Near collision between a Pacific CT4B, VH-YAB and a Beech 1900D, VH-NTL, 4 km NE Armidale, 20 June 2000

The pilot of an Instrument Flight Rules (IFR) CT4 Airtrainer
made an inbound report on the Armidale common traffic advisory
frequency (CTAF) when at 8 NM southwest of the aerodrome. Four
minutes later the pilot broadcast that he was overhead, with the
intention of conducting an NDB/DME approach to runway 05.

Subsequently, an IFR Beech 1900 taxied at Armidale for departure
from runway 05. Both aircraft had been given traffic information on
each other by Brisbane air traffic services. When the Beech 1900
crew broadcast that they were taxiing, the CT4 pilot advised that
he was about to turn inbound on the sector 1 entry for the runway
05 NDB/DME procedure and was maintaining 5,800 ft.

The Beech 1900 crew acknowledged the call. The CT4 pilot then
awaited the lining up or rolling call from the Beech 1900 crew so
that they could arrange mutual separation.

After completing the inbound turn the CT4 had approximately 2 NM
to run on the inbound leg of the sector 1 entry. At that stage the
pilot observed a Traffic Collision Alert Device (TCAD) indication
that an aircraft was 1,100 ft below, climbing directly toward his
aircraft and at a distance of 1.3 NM. The CT4 pilot therefore made
an immediate broadcast on the CTAF, transmitting his position as 2
NM northeast at 5,800 ft. The Beech 1900 crew responded stating
that they were in a right turn passing 5,800 ft. The pilot of the
CT4 then observed, through a break in the cloud, the Beech 1900 in
his 6 o'clock position at the same level and moving away.

The Beech 1900 crew reported that while maintaining runway
heading after takeoff, they levelled at 4,500 ft for a short time
to ensure separation. They later stated that they had interpreted
the CT4's position as being outbound on the Runway 05 NDB approach
and to the south-west of the NDB; therefore, it was not perceived
to be a confliction.

The CT4 pilot reported the conditions as generally IMC with a
few breaks in the cloud at his level but with no significant
vertical visibility. The Beech 1900 continued climbing in a right
turn in accordance with the published company procedures for IMC
departures at Armidale. The CT4 landed from the runway 05 NDB
approach without further incident.

Recorded radio transmissions confirmed that the Beech 1900 crew
gave a taxi broadcast for runway 05 that included the phrase
"shortly entering and backtracking". They did not subsequently
advise that they were about to commence take-off, as directed in
the Aeronautical Information Publication. The crew could not
explain that oversight.