What happened
On 9 January 2011, a Pierre Robin DR400/180 Regent, registration G-GLKE, was performing a private flight from Bodmin Airfield in Cornwall. The flight began with a displaced takeoff position due to soft ground at the start of the runway. During pre-takeoff procedures, the pilot conducted power checks and verified that no carburettor icing was present by applying carburettor heat.
As the aircraft commenced its takeoff roll on Runway 3ually, the engine RPM appeared normal and the aircraft initially accelerated as expected. However, as the aircraft reached rotation speed, it failed to accelerate or climb effectively. Despite the aircraft exceeding the 54 kt rotation speed, the pilot found the aircraft struggling to gain altitude, requiring increasing nose-up elevator input. The aircraft eventually lifted off with an excessively high nose-up pitch, causing a wingtip to strike the ground. The aircraft subsequently veered off the runway, striking a hedge at the airfield perimeter before coming to a halt. There were no injuries to the pilot or the two passengers.
The investigation
The investigation focused on the aircraft's inability to climb despite normal engine RPM. While a detailed examination of the engine and its systems was not performed, the investigation established that the environmental conditions presented a significant risk of carburettor icing. The temperature was 7°C with a dew point of 2°C. The pilot noted that other aviators at the airfield had reported experiencing carburettor icing on that same day.
Findings
- The aircraft sustained damage to the propeller, engine cowlings, both wings, the undercarriage, and the elevator.
- The primary factor contributing to the loss of performance was carburettor icing.
- Atmospheric conditions (7°C temperature and 2°C dew point) were consistent with a high probability of icing, as defined by the CAA's safety guidelines.