Airprox - Cessna Aircraft 182R, and Piper Aircraft PA-28 Jandakot, WA, 13 October 2004

The radar data indicated that the Warrior departed Jandakot via
'Yangebup Lake' and 'Lake Thomson', which were tracking points
published for VFR aircraft departing to the south. After passing
overhead Lake Thompson, the pilot of the Warrior turned onto a
westerly heading, tracking towards the coast at an altitude of
1,500 ft. The aircraft turned onto a southerly heading approaching
the coast and passed about 0.5 NM to the southwest of Shipyard (see
Figure 1).

General Aviation Aerodrome Procedures (GAAP) were in use at
Jandakot. Procedures published in the Airservices Australia
Aeronautical Information Publication (AIP), ENR 1.1, 30.3(d)
stipulated that when departing, the pilot must:

track via departure procedures (if any) for the particular GAAP
aerodrome as specified in ERSA [En route Supplement Australia], or
track well clear of GAAP approach points and associated VFR routes,
to reduce possible conflict with inbound aircraft.

The ERSA entry for Jandakot stated that aircraft departing via
Yangebup Lake should climb to an altitude above 1,500 ft as soon as
practical upon leaving the control zone.

The AIP ENR 1.1, 31.5 stipulated that whenever possible, pilots
of aircraft arriving from outside controlled airspace:

must track visually via a GAAP aerodrome approach point as
specified in ERSA.

The ERSA nominated 1,500 ft as the inbound altitude for arriving
aircraft and Shipyard as one of the aerodrome approach points.

The pilot of the Warrior held an overseas flight crew licence
and was operating in accordance with a CASA-issued Certificate of
Validation. That validation had been recently issued and recognised
the pilot's overseas qualifications and permitted the pilot to
operate Australian-registered aircraft, while engaged in private
day VFR operations. As part of the process of validation, the pilot
had undertaken training on local procedures for operating at
Jandakot.

The pilot of the Warrior reported that he did not see the
opposite direction aircraft.

Radar data confirmed that the pilot of the Warrior departed
Jandakot via the relevant tracking points, but remained at 1,500 ft
and tracked towards the coast. That tracked the aircraft towards an
aerodrome approach point, at the same altitude as used by inbound
aircraft.

The investigation concluded that if the Warrior pilot had, as
recommended in the En Route Supplement Australia, climbed above
1,500 ft when clear of the Jandakot control zone, a conflict with
inbound aircraft would have been less likely to occur.

At about 1125 Western Standard Time on 13 October 2004, a Cessna
Aircraft Company 182R (C182), registered VH-WPF, was inbound to
Jandakot at 1,500 ft. It was approximately 1 NM south of the
aerodrome approach point 'Shipyard' when it conflicted with an
aircraft travelling in the opposite direction. The pilot reported
sighting the aircraft at close range and initiated a steep right
turn to avoid a possible collision. The aircraft were outside
controlled airspace and operating under the Visual Flight Rules
(VFR). The Australian Transport Safety Bureau classified the
occurrence as both an Airprox¹ and a
serious incident². Recorded radar
data and a subsequent radio transmission, positively identified the
other aircraft as a Piper Aircraft Corporation PA28-151 (Warrior),
registered VH-PMW.

An occurrence in which two or more aircraft
come into such close proximity that a threat to the safety of the
aircraft exists or may exist, in airspace where the aircraft are
not subject to an air traffic separation standard or where
separation is a pilot responsibility.
Annex 13 to the Convention on International
Civil Aviation defines a serious incident as:

An incident involving circumstances indicating that an accident
nearly occurred.

Note 1.- The difference between an accident and a serious
incident lies only in the result.

Note 2.- Examples of serious incidents can be found in Attachment C
of Annex 13 and in the International Civil Aviation Organization's
Accident/Incident Reporting Manual (Doc 9156).