump. The aircraft performed a 180-degree turn to approach the opposite runway; however, during the maneuver, the engine power momentarily recovered before failing completely.
Unable to maintain flight, the pilot attempted an emergency landing in a nearby field. The aircraft struck trees, causing the airframe to sustain heavy damage and the wings to be destroyed. The occupant in the rear seat sustained fatal injuries due to an impact with a tree branch, while the pilot in the front seat sustained minor injuries.
The investigation
The CIAIAC examined the wreckage and the engine components to identify the source of the power loss. Investigators confirmed that the fuel selector valve was in the "reserve and priming" position, which is required for the manual pump to function. The investigation also verified that the fuel system, including the carburetor and fuel lines, contained sufficient fuel.
Technical inspections of the engine revealed that the ignition system—including the magnetos, distributor cables, and spark plugs—was functioning correctly and providing adequate voltage. The intake manifold and valves for cylinders 2, 3, and 4 were operating normally, though the valves for cylinder No. 1 were damaged by the impact. While no conclusive mechanical failure was identified, investigators noted that a vapor lock could have potentially disrupted the fuel-air mixture, leading to the power loss.
Findings
- The primary cause of the accident was an emergency landing off-field necessitated by the loss of engine power.
- The engine's ignition and fuel delivery systems were found to be in working order prior to the impact.
- The aircraft sustained significant structural damage, including the destruction of the wings and landing gear.
- The fatal injury to the rear occupant was caused by direct impact with a tree branch during the crash.