What happened

On the evening of 6 August 2016, Jetstar Airways flight JQ12, a Boeing 787 aircraft, registered VH-VKK, departed from Tokyo, Japan on a scheduled passenger transport flight to the Gold Coast, Queensland. On board the aircraft were two flight crew, nine cabin crew and 309 passengers.

The aircraft was pushed back from the gate at Narita Airport, Tokyo, at 1133 UTC.^[1] About two hours into the flight, the flight crew received an engine indication and crew alerting system (EICAS) message ELEC GEN DRIVE R2, which indicated a fault with the number 2 generator in the right engine. The flight crew performed the checklist actions for that fault, which included disconnecting the number 2 generator drive from the engine driven accessory gearbox (AGB) and starting the auxiliary power unit to supplement the aircraft electrical power with the auxiliary power unit driven generators.

About 30 minutes later, cruising at FL 400,^[2] the secondary engine instruments appeared^[3] on the flight crews’ multi-function displays and the flight crew detected there was a low oil quantity indication for the right engine. While the flight crew investigated the engine indications, another EICAS message annunciated, ENG OIL PRESS R, which indicated low oil pressure in the right engine. The flight crew performed the checklist actions for low oil pressure in the right engine. The right engine auto-throttle was switched off and the right engine thrust lever retarded to idle. The low oil pressure EICAS message momentarily cleared before it returned again, and the flight crew shut down the right engine in accordance with the checklist procedures.

The captain identified Guam Airport as the nearest suitable airport, about 370 km to the south of their position. They made a PAN^[4] call to Guam air traffic control, who provided them with a clearance to manoeuvre as required for a landing at Guam Airport. The flight crew sent a message using the aircraft communications addressing and reporting system to their operations control that they were diverting the aircraft to Guam. They descended the aircraft to FL 220 due to single engine performance limitations and diverted around some weather as they tracked towards Guam Airport. The captain reported that they made an uneventful one engine landing on runway 24 at about 1520 UTC.

After the aircraft vacated the runway, the captain held the aircraft on the taxiway to allow the airport emergency services to inspect the engine before they taxied the aircraft to the arrival gate. The aircraft was shut down at the arrival gate without further incident.

Maintenance findings

When the engine cowls were opened for the initial inspection there was a large quantity of oil found throughout the engine and a considerable amount of metallic debris found within the engine oil system. A data download of the engine was performed and the results were sent to GE Aviation, the engine manufacturer, for review. GE Aviation provided options for returning the aircraft to service, of which Jetstar determined an engine change was the most expeditious.

Engine manufacturer findings

GE Aviation found there was no history or shift in oil system parameters except for the chip count^[5] on this flight. Chips are detected and recorded by the engine debris monitoring system (DMS), within the engine oil system.

On the incident flight, the right engine oil system started to detect chips from about one hour into the flight. The chip count reached seven when the crew were alerted to disconnect the number 2 generator. At 1415 a status message was generated for ENG OIL DMS R, which indicated the chip count for the right engine had reached eight.

Between 1415 and 1419 the chip count reached 11, there was a rapid loss of engine oil, a momentary spike in vibration from the engine number 1 bearing, and the EICAS message to the flight crew reporting low engine oil pressure. The engine was shut down and the aircraft landed about 52 minutes later.

Engine driven gearboxes

Engine rotation is transmitted to an inlet gearbox (IGB) with a radial driveshaft, which connects to a transfer gearbox (TGB). The TGB transmits the engine speed to the AGB via a horizontal driveshaft (Figure 1). The AGB drives the accessories necessary for engine operation and other aircraft services, such as the generators for the aircraft electrical system. The engine oil system provides lubrication, cooling and removes debris from the gearboxes.

Figure 1: Engine driven gearboxes

Source: Boeing, annotated by ATSB

Transfer gearbox damage

On inspection, the TGB housing was found to be fractured (Figure 2). The TGB oil screen was found with metallic debris and the engine oil DMS sensor was found with metallic debris (Figure 3). The manufacturer’s inspection of the TGB failure indicated it was consistent with a known failure mode of the TGB described in their service bulletin (SB) 72-0298.

Figure 2: Transfer gearbox damage

Source: Jetstar Airways

Figure 3: DMS sensor and TGB oil screen metallic debris

Source: Jetstar Airways

GE Aviation service bulletin 72-0298

GE Aviation SB 72-0298 revision 0, dated 31 March 2016, is applicable to all GEnx‑1B engines, which were the engines fitted to VH-VKK at the time of the incident. The SB introduces a new transfer gearbox (TGB) configuration. According to the SB:

Pre-modified TGBs have a radial bevel gear with potential resonance modes (see Resonance) in the engine operating range. Excitation of resonance modes may lead to a gear fracture, which can result in engine oil loss and an in-flight shut down. The SB modification introduces a new damper ring groove to the radial bevel gear and a damper ring to mitigate the excitation of the resonance modes.

GE Aviation recommended the compliance periods for the SB in Table 1 below, which are based upon the number of cycles since new (CSN) for the TGB as of 31 March 2016.

Table 1: SB 72-0298 compliance

Jetstar management of service bulletin 72-0298

The SB related modifications for the Jetstar 787 fleet was managed with a risk profile developed by GE Aviation. The risk profile had four levels of risk for TGB failures, which depended on a number of engine operating factors in addition to the TGB CSN. Jetstar responded to the SB terminating action by immediately sourcing additional post-modification units from the manufacturer and prioritised the TGB modification in accordance with the order of highest to lowest TGB risk until the incident flight. The incident engine TGB was identified as the lowest risk (based on lowest CSN, limited in-service operational data and GE Aviation recommendations) for the Jetstar fleet at the time of the incident.

The incident engine TGB had 181 CSN at the time of the incident and therefore the compliance date to complete the SB for this engine was 31 March 2017. The engine modification to comply with the SB for the incident engine was scheduled for 31 December 2016.

Resonance

All machinery have a natural frequency of vibration. If a particular abnormality in the machinery generates a forced vibration, which vibrates in-phase and at the same frequency as the natural frequency of vibration, then the energy will magnify. The frequency at which this occurs is known as the resonant frequency (Figure 4). If there is insufficient damping present at the resonant frequency, then the amplitude of the vibrations will increase with each cycle. Excessive movement of components with high energy can cause a catastrophic failure of the machinery.

