What happened
On 14 June 2009, a Grob G115E (Tutor), registration G-BYXR, was conducting an air experience flight for a cadet on behalf of the Royal Air Force. While performing aerobatic manoeuvres in uncontrolled airspace near Drayton, Oxfordshire, the aircraft collided with a Standard Cirrus glider, registration G-CKHT.
The collision occurred when the Tutor's left wing struck the glider's fin and right tailplane. The impact caused the glider's tail section to detach, rendering the glider uncontrollable. The glider pilot successfully deployed a parachute and landed safely. However, the Tutor entered a spin and subsequently a steep dive. While the aircraft remained controllable following the impact, the pilot was unable to recover from the dive, and the aircraft struck the ground. Both the pilot and the cadet were fatally injured.
Following the impact, the cadet managed to release their harness and move the canopy handle to the open position, though the canopy jettison mechanism was not successfully operated.
The investigation
The AAIB investigation examined the flight conditions, the mechanical state of both aircraft, and the medical history of the pilot. The investigation established that the area was experiencing high traffic density due to significant gliding activity.
Investigators found that the Tutor pilot's medical condition, Ankylosing Spondylitis, significantly restricted his head mobility, which hindered his ability to maintain a standard lookout. Furthermore, the investigation noted that the pilot's spinal column was fused, making him highly susceptible to fractures from trauma. It was determined that the impact likely caused a spinal fracture, leading to the pilot's incapacitation.
Regarding the aircraft, the investigation found that the Tutor's canopy jettison handle had not been removed from its housing, a necessary step for successful canopy deployment. Additionally, the glider's FLARM system was not compatible with the Tutor's transponder, limiting the effectiveness of electronic conspicuity.
Findings
- **Neither pilot saw the other in sufficient time to avoid the collision.*
- The pilot's medical condition, Ankylosing Spondylitis, limited his ability to perform an effective lookout and increased his vulnerability to spinal injury.
- High traffic density in the local uncontrolled airspace increased the risk of a mid-air collision.
- The Tutor pilot likely became incapacitated due to a spinal fracture sustained during the collision.
- The cadet's ability to jettison the canopy was compromised because the locking lever had not been removed from its housing.
- There was no onboard traffic alerting system installed in the Tutor.