What happened
On 3 February 2020, an Air Canada Boeing 767-375ER, registration C-GHOZ, was performing a takeoff from runway 36L at Madrid-Adolfo Suárez Airport, bound for Toronto. Two seconds before rotation, the left rear wheel of the main landing gear (tyre number 5) experienced a sudden burst. The explosion was caused by a sharp foreign object (FOD) measuring approximately 1.5 mm wide and 70 mm long that was present on the runway.
The force of the tyre burst caused fragments of the tread to be ingested by the number 1 engine, resulting in internal damage and visible flames. The crew successfully continued the takeoff but immediately initiated procedures to shut down the affected engine and declared a Mayday. Due to the high landing weight, the crew entered holding patterns at 5,000 and 8,000 feet to consume fuel until the aircraft reached a safe landing weight.
During the emergency, a military aircraft was utilized to inspect the landing gear for damage. The aircraft eventually landed safely on runway 32L. Due to the intense heat generated during the landing, the brakes required cooling via fans before the aircraft could exit the runway. There were no injuries among the 130 passengers or the 8 crew members.
The investigation
The CIAIAC investigation examined flight data recorder (FDR) sequences, airport surveillance footage, and the physical condition of the aircraft. The investigation reconstructed the timeline of the tyre failure, the engine flame, and the subsequent engine shutdown. Investigators also reviewed the coordination between Air Traffic Control (ATC) and the airport management during the emergency handling and the effectiveness of the communication regarding the runway contamination.
Findings
- The primary cause of the incident was the presence of a sharp foreign object (FOD) on runway 36L.
- The object punctured tyre number 5, leading to its immediate explosion.
- Secondary damage included engine ingestion of tyre fragments, vibrations, and damage to a landing gear tilt sensor, which initially prevented the gear from retracting.
- The crew managed the emergency effectively, following correct procedures for engine shutdown and fuel management.
Safety action
- AENA (the runway and apron service provider) is recommended to study improvements for detecting foreign object debris on the runway.
- ENAIRE (the air navigation service provider) is recommended to incorporate this event into training plans to ensure precise terminology during emergencies, assess the need for runway inspections following takeoff-phase emergencies, and include tyre explosion protocols in their Emergency Response Plans.