What happened
On 9 September 2016, a Piper PA-28-161 Warrior II, registration EC-JCI, was taxiing toward the runway 27 holding point at Seville Airport for a local VFR flight. During the taxi operation on taxiway A-5, the pilot noticed a loss of braking effectiveness. The unbalanced braking caused the aircraft to veer off the taxi and into an adjacent cotton field.
Following the excursion, smoke was observed emanating from the aircraft. The brakes on the right main landing gear caught fire, and the flames subsequently spread to the right wing. The pilot and passenger evacuated the aircraft under their own power, and airport firefighting services arrived quickly to extinguish the blaze. There were no injuries to the two occupants, though the aircraft sustained significant damage to the landing gear and wing.
The investigation
The CIAIAC investigation examined the aircraft's maintenance history, the pilot's experience, and the mechanical condition of the braking system. Investigators found that the aircraft's brake discs and blocks were in a severely degraded state and should have been replaced during previous scheduled maintenance.
Technical analysis revealed that the taxi operation involved excessive use of the brakes rather than the throttle. The investigation also noted that the presence of wheel fairings on the landing gear made it difficult to visually inspect the condition of the brake blocks during pre-flight inspections. Furthermore, the investigation identified that a broken hydraulic line had caused hydraulic fluid to spill, contributing to the fire's intensity.
Findings
- The primary cause of the taxiway excursion was the faulty operation of the brake system due to improper maintenance.
- The brake assembly overheated and ignited due to the highly worn condition of the brake components and the excessive use of brakes during a long taxi route.
- The maintenance technician involved in the aircraft's upkeep was rated for turbine airplanes but lacked the specific rating for piston engines.
- The design of the wheel fairings hindered effective pre-flight inspections of the brake blocks.
- High ambient temperatures and the leakage of hydraulic fluid contributed to the fire spreading to the right wing.