What happened
On 28 October 2009, a Boeing 747-41R, registration G-VROC, was performing a scheduled passenger service from Johannesburg International Airport to London Heathrow. During the takeoff roll on Runway 03L, after passing the V1 decision speed, the flight crew experienced a loud thud followed by lateral vibrations and oscillations through the control column and rudder pedals.
Despite the vibrations, the crew continued the takeoff. Once a positive rate of climb was established, the landing gear was retracted, at which point the unusual airframe vibrations ceased. Following a consultation with the operator's engineering support and a review of the Flight Crew Training Manual, the pilots decided to proceed to their destination. During the flight, the crew coordinated with air traffic control to advise of the potential tyre failure and requested a runway inspection at Johannesburg.
Upon arrival at London Heathrow, the aircraft landed safely, but the crew noted the aircraft was leaning slightly to the right. An inspection by airport fire and rescue services revealed damage to the No 14 tyre on the right main landing gear. The aircraft was subsequently towed to a stand.
The investigation
Investigators examined the aircraft and recovered debris from the Johannesburg runway, including large sections of tyre, aluminium honeycomb, and a metal part. Analysis of the G-VROC flight data recorder revealed that the tyre burst at approximately 160 kt. The flight data showed rapid fluctuations in acceleration, likely caused by the tyre failure or the resulting shockwave.
Examination of the No 14 tyre showed an X-type burst pattern, which is characteristic of a high-pressure blowout. While the manufacturer could not definitively identify the cause due to missing material, they concluded that penetration by a foreign object was the most probable cause.
Further inspection of the landing gear revealed that a component of the right landing gear shock strut inboard door had detached. The investigation determined that a metal lug and rod had failed due to static tensile overload, likely when the ruptured tyre carcass struck the landing gear door during the takeoff roll.
Findings
- The No 14 tyre burst during the takeoff ground roll at approximately 160 kt.
- The burst was likely caused by the tyre running over a foreign object, though the specific object could not be identified.
- The failure of the tyre carcass led to the impact and subsequent failure of the landing gear door components.
- The flight crew's decision to continue to the destination was consistent with manufacturer training guidance.