On 26 November 2016, a Bombardier DHC-8-402 aircraft, registered VH-QOV (QOV), operating scheduled passenger flight QF2320 from Brisbane, commenced descent to Bundaberg Airport, Queensland (Qld). At about the same time, a Eurocopter MBB-BK 117 helicopter, registered VH-EHQ (EHQ), was being prepared to depart Bundaberg.
The flight crew of QOV made the required broadcasts while on approach to Bundaberg and received no responses from other potentially conflicting aircraft. While QOV was on final approach, EHQ departed on a potentially conflicting flight path to QOV. The flight crew of QOV received a traffic advisory on EHQ and was able to visually sight the helicopter. By this time EHQ had commenced a turn to their destination and the projected flight paths of the aircraft were now clear.
The incident highlights the fundamental importance of effective communication, particularly during operations at a non-controlled aerodrome.
On 26 November 2016, at about 0908 Eastern Standard Time (EST), a Bombardier DHC-8-402 aircraft, registered VH-QOV (QOV), operating scheduled passenger flight QF2320 from Brisbane, commenced descent to Bundaberg Airport, Queensland (Qld). At about the same time, a Eurocopter MBB-BK 117 helicopter, registered VH-EHQ (EHQ) was being prepared to depart Bundaberg. The crew of EHQ had been tasked to conduct a visual flight rules (VFR) flight to search for potential wreckage from a trawler missing off the Qld coast.
Bundaberg is a non-controlled airport with a common traffic advisory frequency (CTAF). A CTAF is a designated frequency on which pilots make positional broadcasts when operating in the vicinity of a non-controlled aerodrome. Bundaberg is also equipped with an aerodrome frequency response unit (AFRU) with a pilot activated light (PAL) option. When a pilot transmits on the correct frequency, the AFRU will provide an automatic response, either ‘Bundaberg CTAF’ (if the frequency has not been used in the previous five minutes) or a beep-back. At night, or at other times of low natural light levels, transmitting three one second pulses, one second apart, on the frequency will activate the runway lighting and the transmission will change to the aerodrome name and CTAF with either ‘runway lights on’ or ‘no runway lights’. At other times, this action will activate the precision approach path indicator (PAPI).
At 0912, three one second pulses were broadcast on the Bundaberg CTAF. This resulted in the AFRU correctly responding automatically, ‘Bundaberg Aerodrome no runway lighting’. Two seconds later a single one second pulse was also broadcast on the CTAF. The next recorded CTAF broadcasts were those made by the flight crew of QOV while on approach to Bundaberg. Broadcasts were made at 27 NM, 10 NM and 5 NM and on each occasion the flight crew received the AFRU beep-back. No responses from other aircraft were heard.
While QOV was on final approach to Bundaberg, EHQ taxied for departure from a position to the east of runway 32. The helicopter taxied a short distance, took off and once airborne commenced a left turn tracking initially towards Hervey Bay.
During EHQ’s departure, the flight crew of QOV received a traffic advisory (TA) from their aircraft’s traffic alert and collision avoidance system (TCAS). On receipt of the TA, the flight crew of QOV attempted to sight the traffic causing the alert. After a few seconds, they identified a helicopter, later determined to be EHQ, in their 2 o’clock position around 1.5 NM, and around 1,000 ft below their aircraft. The helicopter was clear of their projected flight path and accordingly the flight crew continued the approach, landing without further incident.
After landing, the flight crew of QOV made two broadcasts on the CTAF to identify the helicopter. These were unsuccessful and they requested, on area frequency, if air traffic control knew the identity of the helicopter. The pilot of EHQ heard this exchange and subsequently identified themselves also advising they had not heard the earlier broadcasts made by the flight crew of QOV.
Pilot comment VH-EHQ
The pilot of EHQ provided the following comments:
- The flight was routine, preparations for the flight were not rushed with normal pre-departure checks conducted. They recalled completing normal communication checks including ensuring all frequencies were set correctly and at appropriate volumes. They also recalled hearing an aircraft broadcast on the air traffic control area frequency, and a response from the AFRU when the PAPI was activated. They did not hear any other broadcasts made by the flight crew of QOV.
- Normally, when departing from a location similar to the one they did on the day of the incident, the pilot advised they would make a taxi call and a call departing on the CTAF. They recalled making these calls but could not recall if an AFRU response was received.
- During the left turn after departure, the crew of EHQ sighted QOV on final approach, clear of their projected flight path.
- After departure, they heard the flight crew of QOV on area frequency attempting to determine the identity of the helicopter. They identified themselves and subsequently checked their communications set up, with nothing abnormal found.
Captain’s comment VH-QOV
The Captain of QOV provided the following comments:
- They had made all of the necessary CTAF broadcasts, receiving the AFRU response, and did not receive any broadcasts made by EHQ.
- They were surprised upon receipt of the TA, but had quickly visually identified the traffic and confirmed it was not on a conflicting flight path.
The ATSB reviewed all available recordings from air traffic control and the Bundaberg CTAF. All broadcasts made by the flight crew of QOV and the AFRU responses were recorded. There were no identifiable recordings of broadcasts made by the pilot of EHQ. The ATSB was not able to determine why the broadcasts reportedly made by the pilot of EHQ were not transmitted on the CTAF or why the crew were not able to hear the broadcasts made by the flight crew of QOV. It is probable that the pilot did not correctly configure and operate the helicopter’s communications system.
These findings should not be read as apportioning blame or liability to any particular organisation or individual.
- It is probable the pilot of EHQ did not correctly configure and operate the helicopter’s communications system for CTAF operations while departing Bundaberg airport and they did not detect the error.
As a result of this occurrence, the pilot of EHQ has advised they now transmit on the CTAF and activate the lighting to confirm they have the correct radio frequency and volumes selected.
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 such concern is Safety around non-controlled aerodromes, which highlights that it is difficult for pilots to detect another aircraft through visual observation alone. The ATSB has identified that insufficient communication between pilots operating in the same area is the most common cause of safety incidents near non-controlled aerodromes.
This incident highlights the fundamental importance of effective communication, particularly during operations at a non-controlled aerodrome. The Civil Aviation Safety Authority (CASA) has produced several publications and resources that provide important safety advice related to operations in the vicinity of non-controlled aerodromes. Relevant guidance and explanatory material provided by CASA includes the following:
- CASA Civil Aviation Advisory Publication (CAAP) CAAP 166-1(3) Operations in the vicinity of non-controlled aerodromes
- CAAP 166-2(1) Pilots’ responsibility for collision avoidance in the vicinity of non-controlled aerodromes using ‘see-and-avoid’
- Operations at non-controlled aerodromes booklet.
- When a TA is issued, pilots are instructed to initiate a visual search for the traffic causing the TA.
- TCAS is an aircraft collision avoidance system. It monitors the airspace around an aircraft for other aircraft equipped with a corresponding active transponder and gives warning of possible collision risks.
- 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.