Two aircraft, both maintaining flight level 350, were on converging tracks with the same estimate for overhead Morawa NDB, Western Australia. A controller noticed the potential conflict and alerted the sector controllers managing the flights, who acted to resolve the situation.  There was a loss of separation assurance. 

Discontinuation:

Section 21 (2) of the Transport Safety Investigation Act 2003 (TSI Act) empowers the Australian Transport Safety Bureau (ATSB) to discontinue an investigation into a transport safety matter at any time. Section 21 (3) of the TSI Act requires the ATSB to publish a statement setting out the reasons for discontinuing an investigation.

On 26 October 2012, the ATSB commenced an investigation into an airspace event involving a Boeing 717-200 aircraft, registered VH-NXQ, and a Boeing 777-312ER aircraft, registered 9V-SYI, near the Morawa non-directional radio beacon, Western Australia, on 25 October 2012.

Examination of the information collected during the investigation indicated that although there was a loss of separation assurance, the potential conflict between the two aircraft was detected and actively managed by air traffic control. This ensured that the required separation standard was maintained.

The ATSB did not find any systemic issues had contributed to the occurrence and assessed that no safety issues would be identified through further investigation. On that basis, the ATSB has decided to discontinue its investigation.

What happened

On 19 October 2012 a Fokker F100 aircraft (F100), registered VH-NQE, was being operated on a passenger charter flight from Perth Airport to Nifty Aerodrome in the Pilbara region of Western Australia. The weather for the approach into Nifty included high-based cumulus cloud and isolated thunderstorms. The temperature on the ground was 38 °C.

As the flight crew were positioning the aircraft for a 5 NM (9 km) straight-in approach into a slight headwind, they received a windshear caution. In response, the crew increased the approach speed and extended the speed brake to stabilise the approach.

The approach continued and apart from a few minor speed variances, the conditions appeared relatively benign. As the aircraft was in the final stages of the approach and descending from 80 ft to 30 ft above ground level, the airspeed dropped from 133 kt to 110 kt and the rate of descent increased to about 1,000 ft/min. The loss of airspeed occurred over a period of 3 seconds and by touchdown the aircraft was being affected by a 32 kt tailwind.

The aircraft touched down on the runway threshold, almost 300 m short of the normal touchdown point, and bounced. The high rate of descent at initial touchdown resulted in a hard landing with significant aircraft damage. There were no reported injuries to passengers or crew.

What the ATSB found

The ATSB found that when the aircraft was on approach to land at about 80 ft above ground level, the flight path almost certainly coincided with the strong outflow of a dry microburst, resulting in a performance-decreasing windshear that led to the rapid drop in airspeed, high sink rate, undershoot and a hard landing. Also, the aircraft was not fully configured for an approach in known or suspected windshear conditions, reducing the capability of the aircraft to recover from the high sink rate associated with a microburst event.

What's been done as a result

As a result of this occurrence, the operator sought to improve the weather information available at aerodromes serviced by their F100 fleet and modified its simulator training program along with consolidation of the windshear procedures/guidance. The operator also provided additional guidance in the use of flap following receipt of a windshear caution during approach and planned to introduce a new threat-based take-off and landing briefing model.

Safety message

The circumstances of this occurrence show that operators of transport category aircraft may need to review the guidance provided to crews to ensure that the risk of windshear associated with both thunderstorms and dry microbursts, is effectively managed.

What happened

On 17 October 2012, a Boeing 737-838 aircraft, registered VH-VXB and operated by Qantas Airways Limited (Qantas), was conducting a flight from Adelaide, South Australia to Canberra, Australian Capital Territory. The flight crew received an approach clearance into Canberra via a standard arrival route (STAR) and then an Area Navigation (Required Navigation Performance) (RNAV (RNP)) instrument approach to runway 35 at Canberra Airport. Just prior to commencing descent, at about 2030 Eastern Daylight-saving Time, air traffic control (ATC) cancelled the STAR and cleared the aircraft to track direct to the initial approach fix, HONEY, via a high-speed descent. As the aircraft approached 8,000 ft, ATC provided a descent clearance to 7,000 ft and also cleared the aircraft for the approach. As the aircraft approached HONEY it descended below the 7,000 ft altitude clearance limit. After being alerted to this by ATC, the flight crew climbed the aircraft back to 7,000 ft and continued the approach to land.

What the ATSB found

The ATSB found that, as the aircraft approached 8,000 ft, the auto-flight system vertical mode changed from a flight management computer‑derived and managed vertical navigation mode into the vertical speed mode. This was followed by a number of automated, but unnoticed, and crew‑initiated changes in the aircraft’s auto-flight system vertical mode. The combination of auto‑flight system mode changes and the management of the airspeed during the descent resulted in a high workload environment where the 7,000 ft altitude clearance limit was overlooked by the flight crew.

The ATSB also found that, on receipt of the approach clearance, the Qantas RNAV (RNP) approach procedures allowed the flight crew to remove the current limiting altitude from the auto‑flight system’s Mode Control Panel (MCP) and set the decision altitude. Application of this procedure by the flight crew removed the last automated safety system available to them to prevent descent through the current altitude limitation, well before the aircraft was established on the approach.

