What happened
On 15 January 2005, a Learjet 35A, registered ZS-SES, was operating a domestic charter flight from Air Force Base Waterkloof Aerodrome to Umtata Aerodrome. The flight was being conducted as a replacement for a South African Air Force aircraft that had been grounded due to communication issues.
During the takeoff roll on Runway 01, the aircraft reached a speed of approximately 125 knots when the crew encountered intense vibrations originating from the left side of the plane. This was accompanied by the aircraft beginning to veer toward the left. The crew immediately decided to abort the takeoff. Despite the instability, the pilot managed to maintain the runway heading, eventually bringing the aircraft to a stop near the threshold of Runway 19. There were 0 fatalities and 0 injuries among the ten people on board.
The investigation
The investigation focused on the mechanical failure that occurred during the high-speed portion of the takeoff roll. While the aircraft's tires and the anti-skid system sustained damage during the event, the investigation examined the maintenance history and the specific nature of the tire failure. Records showed the aircraft's last major periodic inspection had been completed in July 2004.
Findings
Investigators determined that the primary cause of the incident was a burst tyre which released debris capable of severing the electrical wiring for the anti-skid system. While no manufacturing defect was identified in the tires, the investigation noted that under-inflation may have contributed to the failure of the outboard tire. The failure of the inboard tire was attributed to the resulting friction and overload caused by the initial outboard failure and the subsequent loss of anti-skid functionality.