The captain’s abrupt, last-minute turn to avoid clouds caused a momentary loss of control of a Jetfly Pilatus PC-12 during its descent to France’s Brive-Souillac Airport. According to French aircraft accident investigation agency BEA, the Oct. 12, 2021 “serious incident” involved stall warning activation and an unintentional descent below the minimum safe altitude (MSA) before the aircraft was recovered.
During the descent, the chartered PC-12 encountered intense turbulence after passing through a cloud mass, for which the airborne weather radar was showing weak precipitation. To ensure the comfort of the three passengers, the copilot insisted that the captain (pilot flying) avoid another cloud mass that she could see ahead of them. Relying on his radar, the captain “refused to change the flight path and continued descending to the 3,000-foot MSA for which he had been given clearance.”
At the continued insistence of the copilot, when the single-engine turboprop was “very close” to the cloud mass and approaching the 3,000 feet, the captain “without warning or adjusting the engine power disengaged the autopilot and turned suddenly and abruptly.”
The stall warning sounded and the airplane descended nearly 600 feet below the MSA before the captain leveled the wings and increased engine power to climb back to 3,000 feet. The remainder of the approach and landing was conducted without further incident.