What's been done as a result

Following this occurrence, Qantas changed their RNAV (RNP) approach procedures to only allow the altitude on the MCP to be changed from the current limiting altitude once the aircraft was within 2 NM (4 km) of commencing the approach.

Safety message

This occurrence highlights the importance of paying continuous attention to active and armed auto-flight modes and the need to continually monitor descent profiles and airspace limitations in relation to the aircraft’s position, irrespective of the expectation that the descent is being managed by the auto-flight system. The adverse effect of workload and task focus on flight crew performance and the importance of robust procedures for high-precision approaches are also illustrated.

On 11 October 2012, at 0845 Eastern Standard Time a Robinson R44 Raven 1 helicopter departed a property near Mount Molloy for Georgetown, Queensland, on a private flight. On board the helicopter were the pilot and one passenger. Shortly after becoming airborne the helicopter experienced a loss of power. The pilot performed a 180° turn to the left and autorotated to a suitable area within autorotative distance, which was a contour drain located downslope from the departure point. The helicopter came to rest and remained upright, and the pilot and passenger were able to exit without injury. The helicopter was substantially damaged. 

The helicopter was inspected, and the left magneto was found to have a badly worn distributor block, which allowed the timing gear to move and alter the internal timing by approximately 40°. 

Pilots are encouraged to perform a self-briefing prior to every take-off to serve as a reminder of the actions to be performed in the event of an emergency.

Aviation Short Investigation Bulletin – Issue 15

At about 0444 on 26 September 2012, the 104.5 m LPG tanker MT Norgas Cathinka collided with the 96 m ferry Bahuga Jaya in Sundra Strait, Indonesia. The Bahuga Jaya sank as a result of the collision, with the reported loss of 8 lives.

The Indonesian National Transportation Safety Committee (NTSC) is responsible for investigating this occurrence. The NTSC requested assistance from the Australian Transport Safety Bureau (ATSB) in the replay, display and analysis of voyage data recorder (VDR) data from the MT Norgas Cathinka. To assist the NTSC and provide protection of the recorded data and analyses, the ATSB initiated an External Investigation under the provisions of the Transport Safety Investigation Act 2003.

For further information in relation to the investigation of this accident, please refer to the NTSC.

National Transportation Safety Committee
Ministry Of Transportation Republic Of Indonesia
Transportation Building 3^rd Floor
Jalan Medan Merdeka Timur No. 5
Jakarta Pusat 10110
Indonesia

Phone  :  +62 21 384 7601
Email    :  knkt@dephub.go.id

Website: http://knkt.dephub.go.id/knkt/ntsc_home/ntsc.htm

On 29 September 2012, a Cessna P206B aircraft, registered VH-EGG, departed Gympie on a private flight to Monduran, Queensland.

During the landing, a significant wind gust was experienced, resulting in a hard landing on the main landing gear. The aircraft bounced and the pilot applied a small amount of power in an attempt to regain control. A second wind gust of greater intensity then occurred. The aircraft stalled and touched down hard on the nose landing gear. The pilot maintained directional control and the aircraft came to a stop. The aircraft sustained damage to the propeller, nose landing gear, and lower engine cowls.

This incident highlights the importance of conducting a go-around as soon as landing conditions appear unfavourable.

Aviation Short Investigation Bulletin – Issue 14

At approximately 1325 hours Eastern Standard Time on 26 September, 1970, a Piper PA23-250 Aztec aircraft, registered VH-SPM, collided with the precipitous face of a ravine, 490 feet below the main line of a ridge, on the eastern slopes of Mt. Scratchley in the Territory of Papua. The aircraft was engaged on a charter flight for the carriage of passengers and baggage from Kokoda to Port Moresby. The aircraft reported its departure from Kokoda but, when it did not arrive at Port Moresby, search and rescue procedures were initiated. The wreckage was sighted on 1 October, 1970 in dense rain forest, 10,100 feet above mean sea level. At first, the efforts of ground rescue parties to reach the wreckage were frustrated by extremely bad weather conditions, the high altitude and the precipitous terrain. Thirteen more days elapsed before a member of a mountain rescue party reached the accident site to find that the aircraft had been destroyed by impact forces and the pilot and the three passengers on board· had suffered fatal injuries.

On 5 October, 2012, a Beech 1900 VH-EMK was operating a passenger carrying charter flight from Darwin to Jabiru, Northern Territory.

With no response to their broadcasts on the local Jabiru aerodrome frequency, and no other aircraft observed on the aircraft traffic monitoring system, the crew continued their approach onto runway 09 at Jabiru. When approaching 5 NM to touchdown, the crew observed a ‘glint’ on the runway and broadcast on the local frequency, again with no response.

At about the same time, an Airparts FU-24, VH-HVP, had broadcast entering and back-tracking the runway for a departure in the opposite direction. The pilot of HVP heard a broadcast from EMK and believed they were further back in the approach.

As HVP was commencing the take-off run, the crew in EMK and the pilot in HVP saw each other and both immediately initiated avoidance manoeuvres.

