Aircraft proximity event between a Bell 206, VH-WCS and a PZL Bielsko 51, VH-XOP, Gympie (ALA), Queensland, on 4 December 2013

On 4 December 2013, at about 1440 Eastern Standard Time (EST), a PZL Bielsko 51 glider, registered VH-XOP (XOP), was winched at the Gympie aeroplane landing area (ALA). About 20 minutes later, the glider entered the circuit on downwind at about 900 ft above ground level (AGL), and the pilot broadcast a downwind call on the common traffic advisory frequency (CTAF).

At about the same time, a Bell 206 helicopter, registered VH‑WCS (WCS), was conducting circuits from runway 32. The instructor of WCS broadcast on the CTAF when turning base and subsequently heard the downwind call of XOP. At that time he sighted the glider on mid-downwind. Soon after, the pilot of XOP broadcast turning base. The glider pilot then commenced a diagonal base leg, on about a 45° angle from the downwind leg.

WCS turned onto final and the instructor broadcast a final call. The instructor reported that at this time, he assumed the glider was on late downwind or base leg. The pilot of XOP then reported broadcasting a final call, but neither pilot heard the other pilot’s finals broadcast.

About 90 seconds later, the instructor of WCS sighted the glider to his right, at about the same height and about 10 m away. The pilot of XOP also observed the helicopter to his left and slightly above. In response, he lowered the nose of the glider to increase the airspeed to stay below the helicopter. The glider then landed on the grass to the left of the runway.

The instructor of WCS took control of the helicopter from the student, conducted a clearing turn and subsequently landed on the sealed runway.

This incident highlights the importance of broadcasting radio calls to alert pilots and assist in see-and-avoid practices. It serves as a reminder to keep a good lookout for other aircraft, particularly around non-controlled aerodromes.

Aviation Short Investigation Bulletin - Issue 26