Separation issue

On 25 November 2010, a De Havilland Canada DHC-8-202 aircraft, registered VH-SDA (SDA), was taxied to runway 03 at Port Macquarie, New South Wales for a scheduled passenger service to Sydney.

After lining up on runway 03, the pilot in command (PIC) of SDA observed a traffic return on the aircraft's traffic alert and collision avoidance system (TCAS) indicating that an aircraft was behind them, about 400 ft above and descending. As a precaution, the take-off was expedited.

At the same time, a Beech Aircraft Corporation 58 aircraft, registered VH-VFG (VFG), was on final approach to runway 03. After observing SDA commence the take-off, the crew initiated a go-around and positioned the aircraft to the right of the runway centre line to maintain separation with SDA.

At about 600 ft, the crew of SDA noted that the TCAS was indicating that VFG was about 100 ft above and climbing. The PIC of SDA discontinued the aircraft's climb and turned left onto a westerly heading.

Both crews attempted to contact each other on the Port Macquarie common traffic advisory frequency (CTAF) but received no response. The crews eventually established communications on the Brisbane Centre frequency.

Following the incident, the copilot of SDA reported that he may have mistuned the CTAF prior to taxiing. A subsequent engineering inspection by the operator determined that the aircraft's radio transceiver was faulty.

The operator of SDA has advised the ATSB, that as a result of this incident, a safety alert was issued to pilots emphasising the radio requirements for when operating on the CTAF. In addition, the operator also intends to conduct a review of their CTAF operating procedures.

On 3 March 2011, a Tiger Airways operated Airbus Industrie A320-232, registered VH-VNG (VNG) and a Pilatus Aircraft Ltd PC-12/45, registered VH-FMP (FMP), were on approach to Alice Springs Airport, Northern Territory. Both aircraft were operating under instrument flight rules (IFR).

The Alice Springs tower was closed, giving the pilots responsibility for organising their own separation. Both flight crews provided a number of updated estimates for their arrival into Alice Springs during the approach. The pilots of VNG estimated their position to be established on finals at time 11 (1941 CST) and FMP estimated their position established on the Instrument Landing System (ILS) at the same time. The conflict between the estimates was not initially recognised by either crew.

As both aircraft approached the initial approach fix, the potential conflict was realised, and separation was organised. During the separation manoeuvring, the pilot of FMP turned towards VNG, and a Traffic Collision Avoidance System Resolution Advisory warning was activated. The pilots of VNG conducted a missed approach and FMP continued the turn behind VNG.

Tiger Airways have conducted a risk assessment on operating into non-towered aerodromes. As a result of that assessment, they have rescheduled all Alice Springs flights so that they operate within active tower hours. They have also made a policy decision that flights will not be scheduled into CTAF aerodromes outside of tower hours for all future schedule developments.

On 12 October 2010, a Piper Aircraft Corporation PA-31-350 aircraft, registered VH-TAS (TAS), departed Griffith, New South Wales on scheduled freight service to Narrandera.

When about 37 km from Narrandera, the pilot broadcast an inbound call on the common traffic advisory frequency (CTAF). Shortly after, the pilot heard a broadcast from the pilot of a Cessna Aircraft Company 441 aircraft, registered VH-XBC (XBC), advising that he was taxiing for runway 32. The pilot of TAS attempted to contact the pilot of XBC a number of times, but received no reply.

When established on final for runway 14, the pilot observed the landing lights of XBC taking off on the reciprocal runway, runway 32.  The pilot of TAS initiated a right turn. The pilot of XBC observed TAS turning and elected to continue straight ahead. The aircraft passed at about 500 ft above ground level (AGL), with an estimated horizontal distance between 1-2 km.

Subsequent communications between the two pilots identified that the pilot of XBC did not hear any broadcasts made by the pilot of TAS until after the incident occurred.