It was found that the radio in HVP had not been broadcasting, due to an incorrectly positioned switch.

As a result of this incident, the operator of VH-HVP has arranged for all pilots to re-visit company Standard Operating Procedures on radio transmissions and low-level survey flying.

This incident demonstrates the importance of checking the serviceability of radio equipment prior to flight. In particular, the use of available resources such as AFRU for ensuring the radio is transmitting.

Aviation Short Investigation Bulletin – Issue 15

Update 12 November 2012 - Preliminary factual report release

On 3 October 2012, the ATSB commenced an investigation into an accident involving a Robinson R22 Beta helicopter, registered VH-LLF, which collided with terrain 130 km west of Halls Creek, Western Australia.

The ATSB has released its preliminary factual report  into the collision. The information contained in the report is derived from the initial investigation of the occurrence. Readers are cautioned that new evidence will become available as the investigation progresses that may alter the circumstances as depicted in the preliminary report. As such, no analysis or findings are included in the report.

In the late afternoon on 3 October 2012, the pilot of a Robinson R22 Beta collided with terrain in a gorge on the Gliddon River (near the Margaret River).

The tail of the helicopter collided with an overhanging rock formation and a section of the tail boom separated from the fuselage. The helicopter rolled to the left and descended out of view of witnesses. The helicopter was found submerged on its right side with substantial damage. The pilot was deceased.

The ATSB attended the accident site, but was unable to closely examine the submerged wreckage. From the surface it was evident that the cabin roof was crushed in, both main rotor blades had severed a short distance from the main rotor hub, and one of the fuel tanks had detached from the aircraft structure.

The investigation is continuing and will include analysis of the available information to identify safety factors.

It is anticipated that the investigation will be completed by April 2013.

Read the

What happened

On 28 September 2012, an en route air traffic controller acknowledged a Route Adherence Monitor (RAM) alert in respect of a Boeing Company 737‑8BK aircraft, registered VH-VUM (VUM), on a scheduled passenger service between Sydney, New South Wales and Brisbane, Queensland. Believing that VUM was destined for Newcastle Airport under Department of Defence air traffic control jurisdiction, the controller erroneously inhibited the flight data record (FDR) for VUM. This action cancelled the RAM alert.

The inhibition of the FDR, in combination with the controller’s altitude filter being set at a lower flight level than appropriate to the combined sectors under the controller’s jurisdiction, meant that VUM’s FDR registered as a ‘not concerned’ aircraft track. Subsequently, due to this ‘not concerned’ status, the controller did not see or interrogate VUM’s FDR for the rest of the time it was under their jurisdiction. Similarly, the FDR did not attract the attention of two Inverell sector controllers after it entered and crossed their sector until they responded to a frequency change request from the flight crew of VUM.

There was no loss of separation with other aircraft for the resulting period that the aircraft operated without the active provision of ATC services and, during the course of the occurrence, two-way communications in controlled airspace remained available. However, maintenance of the minimum aircraft separation standards during this period was not assured. There was a loss of separation assurance.

What the ATSB found

High-reliability systems like air traffic control have many layers of controls to minimise risks associated with operational hazards. These controls were ineffective in this case as a result of a number of factors, including human perception and attention issues, the training of controllers with regard to ‘not concerned’ tracks, and the level of system protection against the potential impact of such tracks. Specifically, error‑tolerant system designs that aid in the detection and recovery of inadvertently-inhibited tracks offer another defence against this type of occurrence.

Two safety issues were identified as a result of this investigation. The first relates to the provision of awareness training for en route controllers who are routinely exposed to ‘not concerned’ radar tracks, which can lead to a high level of expectancy that such tracks are not relevant for aircraft separation purposes. The second issue relates to the limited protections against a controller mistakenly inhibiting an aircraft and need for procedures to account for the limitations in the interoperability between the Australian Advanced Air Traffic System/Australian Defence Air Traffic System.

What's been done as a result

In response to the occurrence, Airservices has amended its air traffic controller ab-initio training exercises to include ‘not concerned’ track scenarios to ensure that training emphasised the importance of scanning ‘not concerned’ radar tracks. The scenarios will also be included in operational simulation training where appropriate. Furthermore, Airservices will use this occurrence to raise awareness of black tracks and the need to scan ‘not concerned’ tracks amongst its air traffic control staff.

In respect of equipment interoperability, Airservices and the Department of Defence are currently working towards implementing a harmonised joint civil military air traffic service system via the OneSky Program. Once implemented this system will increase air traffic management interoperability between both organisations.

Safety message

This occurrence highlights the fallibility of human attention/perception and the resulting risk of involved parties being ‘primed’ to the circumstances of an occurrence to the extent that they automatically (but incorrectly) perform actions that they perceived were correct. There is the potential for additional error-tolerant design improvements to complement existing air traffic system human machine interface risk controls to reduce the likelihood of such behaviour.

Humans can also experience difficulty detecting display targets that are subtle, unexpected and deemed of low information value. This occurrence showed a reduced awareness among controllers of the potential impact of black, ‘not concerned’ tracks in an en route airspace environment, which might be addressed by additional controller training or through an integrated air traffic management system.