Figure 4: Resonant frequency for damped and undamped vibration

Source: ATSB

Jetstar Airways extended diversion time operations

Twin engine turbine aeroplanes are normally restricted to operating on routes where if an engine fails or is shut down in-flight, the aircraft is within 60 minutes flight time, at the cruise speed for one engine inoperative, to a suitable airport. Extended diversion time operations (EDTO) permit the Boeing 787 to operate on routes which are further than the 60 minutes flight time in the event of an engine in-flight shut down (IFSD). EDTO approval for an operator is subject to the continuous monitoring of the engine IFSD rate.

For the Jetstar Boeing 787 fleet the EDTO approval at the time of the incident was for up to 180 minutes, which required a target IFSD rate of not greater than 0.02 per 1,000 flight hours. Prior to the incident flight, Jetstar were operating at a rolling 12 month IFSD rate of 0 per 1,000 flight hours, which increased to 0.0096 post-incident. Jetstar have performed several unscheduled engine changes on their 787 fleet since introduction into service, but no changes prior to the incident flight related to the fault condition identified in SB 72-0298.

ATSB comment

The ATSB notes that the failure of the TGB and loss of oil is a potential failure mode known to the engine manufacturer and operator. This condition is under risk management through the service bulletin process and the operator was within the compliance period at the time of the incident. Prior to the incident flight, the incident TGB was assessed as being in the lowest risk profile for the operator’s fleet.

Safety action

Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following proactive safety action in response to this occurrence.

Jetstar Airways

In light of the incident, Jetstar amended their TGB modification schedule in order to prioritise at least one engine TGB on each aircraft airframe in their fleet at the earliest opportunity (known as depairing or decoupling). The fleet was completely depaired from 26 August 2016. Jetstar completed the modification programme for their fleet in November 2016.

Safety message

This incident highlights the importance of flight crew complying with checklist actions when dealing with a fault condition. Inflight, the crew did not have knowledge of the extent of the damage to the engine TGB. However, by following their training and checklist procedures, they reduced the risk of a potential escalation of the fault.

Short Investigations Bulletin - Issue 55

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

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1. Coordinated Universal Time (abbreviated UTC) is the time zone used for civil aviation. Local time zones around the world can be expressed as positive or negative offsets from UTC.
2. At altitudes above 10,000 ft in Australia, an aircraft’s height above mean sea level is referred to as a flight level (FL). FL 400 equates to 40,000 ft.
3. The secondary engine instruments are only displayed when an abnormal condition is detected.
4. An internationally recognised radio call announcing an urgency condition which concerns the safety of an aircraft or its occupants but where the flight crew does not require immediate assistance.
5. Chip count refers to metallic debris detected within the engine oil system, which may be a leading indicator of machinery failure. Chip count indicates the number of metal chips detected by the debris monitoring system.

What happened

At about 1330 Western Standard Time (WST) on the 7 August 2016, a Skippers Aviation de Havilland DHC‑8-106 aircraft, registered VH-XFP (XFP), departed Perth Airport for Shark Bay Western Australia. Two flight crew, one cabin crew and 30 passengers were on board the regular public transport flight.

At about 10,000 ft, the flight crew conducted the transition checklist items that included checking the cabin pressurisation system and noted that everything was operating normally. The captain observed that the cabin altitude^[1] was about 4,000 ft, the rate of climb was between 250 ft and 500 ft, and the maximum differential pressure between the outside air pressure and the cabin air pressure was about 2.5 to 3 psi (Figure 1).

Figure 1: Cabin pressure indicator panel showing the cabin differential pressure, cabin altimeter and cabin altitude rate of climb indicators

Source: Aircraft Maintenance Manual, modified by the ATSB

At about flight level (FL) 176^[2] the flight crew engaged the autopilot. As the aircraft approached the cruising altitude FL 180, the master warning activated and the cabin pressure warning light^[3] illuminated. The crew observed that the cabin altitude indicated about 12,600 ft with an excessive rate of climb, where the rate of climb indicator had gone to its maximum indicated reading. They conducted their phase one memory checklist items for a rapid depressurisation and an emergency descent. Both crewmembers fitted their oxygen masks and the captain, who was not the flying pilot, took control of the aircraft. The captain made an announcement through the aircraft’s public announcement (PA) system. However, the announcement was muffled and distorted and the cabin crewmember did not understand what was being said. The cabin crewmember tried contacting the flight crew but did not get a response. The flight crew selected the passenger seat belt sign on and commenced an emergency descent. The cabin crewmember realised that the aircraft was in a descent, fastened their seatbelt and using the PA system instructed the passengers to do the same. The cabin crewmember did not use supplemental oxygen (available at the flight attendant seat), as they were not aware of the nature of the emergency. Oxygen was not made available for passengers (see Passenger oxygen requirements below). The first officer declared an emergency (PAN PAN)^[4] to air traffic control and advised that they were on descent through FL 175.

The captain levelled the aircraft at about 10,000 ft, re-engaged the autopilot and the crew conducted the cabin pressurisation failure checklist. The crew were not able to regain control of the cabin pressurisation. The maximum cabin altitude observed by the crew was just over 14,000 ft and this had returned to 10,000 ft when the aircraft was at an altitude of about 10,000 ft. The cabin pressure warning light remained on. The captain called the cabin crewmember and informed them that they were returning to Perth. The cabin crewmember then carried out a cabin check to ensure that the passengers were not injured and the cabin was secured.

The flight crew contacted the operator’s maintenance personnel and were not able to isolate the reason for the fault. As the aircraft was above the maximum landing weight, they tracked to Rottnest Island to conduct a holding pattern to burn enough fuel to reduce the weight for a landing at Perth. The cabin pressure warning light extinguished on the way to Rottnest Island. The aircraft returned for a landing at Perth without further incident. The two flight crew, one cabin crew and 30 passengers were not injured and the aircraft was not damaged.

Passenger Oxygen requirements

Due to the lower altitudes that this aircraft model operates at, drop down oxygen masks for passengers and cabin crew were not installed nor required. Instead, the aircraft was supplied with portable oxygen bottles that can be handed out throughout the cabin to 10 per cent of the occupants, providing oxygen for half an hour. This is in accordance with Civil Aviation Order 20.4 (7) Supplemental oxygen requirements for pressurised aircraft engaged in flights not above flight level 250:

7.5 Supplemental oxygen for passengers

(a) where the aircraft can safely descend to Flight Level 140 or a lower level within 4 minutes at all points along the planned route and maintain Flight Level 140 or a lower level for the remainder of the flight — to provide 10% of the passengers with supplemental oxygen for 30 minutes or 20% of the passengers with supplemental oxygen for 15 minutes;

Captains comment

The captain reported practicing emergency descents and pressurisation faults about two weeks prior to the occurrence when conducting simulator training. They commented how valuable that training was to be prepared for this type of occurrence where they could identify that it was not a gradual or subtle depressurisation.

