What happened
On 16 July 2002, a Robin R2120U, registration G-BZYZ, was performing a solo circuit flight for a pilot's conversion to type at White Waltham Airfield. During the third circuit, following a touch-and-go landing, the pilot noted that the engine seemed to be producing insufficient power, though no specific instruments indicated a malfunction.
As the aircraft became airborne, the stall warning horn activated immediately. Despite lowering the nose, the aircraft' continued to climb sluggishly. As the pilot reached the end of the runway, a left turn was initiated while the stall warning was still sounding. Witnesses observed the aircraft in a high nose attitude before it entered a stall at roughly 50 feet, resulting in a rapid descent and ground impact. The pilot sustained minor injuries, but the aircraft was damaged beyond economic repair.
The investigation
The investigation established that the pilot had inadvertently left the carburettor heat control in the ON position, which restricted the maximum power available from the engine. This error, combined with the pilot's lack of familiarity with the specific circuit pattern and the aircraft type, contributed to the loss of control. The investigation also noted that the hazy meteorological conditions may have hindered the pilot's perception of the aircraft's pitch.
Additionally, the investigators examined a hand-held fire extinguisher mounted to the rear bulkhead. During the impact, the deceleration caused the extinguisher to break free from its spring clips, flying through the canopy and narrowly missing the pilot's head. The mounting was found to be inadequate, as it was only designed to withstand a 9g longitudinal deceleration, whereas modern standards require resistance to 18g.
Findings
- The pilot's decision to enter a climbing turn while the stall warning was active.
- The engine power was reduced because the carburettor heat was left in the ON position.
- The pilot's lack of familiarity with the aircraft type and the specific airfield circuit requirements.
- The inadequacy of the fire extinguisher restraint, which failed under low g-loading.
- The lack of documentation regarding the fire extinguisher installation, which prevented the CAA from assessing its compliance with safety standards during the aircraft's certification.