Cabin Vibration And Noise Investigations On Two Pilatus PC-12 Aircraft

Hooting noise problems were reported by some customers of the Pilatus PC-12 aircraft during operational flight. Theoretical analyses indicated a possible interference between engine excitation and vibration and acoustic resonance modes of the aircraft fuselage. To verify the analytical investigations and to identify the possible sources of the hooting noise problems, dedicated ground vibrations tests were performed on two PC-12 aircraft.