What happened
A Boeing 747 cargo airplane was taxiing for departure when the crew heard a thumping noise. The crew initially believed the sound was caused by the tires traveling over a rut in the pavement and continued taxiing.
During the takeoff roll, as the aircraft reached approximately 130 knots indicated airspeed (IAS), the captain experienced a second thump accompanied by substantial vibration. The captain initiated an aborted takeoff at approximately 148 knots IAS, applying maximum braking and maximum reverse thrust. The aircraft's speed increased to 166 knots before it began to decelerate.
The airplane exited the paved portion of the runway and entered a clearway consisting of soft dirt. It came to a stop approximately 486 feet beyond the end of the pavement as the landing gear wheels sank into the soft terrain. There were no injuries reported.
The investigation
Investigators found significant shredded tire debris and gouge marks, consistent with tire wheel rims, on the runway approximately 1,500 feet from the start of the runway.
An inspection of the landing gear revealed that the number 11 and number 12 tires, located as the two aft tires on the right body landing gear assembly, were shredded and destroyed. Regarding the other tires:
- Tires 1 through 4 were undamaged and inflated.
- Tire 5 was cut, torn, and flat.
- Tires 6, 7, and 8 were flat.
- Tires 9 and 10 remained inflated.
- Tires 13, 14, 15, and 16 were flat.
- The nose wheel tires were undamaged and inflated.
The aircraft sustained additional damage to the underside of the right flap assembly, a landing gear door, the brake assemblies, and the right main landing gear hydraulic brake system. At the time of the incident, the takeoff gross weight was 794,200 pounds, while the runway takeoff gross weight was 795,300 pounds.