On 21 March 2010, a Gippsland Aeronautics GA8 Airvan aircraft, registered VH-AJZ, departed East Wallabi Island, in the Abrolhos Islands group, for a return flight to Geraldton, Western Australia (WA), under visual flight rules. On departure, the pilot reported observing a line of thunderstorms with frequent lightning, oriented in about a north-south direction, and approaching Geraldton from the west.

At about 27 km from Geraldton, flying through moderate rain, the pilot noted a vacuum pump failure. At about 11 km, the pilot encountered hail, and at 6 km a '...blanket of rain...' which had obscured the aerodrome, and turbulence which had increased '...quite dramatically...'.

The pilot turned the aircraft away from the line of storms to the south of Geraldton, and at 24 km and at about 1500, elected to conduct a precautionary landing. The pilot selected a suitable landing area in a paddock and landed the aircraft. The aircraft was undamaged and there were no injuries to the pilot or passengers.

Subsequent to this occurrence, the operator provided its pilots with a means for more reliable access to up-to-date weather information when on the ground at the Abrolhos Islands group.

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 26 February 2010, a Cessna Aircraft Company U206G aircraft, registered VH-WYN, departed Forest River, Western Australia (WA) on a charter passenger flight to Kununurra, WA under visual flight rules (VFR) conditions.

Shortly after departing Forest River, the pilot observed dark clouds in the direction of Kununurra. The pilot listened to the aerodrome weather information service (AWIS) at Kununurra and determined that the conditions were appropriate to continue the flight. While en route, the weather conditions deteriorated further. The pilot diverted to the east in an attempt to avoid the weather, however, a rain band was also moving in a north-easterly direction.

The pilot reported that the weather conditions deteriorated around the aircraft and after considering the available options, the instrument flight rated pilot elected to enter instrument meteorological conditions (IMC). The aircraft was flown through moderate to heavy rainfall and light turbulence for a period of between 1 and 2 minutes, but remained clear of cloud. The remainder of the flight was conducted in visual meteorological conditions (VMC) and the aircraft landed at Kununurra without further incident.

Weather-related general aviation accidents remain one of the most significant causes for concern in aviation safety; the often fatal outcomes of which are usually all the more tragic because they were avoidable.

The ATSB has published several weather-related research reports. The Civil Aviation Safety Authority (CASA) also provides pilots with weather-related educational resources.

On 4 March 2010, a Boeing 717-200 aircraft, registered VH-NXM, was being prepared to depart Ayers Rock, Northern Territory (NT) on a scheduled passenger flight to Cairns, Queensland (Qld).

At about 1500 Central Standard Time, the passengers had boarded the aircraft and the pilot in command instructed the cabin crew to close the aircraft doors. The cabin crew member allocated to the forward left door had difficulty unlatching the door, so the cabin crew member allocated to the forward right door came to assist. The assisting cabin crew member placed one foot outside the aircraft onto the portable stairs to assist with closing the door. At this point, ground personnel commenced moving the portable stairs and the assisting cabin crew member fell through the open door onto the apron. The cabin crew member sustained a fractured left arm, a sprained right wrist and some other minor injuries.

The aircraft operator and ground handling agent advised the ATSB that as a result of this occurrence, the ground handling agent has issued an interim procedure, which includes increased safety checks to ensure that the aircraft's doors are closed prior to the removal of the portable stairs.

On 15 March 2010, an Airbus A320-232, registered VH-VQO, departed Adelaide, South Australia on a scheduled passenger flight to Darwin, Northern Territory. On board were six crew and 175 passengers. When climbing through 12,000 ft, the flight crew observed a loss of thrust from the number 2 (right) engine, accompanied by a loud bang and several warning indications. Passengers also reported seeing flames and smoke emanating from the right engine tailpipe.

The crew shut down and discharged both fire bottles into the right engine. They then returned and landed at Adelaide.

A post-landing inspection by maintenance personnel found metal debris and evidence of a fire in the tailpipe of the right engine. Removal and examination of the engine revealed evidence of a titanium fire that originated in the vicinity of the 6th stage high pressure compressor.