The captain reported that there was no warning or anything that would have indicated that there was a cabin pressurisation failure apart from the activation of the cabin pressure warning system.

The captain was not aware that the PA to the cabin was muffled. The captain also reported that the cabin crewmember had not heard the instruction for cabin crewmembers to use supplemental oxygen until after the flight had landed.

Operator comments

The operator conducted an investigation into the occurrence, and after testing of the forward safety outflow valve, found that it was outside the aircraft maintenance manual specifications, and believed that it was the reason for the cabin pressurisation failure.

The operator reported that during the occurrence, the captain made a public announcement, which the passengers and cabin attendant did not understand as the announcement was muffled and distorted. The pilot’s oxygen mask audio system was tested and found to be serviceable. The most likely reason that the announcement was not heard clearly was that the oxygen masks might have distorted the communication.

Safety analysis

The forward outflow valve was not operating as required which led to a rapid depressurisation of the aircraft as it approached its cruising altitude.

The PA announcement from the captain was muffled, resulting in the cabin crewmember not initialling realising that the flight crew were conducting an emergency descent and that they should use supplemental oxygen.

Findings

These findings should not be read as apportioning blame or liability to any particular organisation or individual.

• The aircraft’s cabin pressurisation system failed resulting in the aircraft depressurising.
• The PA to the cabin was muffled as the crew were using oxygen masks and potentially critical information was not communicated to the flight attendant and the passengers.
• The flight crew fitted their oxygen masks immediately, when they noticed, at about 12,600 ft cabin altitude that the cabin pressure warning system had activated.

Safety action

Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following proactive safety action in response to this occurrence.

Skippers Aviation

As a result of this occurrence, the aircraft operator has advised the ATSB that they are taking the following safety actions:

Raise pilot awareness on the difficulty of communication when they fit an oxygen mask and its effect on their clarity of speech. In such cases, they may be required to be more deliberate and punctuate their instructions.

The continuing airworthiness management system will continue to monitor XFP for any associated defects. The faulty valve will be overhauled to determine why it failed.

Safety message

The reaction time for pilots to fit oxygen masks is of critical importance when there is a cabin pressurisation failure. For the crew in this occurrence, it was the first action taken when they detected that the cabin pressure warning light was on. A misconception is that it is easy to recognise the symptoms of hypoxia and take corrective action before becoming seriously impaired. The signs and symptoms vary depending on the individual, the altitude and the extent of the exposure. While other significant effects of hypoxia usually do not occur in a healthy person in an unpressurised aircraft below 12,000 ft above mean sea level (AMSL), there is no assurance that this will always be the case. Furthermore, the altitude range of impairment due to hypoxia is best described as a continuum; there is no definitive altitude at which the effects of hypoxia begin or end. To mitigate the risk associated with these variations, if hypoxia is suspected, a descent to altitudes below 10,000 ft AMSL is suggested.

Additional information is provided in the following publications:

The ATSB research report, Depressurisation Accidents and Incidents Involving Australian Civil Aircraft (B2006/0142), is available from the ATSB website.

The ATSB investigation report ‑Pilot and Passenger Incapacitation Beech Super King Air 200, VHSKC, Wernadinga Station, Qld, 4 September 2000 (200003771), is available from the ATSB website.

US Federal Aviation Administration (FAA) Advisory Circular AC 61-107B Aircraft Operations at Altitudes Above 25,000 Feet Mean Sea Level or Mach Numbers Greater Than .75/ with Change 1, is available from the FAA website.

Short Investigations Bulletin - Issue 55

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

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1. Pressurisation of the cabin is displayed as cabin altitude and is the equivalent to outside pressure at different altitudes. A cabin altitude of 4,000 ft corresponds to an atmospheric pressure of 4,000 ft.
2. Flight level: at altitudes above 10,000 ft in Australia, an aircraft’s height above mean sea level is referred to as a flight level (FL). FL 176 equates to 17,600 ft.
3. If the cabin altitude exceeds 10,000 ft, this automatically illuminates the ‘CABIN PRESS’ warning light on the warning light panel. The light will remain illuminated until the cabin altitude decreases below 10,000 ft.
4. PAN PAN: an internationally recognised radio call announcing an urgency condition which concerns the safety of an aircraft or its occupants but where the flight crew does not require immediate assistance.

The Safety Investigation Board (SIB) of the Pakistan Civil Aviation Authority is investigating an engine failure and runway excursion involving a Beechcraft 1900D aircraft, registered AP-BII that occurred on 18 March 2016. On 4 August 2016, the SIB requested the appointment of an ATSB investigator as accredited representative to the SIB investigation in accordance with clause 5.23 of Annex 13 to the Convention on International Civil Aviation Aircraft Accident and Incident Investigation.

The SIB requested the ATSB accredited representative to oversight a technical examination of the aircraft’s engine at a maintenance facility in Brisbane, Queensland. To facilitate this support, the ATSB initiated an investigation under the Australian Transport Safety Investigation Act 2003.

On 6 January 2017, the SIB advised the ATSB that, as all investigation work within Australia had now been completed, ATSB assistance was no longer required.

The SIB is responsible for, and will administer the release of the final investigation report into the occurrence involving AP-BII. Any enquiries regarding the SIB investigation should, in the first instance, be directed to the:

Safety Investigation Board
Pakistan Civil Aviation Authority
CAA Office Complex
Lethrar Road
Rawalpindi
Pakistan 

Phone: +92 51 44 72750
Fax:      +92 51 44 72754
Email:   psib@caapakistan.com.pk

The information contained in this web update is released in accordance with section 25 of the Transport Safety Investigation Act 2003.

What happened

On the morning of 4 August 2016, Qantas Flight QF61, an Airbus A330 aircraft, registered VH‑QPC, was prepared for departure from Brisbane Airport, Queensland, for a flight to Narita Airport, Tokyo, Japan.

