Occurrence Briefs are concise reports that detail the facts surrounding a transport safety occurrence, as received in the initial notification and any follow-up enquiries. They provide an opportunity to share safety messages in the absence of an investigation.
On 23 April 2020, the pilot of a Diamond DA 40 was conducting a solo navigation flight from Gold Coast, Queensland to Brisbane West Wellcamp (Wellcamp), Queensland. On the same day, the pilot of a Cessna 172 was conducting a return solo navigation flight from Gold Coast and had planned to conduct circuit training at Wellcamp on the return leg.
The standard circuit altitude at Wellcamp is 2,500 ft for piston aircraft utilising a non-standard right-hand circuit for runway 12 to avoid high terrain to the north-east of the runway. At about 1430 Eastern Standard Time, the pilot of the DA 40 overflew active runway 12 at Wellcamp at 3,500 ft with the intention of descending on the dead side to join a right circuit. Around this time, the 172 was approaching the aerodrome from the west. Both pilots reported broadcasting on the common traffic advisory frequency (CTAF).
The pilot of the DA 40 conducted two descending orbits to join at the correct circuit height and as the aircraft turned back towards the runway to join midfield, the pilot detected the 172 on a converging track (Figure 1) and manoeuvred the aircraft to increase separation.
The two aircraft passed within close proximity, resulting in a vertical separation of approximately 100 ft and a horizontal separation of 300 m.
Figure 1: Relative flight paths and position of detected conflict (Diamond DA40 represented by green line, Cessna 172 represented by red line)
Source: Google Earth. Annotated by the ATSB
The 172 pilot had made an inbound call at 10 NM stating that they were, ‘on descent to 2,500 for midfield crosswind for left base runway 12.’ The pilot reported being aware of the requirement to conduct right-hand circuits for runway 12 but recalled hearing traffic already in the circuit area conducting left circuits and elected to follow the existing traffic. A descent to circuit height was conducted on the dead side for a left circuit; however, this resulted in the aircraft tracking in the opposite direction to circuit traffic at the same height. After the 172 pilot observed the DA 40 pass in close proximity, a CTAF call was made to query the runway direction, which was relayed as the published right-hand circuit. The 172 pilot elected to discontinue the approach to Wellcamp and climbed away on the dead side of the circuit before continuing on the navigation exercise.
The operator of the 172 has advised the ATSB that during their internal investigation, it was apparent that there was some confusion as to what direction circuits were actually being conducted prior to the arrival at Wellcamp. Although the query regarding circuit direction was made late by the pilot, this action avoided any further conflict.
This incident highlights the need for pilots to consult the En Route Supplement Australia (ERSA) when flying to an unfamiliar aerodrome. As illustrated by this incident, not all non-controlled aerodromes follow the same procedures. Being aware of local traffic procedures helps pilots to anticipate the likely position of other aircraft.
Additionally, this incident reinforces the need for pilots to maintain situational awareness and a vigilant lookout at all times. This is especially important when operating at non-controlled aerodromes where pilots are responsible for monitoring and broadcasting their intentions on the CTAF as effective communication is vital to the prevention of potential conflicts developing. Research conducted by the ATSB has found that insufficient communication between pilots contributes to a breakdown of situational awareness. Further information about operating safely at non-controlled aerodromes can be found on the ATSB website, A pilot's guide to staying safe in the vicinity of non-controlled aerodromes and the CASA website, Radio procedures in non-controlled airspace.
The ATSB SafetyWatch highlights the broad safety concerns that come out of our investigation findings and from the occurrence data reported to us by industry. One of the priorities is Non-controlled airspace.
About this report
Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.