What happened
On 28 April 2012, a pilot and one passenger departed RAF Kinloss in a Reims Cessna FA152 Aerobat, registration G-MPBH, for a local flight. After initially flying along the coast, the pilot turned inland toward Aviemore. During the flight, the pilot noticed two birds directly ahead and executed a sharp pull-back on the control wheel to avoid a collision. This manoeuvre brought the aircraft close to the cloud base, prompting the pilot to lower the nose to descend into clearer air.
While communicating with Inverness ATC to report his intentions, the pilot retarded the throttle. Upon attempting to increase power to level the aircraft, the engine failed to respond. Despite efforts to restart the engine, the power remained unavailable. The pilot issued a MAYDAY call and identified a suitable field for an emergency landing. However, the chosen landing site featured a steep downhill slope that terminated in a sharp drop. The pilot was unable to stop the aircraft before overrunning the field and descending the slope.
The investigation
The investigation examined the aircraft's condition and the environmental factors present at the time of the accident. Post-flight inspections of fuel samples showed no abnormalities. The aircraft sustained substantial damage to the propeller, nose leg, and the engine area forward of the firewall, along with damage to the left wing and a resulting fuel leak. Both occupants escaped the aircraft through the doors without injury.
Findings
- The engine failed to respond to throttle movement following a period of idling.
- Carburettor icing was identified as a significant risk factor, given the moist conditions and temperatures present that morning.
- The pilot's sudden manoeuvre to avoid birds led to an inadvertent climb toward the cloud base, necessitating a reduction in power which may have contributed to the engine's inability to recover power.