The engine was identified in an engine manufacturer service bulletin. This included new production engines that received a limited number of High Pressure Compressor Stage 6 Stator Vanes from the suspect batch. The engine manufacturer recommended certain serial number engines (which included the incident engine) in this category remain in service until the next scheduled overhaul shop visit. It was considered likely that the partial power loss was initiated by a failure of one or more of these vanes.

The operator advised the Australian Transport Safety Bureau (ATSB) that it had been operating four engines (one on each of four aircraft) that were identified within the service bulletin.

At the time of writing this report, the operator was working with the engine manufacturer to remove all four engines from service by September 2010.

The plan for the flight was for the tug aircraft to air-launch the glider and then to fly to Tipton to retrieve another glider. The glider pilot indicated to the tug pilot that he wanted to be towed to a thermal to the north west of the strip. Flying conditions in the area were reported to have been moderately turbulent.

Radio communications for the initial tow-rope hook-up were normal, with the tug pilot responding normally to the glider pilot's instructions. After becoming airborne, the tug pilot made a right turn through about 40°, onto a heading of 340°, and continued the climb. When the aircraft were about 1,200 ft AGL they encountered a strong thermal. After both aircraft had stabilised in the thermal, the glider pilot noted that the variometer was indicating lift in excess of 10 kt. He then disconnected the tow and transmitted 'rope gone' over the radio while commencing a right turn. He observed the tug aircraft begin a gentle turn to the left.

The glider pilot completed a turn through 360° and decided to fly another orbit, but at a greater angle of bank to better utilise the thermal. When heading approximately south-west at about 1600 ft, the glider suddenly yawed violently to the right and the control column was torn from the pilot's hand. At the same time, the glider adopted a steep nose down altitude. The pilot was able to regain control of the glider at a height of about 11 00 ft above ground level and saw the tug aircraft below spiralling anticlockwise towards the ground.

The pilot was able to control the glider by the use of left rudder and almost full right aileron. A right circuit was flown and the glider landed on the departure strip.

A ground witness observed the release of the tow but did not observe the mid-air collision. He and another ground witness observed the tug aircraft spiral and dive vertically into the ground. The tug aircraft impacted the ground at an indicated airspeed of 116 kts and was destroyed.

Damage to the glider was restricted to its left wing. The inboard half of the left aileron had been broken off in a downward motion. The trailing edge of the left wing was split for most of its length, and a small dent was present on the trailing edge about 500 mm from the wing root.

Examination of the impact marks on both aircraft indicated that the left wing of the tug had collided with the trailing edge of the left wing of the glider when it was banked right at about 40°. The strut attachment area on the front spar of the tug's wing had impacted the glider about 300 mm inboard of the aileron while the tug was moving outboard relative to the glider. The leading edge of the tug wing had then broken off part of the glider aileron and become snagged on the wing at the aileron cutout. This tore the wing fabric, destroying the aerofoil shape of the outboard section of the left wing. The top of the tug's left wing was then dragged inboard and rearwards across the lower surface of the glider's left wing. The top left corner of the cockpit roof of the tug probably made light contact with the trailing edge of the left wing of the glider at a point about 500 mm from the wing root. This indicated that the angle of bank of the tug was about 23° greater than that of the glider at the time of collision.

Analysis of the possible flight paths from glider release to the impact point indicated that the tug pilot might not have heard the glider pilot call 'rope gone' and could have been still trying to maintain the glider in the thermal, pending tow release by the glider pilot. It could not be determined why the tug remained in the thermal. It is possible that the tug pilot was aware that the glider pilot had released and was using the strong thermal updrafts in the manner of a glider. Other tug pilots report that it is difficult to determine if the glider is still under tow in turbulent conditions. Thus, it is possible that the tug pilot was unaware that the glider pilot had released.

The glider pilot reported that there was a significant amount of radio traffic on the local airstrip frequency at the time he released the tow. This was caused by the number of gliders in the air in both the local and Kingaroy areas. Gliding organisations use one radio frequency for operations at the airstrip and another for area operations. However, it was reported that the airstrip frequency was used almost exclusively while the area frequency received little use. In this instance, the frequency for airstrip operations was also the Kingaroy common traffic advisory frequency (CTAF).

Significant factors

The following factors were considered relevant to the development of the accident:

 The tug remained in the thermal for reasons that could not be determined.

1. The tug pilot did not see the glider in time to avoid a collision.
2. The tug pilot was unable to regain control of his aircraft due to the damaged wing.

