Report: In-flight upset of Airbus A330 near Australia

December 19, 2011

The Australian Transport Safety Bureau (ATSB) issued the final report of their investigation into an in-flight upset accident involving an Airbus A330 in 2008.

On 7 October 2008, an Airbus A330-303 aircraft, registered VH-QPA and operated as Qantas flight 72, departed Singapore on a scheduled passenger transport service to Perth, Western Australia. While the aircraft was in cruise at 37,000 ft, one of the aircraft’s three air data inertial reference units (ADIRUs) started outputting intermittent, incorrect values (spikes) on all flight parameters to other aircraft systems. Two minutes later, in response to spikes in angle of attack (AOA) data, the aircraft’s flight control primary computers (FCPCs) commanded the aircraft to pitch down. At least 110 of the 303 passengers and nine of the 12 crew members were injured; 12 of the occupants were seriously injured and another 39 received hospital medical treatment.

Although the FCPC algorithm for processing AOA data was generally very effective, it could not manage a scenario where there were multiple spikes in AOA from one ADIRU that were 1.2 seconds apart. The occurrence was the only known example where this design limitation led to a pitch-down command in over 28 million flight hours on A330/A340 aircraft, and the aircraft manufacturer subsequently redesigned the AOA algorithm to prevent the same type of accident from occurring again.

Each of the intermittent data spikes was probably generated when the ADIRU’s central processor unit (CPU) module combined the data value from one parameter with the label for another parameter. The failure mode was probably initiated by a single, rare type of internal or external trigger event combined with a marginal susceptibility to that type of event within a hardware component. There were only three known occasions of the failure mode in over 128 million hours of unit operation. At the aircraft manufacturer’s request, the ADIRU manufacturer has modified the LTN-101 ADIRU to improve its ability to detect data transmission failures.

At least 60 of the aircraft’s passengers were seated without their seat belts fastened at the time of the first pitch-down. The injury rate and injury severity was substantially greater for those who were not seated or seated without their seat belts fastened.

The investigation identified several lessons or reminders for the manufacturers of complex, safety‑critical systems.

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Tiger Airways suspension lifted

August 10, 2011

The Civil Aviation Safety Authority has lifted the suspension of Tiger Airways Australia Pty Ltd, effective from Wednesday 10 August 2011.

This follows a thorough investigation by CASA into safety issues within Tiger Airways Australia.

As a result of the investigation and consistent with previous actions taken by CASA, a new set of conditions has been imposed on Tiger Airways Australia’s air operator’s certificate.

These conditions address key areas of operational importance within Tiger Airways and will underpin ongoing improvements in the airline’s safety performance. To continue to operate Tiger must comply with the conditions while they are in place.

Areas the conditions cover include:

  • pilot training and proficiency
  • pilot rostering and fatigue management
  • currency and revision of operational manuals and related documents
  • improved change-management processes and the appointment of additional qualified personnel in key positions
  • amendments to the airline’s safety management system

Tiger Airways Australia was required to demonstrate it had complied with the necessary safety requirements before it was permitted to resume operations.

These requirements included additional simulator and ground training for Tiger’s pilots.

The number of sectors Tiger Airways may fly is initially limited to a maximum of 18 a day during August 2011. Increased operations after August will be subject to CASA approval.

CASA suspended the air operator’s certificate of Tiger Airways Australia on 2 July 2011.

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CASA issues Tiger Airways suspension update

July 29, 2011

The Australian Civil Aviation Safety Authority (CASA) has given Tiger Airways Australia a set of conditions which can form the basis for the airline resuming operations.

A number of these conditions must be satisfied before any flights can be undertaken. Others require Tiger Airways to take ongoing actions, to CASA’s satisfaction, as the airline builds back up to a normal schedule.

The conditions do not allow for a resumption of operations until CASA is satisfied Tiger is able to do so safely.

If Tiger accepts these conditions, there will be no need for CASA to pursue its application in the Federal Court for an order continuing the suspension of the airline’s operating certificate. In the meantime, Tiger remains suspended and the matter is listed to be heard by the Federal Court on 1 August 2011.

CASA suspended the operations of Tiger Airways Australia on 1 July 2011 due to serious and imminent risk to air safety.

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CASA to seek to extend Tiger Airways Australia suspension

July 6, 2011

The Civil Aviation Safety Authority (CASA) is to seek to extend the suspension of Tiger Airways Australia Pty Ltd.

CASA suspended Tiger Airways Australia’s operations on 2 July 2011 because it believed permitting the airline to continue to fly posed a serious and imminent risk to air safety.  On July 6 CASA reported that it was seeking a continuation of the suspension until 1 August 2011 through an application to the Federal Court.

If CASA completes its investigations and determinations before 1 August 2011 and is satisfied Tiger Airways Australia no longer poses a serious and imminent risk to air safety it may be possible for it to resume operations earlier. The suspension of Tiger Airways Australia’s operations remains in place at until either the Federal Court refuses CASA’s application or CASA withdraws it.

