What happened
On December 21, 2000, a Gates Learjet 35A, registered ZS-TOW, was operating a domestic charter flight from Cape Town International Airport to Johannesburg International Airport. Upon arriving at Johannesburg, the aircraft landed on runway 03R at approximately 1708 Z. The landing occurred immediately following a period of heavy rainfall.
Shortly after the aircraft made contact with the runway, the pilot experienced significant aquaplaning. This loss of traction led to the simultaneous bursting of all four main wheel tyres. Despite the loss of tyre integrity, the aircraft remained under control and came to a safe stop on the runway with no injuries to the crew and no further incidents reported.
The investigation
Investigators examined the aircraft's landing gear following the event. The inspection confirmed that all four main wheel tyres had developed flat spots and had deflated. Notably, the brake assemblies showed no evidence of overheating or structural damage.
Maintenance records indicated that the aircraft had undergone its last Maintenance Program Inspection (MPI) on November 25, 2000, with the airframe having approximately 5763.30 total hours at the time of the incident. The maintenance director for the operator, Execujet South Africa, reviewed the tyre condition and concluded that the evidence strongly supported a landing involving aquaplaning. Furthermore, the investigation found no evidence that the Anti-Skid system had been deactivated, as the cockpit configuration would have displayed four red warning lights had the system been turned off.
Findings
- The primary factor in the tyre failure was aquaplaning on the runway surface caused by heavy rain.
- The loss of traction resulted in the bursting of all four main wheel tyres and the development of flat spots.
- There was no evidence of mechanical failure within the braking system or improper deactivation of the Anti-Skid system.