The flight dispatcher, responsible for flight planning, started building the flight plan for QF61 at about 0800 Eastern Standard Time (EST) at the company integrated operations centre (IOC). In addition to the destination of Narita Airport, the flight plan included two destination alternate^[1] airports, Haneda Airport, Tokyo, Japan and Saipan International Airport, Saipan (Figure 1). Saipan Airport was also the extended diversion time operations (EDTO)^[2] alternate airport (see Extended diversion time operations).

During the process of building the flight plan, the flight dispatcher noticed one of the aircraft’s two global positioning system (GPS) navigation units was recorded as an unserviceable item on the aircraft minimum equipment list (MEL).^[3] The flight dispatcher also identified that two serviceable GPS units were required at dispatch, due to the forecast westerly winds, to allow the use of Saipan Airport runway 25 GPS approach as an alternate airport for destination and EDTO purposes. Therefore, they contacted the section of the IOC responsible for aircraft maintenance (maintenance watch) to check if the unserviceable MEL item (GPS 2) would be cleared before the aircraft’s departure.

Maintenance watch indicated that the unit would be fixed and the unserviceability removed before the aircraft departed.^[4] The flight dispatcher completed the flight planning documents with the GPS 2 unit listed as an unserviceable MEL^[5] item – with the expectation that this would be removed before departure. However, the dispatcher did not make a note in the flight planning documents to advise the flight crew that this MEL item should be cleared before the flight departed. They then sent the documents to the flight crew about 85 minutes prior to the scheduled departure time.^[6]

The captain for QF61 signed on for work at Brisbane Airport at 0945, after receiving an electronic copy of the flight plan and briefing package. After reviewing the package, the captain requested an additional 1,700 kg of fuel to allow for a second mainland Japan destination alternate airport (Nagoya in addition to Haneda) (Figure 1). They then discussed the implications of the unserviceable GPS 2 unit with the other two flight crewmembers.

Figure 1: QF61 Destination and EDTO alternates

Source: Google earth, annotated by ATSB

The captain initially thought that two GPS units were required at dispatch because the Saipan Airport runway 25 approach procedure required GPS. However, after further discussion they decided that they were mistaken as maintenance and flight dispatch were aware one GPS was unserviceable and the captain had very few past experiences of an incorrect serviceability requirement at dispatch. One flight crew member then mentioned that the flight crew operating manual indicated one GPS unit was required.^[7]

The captain referred to the MEL. The MEL includes the MEL items and their associated operational procedures. The operational procedures may impose additional operational requirements to what is documented in the MEL items. The MEL item for the aircraft GPS function indicated only one GPS unit was required at dispatch. However, the associated operational procedures indicated that ‘primary means GNSS approval’^[8] was required at dispatch if the alternate airport arrival procedure requires GPS navigation. ‘Primary means GNSS approval’ indicated the requirement for two operational GPS units. When the captain reviewed the MEL operational procedures they considered the reference to ‘alternate’ to be a reference to destination alternate airport and not to an EDTO alternate airport. They planned to use Saipan as an EDTO alternate airport and not a destination alternate airport, having already decided to add a second mainland Japan destination alternate airport. This fitted with their expectation that the unserviceable GPS 2 MEL item was acceptable for their flight.

The flight departed from Brisbane with 12 crew and 231 passengers on board and proceeded in accordance with the flight plan. As QF61 travelled north along the east coast of Australia, the captain was uncomfortable with their decision to accept the aircraft with GPS 2 listed as unserviceable.^[9] Therefore, the captain reviewed the flight plan and the publications. They concluded they had misinterpreted the MEL operational procedures reference to alternate airport requirements and that their flight plan required two serviceable GPS units to use the Saipan Airport runway 25 GPS approach for destination or EDTO alternate airport purposes.

The captain identified Guam Airport (runway 24R VOR/DME^[10]) as a suitable airport to plan to use instead of Saipan Airport for their EDTO alternate airport and briefed the other two flight crew members. However, one flight crew member queried if Guam could be used for replanning in lieu of Saipan without two serviceable GPS units. The attention of this flight crewmember was drawn to a note on one of the Guam terminal plate pages (Figure 2), which indicated runway 24R required ‘primary means GNSS approval’ for use as an alternate airport. However, the captain considered that this was a reference to the destination alternate (which required two separate approaches) and that the runway 24R VOR/DME approach could be used for EDTO alternate purposes (see Use of Guam Airport as an adequate aerodrome).

The captain entered a new critical point^[11] between Tokyo and Guam (in lieu of Saipan) into the aircraft flight management and guidance computer. The computer calculated that an extra 800 kg of fuel was required, which was within the limits of the extra fuel the captain requested before departure. The flight continued to Narita Airport and landed without further incident.

The GPS 2 unit was observed by the crew to be serviceable throughout the flight. It was tested by maintenance at Narita Airport, found to be serviceable, and then removed from the MEL unserviceability list before the next flight.

Extended diversion time operations

For the A330, extended diversion time operations (EDTO) apply at any stage of the flight where the flight time to an adequate aerodrome (EDTO alternate), at the one engine inoperative cruise speed, is greater than 60 minutes. The EDTO limit for the A330 is 180 minutes.

For further information on EDTO requirements refer to Civil Aviation Advisory Publication 82-1(1): Extended diversion time operations (EDTO)

Use of Guam Airport as an adequate aerodrome

In accordance with Civil Aviation Order 82.0 paragraph 2.1, an EDTO alternate aerodrome requires at least one suitable authorised instrument approach procedure. Therefore, the Guam Airport runway 24R VOR/DME approach could be used by flight QF61 for this purpose.

If Guam Airport runway 24R had been used as a destination alternate airport, then two instrument approach procedures, which do not use a common ground based radio navigation aid, would have been required. In this case, the runway 24R GPS approach would have been required as the second approach and therefore two serviceable GPS units would have been required at dispatch. Hence the reference to ‘primary means GNSS approval’ for runway 24R on the Guam terminal plate page, which caught the attention of one of the flight crew members (Figure 2).

For further information about alternate requirements for international IFR^[12] operations outside Australia, refer to Civil Aviation Safety Authority Manual of Standards 173 paragraph 8.1.11.

Figure 2: Guam terminal procedures note for Qantas operations

Source: Aircraft captain, annotated by ATSB

Global positioning system unserviceability

The number 2 GPS was recorded as unserviceable and raised as an MEL item for QPC on 31 July 2016. The A330 GPS MEL had a repair interval of 10 consecutive calendar days and was scheduled for repair on 8 August 2016. No change was made to this schedule prior to the dispatch of flight QF61 on 4 August 2016.

