Qantas Flight 72
Encyclopedia
Qantas Flight 72 was a scheduled flight from Singapore Changi Airport
Singapore Changi Airport
Singapore Changi Airport , Changi International Airport, or simply Changi Airport, is the main airport in Singapore. A major aviation hub in Southeast Asia, it is about north-east from the commercial centre in Changi, on a site....

 to Perth Airport
Perth Airport
Perth Airport is an Australian domestic and international airport serving Perth, the capital and largest city of Western Australia. The airport itself is located in the suburb of Perth Airport....

 on 7 October 2008 that made an emergency landing at Learmonth airport
RAAF Learmonth
RAAF Learmonth, also known as Learmonth Airport , is a joint use Royal Australian Air Force base and civil airport. It is located near the town of Exmouth on the north-west coast of Western Australia. As an RAAF base, Learmonth is one of the RAAF's three 'bare bases'...

 near the town of Exmouth, Western Australia
Exmouth, Western Australia
-Further reading:* Western Australia. Ministry for Planning. Exmouth-Learmonth structure plan. Perth, W.A. : Western Australian Planning Commission...

 following an inflight accident featuring a pair of sudden uncommanded pitch-down manoeuvres that resulted in serious injuries to many of the occupants. The injuries included fractures, lacerations and spinal injuries. At Learmonth, the plane was met by the Royal Flying Doctor Service and CareFlight
CareFlight International Air Ambulance
CareFlight International Air Ambulance is an Australian registered charity that operates air ambulances and specialist medical teams to patients anywhere in the world. The organisation was incorporated in 1986 when its first helicopter, a Squirrel AS350B was commissioned...

, where 14 people were airlifted to Perth for hospitalisation, with 39 others also attending hospital. Two planes were sent by Qantas to Learmonth to collect the remaining passengers and crew. In all, 1 crew member and 11 passengers suffered serious injuries, while 8 crew and 95 passengers suffered minor injuries. The Australian Transport Safety Bureau
Australian Transport Safety Bureau
The Australian Transport Safety Bureau is Australia’s national transport safety investigator. The ATSB is the federal government body responsible for investigating transport-related accidents and incidents within Australia. It covers air, sea and rail travel. The Australian Transport Safety...

 investigation found fault with one of the aircraft's Air Data Inertial Reference Unit
Air Data Inertial Reference Unit
An Air Data Inertial Reference Unit is a key component of the integrated Air Data Inertial Reference System , that supplies air data and inertial reference information to the pilots' Electronic Flight Instrument System displays as well as other systems on the aircraft such as the engines,...

s.

Aircraft

VH-QPA was delivered new to Qantas on 26 November 2003, initially as an A330-301. It later had a change in engine type fitted and was re-designated as an Airbus A330-303 in November 2004.

Flight details

The accident began at 12:40:28 WST
Time in Australia
Australia uses Standard time, i.e: the same well defined time for a region. The proper names of Australia's time zones are Australian Western Standard Time , Australian Central Standard Time , and Australian Eastern Standard Time...

. The aircraft was travelling at around 37000 feet (11,277.6 m) when pilots received an electronic message warning them of an irregularity with autopilot and inertial reference systems. The autopilot
Autopilot
An autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. An autopilot can refer specifically to aircraft, self-steering gear for boats, or auto guidance of space craft and missiles...

 disengaged automatically, and the aircraft climbed 200 feet (61 m) under manual control. The autopilot was re-engaged when the aircraft returned to the prior selected flight level before the autopilot was disengaged for the remainder of the flight. At 12:42:27 the aircraft made a sudden uncommanded pitch down manoeuvre, recording , reaching 8.4 degrees pitch down and rapidly descending 650 feet (198.1 m) in about 20 seconds before the pilots were able to return the aircraft to the assigned cruise flight level. At 12:45:08 the aircraft then made a second uncommanded manoeuvre of similar nature, this time reaching , 3.5 degrees pitch down and descending 400 feet (121.9 m) in about 16 seconds before being returned to level flight. Unrestrained passengers and crew as well as some restrained passengers on board were flung around the cabin or crashed on overhead luggage compartments. The pilots stabilised the plane and declared a state of alert (a pan-pan
Pan-pan
In radiotelephone communications, a call of three repetitions of pan-pan is used to signify that there is an urgency on board a boat, ship, aircraft or other vehicle but that, for the time being at least, there is no immediate danger to anyone's life or to the vessel itself. This is referred to as...

