Aviation safety investigations & reports

Near collisions involving Piper PA-28-151, VH-SEW; Cessna 172, VH-JBC; and Cessna 182, VH-BMS overhead Parramatta, New South Wales, on 15 April 2020

Investigation number:
Status: Discontinued
Phase: Final report: Dissemination Read more information on this investigation phase


Download Final Report
[Download  PDF: 632KB]
Section 21 (2) of the Transport Safety Investigation Act 2003 (TSI Act) empowers the ATSB to discontinue an investigation into a transport safety matter at any time. Section 21 (3) of the TSI Act requires the ATSB to publish a statement setting out the reasons for discontinuing an investigation. The statement is published as a report in accordance with section 25 of the TSI Act, capturing information from the investigation up to the time of discontinuance.

Overview of the investigation

The occurrence

On 28 April 2020, the ATSB commenced a transport safety investigation into a near collision involving 3 aircraft near Bankstown Airport, New South Wales on 15 April 2020. At that time, all 3 aircraft were converging on the Paramatta checkpoint within the Bankstown Airport lane of entry (LOE),[1] which was in non-controlled Class G airspace.


At about 1315 Eastern Standard Time,[2] the pilot of a Piper PA-28-151 aircraft, registered VH-SEW (SEW), departed Camden Airport on a private flight under visual flight rules (VFR).[3] The purpose of the flight was to complete the ‘Victor 1 South’[4] VFR coastal route and then return to Camden. After take-off, the pilot tracked to Prospect Reservoir at 2,300 ft. Upon reaching Prospect Reservoir, the pilot changed their radio to the Bankstown Tower frequency to monitor traffic inbound to Bankstown Airport. They then turned towards the Parramatta central business district[5] to join the LOE northbound. The pilot changed their radio to the Sydney Centre frequency after passing Parramatta.


Shortly after SEW took off, the instructor and student pilot of a Cessna 172S aircraft, registered VH-JBC (JBC), also departed Camden on a navigation check flight to Cessnock Airport. JBC was also tracking northbound via Prospect Reservoir to join the LOE at Parramatta. When about 3 NM (6 km) south of Prospect Reservoir, the student pilot turned the aircraft towards Parramatta. The student pilot had set Bankstown Tower on their primary radio and was monitoring Sydney Centre on their secondary radio.


At about 1328, the instructor and student pilot of a Cessna 182 aircraft, registered VH-BMS (BMS), departed Bankstown Airport on a pre-commercial flight test to Remlap Park Airport via the LOE. BMS joined the LOE northbound at the perimeter of the Bankstown control zone and tracked to Parramatta. The crew were monitoring the Sydney Centre frequency.

Figure 1 shows the approximate tracks of the 3 aircraft.

The incident

At about 1330, the instructor in JBC identified traffic (being SEW) in the 9 o’clock[6] position and confirmed this with the student pilot. Shortly after, the instructor observed SEW descend ‘rather sharply’ and they lost sight of the aircraft in the urban background. The student pilot slowed the aircraft before the instructor observed SEW climb from the left and in front of JBC in close proximity. The instructor took control of the aircraft and manoeuvred to avoid SEW. The pilot of SEW reported that they had not seen any other aircraft operating in the area at that time. Air traffic control radar data showed that SEW and JBC were both at 1,900 ft, with a minimum horizontal separation of 0.2 NM (0.4 km).

As BMS approached Parramatta, the student verbally indicated that they had sighted 2 aircraft ahead (SEW and JBC). The student elected to maintain 1,700 ft. They continued up the LOE and commenced overtaking JBC. However, the manoeuvre made by JBC to avoid SEW put JBC in close proximity to BMS. At about 1331, the radar data showed a minimum vertical separation of 200 ft and horizontal separation of 0.2 NM (0.4 km) between JBC and BMS. The instructor of JBC then requested flight following[7] from Sydney Centre to assist with their awareness of other traffic.

No broadcasts were made by either of the pilots when approaching and transiting the LOE.

Figure 1: Approximate aircraft flight paths

Source: Airservices Australia, annotated by the ATSB

Investigation activities

During the investigation, the ATSB:

  • interviewed the pilot in command of each aircraft
  • reviewed air traffic control recordings
  • reviewed ATSB occurrence data of similar events
  • consulted several flying schools and aero clubs
  • reviewed the guidance available to pilots operating within the vicinity of Bankstown Airport and the LOE.

ATSB observation

The ATSB found that the pilots were relying on unalerted see-and-avoid principles for identifying other aircraft. This limited their situational awareness when converging on the Paramatta checkpoint in the Bankstown Airport lane of entry and resulted in the aircraft coming into close proximity.

Safety message

The practice of see-and-avoid has long been recognised as the primary method for minimising the risk of collision when flying in visual meteorological conditions;[8] it is considered a crucial element of a pilot’s situation awareness. The effective use of such is particularly crucial in Class G airspace, where aircraft separation is the pilot’s responsibility.