Flight dispatcher comment

The flight plan had a free text box on the front page, which the flight dispatcher used to communicate the presence of a tropical storm to the flight crew in the incident flight. The flight dispatcher commented that in future they would use this free text box to communicate to the flight crew if they expected a change to the MEL status of the aircraft before dispatch.

ATSB comment

The ATSB notes that in large organisations there may be multiple departments with responsibilities for the dispatch of an aircraft. Whereas procedures are normally executed within a department, processes often involve multiple departments. Cross-checks occurred within the IOC and separately among the flight crew during this incident flight, but the cross-checks were not conducted between the departments, where personnel had a different mental model of the situation. The flight dispatcher believed the GPS 2 MEL item would be cleared before flight and the captain believed the flight was planned to be released with the GPS 2 as an unserviceable MEL item.

Safety message

This incident highlights the importance of personnel challenging their own assumptions when something does not appear right in the environment. After the dispatch of QF61 from Brisbane Airport, the captain experienced a ‘gut feeling’ that something was not right. Rather than ignore their sense of unease, the captain reviewed the flight plan and company documents, identified the problem and resolved the issue so that the flight could continue without compromising safety. Throughout the process, they kept the other flight crewmembers informed of the problem they had identified and their decision-making, which enabled the crew to provide feedback to the captain.

Aviation Short Investigations Bulletin - Issue 54

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

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1. Alternate airport is the airport chosen in advance which the aircraft can divert to in the case that the destination airport has weather below the minimum conditions allowable for landing.
2. EDTO was previously called extended operations (ETOPS). For the purpose of this report EDTO will be used.
3. The MEL is a list of aircraft systems which are approved to be inoperative when the aircraft is dispatched.
4. The investigation was unable to determine who the flight dispatcher spoke to from the maintenance watch section.
5. The hardcopy Technical Log on board the aircraft is the legal document for raising and clearing MEL items and therefore an unserviceability may be cleared by maintenance after flight planning is completed.
6. The flight planning documents included a nine page flight plan and 32 page briefing package with weather, notice to airmen (NOTAM) and MEL report.
7. This was an inflight requirement as opposed to a dispatch requirement. The dispatch requirement includes system redundancies to account for unforeseen failures.
8. Global navigation satellite system (GNSS) supports the aircraft GPS unit.
9. GPS 2 operated throughout the flight without fault.
10. Ground based radio navigation aid using VOR for steering guidance with DME distance information.
11. The flight plan critical point is the point between two airports, which are equi-distant in time and fuel. The critical point is used to aid decision making between continuing to a destination and diverting to an alternate if a problem occurs in flight. The critical point for QF61 was based on the critical flight condition of one engine inoperative and the cabin depressurised.
12. Instrument flight rules (IFR): a set of regulations that permit the pilot to operate an aircraft to operate in instrument meteorological conditions (IMC), which have much lower weather minimums than visual flight rules (VFR). Procedures and training are significantly more complex as a pilot must demonstrate competency in IMC conditions while controlling the aircraft solely by reference to instruments. IFR-capable aircraft have greater equipment and maintenance requirements.

On 13 April 2016, a Pilatus Britten Norman Turbine Islander (BN-2T) twin-turboprop aircraft, registered P2-SBC, departed from Tekin, West Sepik Province for Kiunga, in Western Province, Papua New Guinea (PNG). A pilot and 11 passengers were onboard the aircraft. While on approach to land, the aircraft impacted heavily into terrain, approximately 1,200m west of the runway. The aircraft was destroyed and there were no survivors.

The Accident Investigation Commission (AIC) of Papua New Guinea conducted an investigation into the accident in accordance with their obligations as the State of Occurrence under Annex 13 to the Convention on International Civil Aviation. The AIC requested technical assistance from the Australian Transport Safety Bureau (ATSB) to examine items recovered from the aircraft, including cockpit instruments and personal electronic devices. In providing this support, the ATSB commenced an external investigation under the Transport Safety Investigation Act 2003.

The ATSB has completed its examination of the recovered items. The results of the instrument examination along with a copy of the recovered data from the electronic devices was provided to the AIC.

The AIC has released the final investigation report into this accident, which is available at www.aic.gov.pg. Specific enquiries related to this accident should be addressed to the AIC by email at infor@aic.gov.pg, or in writing to:

Chief Executive Officer
Accident Investigation Commission
PO Box 1709   
Boroko, NCD
Papua New Guinea

What happened

On the morning of 6 August 2016, the flight crew of an Airnorth Embraer EMB-120 aircraft, registered VH-ANQ (ANQ) (Figure 1), prepared to conduct flight TL414 from Darwin to Groote Eylandt, Northern Territory. On board were three crew and 30 passengers. The first officer for the flight was undergoing training to become a captain. This involved undertaking all tasks normally performed by the captain including the completion of the aircraft trim sheet.^[1]

At about 0530 Central Standard Time (CST), the flight crew arrived at ANQ. They discovered that the refueller was running late and the aircraft servicing had not been completed. The aircraft load information also arrived about 10 minutes late. In an attempt to depart on time, the first officer (acting as the captain) completed the trim sheet more quickly than usual and did not conduct their usual double check to confirm that it was completed correctly. The completed trim sheet indicated 3° nose-up trim^[2] should be used for the take-off. The first officer did not pass the completed trim sheet to the captain (acting as the first officer) to sight as is required by the company standard operating procedure.

At about 0555, the crew started the take-off roll. As the aircraft rotated,^[3] the captain (the pilot flying) noted the aircraft felt out of trim, so adjusted the trim and completed a normal rotation. After the initial climb, the captain asked to review the trim sheet. The captain found that the first officer did not include 584 kg of baggage and freight in the take-off trim setting calculation. The captain and first officer recalculated the aircraft trim and found the correct trim setting for the take-off should have been 0.8° nose-up. The crew rechecked the trim sheet which showed the aircraft was within all weight and balance limitations.

The flight proceeded to Groote Eylandt without further incident.

Figure 1: Embraer 120, VH-ANQ

Source: Simon Coates

First officer comment

The first officer of ANQ provided the following comment:

• Due to the late arrival of the loading paperwork and the passengers sitting in the aircraft longer than was usual, they felt pressured to complete the trim sheet quickly and pass it to the customer service officer who was standing behind them.

