What happened
On July 7, 2009, a B73/800NG, registration VT-AXP, was accelerating for departure from Sharjah International Airport toward Trivandrum, India. During the takeoff roll, as the aircraft reached an indicated airspeed between 130 and 140 knots, the pilot in command felt a distinct jerking motion accompanied by a leftward drift.
In response to this instability, the crew initiated a rejected takeoff procedure. The aircraft continued to accelerate to a groundspeed of approximately 147 knots before the engines were retarded and deceleration began. The aircraft eventually came to a complete stop on the runway. While no fire or smoke was detected, the high-energy stop resulted in the four main landing gear brakes seizing due to extreme heat. Passengers and crew, totaling 178 persons, were evacuated via mobile airstairs without any injuries reported.
The investigation
Investigators from the GCAA examined the aircraft after it was towed to a maintenance area. Laboratory analysis of the braking system by Honeywell revealed that while the brakes were functional prior to the event, the intense deceleration caused a weldment of the brake wear surfaces.
Examination of the tyres by Goodyear and the investigation team identified that the left-hand inboard tyre had suffered significant damage, losing a large chunk of rubber. This debris struck the lower surface of the left-hand inboard flap, causing a dent. The investigation ruled out foreign object damage (FOD) on the runway and determined that the tyre had been operating in a deflated state, evidenced by wider-than-normal skid marks on the pavement.
Findings
- The primary cause of the high-energy rejected takeoff was the damage to the left-hand inboard tyre, which created the jerking motion felt by the pilot.
- The specific origin of the tyre damage could not be determined.
- The intense braking required to stop the aircraft at high speed led to the seizure of the main landing gear brakes.
- The aircraft's flight preparation, crew licensing, and airworthiness documentation were all found to be in order.
Safety action
- The Indian Civil Aviation Authority was advised to ensure the operator follows its internal procedures regarding tyre management.
- The GCAA recommended that all B737-800 operators in the UAE be made aware of the incident to evaluate if more frequent or enhanced tyre inspections are necessary.