What happened
On 23 November 2022, a Reims Cessna F406, registration G-RVLY, was conducting a commercial cargo flight from East Midlands Airport to Isle of Man Airport. During the descent towards the airfield, the aircraft encountered intense atmospheric instability caused by an approaching occluded front.
As the aircraft descended through 3,000 ft, the turbulence became so severe that the autopilot disengaged, forcing the pilot to take manual control. The flight experienced significant altitude fluctuations, with the aircraft dropping to a minimum of 1,2 and 00 ft amsl. During the encounter, the pilot reported experiencing negative g-forces, intermittent stall warnings, and a period of "tunnel vision." Despite the extreme conditions, the pilot managed to stabilize the aircraft and climb away from the airport, eventually diverting back to East Midlands Airport.
The investigation
The AAIB examined radar data, radio communications, and meteorological reports to reconstruct the event. The investigation confirmed that the aircraft was operating in instrument meteorological conditions (IMC) and was not equipped with weather radar or windshear detection systems. Investigators also reviewed the pre-flight briefing, which included forecasts indicating the potential for isolated severe turbulence and squalls due to the active frontal system.
Findings
- The primary cause of the incident was the encounter with severe turbulence generated by an active occluded front.
- The aircraft lacked onboard weather radar or windshear detection equipment to provide early warning of the approaching instability.
- While the forecast indicated the possibility of severe turbulence, the weather conditions at the airfield remained within the aircraft's landing limits, which did not prevent the commencement of the approach.
- The pilot's recent training in Upset Prevention and Recovery Training (UPRT) was a critical factor in successfully managing the aircraft through the extreme oscillations and maintaining control.