A recent research report published by the ATSB identified that the most prevalent type of accident or incident occurring at non-towered aerodromes involved conflicts between aircraft, or between aircraft and ground vehicles. Despite this, operations at these aerodromes are generally safe. However, pilots should ensure that they maintain awareness of their surroundings and of other aircraft, fly in compliance with procedures, and be observant, courteous and cooperative at all times.

On 17 March 2010, a Cessna Aircraft Company 152 (C152), registered VH-PVV, and a Robinson Helicopter Co. R44 (R44), registered VH-HUL, were operating from the Cessnock Common Traffic Advisory Frequency (CTAF) aerodrome, New South Wales (NSW). A flight instructor and student pilot were on board the C152 and were preparing to take off from runway 35 to commence a session of dual circuit training. At about the same time, the R44 was taxied for a departure from runway 17 grass-left on a private flight with only the pilot on board the helicopter. Both aircraft were operating under the Visual Flight Rules (VFR) in Visual Meteorological Conditions (VMC). Both aircraft's radio communication systems were serviceable and used by the pilots during the occurrence sequence.

The pilot in command (PIC) of the C152 reported taking evasive action, shortly after becoming airborne on runway 35, to avoid the R44 allegedly taking off in the opposite direction. The PIC of the R44 reported that he had positioned the helicopter outside of the runway 17 flight strip and had sighted the C152 taking off. The R44 pilot also reported that he had just transitioned into forward flight from the hover when the C152 was abeam his position and that at no time did a collision risk exist. However, the C152 pilot was adamant that the R44 commenced the take-off along runway 17 and presented an imminent collision risk.

The differing accounts from both pilots could not be reconciled. No additional reports from potential eyewitnesses were received by the ATSB. The incident serves as a useful reminder for both fixed-wing and rotary-wing pilots to review the various requirements governing their respective operations at CTAF aerodromes and, in particular, to be mindful that helicopters may not be operating to the same pattern as fixed-wing aircraft. Pilots are advised to consult relevant Civil Aviation Advisory Publications (CAAPs), effective 3 June 2010, regarding changes to operations at non-towered (non-controlled) aerodromes.

On 14 February 2007 at about 1127 Eastern Daylight-saving Time, the pilot of a Cessna Aircraft Company 182T (182) was positioning to conduct a sector entry for an area navigation (RNAV) global navigation satellite system (GNSS) arrival procedure to runway 06 at Camden Aerodrome, NSW. The aircraft was approaching the aerodrome from the east. At the same time, the pilot of a Cessna Aircraft Company 210L (210) was approaching Camden from the south-west with the intention of conducting a Camden runway 06 straight-in RNAV (GNSS) approach. The two aircraft had similar estimated times of arrival at the approach commencement waypoint. They were both being operated under the instrument flight rules (IFR), in Class G airspace.

The air traffic controller provided the pilots with mutual radar based traffic information. The pilot of the 210 contacted the controller and was provided with traffic information about the 182. The pilot of the 182 climbed the aircraft to minimise the risk of a collision as he was unsure of the intentions of the pilot of the 210. Recorded radar data showed that, when the aircraft passed, there was 500 ft vertically and 2.1 NM laterally between them.

On 5 January 2007, a Piper PA-28R-201 Arrow, registered VH-TBB, was approaching Port Macquarie Airport, NSW, in class G airspace under the visual flight rules from the south. The aircraft had descended from 2,500 ft above mean sea level and was approaching to join the circuit on left crosswind for runway 03. At about the same time, a de Havilland Dash 8 aircraft, registered VH-TQZ, and a Piper PA-31 Mojave, registered VH-PGW, both operating under the instrument flight rules, were preparing to depart from the airport. The airspace surrounding Port Macquarie Airport was designated as a common traffic advisory frequency (CTAF) (R), where the carriage and use of very high frequency radio was required.

