Key points:
Incorrect airspeed indications were displayed on the left PFD, triggering miscompare alerts;
Spurious instrument readings can create a more complex scenario for pilots than a complete instrument failure
Differing airspeed indications on a PC-12 aircraft’s two primary flight displays due to a blocked pitot tube underscores the complexity of managing spurious instrument readings, an Australian Transport Safety Bureau (ATSB) investigation notes.
On the evening of 22 June 2020, a Royal Flying Doctor Service Pilatus PC-12/47E was conducting a positioning flight from Perth’s Jandakot Airport to Albany, on Western Australia’s southern coast, with a pilot, a doctor and a flight nurse on-board.