A malfunctioning stall-warning alert is blamed for causing a crash that resulted in the destruction of a Royal Canadian Mounted Police (RCMP) Pilatus PC-12 and serious injuries to the pilot, the sole occupant. A report recently released by the Canadian Transportation Safety Board (TSB) concludes that a faulty sensor caused the stall warning signal and audio alarm to activate shortly after takeoff from Whitehorse International Airport (CYXY), Yukon, Canada. The pilot became sufficiently distracted as he tried to return to the airport that he crashed on landing.
The accident occurred on April 17, 2023. The pilot, a special constable of the RCMP, had just dropped off two other officers at Whitehorse and was trying to return to home base at Yellowknife Airport (CYZF), Northwest Territories, about 650 miles east. Though instrumentation on board showed appropriate airspeed and other indications, the aural alert activated indicating an imminent stall. The pilot’s first attempt to land was unsuccessful and he went around for a second approach.
According to the TSB report, “At the same time, the pilot was also becoming increasingly concerned by the continuous aural stall warning and started to believe that there may be something seriously wrong with the aircraft.” The single-engine turboprop entered a sudden descending right turn and its right wing hit the ground. Subsequently, the left wing hit a pile of millings alongside the runway and separated from the fuselage, which rolled over and slid 40 meters, coming to rest on a service road.
The pilot suffered head injuries but was able to exit the wreckage on his own. The TSB report revealed that the Pilatus is equipped with an “inhibit switch” to mute the aural warnings in the event of a malfunction such as this one. The pilot was not aware of the switch and the board reported that the operating handbook provided “limited guidance” to its use. According to the report, the RCMP has since updated its emergency training and procedures for PC-12 pilots, reviewed its PC-12 fleet, and contacted Pilatus about acquiring new sensors.
The people responsible for the loonies and twonies need to understand the need for regular recurrent training when aircraft of this size and capability are piloted by a single pilot doing his/her very best to accomplish the mission with no backup whatsoever in the “sparsely settled areas” of the north ( anywhere 100 miles north of the U.S. border. Pretty tragic for all concerned.
Aviate, Navigate, Communicate.
First order of business, FLY the airplane