Captain comment

The captain of ANQ provided the following comments:

• As the first officer was approaching the end of their training, the captain felt comfortable with the first officer’s ability to complete the trim sheet without error.
• The company operating procedure required both flight crew to sight the trim sheet. However, this did not normally occur in operations.
• The pre-flight delays had compounded to give the first officer 10 minutes to complete the pre-flight paperwork instead of the usual 20 minutes. As part of the training, the captain wanted to observe how the first officer managed the pre-flight delays and did not assist unless requested.
• The day prior to the incident, the captain reported raising concerns regarding the pressure being placed on first officers training to become captains to complete the trim sheet in under two minutes. They felt that the focus during training should be on completing the trim sheets correctly before the speed naturally increases. It is better to take extra time to complete the trim sheet correctly and double check. If the time had been taken to double check, the error may have been identified.
• The captain felt company communications to flight crew had a large focus on flights departing on time. This placed pressure on the flight crew to rush their pre-flight preparations.
• The captain found the manual trim sheets used for EMB-120 operations laborious and presented a high risk of error.

Safety action

Whether or not the ATSB identifies safety issues in the course of an investigation, relevant organisations may proactively initiate safety action in order to reduce their safety risk. The ATSB has been advised of the following proactive safety action in response to this occurrence.

Operator

As a result of this occurrence, the aircraft operator has advised the ATSB that they are taking the following safety actions:

Change to procedure

The company standard operating procedure ‘Completion of the Trim Sheet’ has changed from both flight crew being required to sight the trim sheet to include a requirement for both flight crew members to cross check the trim sheet and take-off/landing data card for correctness.

Safety message

The NASA Aviation Safety Reporting System Hurry-Up Study examined 125 incident records that involved time related problems. The study found that in 63% of incidents the error took place in the pre-flight phase. The report suggested using the following strategies to reduce the frequency of time-related errors:

• Maintain an awareness of the potential for the ‘Hurry-Up Syndrome’ in pre-flight and taxi-out operational phases.
• When pressures to ‘hurry-up’ occur, particularly in the pre-flight operational phase, it is a useful strategy for pilots to take the time to prioritise their tasks.
• If a procedure is interrupted for any reason, returning to the beginning of that task and starting again will significantly reduce the opportunity for error.
• Practicing positive crew resource management technique will eliminate many errors -- effective crew coordination in ’rushed’ situations will catch many potential problems.
• Strict adherence to checklist discipline is a key element of pre-flight and taxi-out task execution.
• Defer paperwork and non-essential tasks to low workload operational phases.

Data errors, such as the wrong figure being used as well as data being entered incorrectly, not being updated, or being excluded, happen for many different reasons. The ATSB web page Data input errors highlights that no one is immune from data input errors. However, risk can be significantly reduced through effective management and systems

The ATSB research report Take-off performance calculation and entry errors: A global perspective concluded that despite advanced aircraft systems and robust operating procedures, accidents continue to occur during the take-off phase of flight. It is imperative that the aviation industry continues to explore solutions to firstly minimise the opportunities for take-off performance parameter errors from occurring and secondly, maximise the chance that any errors that do occur are detected and/or do not lead to negative consequences.

Aviation Short Investigations Bulletin - Issue 54

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

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1. Trim sheet is a method used to determine the take-off elevator trim setting. The sheet uses the position and weight of items carried within the aircraft to determine the total aircraft weight and balance.
2. Trim adjusts the longitudinal balance of the aircraft. As items of different weights are loaded at different positions in the aircraft the balance changes. Take-off trim adjustments allow for this change to achieve a neutral force through the pilot control column during the take-off.
3. Rotation is the positive, nose-up, rotation of an aircraft about the lateral (pitch) axis immediately before becoming airborne.

On 7 April 2016, a GippsAero GA8-TC 320 Airvan (GA8) aircraft, registered P2-MFM, was being flown from Kiunga to Yehibi, Papua New Guinea. Shortly after touch-down and around 140m into the landing roll, the wheel and axle assembly from the left main landing gear leg separated from the aircraft. The pilot was able to bring the aircraft to a controlled stop.

Subsequent inspection of the right landing gear leg from P2-MFM found that it was cracked in the welded region of the axle assembly. Inspections of other aircraft in the operator's GA8 fleet, identified that numerous main landing gear legs were cracked in the same location.

The Civil Aviation Safety Authority (CASA) commenced an airworthiness investigation into the circumstances surrounding this issue. CASA requested technical assistance from the Australian Transport Safety Bureau (ATSB) to conduct a detailed metallurgical examination of the main landing gear axles from P2-MFM. To facilitate this assistance, the ATSB initiated an external investigation under the provisions of the Transport Safety Investigation Act 2003.

The ATSB has completed its examinations. Fatigue cracking and fracture was associated with marginal weld penetration between the landing gear parts and was influenced by the manufacturer's original welding processes. The manufacturer revised the assembly drawing in 2009, including enhancements to the welding procedure, such that the latest axle design is likely to have improved fatigue endurance. The ATSB was not aware of any instances of cracking of axles manufactured to the latest revision.

On 7 June 2016, the manufacturer released service bulletin SB-GA8-2016-169 (Issue 1) that recommended inspections of the axle area be conducted at service intervals not exceeding 110 hours.

A report detailing the ATSB's examination and findings was provided to CASA, the aircraft operator and the aircraft manufacturer, on 6 October 2016. Enquiries relating to the investigation should be directed to CASA on 131 757.

Figure 1: GA8 main landing gear, wheel and brake assembly showing the location of cracking and fracture on the axle assembly.

Source: GippsAero / modified by ATSB

What happened

On 8 August 2016, at about 0700 Central Standard Time (CST), a Beech 58 aircraft, registered VH-UZO (UZO), departed Gove Airport, Northern Territory, for a flight to Elcho Island Airport, Northern Territory. On board were a pilot and four passengers.

During the initial climb, the pilot selected the landing gear up and noted the landing gear motor stopped after a shorter time interval than expected. At this time, the passengers reported hearing a crunching sound. The pilot observed that the landing gear unsafe light remained illuminated after the landing gear motor stopped.

