What happened
On August 3, 2017, an Air Tractor AT-401-B, registration EC-GYX, operated by Servicios Agrícolas Aéreos, S.A. (SAASA), was conducting a training flight near La Puebla del Río, Spain. The mission involved practicing short-field takeoffs with a load. The aircraft had been fueled to 70% capacity and was carrying 1,000 liters of water.
During the takeoff roll on the Huerta de la Arena landing strip, the aircraft failed to lift off. The pilot attempted an emergency discharge of the water load approximately 100 meters before the end of the runway. The aircraft continued down the runway, exited the paved surface, and entered a nearby rice field. After rolling through the field, the aircraft sank into the mud and overturned, coming to rest in an inverted position. The pilot was uninjured and able to exit the aircraft on his own.
The investigation
The CIAIAC investigation examined the aircraft's configuration, maintenance records, and the pilot's actions. The investigation confirmed that the pilot was properly rated and experienced, and the aircraft was airworthy with all maintenance up to date. The aircraft's weight and center of gravity were within approved limits for the operation.
Investigators analyzed the takeoff procedures outlined in the approved Airplane Flight Manual (AFM). The manual specifies different flap settings for normal takeoffs (retracted) versus takeoffs with a full hopper load and short strips (10° flaps). Post-accident inspection revealed that the flaps were in the full flaps position (26° deflection).