What happened
On 16 July 2011, a Boeing 727-281, registration C-GKFJ, was performing a scheduled cargo flight from Moncton to St. John's. The flight, operated by Kelowna Flightcraft Air Charters Ltd., arrived at St. John's International Airport amidst weather conditions involving fog, drizzle, and gusting winds.
During the landing on Runway 11, the aircraft touched down approximately 1850 feet beyond the threshold at a speed exceeding required parameters. Shortly after the crew applied maximum wheel braking, the aircraft began to skid. The crew was unable to maintain directional control or decelerate sufficiently, eventually departing the paved surface. The aircraft came to a stop in the grass and mud approximately 350 feet beyond the end of the runway. There were no injuries reported, and the aircraft sustained only minor damage.
The investigation
The investigation examined several technical and operational factors, including the condition of the runway surface, tire maintenance, and the operator's safety management systems. Investigators analyzed the aircraft's flight data and cockpit voice recordings, noting that the anti-skid system was functional but that the crew maintained continuous brake pressure even after skidding began.
Technical inspections of the landing gear revealed that three of the four tires were more than 80% worn. Furthermore, the investigation looked into the runway's microtexture and macrotexture, finding the surface to be smooth, which can contribute to hydroplaning. The investigation also reviewed the operator's Safety Management System (SMS) and the airport's risk assessment processes regarding runway overruns.
Findings
- The aircraft touched down at an excessive airspeed, which significantly reduced the available stopping distance.
- Reverted rubber hydroplaning occurred due to the combination of a wet runway and excessive tire tread wear.
- The crew's decision to maintain maximum braking during the skid reduced the effectiveness of the anti-skid system.
- The use of highly worn tires (exceeding 80% wear) significantly decreased wet-runway traction.
- The lack of runway grooving and the smooth microtexture of the pavement contributed to the loss of braking and directional control.
- Ineffective safety management practices at both the operator and airport levels prevented the timely identification and mitigation of known hazards, such as frequent brake heating and previous runway overruns.