 is broadcast), which was later updated to a mayday
Mayday (distress signal)
Mayday is an emergency procedure word used internationally as a distress signal in voice procedure radio communications. It derives from the French venez m'aider, meaning "come help me"....

 when the extent of injuries was relayed to the flight crew.

Investigation

The ATSB investigation is supported by the Australian Civil Aviation Safety Authority
Civil Aviation Safety Authority
The Civil Aviation Safety Authority is the Australian national aviation authority , the government statutory authority responsible for the regulation of civil aviation.-History:...

 (CASA), Qantas, the French Bureau d'Enquêtes et d'Analyses pour la sécurité de l'Aviation Civile
Bureau d'Enquêtes et d'Analyses pour la sécurité de l'Aviation Civile
The Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation Civile is an agency of the French government, responsible for investigating aviation accidents and making safety recommendations based on what is learned from those investigations. It is headquartered in Building 153 on the grounds...

 (BEA) and Airbus
Airbus
Airbus SAS is an aircraft manufacturing subsidiary of EADS, a European aerospace company. Based in Blagnac, France, surburb of Toulouse, and with significant activity across Europe, the company produces around half of the world's jet airliners....

. Copies of data from the aircraft's flight data recorder and cockpit voice recorder
Cockpit voice recorder
A cockpit voice recorder , often referred to as a "black box", is a flight recorder used to record the audio environment in the flight deck of an aircraft for the purpose of investigation of accidents and incidents...

 were sent to the BEA and Airbus.

The aircraft was equipped with a Northrop Grumman
Northrop Grumman
Northrop Grumman Corporation is an American global aerospace and defense technology company formed by the 1994 purchase of Grumman by Northrop. The company was the fourth-largest defense contractor in the world as of 2010, and the largest builder of naval vessels. Northrop Grumman employs over...

 made ADIRS, which investigators sent to the manufacturer in the US for further testing.
On 15 January 2009 the EASA issued an Emergency Airworthiness Directive
Emergency Airworthiness Directive
An Emergency Airworthiness Directive is a directive issued when an unsafe condition exists that requires immediate action by an aircraft owner or operator. EADs are published by a responsible authorities such as FOCA, EASA or FAA related to airworthiness and maintenance of aircraft and aircraft...

 to address the above A330 and A340 Northrop-Grumman ADIRU problem of incorrectly responding to a defective inertial reference.

The Australian Transport Safety Bureau
Australian Transport Safety Bureau
The Australian Transport Safety Bureau is Australia’s national transport safety investigator. The ATSB is the federal government body responsible for investigating transport-related accidents and incidents within Australia. It covers air, sea and rail travel. The Australian Transport Safety...

 (ATSB) identified in a preliminary report that a fault occurred within the Number 1 Air Data Inertial Reference Unit
Air Data Inertial Reference Unit
An Air Data Inertial Reference Unit is a key component of the integrated Air Data Inertial Reference System , that supplies air data and inertial reference information to the pilots' Electronic Flight Instrument System displays as well as other systems on the aircraft such as the engines,...

 (ADIRU) and is the "likely origin of the event". The ADIRU (one of three such devices on the aircraft) began to supply incorrect data to the other aircraft systems.

