Loss of separation involving a Piper PA-39, VH-ICS and Piper PA-31, VH-AWW, 56 km east-north-east of Wagga Wagga, New South Wales, on 22 March 1994

While enroute between Corryong and Bathurst, the pilot of VH-ICS called Canberra Approach and requested a clearance to enter Canberra controlled airspace. An attempt was made by air traffic control to identify the aircraft but due to poor radar coverage, in the area and the aircraft's altitude, this could not be achieved. In response the pilot was instructed to remain outside controlled airspace.

Subsequently a brief radar return from VH-ICS was observed in the Wagga controlled airspace, about 20NM west of the planned track of the aircraft. There was inadequate radar contact to allow radar separation standards to be applied. The aircraft track conflicted with that of VH-AWW which was tracking in the opposite direction.

The pilot of VH-ICS said, that in hindsight, he should have planned a route that had more navigational aids to assist with track maintenance. He was tracking on a back bearing from the Corryong NDB and was unable to obtain a distance from the Canberra international DME. Hence, he was unable to accurately determine his position and ascertain that he was off the planned track.

Significant Factors

The following factors were considered relevant to the development of the incident:

1. The route planning by the pilot was poor.

2. The aircraft was not equipped with a domestic DME.

3. The enroute track maintenance by the pilot was inadequate.