On short final for runway 03, the pilot of the Arrow reported seeing the Dash 8 enter the runway. He immediately broadcast his position and prepared to initiate a missed approach. The crew of the Dash 8 saw the approaching Arrow at the same time as the Arrow pilot's broadcast. They advised that they would vacate the runway without delay, vacating via taxiway B1 as the Mojave pilot manoeuvred his aircraft to assist the Dash 8's runway departure. The pilot of the Arrow continued his approach and landed.

On 16 October 2008, at about 0615 Eastern Standard Time, the pilot of a Fairchild Industries SA227, registered VH-UZA, took off from runway 32 at Mackay Airport, Qld. At the same time, the flight crew of another Fairchild Industries SA227, registered VH-EEO, was conducting a backtrack on the active runway 32.

The crews of both aircraft took avoiding action.

There were a number of opportunities for the departing pilot to have confirmed that his aircraft radio was operating correctly, and to have verified the actual position of the backtracking aircraft. Had the departing pilot availed himself of those opportunities, he would have been afforded an increased level of assurance that the runway was clear.

Confirmation that runway 32 was clear prior to commencing the departure was attempted, but not obtained, by the departing pilot.

On 1 May 2008 at about 2216 Eastern Standard Time, an Airbus Industrie A320 aircraft, registered VH-VQS, was conducting the runway 32L (left) instrument landing system missed approach procedure at Launceston Aerodrome, Tasmania. During the climb, the A320 came into close proximity with a Boeing Company 737 that was manoeuvring at 3,100 ft above mean sea level about 5 NM (9 km) to the north-west of the aerodrome. The lateral separation between the aircraft reduced to within 3 NM (5 km) and zero vertical separation as the A320 climbed through 3,100 ft. No Traffic Alert and Collision Avoidance System alerts were generated during the occurrence.

Both aircraft were operating scheduled passenger services from Melbourne, Victoria and had arrived at Launceston outside the normal operating hours of the Launceston air traffic control tower. Separation between the aircraft was therefore the responsibility of the respective flight crews. In this instance, a breakdown in the communication and interpretation of the respective flight crews' separation planning contributed to the proximity event.

On 23 June 2006 at about 1730 Eastern Standard Time, a Beech Aircraft Corp 58 (Baron) was conducting a global positioning system (GPS) arrival procedure for arrival at Orange Aerodrome, NSW. The aircraft was approaching the aerodrome from the west. At the same time, a SAAB Aircraft AB SF-340B (SAAB) was conducting an Orange runway 29 straight-in area navigation global navigation satellite system (RNAV GNSS) approach. The two aircraft had the same estimated time of arrival at Orange Aerodrome. They were both being operated under the instrument flight rules and were in instrument meteorological conditions.

At the missed approach point of the GPS arrival procedure, and at an altitude of 4,220 ft, the pilot of the Baron had not become visual with the aerodrome. He commenced the published missed approach procedure and made a transmission on the Orange common traffic advisory frequency (CTAF) to advise local traffic that he was conducting that procedure. That required the pilot to track a bearing of 098 degrees magnetic from the Orange non-directional beacon and to climb the Baron to the minimum sector altitude of 5,200 ft above mean sea level.

The captain of the SAAB advised the pilot of the Baron that, in order to maintain separation, the pilot of the Baron would have to manoeuvre his aircraft. The pilot of the Baron manoeuvred his aircraft accordingly.

A preliminary investigation into a category 4 occurrence that occurred at Sydney Aerodrome on 29 June 2006, which involved a reduction in the required visual separation standard between a departing Boeing Aircraft Company 737 (B737) aircraft and an arriving Robinson Helicopter Company R44 (R44) helicopter, determined that the pilot of the R44 had sight of the B737 at all times, and that there was no risk of a collision between the B737 and the R44.

The inadvertent reduction in the required visual separation standard was as a result of the pilot in command of the R44 misjudging the acceleration of the B737 during its take-off roll. The likely safety outcomes of continued investigation did not warrant further allocation of resources.

Status: Downgraded the occurrence to category 5 and investigation discontinued.