What happened
On August 6, 2002, at approximately 19:15 local time, an Air Tractor AT-502, registration EC-EIN, was engaged in an aerial firefighting mission near Casas de Ves, Albacete. The aircraft had departed from Carcelén aerodrome to combat a fire at a nearby campsite. After arriving at the scene, the pilot performed a water and foam drop, releasing 1,500 liters of suppressant.
Approximately five to six seconds after the discharge, the pilot noticed the engine was not responding. In an attempt to restart the engine, the pilot activated the electric fuel pump and set the flaps to an intermediate position. However, the aircraft was unable to clear an ascending terrain feature. The aircraft struck several pine trees, causing significant damage to the wings, engine, propeller, and landing gear, before finally colliding with a stone wall.
The pilot sustained one serious injury, specifically a fractured sternum, and was able to evacuate the aircraft on his own.
The investigation
Investigators examined the wreckage and the engine components, including the Pratt & Whitney Canada PT6A-34AG turboprop. A detailed inspection of the engine, conducted with the manufacturer's participation, revealed no evidence of mechanical failure or malfunction prior to the impact. The compressor and power turbine blades showed no significant damage or signs of pre-impact failure. The investigation also focused on the engine control quadrant, specifically the fuel cutoff lever.
Upon inspection of the engine controls, investigators found the fuel cutoff lever in the fully aft position, which cuts off the fuel supply. Crucially, the locking tab designed to prevent the lever from inadvertently moving into the cutoff position was found to be in perfect condition, meaning it had not been bent or broken by the impact. This indicated that the lever had been moved to the cutoff position by an action other than the crash itself.
Findings
- The engine power loss was caused by an interruption of the fuel supply.
- The fuel cutoff lever was likely moved to the shutoff position inadvertently after the water drop.
- The pilot failed to ensure the fuel cutoff lever was properly secured in the 'Flight Idle' position, as required by the flight manual, following the takeoff and discharge sequence.
- The aircraft's inability to clear the rising terrain was a direct result of the engine's loss of power during a critical phase of flight.