Rather than continue the flight to Elcho Island, the pilot returned the aircraft to hold overhead Gove Airport while they attempted to ascertain the reason for the landing gear malfunction. The pilot noted that the circuit breaker for the landing gear had tripped, so reset the circuit breaker and selected the landing gear down. The landing gear unsafe light remained illuminated and the circuit breaker tripped again. The pilot then contacted the aerodrome reporting officer (ARO) and requested a visual confirmation of the position of the landing gear. The ARO reported that all landing gear appeared to be fully retracted.

Given that normal landing gear extension had been unsuccessful, the pilot elected to conduct an emergency landing gear extension. The Beech 58 emergency landing gear extension requires the pilot to engage a handle into the landing gear gearbox positioned behind the front seats. The handle is then turned counterclockwise to manually lower the landing gear. Fully extending the landing gear takes about 50 turns of the handle.

The pilot held the aircraft to the north of Gove Airport and engaged the autopilot while they conducted the emergency landing gear extension procedure. The pilot reported that no resistance was felt through the extension handle when attempting the landing gear extension, the handle felt like it was not connected. The pilot then flew back overhead Gove Airport for the ARO to again report on the position of the landing gear. The ARO reported that the landing gear remained retracted. The pilot then resumed holding, and calculated that they had sufficient fuel to continue to hold for a further two hours and 15 minutes. While holding, the pilot contacted the company chief pilot and engineer to assist with further troubleshooting the malfunction. The engineer examined the aircraft wiring diagram and another Beech 58 parked at the airport. The engineer then described several methods to isolate various parts of the electrical system to identify any problem which prevented the landing gear from extending. Over the next two hours, the pilot tried these methods along with multiple attempts of the emergency landing gear extension procedure. Despite the pilot’s attempts, the landing gear remained retracted.

At about 0930, the pilot prepared for a wheels up landing. They briefed the passengers on the use of seatbelts, bracing position, emergency exit locations and actions to be taken after the landing. The ARO arranged for the emergency services to be in attendance. The pilot discussed with the chief pilot whether to land on the runway or adjacent dirt. As the runway provided a hard, smooth surface of known condition, the pilot elected to land on the runway. The chief pilot then briefed the emergency services on the intended actions of the pilot. The pilot reviewed the wheels up landing procedure in the pilot operating handbook (POH), and elected to conduct a flaps up landing to minimise damage.

At about 0945, the aircraft approached the runway. Just before the aircraft touched down, the pilot shut the engines down in accordance with the POH wheels up landing procedure. As the aircraft slid along the runway, smoke filled the cabin and the pilot selected the fuel off. Once the aircraft came to a stop (Figure 1), the occupants immediately exited the aircraft. The pilot directed the passengers to a safe location behind the aircraft.

No persons were injured, and the aircraft was substantially damaged in the accident.

Figure 1: VH-UZO after the wheels up landing

Source: Pilot

Pilot comments

The pilot of VH-UZO provided the following comments:

• To assist in troubleshooting the malfunction, multiple videos of the actions taken by the pilot and indications presented by the aircraft systems were sent to the engineer.
• The passengers were engaged to assist in the attempts to lower the landing gear. The passenger in the seat next to the pilot held the POH. Other passengers also attempted to wind the emergency landing gear handle.
• The passengers were directed to evacuate to the rear of the aircraft. The pilot has subsequently learned that the safer option is to direct passengers to the side of the aircraft and upwind, away from fuel vapours.

Engineering report

A post-accident examination of the landing gear system found that the gear box shaft bearing had fractured. This bearing secures and aligns the shaft worm drive, which attaches both the emergency handle mechanism and the electric motor to the gear box. Failure of the bearing allowed the shaft worm drive to disconnect from the gearing. The drive became jammed, causing further damage to the gear box. Damage to the gear box prevented normal operation and caused the electric motor to overload and trip the circuit breaker. The bearing failure also prevented the emergency handle from connecting to the gear box.

Safety message

Even though the operation was conducted single-pilot, this accident provides a good example of effective crew resource management techniques. The pilot quickly established that the available fuel endurance allowed ample time to carefully consider the circumstances and attempt to resolve the issue. They engaged company personnel, using multiple means, to provide as much information as possible and attempt to identify a solution to the malfunction and sought the assistance of the ARO to inspect the aircraft and to alert emergency services. Holding over an easily identifiable position, and using the passengers where appropriate to assist with management of the emergency, also reduced pilot workload. The pilot also prepared the passengers for the wheels up landing, this minimised the risk of injury and ensured the evacuation was controlled and orderly.

Aviation Short Investigations Bulletin - Issue 53

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

What happened

On the morning of 27 July 2016, V/Line passenger train 8309 departed Melbourne for Shepparton, Victoria. The train consisted of a locomotive hauling four passenger cars and was crewed by a driver and conductor. There were 22 passengers on board when the train approached the regional town of Toolamba, south of Shepparton.

At about 1147 the train had passed Toolamba, and approached the Pogue Road level crossing travelling north at about 100 km/h. At about the same time, a utility vehicle was travelling east along Pogue Road and was approaching the level crossing. The crossing was controlled by a Stop sign (Figure 1) that required road users to stop near the crossing and look for trains.

Figure 1: Pogue Road level crossing viewed from the direction of the car’s approach

Source: Chief Investigator, Transport Safety (Vic)

The driver of the car travelled this route almost daily and was familiar with the crossing. On this day, he had driven into town earlier that morning and was returning home. On the approach to the crossing, the driver’s view towards the train was obscured by an orchard and road side trees to the south-west of the crossing (Figure 2).

Figure 2: Pogue Road approach to the level crossing. The view to a train approaching from the right was obscured by road-side vegetation and an orchard.

Source: Chief Investigator, Transport Safety (Vic)

When the train came into view, the driver applied the vehicle’s brakes, leaving skid marks on the gravel road about 40 m in length. However, the vehicle could not be stopped before the crossing and collided with the first passenger carriage behind the locomotive. The impact was to the underframe area of the carriage and dislodged a diesel fuel tank from the train. The passenger compartment remained intact and there were no reported passenger injuries. The road vehicle was severely damaged (Figure 3) and its driver suffered bruising injuries.

Figure 3: Damaged road vehicle and the fuel tank from the impacted rail car.

Source: V/Line Pty Ltd

The train driver had sounded the train horn as the train approached the whistle board that was located 400 m from the crossing, and again a short distance before the crossing. He reported that he did not see the road vehicle. The impact of the car on the train alerted the driver to the collision and he made an emergency brake application.

