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.
In VMC within a GAAP CTR, the pilot in command was primarily responsible for ensuring separation from other aircraft. Consequently, despite the IFR category of the Duchess, the instructor and the pilot in that aircraft were required to maintain a lookout for other aircraft until leaving the CTR. The instructor in the Duchess was probably distracted by the coaching and assessing role such that he did not appreciate the potential for conflict and therefore did not look out, in the required direction, for the other aircraft.
The instructor in the Cherokee saw the Duchess on the runway but did not take action to maintain sight of that aircraft after it was obscured by the Cherokee's engine cowl. Had the instructor kept sight of the Duchess the occurrence was unlikely to have happened.
The inbound track adopted by the pilot of the Cherokee made it more likely that it would conflict with IFR aircraft departing the CTR on climb to an altitude above 2,000 ft. The radar information indicated that some pilots of inbound aircraft enter the circuit via early downwind instead of crosswind.
Pilots operating in GAAP CTRs need to understand that the practice of entering the CTR via wide or oblique crosswind reduces the safety benefit of GAAP entry procedures. Also, that maintenance of situational awareness is a precursor to being able to attend to areas of potential conflict adequately, when operating at GAAP aerodromes.
The Duchess pilot was cleared to operate in the CTR such that the procedural defences used to minimise the likelihood of conflict between arriving and departing aircraft were negated. The situation could have been assisted by the provision of traffic information by ATC to the pilot of the Duchess and/or the Cherokee pilot.
|Date:||17 July 2002||Investigation status:||Completed|
|Time:||1225 hours EST|
|Location:||2 km NW Bankstown, Aero.|
|State:||New South Wales||Occurrence type:||Near collision|
|Release date:||20 March 2003||Occurrence category:||Incident|
|Report status:||Final||Highest injury level:||None|
Aircraft 1 details
|Aircraft manufacturer||Piper Aircraft Corp|
|Type of operation||Flying Training|
|Damage to aircraft||Nil|
|Departure point||Bankstown, NSW|
|Departure time||1130 hours EST|
Aircraft 2 details
|Aircraft manufacturer||Beech Aircraft Corp|
|Type of operation||Unknown|
|Damage to aircraft||Nil|
|Departure point||Bankstown, NSW|
|Departure time||1223 hours EST|