What happened
On May 14, 2005, at approximately 09:00 h, a Piper PA-25, registration EC-BBI, was performing agricultural operations as part of a rice sowing campaign in the municipality of Aznalcázar, Seville. The aircraft was preparing for its second flight of the morning at the Hato Blanco farm.
During the takeoff roll, the aircraft veered off the runway and traveled approximately 30 meters before falling into an adjacent canal. The pilot was able to evacuate the aircraft without injury, but the aircraft was destroyed due to the impact and subsequent submersion in water.
The investigation
The investigation was delayed because the accident was not reported to the CIAIAC until two months after the occurrence. Consequently, investigators were unable to examine the runway or the surrounding terrain for physical evidence. By the time the wreckage was accessed, the aircraft had been largely dismantled.
Investigators examined the right wheel and braking system, which had been preserved by the owner. While the right landing gear strut showed structural deformation, the investigation found no evidence of brake seizure on the disc, nor were there visible traces of hydraulic fluid leaks. The damage found on the wheel rim and the detachment of the brake caliper appeared to be consequences of the runway excursion rather than the cause of it.
Findings
- The pilot reported a potential failure in the right-wheel braking system. The pilot had been using the right brake to counteract engine torque and maintain directional alignment on the runway.
- There were no clear indications of a malfunction in the aircraft's braking systems, though a definitive conclusion was hindered by the lack of immediate access to the wreckage and the subsequent handling of the components.
- The pilot was highly experienced, with over 6,000 total flight hours and 1,500 hours in this specific aircraft type.
- The difficulty of maintaining alignment on unpaved or improvised agricultural strips, combined with the inherent handling characteristics of tailwheel aircraft, may have contributed to the loss of control.