What happened
On February 28, 2012, an Iberia Airbus A340-300, registration EC-GPB, arrived at Carrasco International Airport (SUMU) from Madrid (LEMD). The flight, carrying 249 passengers and 14 crew members, landed on runway 06. The runway surface was wet, and the crew utilized automatic braking and thrust reversers during the landing roll.
Approximately five minutes after the aircraft had reached parking position 35 and the chocks were in place, ground personnel noticed smoke and fire originating from the brake assembly of wheel number 8. The temperature in the brake area had reached approximately 530°C. Ground staff immediately notified the flight crew to release the parking brakes to assist in cooling the brakes.
Ground personnel attempted to suppress the fire using a 50 kg chemical powder extinguisher located at the parking stand, but the unit failed to operate. The fire was eventually extinguished using smaller 8 kg extinguishers taken from nearby support vehicles, including a fuel tanker that was positioned near the aircraft for upcoming servicing.
The investigation
The CIAIA investigation examined the aircraft's maintenance records, the physical condition of the wheel assembly, and the airport's emergency response capabilities. Investigators inspected the removed brake assembly and wheel, finding significant accumulations of grease and debris. The investigation also reviewed the landing data from the Flight Data Recorder (FDR), which showed that while several wheels experienced temperatures exceeding 300°C, only wheel number 8 reached the ignition point.
Furthermore, the commission evaluated the airport's fire suppression equipment and found that the stationary extinguisher at parking position 35 was non-functional, a condition that was also observed in other airport extinguishers during subsequent inspections.
Findings
- The primary cause of the fire was the excessive application of grease on the brake assembly and wheel rim during a previous maintenance task.
- Maintenance procedures for the brake assembly explicitly warn that only a very small amount of grease should be applied, as excessive grease can burn and cause a fire when brakes become hot.
- The failure to adhere to these specific maintenance instructions was the direct cause of the event.
- The airport's fixed fire extinguisher at the parking stand was inoperable.
- The presence of a fuel tanker in close proximity to the aircraft during the incident presented a potential secondary hazard.
Safety action
- The airline was advised to ensure all maintenance personnel strictly follow manufacturer procedures, with particular emphasis on observing all warnings and cautions.
- Recommendations were made to the airport operator to implement more effective controls for portable fire extinguishers and to establish a robust emergency plan for ramp operations.
- The airport operator was advised to improve communication systems and ensure that service vehicles, such as fuel tankers, are managed to avoid obstruction or increased risk during emergency responses.