Safety Action

Recommendation

The use of radios and control of glider operations have been the subject of investigation in three recent, fatal, mid-air collisions between gliders and fixed wing aircraft:

• Tocumwal NSW 2 November 1990 VH-CAG/GXO
• Tocumwal NSW 8 February 1992 VH-UTKlGOR, and
• This accident, Jondaryan Old 1 November 1992 VH-SCT/WGR.

The Bureau of Air Safety Investigation therefore recommends that:

1. The Civil Aviation Authority, in conjunction with the Gliding Federation of Australia, develop and implement national standard operating procedures for radio use in glider operations.

On 4 March 2010, a Boeing Company 717-200 (717) departed Perth, Western Australia (WA) on a scheduled passenger service to Port Hedland, WA.
The aircraft was tracking on a GURAK 3 standard instrument departure, which involved transiting through Pearce military controlled airspace. While maintaining flight level (FL) 1201 and turning left onto a heading of 330 degrees under the control of Pearce air traffic control (ATC), the crew
received a traffic advisory (TA) warning from the traffic alert and collision avoidance system (TCAS). The crew advised ATC and were instructed to continue the turn onto a heading of 360 degrees. During the turn, the crew received a resolution advisory (RA). The crew responded and climbed the aircraft to FL125.

The crew were advised by ATC that the conflicting aircraft, a military-operated Raytheon Aircraft Company 350 (King Air) descending through FL120 on a reciprocal track, had the 717 in sight and was maintaining separation. By this time, the radar separation standard had reduced below the required distance of 3 NM (5.6 km).

This occurrence reinforces the importance of effective coordination between ATC positions, and highlights the challenges faced by air traffic controllers when managing aircraft operating within the same airspace, but under the control of different ATC positions.

A McCauley Propeller Systems propeller hub with an area of transverse cracking extending through the hub mounting boss was received by the Australian Transport Safety Bureau (ATSB) from the Civil Aviation Safety Authority (CASA). CASA requested assistance from the ATSB to conduct an engineering examination of the cracked region.

The examination determined that the crack was the product of a high-cycle, low-stress fatigue mechanism, with the crack origin centred on a mounting stud hole. There were no associated defects or other anomalous features that may have assisted in the crack initiation.

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Released in accordance with section 25 of the Transport Safety Investigation Act 2003.

The aircraft was observed shortly after it had taken off towards the south-east, flying at a very low height along the beach towards the Tangalooma resort. The aircraft flew over the resort area and was seen by witnesses to perform a steep climbing manoeuvre. The aircraft then descended steeply, dived into the water whilst heading in a westerly direction away from the resort, and sank.

The aircraft appeared to be operating normally prior to the accident. There was no physiological or mechanical evidence found which may have contributed to the development of the accident. No defect was found which may have precluded normal engine operation; however, the engine appears to have not been delivering power at the time of impact.

The prevailing wind at the time of the accident was a strong south-easterly which is known to cause mechanical turbulence in the lee of the island. This may have affected the pilot's ability to recover from the manoeuvre under the circumstances.

The investigation did not reveal any reason for the unusually low flight path and manoeuvre immediately prior to the accident. The engine could not be functionally tested because of impact damage.

Significant factor

The following factor was considered relevant to the development of the accident: The pilot attempted a manoeuvre at a height from which safe recovery could not be effected.

On 24 February 2010, a Boeing Company 737-800, registered PK-GMG, was being operated on a scheduled passenger service from Denpasar, Republic of Indonesia to Perth, Western Australia (WA). The aircraft was cleared by air traffic control (ATC) to land on runway 03.

During the landing roll, the crew received instructions from ATC to exit runway 03 by taking taxiway November, the second on their right. In complying, the aircraft was turned onto the cross runway 06, which was active. The crew then received instructions to expedite their exit via taxiway S. The aircraft was exited from the active runway and moved to its parking stand.

This incident is a reminder that all radio communications phraseology should be clear, concise and unambiguous and should reflect international practices and standards where possible, particularly with regard to instructions provided to and received from international aircraft, and in safety critical situations. It is also a reminder to crews to seek clarification of ATC instructions should there be any doubt as to the content or intent of any clearance or instruction.