As the Piper PA-28-161 (Cherokee) tracked from the 2RN inbound
reporting point, which was 5.5 NM southwest of Bankstown Airport,
via crosswind at 1,500 ft to runway 29, the instructor pilot saw a
Beech Aircraft Corporation 76 (Duchess) pass close in front,
tracking from right to left and on climb. The instructor pilot in
the Cherokee turned the aircraft to the right to avoid the Duchess.
Later analysis of the recorded radar information indicated that the
two aircraft had passed about 150 m apart while at the same
altitude.
Pilots of aircraft operating on Bankstown airport or within the
control zone (CTR) were required to operate in accordance with
General Aviation Airport Procedures (GAAP). The Visual Flight Rules
(VFR) Flight Guide stated that GAAP catered for high-density
operations in visual meteorological conditions (VMC). In VMC within
a GAAP CTR, the pilot in command was primarily responsible for
ensuring separation from other aircraft. Air Traffic Control (ATC)
controlled runway operations with landing and take-off clearances
and facilitated a high movement rate by providing traffic
information and/or sequencing instructions.
The GAAP procedures were published in the Bankstown Visual
Pilots Guide and the Aeronautical Information Publication (AIP) En
Route Supplement Australia (ERSA). Bankstown procedures required
pilots of aircraft to enter the CTR via specific reporting points,
including 2RN, at 1,500 ft when runway 29 was the assigned runway
(Figure 1). Pilots of aircraft operating out of the CTR in the
runway 29 direction were required to depart via upwind and to
maintain 1,000 ft until leaving the CTR. That procedure provided
500 ft vertical spacing between arriving and departing aircraft.
Runway 29 Right was the nominated arrivals runway.
The Cherokee was on a VFR training flight with a flying
instructor and student pilot. The student pilot was flying the
aircraft as it tracked inbound to Bankstown Airport while the
instructor briefed the student on geographical points. The
instructor later reported that he did see the Duchess departing but
it became obscured by the engine cowl of the Cherokee.
The Aeronautical Information Publication (AIP), used by pilots
operating flights under the Instrument Flight Rules (IFR), stated
that `arriving IFR aircraft which are visual outside the GAAP CTR,
and can continue visually, must operate VFR within the CTR'. A
pilot operating an IFR aircraft visually would only receive a
traffic information and a sequencing service, and would not be
separated from other traffic. The AIP further stated that
`Departing IFR aircraft must operate VFR within the GAAP CTR until
encountering Instrument Meteorological Conditions (IMC) or leaving
the GAAP CTR, whichever is the sooner'. When aircraft are operating
in conditions less than VMC, ATC will provide separation within the
GAAP CTR. The weather at the time was VMC.
The Duchess was flown by a pilot on an instrument rating flight
test monitored by a flying instructor. The pilot was conducting a
Bankstown One departure on climb to 3,000 ft. The pilot departed
from runway 29 Centre on a heading of 290 degrees M and had been
instructed to report to the aerodrome controller (ADC) when the
Duchess had passed 2,000 ft, the upper limit of the CTR. The
instructor and the pilot in the Duchess did not see the
Cherokee.
The instructor in the Cherokee monitored the ADC frequency as
the aircraft approached 2RN. At 0214:00 the ADC issued departure
and runway entry instructions to the pilot of the Duchess. About 20
seconds later the pilot of the Cherokee reported at 2RN at 1,500 ft
and was subsequently instructed by the ADC to join via crosswind
for runway 29. At 0214:50 the ADC issued a take off clearance to
the pilot of the Duchess. The instructor in the Cherokee recalled
hearing the take off clearance for the Duchess and saw that
aircraft when it was on the runway but lost sight of it behind the
engine cowl of the Cherokee. At 0217:10 the instructor in the
Cherokee reported to the ADC that the aircraft was `joining
downwind and that they had just seen the Duchess'. The ADC
acknowledged that report and at 0217:34 the pilot of the Duchess
reported passing 2,000 ft.
The altitude of the Duchess could not be accurately ascertained,
as the Mode C function of that aircraft's transponder was not
activated. The Mode C function for the Cherokee was activated and
the recorded radar information showed that the aircraft had
maintained 1,500 ft until established on downwind. The instructor
in the Duchess later estimated that the aircraft would have been at
about 1,500 ft at the point where the tracks intersected.
The radar track of the Cherokee showed that the pilot had
tracked directly from 2RN to an early downwind position (Figure 2 -
Track 1). That track was about 0.5 NM west of the recommended
crosswind track (Figure 2 - Track 2). The aircraft tracks recorded
during a 4-hour period on the day of the occurrence showed that
there were a number of other pilots who tracked west of the
recommended crosswind track, depicted in the Bankstown Visual
Pilots Guide, when they entered the circuit area.
The intention of the entry procedure (Figure 1) was to have
pilots enter the circuit, via crosswind, in a position to sight
aircraft on the runway, aircraft departing, and other aircraft in
the circuit. Crossing the extended runway centreline at 90 degrees
also minimised the potential for arrival/departure conflicts as
departing aircraft would generally have been airborne for only a
short period and consequently would not have climbed to the 1,500
ft inbound altitude. Aircraft climb performance is subject to
various factors, including aircraft type and load but generally the
closer an inbound aircraft tracks to the threshold of a departure
runway the more likely that there would be some vertical spacing
between it and departing aircraft.
