On 8 February 2014, at about 1500 Eastern Daylight-savings Time, the pilot of an AMS-Flight DG-303 glider, registered VH-DGA (DGA), broadcast on the local gliding club radio frequency that he would return to land at Bunyan aeroplane landing area (ALA), New South Wales, following a local flight of about 90 minutes duration. The glider was about 5 NM east of the aerodrome and on descent from 10,000 ft above mean sea level (AMSL).
About 10 minutes later, the pilot of a Piper PA-25, registered VH MLS (MLS), broadcast a lining up and rolling call and took off from runway 33 at Bunyan to launch a glider from overhead the aerodrome. At about 1515, when at about 4,000 ft AMSL, in anticipation of the glider pilot releasing the tow cable, the pilot of MLS turned to look behind the aircraft. He confirmed that the glider had released successfully and in accordance with standard operating procedures he then commenced a descending turn to the left.
The pilot of DGA sighted MLS release the glider and commence the turn. As the two aircraft were at about the same altitude and he then observed MLS with the wings level, he assumed the aircraft would then track straight ahead. He commenced a right turn to increase separation between them, and to track towards the joining point for a right downwind for runway 27. He reported that he assumed the pilot of MLS had sighted DGA at that time, and that he did not see MLS again until it was on downwind.
As the pilot of MLS rolled the aircraft’s wings level from the turn, he saw DGA as a white flash passing about 30 ft below him, and reported that he could see the rivets on the glider’s airbrakes.
This incident highlights the importance of communication and the limitations of unalerted see-and-avoid principles.