Near collision involving a Cessna 172F, VH-SKB and Piper PA-31-350, VH-KGN, 10 km south of Moorabbin Aerodrome, Victoria, on 2 July 1993

A report was received from the pilot of VH-SKB saying a Navajo type aircraft had passed about 100 feet above the top of his aircraft, on a reciprocal track. He expressed concern that although the other aircraft was on the radar advisory frequency it had not been passed advice on his aircraft which had the transponder on code 2000. VH-SKB was on a visual flight rules flight. The other aircraft, VH-KGN, was on an instrument flight rules flight. No report was received from the pilot of VH-KGN.

The close proximity took place 10 kilometres south of Moorabbin Airport. This area is in a buffer zone, which extends from 5.5 kilometres to 14.8 kilometres, around the Moorabbin control zone. Within this airspace radar advisory service traffic information is only passed to aircraft operating under instrument flight rules, about other aircraft operating under instrument flight rules.

Significant Factors

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

1. The pilot of VH-SKB did not see the other aircraft in time to allow for an increase in separation.

2. The aircraft were operating in an area where the radar advisory service did not give advice to aircraft operating under instrument flight rules, about aircraft operating under visual flight rules.