Loss of separation involving a Fairchild SA227-DC, VH-KDO and Piper PA-44-180, VH-JQF, 9 km south-east of Melbourne, Victoria, on 6 December 1995

The crew of VH-KDO were given a runway 16 Strathbogie standard instrument departure (SID) and were told to maintain 3000 feet. After take-off they were cleared to climb to 4000 feet.

Shortly afterwards, the air traffic controller noticed the transponder mode C altitude readout increase to above 4000 feet. When the crew were queried on the altitude deviation they promptly descended back to 4000 feet. However, a loss of separation occurred with VH-JQF, an Airwork aircraft, tracking in an easterly direction to the south of Melbourne and maintaining 5000 feet.

Significant Factors

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

1 The crew of VH-KDO did not maintain the assigned altitude of 4000 feet.