Fairchild Industries Inc 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.