An ATSB research report titled Limitations of the See-and-Avoid Principle, showed that, when searching for traffic, alerted see-and-avoid (when a radio is used in combination with a visual lookout) is 8 times more effective than unalerted see-and-avoid (when no radio is used). However, pilots should be mindful that the absence of a traffic broadcast does not necessarily mean the absence of traffic. Pilots should remain vigilant and employ both unalerted and alerted see‑and‑avoid principles to ensure the greatest level of traffic awareness is achieved.

Reasons for the discontinuation

Based on a review of the available evidence, the ATSB considered it was unlikely that further investigation would identify any systemic safety issues or important safety lessons. Consequently, the ATSB has discontinued this investigation.

The evidence collected during this investigation remains available to be used in future investigations or safety studies. The ATSB will also monitor for any similar occurrences that may indicate a need to undertake a further safety investigation.

The ATSB has briefed the Civil Aviation Safety Authority about some of its observations and potential learnings. However, it considered that broader communication of this information would not be of significant benefit to other parties.


  1. Lane/s of entry (LOE): a lane or lanes established to permit passage to and from specified Class D control zones (CTR) such as Bankstown Airport, without entering an adjacent Class C or military CTR. The vertical limits provide separation from overlying control or restricted areas. The Bankstown Airport LOE was a fairly narrow corridor between Sydney CTR to the east and the Richmond CTR to the west.
  2. Eastern Standard Time (EST): Coordinated Universal Time (UTC) + 10 hours.
  3. Visual flight rules (VFR): a set of regulations that permit a pilot to operate an aircraft only in weather conditions generally clear enough to allow the pilot to see where the aircraft is going.
  4. Victor One is a VFR coastal route east of the Sydney control zone between Long Reef and Jibbon Point. The Sydney CTR and the Victor 1 route are depicted on the Sydney visual terminal chart.
  5. Parramatta was a check point within the LOE northbound.
  6. O’clock: the clock code is used to denote the direction of an aircraft or surface feature relative to the current heading of the observer’s aircraft, expressed in terms of position on an analogue clock face. Twelve o’clock is ahead while an aircraft observed abeam to the left would be said to be at 9 o’clock.
  7. Flight following: the provision of an ongoing surveillance information service.
  8. Visual meteorological conditions (VMC): an aviation flight category in which VFR flight is permitted – that is, conditions in which pilots have sufficient visibility to fly the aircraft while maintaining visual separation from terrain and other aircraft.
Download Final Report
[Download  PDF: 632KB]


The ATSB is investigating a reported near collision involving a Cessna 172, VH-JBC, a Piper PA-28s, VH-FZW, and a Cessna 182 VH-BMS near Bankstown Airport, New South Wales (NSW), on 15 April 2020.

At about 1300 hrs while tracking from Camden to Cessnock Airport in NSW, at an altitude of 1,900 ft above mean sea level, the pilots of VH-JBC were overhead Parramatta, where they observed a PA-28 aircraft in close proximity on a converging track. The pilots of VH-JBC conducted evasive action in order to increase the distance between the two aircraft. Soon afterwards, the pilots of VH-JBC sighted a Cessna 182 in close proximity, and again conducted evasive actions to increase the distance between the two aircraft.

The evidence collection phase of the investigation will include interviewing pilots and reviewing air traffic radar and audio data.

A final report will be released at the conclusion of the investigation. Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify relevant parties so appropriate safety action can be taken.

General details
Date: 15 April 2020   Investigation status: Discontinued  
Time: 13:33 AEST   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): overhead Parramatta   Investigation phase: Final report: Dissemination  
State: New South Wales   Occurrence type: Near collision  
Release date: 17 June 2022   Occurrence category: Serious Incident  
Report status: Discontinued   Highest injury level: None  

Aircraft 1 details

Aircraft 1 details
Aircraft manufacturer Cessna Aircraft Company  
Aircraft model 172S  
Serial number 172S8377  
Operator The Scout Association of Australia  
Type of operation Flying Training  
Sector Piston  
Damage to aircraft Nil  
Departure point Camden, New South Wales  
Destination Cessnock, New South Wales  

Aircraft 2 details

Aircraft 2 details
Aircraft manufacturer Cessna Aircraft Company  
Aircraft model 182  
Aircraft registration VH-BMS  
Serial number 18262414  
Type of operation Flying Training  
Sector Piston  
Damage to aircraft Nil  
Departure point Bankstown, New South Wales  
Destination Bankstown, New South Wales  

Aircraft 3 details

Aircraft 3 details
Aircraft manufacturer Piper Aircraft Corp  
Aircraft model PA-28-151  
Aircraft registration VH-SEW  
Serial number 28-7415541  
Type of operation Private  
Sector Piston  
Damage to aircraft Nil  
Departure point Camden, New South Wales  
Destination Camden, New South Wales  
Last update 17 June 2022