CASA is making the application to the Court because investigations into Tiger Airways Australia will not be completed by the end of the initial five working day suspension period.

 

 


CASA grounds Tiger Airways Australia

July 2, 2011

 

The Civil Aviation Safety Authority (CASA) has suspended the operations of Tiger Airways Australia Pty Ltd with immediate effect from Saturday 2 July 2011.

This action has been taken because CASA believes permitting the airline to continue to fly poses a serious and imminent risk to air safety. The suspension of Tiger Airways Australia follows the issue of a show cause notice to the airline in March 2011.

Taking Tiger Airways Australia’s response to this show cause notice into account, CASA subsequently imposed a number of conditions on the airline’s air operator’s certificate. These conditions required actions to improve the proficiency of Tiger Airways Australia’s pilots, improvements to pilot training and checking processes, changes to fatigue management, improvements to maintenance control and ongoing airworthiness systems and ensuring appropriately qualified people fill management and operational positions.

CASA has been closely monitoring the operations of Tiger Airways Australia throughout 2011, with surveillance undertaken at a range of locations. Since Tiger Airways Australia was served the show cause notice there have been further events raising concerns about the airline’s ability to continue to conduct operations safely. In the circumstances, CASA no longer has confidence in the ability of Tiger Airways Australia to satisfactorily address the safety issues that have been identified.

The suspension is in force immediately for an initial five working days, during which time CASA must apply to the Federal Court for an extension of the grounding. If the Federal Court supports CASA’s application the court can continue the suspension for a period of time which will allow CASA to finalise investigations into the safety matters.

Tiger Airways Australia is a low cost airline which commenced services in the Australian domestic airline market on 23 November 2007. It is a subsidiary of Tiger Airways Holdings, a Singapore-based company, which is owned partially by Singapore Airlines. The main base is at Melbourne Airport. The airline operates a fleet of ten Airbus A320 aircraft.

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Study: Aircraft loading occurrences July 2003 to June 2010

December 23, 2010

Incorrect unloading can cause an aircraft to pitch up (photo: ATSB)

The Australian Transport Safety Bureau (ATSB) published a study (AR-2010-044) on aircraft loading occurrences from July 2003 to June 2010.

The report documents the number and types of safety occurrences involving loading of high capacity aircraft to raise awareness within the aviation industry of the associated issues.
Incorrect loading of containers, pallets or bags into aircraft can result in them being outside of weight or centre of gravity operating limits, and this may influence aircraft controllability. Most high capacity aircraft loading occurrences are relatively minor, with cargo locks not being raised being the most common. More serious occurrences have involved shifting cargo and unlisted cargo being loaded onto aircraft. Aircraft performance has been affected in a small number of cases, and the result has been rejected takeoff, extra stabiliser trim, or aircraft control difficulties.

The study concluded that the following practices can help to guard against common loading errors:

  • Perform cross-checks between the mean aerodynamic chord and stabiliser trim setting, for all LIRs.
  • Perform a cross-check of the aircraft weight, as recorded in the aircraft manual –  with the load report weight, and ensure the aircraft registration details are correct on the loadsheet.
  • Flight crew should not accept a loadsheet while the aircraft is being loaded.
  • Incorporate rules within load  control software that stop incorrectly configured aircraft loadsheets from being generated.
  • Remove off-loaded/rejected containers or loads from next to the aircraft where they can potentially get reloaded in error.
  • Use on-board aircraft weight sensors as a cross-check against weight and centre of gravity calculations.

 


Two Australian air operators suspended

July 24, 2010

The Australian Civil Aviation Safety Authority (CASA) has suspended the air operator’s certificates of Skymaster Air Services and Avtex Air Services. These two charter operators, which share the same ownership, are based at Sydney’s Bankstown airport.

CASA believes allowing Skymaster Air Services and Avtex Air Services to continue to operate while CASA completes further safety investigations poses a serious and imminent risk to air safety.

There have been three serious accidents and a number of incidents involving Skymaster aircraft in the last three months. On 15 June 2010 an aircraft operated by Skymaster crashed at Canley Vale in Sydney, with the pilot and a flight nurse killed. Other accidents include a wheels-up landing and a collapsed nose gear on landing. Incidents include a loss of engine power, fuel flow problems and landing gear malfunctions.

CASA’s decision to suspend Skymaster Air Services and Avtex Air Services is also based on issues relating to the safety culture of the operations, aircraft maintenance control and pilot training.

The suspension of Skymaster and Avtex will end in five business days from Friday 23 July 2010, unless CASA applies to the Federal Court for an order to continue the suspension for up to 40 days. During that time CASA will complete its investigation and determine what further action may need to be taken.

CASA’s actions are separate from the continuing investigation into the Canley Vale accident by the Australian Transport Safety Bureau, the independent Commonwealth transport accident investigator.


Study: Steady increase in Australian birdstrikes

June 30, 2010

A new report released by the Australian Transport Safety Bureau (ATSB) highlights ways to manage the risks posed by aircraft hitting birds and reveals that the reported number of  birdstrikes in Australia has steadily increased over the past eight years.

