What happened
On 8 October 2011, a Cessna F172H Skyhawk, registration G-AWMP, was conducting a private flight from the Nene Valley Gliding Club in Cambridgeshire. During the takeoff phase, the aircraft's engine suffered a loss of power. The pilot responded by performing a forced landing in a nearby field, which resulted in substantial damage to the aircraft. The pilot sustained a minor injury to his face but was able to exit the cockpit without assistance.
The investigation
Investigators examined the circumstances leading to the power loss and the aircraft's performance. The airfield surface at the time of the incident consisted of wet, long grass. Weather conditions were characterized by drizzle, 4,000 m visibility, and broken cloud layers between 700 ft and 800 ft.
During the pre-takeoff sequence, the pilot had performed a check of the carburettor heat by applying it and then immediately turning it off after observing a normal RPM drop. The investigation established that this brief check was insufficient to detect the presence of induction ice. The pilot noted that a more prolonged application of the carburettor heat would likely have revealed the icing issue and allowed for its removal prior to departure.
Findings
- The engine power loss was caused by carburettor induction icing.
- The pre-flight check of the carburettor heat was too brief to identify the presence of ice.
- The airfield conditions, specifically the long, wet grass, may have contributed to the circumstances of the takeoff and subsequent landing.