What happened
On July 5, 2005, at approximately 16:30 local time, an Air Tractor AT-802, registration EC-GUF, was performing aerial firefighting operations near Castellbisbal, Barcelona. The aircraft, operated by Avialsa, was tasked with extinguishing a blaze in the area. After executing a water drop at a very low altitude at the leading edge of the fire, the aircraft entered a dense column of smoke.
Following the encounter with the smoke, the pilot attempted to increase power, but the engine became unresponsive. The aircraft lost altitude while flying over an urban area, striking a public street lamp before impacting the terrain. The aircraft then slid down a hillside and through orchards, eventually coming to rest in a streambed where it caught fire. The pilot, who had extensive flying experience, managed to exit the wreckage under his own power, sustaining minor injuries. \n## The investigation
Investigators examined the wreckage, the engine, and the pilot's actions. A detailed inspection of the Pratt & Whitney Canada PT6A-67AG engine was conducted in Canada. While the fire caused significant damage to the fuel system controls and accessories, the inspection ruled out any mechanical malfunction of the engine components prior to the accident. There was also no evidence of fuel starvation caused by air bubbles, as the aircraft had recently refueled and was carrying a significant load of water.
Investigators focused on the possibility of incorrect engine control manipulation. The propeller was found in the feathered position, which is not required for an in-flight restart. The investigation also noted that the start control lever was found in a position that suggested it might have been moved to the 'C' position, which cuts off fuel flow.
Findings
- The engine failed to respond to power increases following a low-altitude water drop.
- Incorrect manipulation of the engine control levers is a primary factor, specifically the possibility that the propeller was inadvertently feathered or the fuel flow was cut off via the start control lever.
- The aircraft entered a smoke column, which may have contributed to the pilot's loss of visual reference or prompted an emergency restart attempt.
- The engine was found to be functioning normally prior to the impact, ruling out mechanical failure or fuel starvation from air bubbles.