The report, which provides aviation birdstrike and animal strike occurrence data between January 2002 and December 2009, shows that in 2009 alone there were 1,340 birdstrikes reported to the ATSB.

The increase in the number of birdstrikes, however, is consistent with the increase in the number of high capacity aircraft movements over the period as well as a greater willingness of people in aviation to report safety occurrences to the ATSB.

Most birdstrikes occur within the confines of aerodromes (less than 5 km). Major and regional towered aerodromes had significantly higher rates of reported birdstrikes than General Aviation Airport Procedures (GAAP) aerodromes, and had considerably increasing rates from 2002 to 2009. GAAP aerodrome birdstrike rates do not appear to have changed.

Engine ingestion makes up 11 per cent of all birdstrike occurrences in high capacity air transport for the 8- year period, and the highest number of damaging birdstrikes occurs in high capacity air transport. Birdstrikes causing multiple parts damaged were not common throughout the period. General aviation had the highest proportion of damaging birdstrikes, with almost 24 per cent of birdstrikes causing damage. Aeroplane wings and helicopter rotor blades are the most commonly damaged aircraft components across all operational types, particularly in general aviation. There have been eight occurrences from the period of 2002-2009 that have resulted in serious aircraft damage, and four that have resulted in injury.

The most common types of birds struck by aircraft were lapwings/plovers, bats/flying foxes, galahs, and kites. Not surprisingly, larger birds were more likely to result in aircraft damage.

Animal strikes were relatively rare. High capacity air transport had the highest average with 11.5 animal strikes per year, with general aviation having the second highest average with 9.3 animal strikes per year. The most common animals involved in strikes were hares/rabbits, kangaroos, wallabies, and foxes/dogs. Damaging strikes mostly involved kangaroos, wallabies and livestock.

Bird hazard control at aerodromes was found to be mostly related to the control of grass height (short or long) and growing specific plants or grass, and the daily or weekly use or auditory deterrents, especially car horns and shotguns.


Report: Ground operations occurrences at Australian airports 1998 to 2008

June 17, 2010

The Australian Transport Safety Bureau (ATSB) released a study of ground operations occurrences at Australian airports from 1998 to 2008. The key to preventing ground occurrences appears to revolve around ensuring effective communication between pilots, ground crews and air traffic services through a process of checks and balances.

The aviation industry has been slow to acknowledge the risks associated with ground operations. While most occurrences on airport aprons and taxiways do not have consequences in terms of loss of life, they are often associated with aircraft damage, delays to passengers and avoidable financial costs to industry.
The most common contributing factor to ground operations occurrences were individual actions. For occurrences between 1998 and 2008, these most frequently involved action errors, where a person deviated either from plans or standard operating procedures. Common examples were towbar connection procedures and pushback errors, like turning back too sharply with the tug and damaging the nose or landing gear of the aircraft. Less frequently, individual action errors were associated with a violation, information, or decision error. Violations involved a deliberate intention to deviate from standard operating procedures. Examples included opening the doors while the aircraft anti-collision beacon was operating, or vehicle drivers failing to give-way to aircraft on the apron or taxiways. Decision errors indicated that planned actions were not adequate for the situation; for example,


ATSB releases report on mishandled go-around at Melbourne

March 5, 2010

The Australian Transport Safety Bureau (ATSB) released the final report AO-2007-044 of their investigation into a serious incident during a go around involving an Airbus A320 at Melbourne, Australia.

On July 21, 2007 an Airbus A320-232 aircraft was being operated on a scheduled international passenger service for Jetstar between Christchurch, New Zealand and Melbourne, Australia. At the decision height on the instrument approach into Melbourne, the crew conducted a missed approach as they did not have the required visual reference because of fog. The pilot in command did not perform the go-around procedure correctly and, in the process, the crew were unaware of the aircraft’s current flight mode. The aircraft descended to within 38 ft of the ground before climbing.
The aircraft operator had changed the standard operating procedure for a go-around and, as a result, the crew were not prompted to confirm the aircraft’s flight mode status until a number of other procedure items had been completed. As a result of the aircraft not initially climbing, and the crew being distracted by an increased workload and unexpected alerts and warnings, those items were not completed. The operator had not conducted a risk analysis of the change to the procedure and did not satisfy the incident reporting requirements of its safety management system (SMS) or of the Transport Safety Investigation Act 2003.

As a result of this occurrence, the aircraft operator changed its go-around procedure to reflect that of the aircraft manufacturer, and its SMS to require a formal risk management process in support of any proposal to change an aircraft operating procedure. In addition, the operator is reviewing its flight training requirements, has invoked a number of changes to its document control procedures, and has revised the incident reporting requirements of its SMS.
In addition to the safety action taken by the aircraft operator the aircraft manufacturer has, as a result of the occurrence, enhanced its published go-around procedures to emphasise the critical nature of the flight crew actions during a go-around.


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