History of the Flight
The aircraft, a Cessna 172R registered as SE-LGL, had recently undergone maintenance to replace three flight control servos and update the autopilot software. This action was prompted by a Service Bulletin following an incident in the United States where the autopilot system issued incorrect commands.
On 11 December 2024, at 15:12 hours local time, a pilot planned a private flight from Örebro Airport to Karlskoga Airport. A GoPro camera mounted on the left window recorded the instrument panel and surroundings.
After takeoff, the pilot climbed to 2,126 feet and engaged the autopilot in heading and altitude hold modes. The aircraft was not trimmed to the reference altitude, causing it to climb slightly. The autopilot initially adjusted the pitch using the elevator servo, then activated the pitch trim servo to assist.
Sequence of Events
Sixteen seconds after autopilot engagement, a yellow warning light illuminated on the pilot's flight instrument. The aircraft's pitch angle increased, and the control yoke moved rapidly forward six seconds later. The pilot gripped the yoke and disengaged the autopilot. Despite this, the pitch angle rose to 56 degrees, airspeed dropped to 26 knots, and the aircraft stalled.
For the next 48 seconds, the flight was uncontrolled, with pitch angles varying between -51 and 49 degrees and bank angles between -9 and -121 degrees. The pilot later stated he believed the autopilot remained engaged throughout the event.
Aircraft Information
The Cessna 172R (SE-LGL) held a valid Certificate of Airworthiness and Airworthiness Review Certificate. The autopilot system had been serviced by the original installer.
Meteorological Conditions
At the time, weather reported wind 210 degrees at 3 knots, no significant clouds, temperature/dewpoint -6/-6°C, and QNH 1030 hPa.
Injuries and Damage
No injuries to the pilot were reported. The aircraft sustained no damage.