What happened
On 26 June 2011, a Jodel D18, registration G-BWVV, was performing a private flight near North Coates Airfield, Lincolnshire. During the flight, the pilot noticed the engine was running roughly at 2,800 ft. While attempting to return to the airfield, the pilot flew a low-level circuit. During the final approach, the aircraft crossed the runway centreline and, while attempting to turn back towards the runway, the aircraft stalled. Despite a brief recovery, a second stall occurred at a very low altitude, resulting in an incipient spin that impacted the ground. The pilot sustained serious injuries but managed to exit the wreckage unassisted.
The investigation
The AAIB examined the wreckage and the engine systems. The investigation found that the engine was operating at reduced power because the choke was in the fully out position, creating an over-rich mixture. The investigation also noted that the cockpit controls for the carburettor heat and the choke were very similar in shape and colour, which could lead to confusion. Furthermore, the fuel selector valve was difficult to read due to a small pointer and a misleading placard. The investigation also looked into the pilot's recent training, noting he had recently undergone tailwheel conversion training but lacked extensive experience on this specific type.
Findings
- The primary cause of the engine malfunction was likely that the pilot mistakenly operated the choke instead of the carburettor heat while checking for icing.
- The aircraft's lack of a stall warning system and minimal natural buffet contributed to the stall occurring without warning.
- The pilot's attempt to fly a tight, low-level circuit in crosswind conditions at an unfamiliar circuit height contributed to the loss of control.
- The similarity in design between the choke and carburettor heat controls increased the risk of error.
- The pilot's use of rudder during the initial wing drop likely prevented a full spin but resulted in a significant loss of altitude.