ATSB Issues Engine Advisory after 2024 Caravan Accident

Australia’s Transport Safety Bureau (ATSB) is urging operators of Pratt & Whitney Canada PT6A-powered aircraft to update training for pilots to include uncommanded engine acceleration malfunctions after investigating a 2024 engine malfunction and subsequent runway overrun accident involving a Cessna 208B Caravan in Queensland. The ATSB concluded the probable cause was a malfunction of the engine’s fuel control unit. 

“Pilots of PT6A turbine single-engine aircraft are trained for ‘roll back to idle’ malfunctions, but not trained for uncommanded engine acceleration malfunctions,” said ATSB director Kerri Hughes. “There is limited awareness by pilots and operators of how to safely respond.”

Hughes added, “While not as immediately dire as an engine failure or roll back to idle, an uncommanded engine acceleration is alarming and requires prompt action to control the aircraft and prevent overstress.”

On Jan. 8, 2024, the aircraft departed Lizard Island for Cairns with one pilot and nine passengers. During climb-out, the pilot heard a change in the engine and observed torque and temperature gauges exceeding redline, while gas generator speed and fuel flow indications were lost. Although propeller RPM remained in the normal range, the engine produced excess power.

The pilot returned to land at Lizard Island, but the high-speed approach resulted in a long landing on the short runway. The aircraft overran the end of the runway at 92 knots, struck sandy terrain and low vegetation, and flipped after the left wingtip contacted the ground. All 10 occupants sustained minor injuries.

Issuing a safety advisory, the ATSB urged operators to document emergency procedures and incorporate scenario-based training. East Air, the accident operator, revised its Cessna 208B quick reference handbook to include an item for unscheduled power increases.