Air Accidents Investigation Branch
During a test flight towards obtaining a Permit to Fly, control of the aircraft was lost. The flight was testing the effects of leading edge stall strips as part of the Light Aircraft Association (LAA) approved test programme. The pilot was fatally injured when the aircraft struck the ground.
The aircraft was found to have been built with a misaligned fin and rudder. This misalignment made a wing drop at the stall more likely, but it did not prevent or restrict the ability of the pilot to recover from the stall nor any subsequent spin or spiral dive that might develop. Although the pilots medical history indicated the possibility of an incapacitation this could not be confirmed or dismissed by the pathologist. The possibility of a control restriction preventing recovery could also not be excluded due to the extensive fire damage to the aircraft.
The LAA took action to alert owners regarding the possibility of a fin and rudder misalignment by issuing a Mandatory Technical Directive (MTD) applicable to all Spitfire Mk 26 and Mk 26B aircraft.