The initial effects of the fault were:
  • false stall
    Stall (flight)
    In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases. This occurs when the critical angle of attack of the foil is exceeded...

     and overspeed warnings
  • loss of attitude information on the Captain's primary flight display
    Primary flight display
    A primary flight display or PFD is a modern aircraft instrument dedicated to flight information. Much like multi-function displays, primary flight displays are built around an LCD or CRT display device...

  • several Electronic Centralised Aircraft Monitor (ECAM) system warnings


About two minutes later, ADIRU #1, which was providing data to the captain's primary flight display, provided very high (and false) indications for the aircraft's angle of attack
Angle of attack
Angle of attack is a term used in fluid dynamics to describe the angle between a reference line on a lifting body and the vector representing the relative motion between the lifting body and the fluid through which it is moving...

, leading to:
  • the flight control computers commanding a nose-down aircraft movement, which resulted in the aircraft pitching down to a maximum of about 8.5 degrees,
  • the triggering of a Flight Control Primary Computer pitch fault.


Airbus has stated that they are not aware of a similar incident occurring previously on an Airbus aircraft. Airbus has released an Operators Information Telex to operators of Airbus A330
Airbus A330
The Airbus A330 is a wide-body twin-engine jet airliner made by Airbus, a division of EADS. Versions of the A330 have a range of and can accommodate up to 335 passengers in a two-class layout or carry of cargo....

 and A340
Airbus A340
The Airbus A340 is a long-range four-engine wide-body commercial passenger jet airliner. Developed by Airbus Industrie,A consortium of European aerospace companies, Airbus is now fully owned by EADS and since 2001 has been known as Airbus SAS. a consortium of European aerospace companies, which is...

 aircraft with procedural recommendations and checklists to minimise risk in the event of a similar incident.

The ATSB's continuing accident investigation will include assessment of speculation that possible interference from Naval Communication Station Harold E. Holt
Naval Communication Station Harold E. Holt
Naval Communication Station Harold E. Holt is located on the northwest coast of Australia, north of the town of Exmouth, Western Australia. The town of Exmouth was built at the same time as the communications station to provide support to the base and to house dependent families of U.S...

 or passenger personal electronic devices could have been involved, although based on initial analysis, the Bureau believes these are unlikely to have been of any impact.

Subsequent Qantas Flight 71 incident

On 27 December 2008, a Qantas A330-300 aircraft operating from Perth to Singapore was involved in an occurrence approximately 260 NM north-west of Perth and 350 NM south of Learmonth Airport at 1729 WST while flying at 36,000 feet. At this time, the autopilot disconnected and the crew received an alert indicating a problem with ADIRU Number 1. The crew actioned the revised procedure released by Airbus after the earlier accident and returned to Perth uneventfully. The ATSB will include the incident in their existing accident investigation.
The incident again fuelled media speculation regarding the significance of the Harold E. Holt facility
Naval Communication Station Harold E. Holt
Naval Communication Station Harold E. Holt is located on the northwest coast of Australia, north of the town of Exmouth, Western Australia. The town of Exmouth was built at the same time as the communications station to provide support to the base and to house dependent families of U.S...

, with the Australian and International Pilots Association
Australian and International Pilots Association
The Australian and International Pilots Association is a trade union and professional association formed in 1981 to represent Qantas and its related companies pilots and flight engineers. The AIPA broke away from the Australian Federation of Air Pilots in the early 1980s...

calling for commercial aircraft to be barred from the area as a precaution until the events are better understood, while the manager of the facility has claimed that it is "highly, highly unlikely" that any interference has been caused.

Compensation

In the aftermath of the accident, Qantas offered compensation to all passengers. The airline announced it would refund the cost of all travel on their itineraries covering the accident flight, offer a voucher equivalent to a return trip to London applicable to their class of travel and pay for medical expenses arising from the accident. Further compensation claims would be considered on case by case basis, with several passengers from the flight pursuing legal action against Qantas. Some have asserted that they were wearing their seatbelts at the time of the incident and some have questioned Qantas' handling of their cases.

External links

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