Whilst returning from a local training flight, the engine lost power during final approach. The instructor conducted a forced landing in a field short of the runway. Although the aircraft sustained significant damage, neither occupant was injured. The weather was good, with scattered cloud at 3,500 ft, the temperature was 20°C and the dew point 13°C.
After recovery of the aircraft, the engine was tested by the aircraft’s maintenance organisation and found to operate normally.
When the temperature and dew point were plotted on the CAA icing conditions chart contained in ‘Safety Sense Leaflet 14, Piston Engine Icing’, it indicated that moderate icing could be expected at cruise power and serious icing at descent power.
The instructor candidly commented: “… the main point to put across to other pilots flying in weather conditions similar to that on the day of my incident is that, even when applying the carb heat for the recommended time as per the POH, icing can still form in the carburettor. It is a lesson I learnt that day and an experience I would not like to repeat!”