What happened
On 8 July 2005, a CAP 222 (registration G-GZOZ) was performing a series of unlimited aerobatic manoeuvres over White Waltham Airfield. The pilot, an experienced aerobatic competitor, was conducting a practice session observed by an instructor from the ground. The flight plan involved performing three repetitions of four specific manoeuvres, including a knife-edge spin.
During the third attempt at a knife-edge spin, the aircraft's flight path deviated from the intended sequence. After completing approximately one and a half to two rotations in pitch, the aircraft entered an unplanned inverted spin. Despite the instructor's radio commands to execute recovery procedures, the aircraft continued to rotate in an inverted attitude. The aircraft eventually descended to a low altitude and impacted the ground at approximately 1,800 ft agl, resulting in one fatality.
The investigation
AAIB investigators examined the wreckage and the aircraft's electronic engine management system. The engine was found to have been operating at idle power at the time of impact. The investigation confirmed that the aircraft's flight control systems were functional and showed no evidence of mechanical failure or control jams. Marks on the rudder pedal linkage indicated that full right rudder was applied at the moment of impact.
Investigators also analysed the physiological stresses placed on the pilot. Due to the high rate of rotation during the transition from the knife-edge spin to the inverted spin, the pilot's head was subjected to significant negative acceleration. The investigation considered whether these forces, combined with the suddenness of the manoeuvre, could have caused disorientation or temporary loss of consciousness.
Findings
- The aircraft entered an unplanned inverted spin during a knife-edge manoeuvre.
- The pilot was subjected to unexpected and high levels of negative acceleration, which likely caused significant vestibular and visual confusion.
- The rapid transition between manoeuvres provided a very limited window of time—estimated at only a few seconds—to identify the direction of the spin and implement the correct recovery technique.
- The pilot's cognitive function may have been impaired by the physiological effects of the negative g-forces experienced during the rotation.