On 15 August 2015, the student pilot of a Cessna 172 aircraft, registered VH-MJK (MJK) conducted a solo flight from Emkaytee aeroplane landing area (ALA) to Bathurst Island Airport, Northern Territory. There the student pilot completed touch-and-go circuits for about 30 minutes on runway 15.

At about 1210 Central Standard Time (CST), a Cessna 404 aircraft, registered VH-ANM (ANM) and operated by Hardy Aviation, departed from Darwin Airport, Northern Territory, on a scheduled flight to Bathurst Island, with a pilot and five passengers on board. The pilot broadcast when inbound and about 15 NM from Bathurst Island Airport on the common traffic advisory frequency (CTAF) of 126.5 MHz, and did not receive any response. At about 1220, the aircraft joined on the downwind leg of the circuit for runway 15, at 1,000 ft above ground level. As the aircraft turned onto base, the pilot sighted MJK also on base, at the same height, closer to the runway and estimated it was about 150 m away.

The pilot of ANM immediately manoeuvred the aircraft to the west to increase separation between the two aircraft. The pilot was unable to contact the pilot of MJK, and observed MJK conduct a touch-and-go.  After the touch-and-go, when upwind of the runway at about 500 ft above ground level, the pilot of MJK sighted ANM to the left, about 500 ft above MJK, and turning onto the downwind leg. The pilot of MJK realised that the radio was selected to an incorrect frequency, and then broadcast a departure call on the CTAF. The pilot of ANM then contacted the pilot of MJK, who advised that the radio had been on the wrong frequency.

The pilot of ANM continued the approach, and landed at Bathurst Island, and MJK returned to Emkaytee without further incident.

The radar data indicated the aircraft came within about 100 ft vertically and 0.6NM at the closest proximity.

The pilot of MJK commented that there were three important learnings from this incident:

  • crosscheck the selected frequency against the flight planning notes
  • ensure the selector reaches the detent when selecting a radio frequency
  • listen for the ‘beep-back’ response from the CTAF to verify the correct frequency has been selected.


Aviation Short Investigations Bulletin Issue 44

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