Fairchild SA227-DC, VH-KEU

A Metro 23 aircraft was conducting Global Positioning System (GPS) approaches to runway 18 at Avalon. Whilst in the holding pattern north of the aerodrome the crew heard a radio broadcast from a Cessna 150 taxiing at Avalon. On leaving the holding pattern, the crew made a broadcast on the Avalon mandatory broadcast zone (MBZ) frequency advising their intentions. There was no response from any other traffic. At 5 NM on final approach to runway 18, the crew made a broadcast advising their intention to conduct a missed approach over the runway 18 threshold. Again, there was no response from any other traffic.

Overhead the threshold, at a height of about 500 ft, the crew heard a broadcast from Avalon Flying Operations (UNICOM) to the pilot of a Cessna, advising that there was a Metro inbound to his right. The Cessna had just become airborne from a grass strip, tracking to the west. The Metro crew sighted the Cessna and had to make a hard right turn and climb to avoid the aircraft.

The Cessna was being operated by a flying training organisation based at Avalon and had departed from an east-west grass strip located to the east of the runway 18 threshold. The grass strip is one of series of strips that were prepared and used by a previous manufacturer based at Avalon; however, none of the strips were depicted on any of the relevant aerodrome charts.

The Metro crew advised that they were not aware of any grass strips at Avalon. Accordingly, the Metro crew may not have associated any broadcasts that included reference to runway 27 as being applicable to Avalon.

The pilot of the Cessna advised that he made taxiing, entering and backtracking, and departure reports but did not get a response, nor did he hear any broadcasts from the Metro. He did, however, receive and respond to a broadcast from the Metro crew while in flight after the incident. Although the Metro crew heard the taxiing call, a number of hangars in the area may have masked radio reception by both aircraft when the Cessna was operating in the area of the grass strips.