What happened
On 6 May 2012, a collision occurred at Aboyne airfield involving a Mainair Blade 912 microlight, registration G-MZBA, and a Schleicher ASW19B glider, registration G-DELA. The microlight pilot was performing a local flight and, due to wind conditions, decided to approach the undesignated Runway 05. The glider pilot was returning to the airfield and had established on the final approach to Runway 27S.
As the microlight approached the runway, the pilot experienced a radio malfunction that prevented him from hearing traffic calls. The duty instructor, observing the potential conflict, issued urgent radio commands to both aircraft to abort the approach. However, the microlight pilot did not receive the warning and was already committed to his landing. Simultaneously, the glider pilot, focused on the runway ahead, did not observe the approaching microlight until the moment of impact. The right wing of the Schleicher ASW19B struck the G-MZBA, causing the microlight pilot to sustain serious injuries, including broken ribs and a head injury.
The investigation
The investigation examined the radio communications, the airfield's operating procedures, and the flight paths of both aircraft. It was established that the microlight pilot had experienced intermittent radio issues, which had been noted during a ground check at a different airfield earlier that day. The investigation also reviewed the use of the undesignated Runway 05, which was not officially marked on the airfield chart due to lack of funding for paving, though it was considered available for landing under club rules.
Findings
- The primary cause of the collision was the microlight pilot's failure to hear the instructor's warning due to a radio malfunction.
- The glider pilot was unable to avoid the collision because his attention was focused on the runway threshold rather than scanning for traffic.
- The use of an undesignated runway increased the risk of traffic conflicts.
- The microlight pilot's limited experience on the flex-wing type may have contributed to his focus on wind conditions rather than circuit traffic.