ATSB comment

Road vehicle driver

The driver was very familiar with the crossing and had used it many times without seeing a train, probably reducing his expectation. This factor and possibly other distractions led to the driver approaching the crossing with a reduced level of vigilance.

Level crossing

Pogue Road is a single-lane gravel road with a speed limit of 100 km/h. It intersected the 100 km/h train line to Shepparton at near right angles. The crossing was controlled by Stop signs (passive control) that required road users to come to a stop and check for trains before proceeding. The signage at the crossing and the advanced warning signage on the approach was in good condition and generally consistent with the Australian Standard for railway crossing signage^[1], with minor variations not material to this incident. There have been no previous near-miss or collision incidents reported at this level crossing.

The road-side vegetation and orchard meant that the view to the track was obscured on the approach to the crossing. The provision of Stop sign traffic control measures is consistent with this configuration, as this required road users to stop in a position that would allow them to sight trains.

Passive control measures at level crossings

A range of studies have found that providing active warnings reduces crash rates by 48 to 88 per cent^[2]. The same paper recommends further research into low-cost warning devices for passive crossings^[3]. On passenger lines, the risk associated with collision extends to rail passengers.

Safety message

Road users are reminded to be vigilant when approaching a passive rail level crossing and check for trains in both directions before crossing.

Rail operators should continue to consider options for reducing the risk of collision at crossings with passive (only) control devices, particularly on passenger line corridors.

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

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1. AS1742.7 Manual of uniform traffic control devices, Part 7: Railway crossings.
2. Edquist, J., Stephan, K., Wigglesworth, E. & Lenne, M. (2009). A Literature Review of Human Factors Safety Issues at Australian Level Crossings, Monash University Accident Research Centre. p40.
3. Ibid., p82.

What happened

On 1 August 2016, at about 0830 Western Standard Time (WST), a Cessna 172 aircraft, registered VH-WKB (WKB), departed from Cape Leveque Aircraft Landing Area (ALA), Western Australia (WA). The pilot (owner) and one passenger were on board the private flight.

Prior to departure, the pilot had checked the amount of fuel in the aircraft’s fuel tanks with a dipstick and estimated there was about 50 litres of fuel remaining. The pilot planned a one hour coastal sightseeing flight to Broome, using a five knot headwind component, at a fuel flow of 35 litres per hour.

Shortly after departure, the pilot noted the headwind component had increased from five knots to about 25 knots. About 45 minutes into the flight, the fuel gauges were indicating lower than the pilot had anticipated, so they initiated a climb to a higher altitude in an attempt to improve their flight range. About one hour and five minutes into the flight, the pilot heard the engine make a ‘bit of a cough’ and noticed the fuel gauges were indicating empty. Considering that their direct track to Broome Airport would require them to fly over water and a residential area, the pilot elected to conduct a precautionary landing.

The pilot identified a clear section of straight road ahead, broadcast a MAYDAY^[1] call and landed the aircraft on the Manari road, about 30 kilometres north of Broome airport (Figure 1). The aircraft had been flying for about one hour and 10 minutes. There were no injuries and the aircraft was not damaged.

Following the landing, the pilot confirmed with Broome Air Traffic Control that they landed safely and cancelled their MAYDAY. Aviation fuel was transported by road, to where WKB had landed and it was refuelled. Two vehicles blocked a section of the road to allow WKB to depart for Broome and the aircraft landed at Broome without further incident.

Weather planning

The pilot checked the area forecast and the Broome airport aerodrome forecast (TAF)^[2] before departure and elected to use the TAF wind of five knots because they planned to fly at about 500 feet. On arrival at Broome Airport, the pilot noted the wind speed on the Broome TAF had increased to 24 knots with gusts to 38 knots.

Figure 1: VH-WBK flight with key events

Source: Google earth, annotated by ATSB

Fuel consumption

In March 2015, the pilot flew the aircraft from Moorabbin Airport, Victoria, to Kununurra Airport, WA, and calculated the average fuel flow was 32 litres per hour. In June 2016, a periodic inspection was conducted, which included a calibration check of the fuel gauges and dipstick.

The day prior to the incident flight, the pilot flew the aircraft to Mitchell Plateau ALA, where it was refuelled with aviation fuel from a drum, and then onward to Cape Leveque (Figure 1). The use of fuel from a drum at Mitchell Plateau precluded an accurate fuel flow check by the pilot and there was no fuel stock available at Cape Leveque during their overnight stay.

Subsequent to the incident flight the pilot calculated the fuel flow had increased from 32 litres per hour to 37 litres per hour.

Safety message

This serious incident highlights how several factors, which on their own were not critical, combined on the day to result in a critical situation for the pilot. The fixed fuel reserve on board at the time of departure was less than the recommended 45 minutes for piston engine aircraft flights, as published in Civil Aviation Advisory Publication 234-1(1) – Guidelines for aircraft fuel requirements. Shortly after departure the headwind component increased and unknown to the pilot, the fuel consumption was greater than planned.

The pilot commented that they were not in a rush and probably too relaxed in their approach to the flight. Consequently, the effect of the change in wind speed on fuel reserves was not given the priority that it required. They also highlighted the importance of aircraft owners confirming fuel consumption after a periodic inspection is conducted.

Aviation Short Investigations Bulletin - Issue 53

About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, a limited-scope, fact-gathering investigation was conducted in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions. Publishing information  Released in accordance with section 25 of the Transport Safety Investigation Act 2003 Published by: Australian Transport Safety Bureau © Commonwealth of Australia 2016 Ownership of intellectual property rights in this publication Unless otherwise noted, copyright (and any other intellectual property rights, if any) in this report publication is owned by the Commonwealth of Australia. Creative Commons licence With the exception of the Coat of Arms, ATSB logo, and photos and graphics in which a third party holds copyright, this publication is licensed under a Creative Commons Attribution 3.0 Australia licence. Creative Commons Attribution 3.0 Australia Licence is a standard form licence agreement that allows you to copy, distribute, transmit and adapt this publication provided that you attribute the work. The ATSB’s preference is that you attribute this publication (and any material sourced from it) using the following wording: Source: Australian Transport Safety Bureau Copyright in material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you wish to use their material, you will need to contact them directly.

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1. Mayday is an internationally recognised radio call for urgent assistance.
2. Aerodrome Forecasts are a statement of meteorological conditions expected for a specific period of time, in the airspace within a radius of 5 NM (9 km) of the aerodrome.