On 7 October 2008, Qantas Flight 72 was scheduled to fly from Singapore Changi Airport (SIN) to Perth Airport (PER). The aircraft, VH-QPA, was delivered new to Qantas on 26 November 2003, initially as an A330-301. In November 2004, it had a change in the type of engines fitted, and was redesignated as an Airbus A330-303.[13]
aci 315 08 pdf 42
The crew was led by Captain Kevin Sullivan (53), a former US Navy (1977-1986) pilot. The first officer was Peter Lipsett, and the second officer was Ross Hales. In addition to the three flight-deck crew members, with nine cabin crew members and 303 passengers, a total of 315 people were on board.[14] Captain Sullivan had 13,592 flight hours, including 2,453 hours on the Airbus A330. First Officer Lipsett had 11,650 flight hours, with 1,870 of them on the Airbus A330. Second Officer Hales had 2,070 flight hours, with 480 of them on the Airbus A330.[15]
On 7 October 2008 at 09:32 SST, Qantas Flight 72, with 315 people on board, departed Singapore on a scheduled flight to Perth, Western Australia. By 10:01, the aircraft had reached its cruising altitude of around 37,000 feet (11,000 m) and was maintaining a cruising speed of Mach 0.82.
The incident started at 12:40:26 WST, when one of the aircraft's three air data inertial reference units (ADIRUs) started providing incorrect data to the flight computer. In response to the anomalous data, the autopilot disengaged automatically. A few seconds later, the pilots received electronic messages on the aircraft's electronic centralised aircraft monitor, warning them of an irregularity with the autopilot and inertial reference systems, and contradictory audible stall and overspeed warnings. During this time, the captain began to control the aircraft manually. The autopilot was then re-engaged and the aircraft started to return to the prior selected flight level. The autopilot was disengaged by the crew after about 15 seconds and remained disengaged for the remainder of the flight.
The Australian Transport Safety Bureau (ATSB) investigation was supported by the Australian Civil Aviation Safety Authority, Qantas, the French Bureau of Enquiry and Analysis for Civil Aviation Safety (BEA) and Airbus.[3] Copies of data from the aircraft's flight data recorder and cockpit voice recorder were sent to the BEA and Airbus.[17]
The aircraft was equipped with an air data inertial reference unit (ADIRU) manufactured by Northrop Grumman; investigators sent the unit to Northrop Grumman in the United States for further testing.[19][20]On 15 January 2009, the European Aviation Safety Agency (EASA) issued an emergency airworthiness directive[21] to address the problem of A330 and A340 aircraft, equipped with the Northrop-Grumman ADIRUs, incorrectly responding to a defective inertial reference.
In a preliminary report, the ATSB identified a fault occurring within the number-one ADIRU as 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.[22][23]
About two minutes later, ADIRU no. 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 (AOA), leading to:[4]
As with other safety-critical systems, the development of the A330/A340 flight-control system during 1991 and 1992 had many elements to minimise the risk of a design error, including peer reviews, a system safety assessment (SSA), and testing and simulations to verify and validate the system requirements. None of these activities identified the design limitation in the FCPC's AOA algorithm.
The ADIRU failure mode had not been previously encountered, or identified by the ADIRU manufacturer in its SSA activities. Overall, the design, verification and validation processes used by the aircraft manufacturer did not fully consider the potential effects of frequent spikes in data from an ADIRU.
Airbus stated that it was not aware of a similar incident occurring previously on an Airbus aircraft. It released an operators' information Telex to operators of A330 and A340 aircraft with procedural recommendations and checklists to minimise risk in the event of a similar incident.[4]
After detailed forensic analysis of the FDR, the FCPC software, and the ADIRU, the CPU of the ADIRU was found to have corrupted the AOA data. The exact nature of the corruption was that the ADIRU CPU erroneously relabelled the altitude data word so that the binary data that represented 37,012 (the altitude at the time of the incident) would represent an angle of attack of 50.625. The FCPC then processed the erroneously high AOA data, triggering the high-AOA protection mode, which sent a command to the electrical flight control system to pitch the nose down.[15]
A number of potential trigger types were investigated, including software bugs, software corruption, hardware faults, electromagnetic interference, and the secondary high-energy particles generated by cosmic rays that can cause a bit flip. Although a definitive conclusion could not be reached, sufficient information from multiple sources enabled the conclusion that most of the potential triggers were very unlikely to have been involved. A much more likely scenario was that a marginal hardware weakness of some form made the units susceptible to the effects of some type of environmental factor, which triggered the failure mode.[15]
Although speculation arose that interference from Naval Communication Station Harold E. Holt or passenger personal electronic devices could have been involved in the incident, the ATSB assessed this possibility as "extremely unlikely".[15]
On 27 December 2008, a Qantas A330-300 aircraft operating from Perth to Singapore was involved in an occurrence about 260 nautical miles (480 km) north-west of Perth and 350 nautical miles (650 km) south of Learmonth Airport at 1729 WST, while flying at FL360. The autopilot disconnected and the crew received an alert indicating a problem with ADIRU no. 1. The crew performed the revised procedure released by Airbus after the earlier accident and returned to Perth uneventfully. The ATSB included the incident in their existing accident investigation of Flight 72.[24] The incident again fuelled media speculation regarding the significance of the aforementioned Harold E. Holt facility, with the Australian and International Pilots Association calling for commercial aircraft to be barred from the area as a precaution until the events could be better understood,[25][26] while the manager of the facility claimed that it was "highly, highly unlikely" that any interference had been caused.[27]
The town and state emergency and health services responded. The Royal Flying Doctor Service and a CareFlight jet ambulance evacuated the 20 more seriously injured people to Perth. Others were treated at nearby Exmouth Hospital. Qantas sent two planes, with medical teams and customs officers, from Perth to Exmouth to help treat the injured people and fly those not hurt back to Perth. People who did not want to fly that night were provided with accommodations in Exmouth.
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 a case-by-case basis,[29] with several passengers from the flight pursuing legal action against Qantas. One couple asserted that they were wearing their seatbelts at the time of the incident and questioned Qantas' handling of their cases.[30][31] Permanently injured flight attendant Fuzzy Maiava was advised not to take an NZ$35,000 compensation payment from Qantas so that he could take part in a class-action lawsuit against Airbus and Northrop Grumman. The case was dismissed on procedural grounds, though, leaving Maiava without compensation. He remained unable to work or drive a vehicle.[32]
In 2018, the events of Qantas 72 were featured in "Free Fall" (season 18, episode 7) in the Canadian TV series Mayday.[33] In May 2019, a book on the incident by Kevin Sullivan (captain of the flight) was published in Australia.[34] In June 2019, Seven Network's Sunday Night featured the events of Qantas 72 through recollections of several passengers and crew who were on board the flight, including Sullivan and flight attendant Fuzzy Maiava, as well as comments from US Airways Flight 1549 captain Chesley "Sully" Sullenberger, but Qantas has banned any of its current employees from being interviewed about the incident, including Diana Casey, an off-duty customer-service manager who helped numerous others on board, despite being injured herself.[35]
As one of the world's leading pump manufacturers, Sulzer provides a wide range of products for engineered, configured, and standard pumping solutions as well as essential auxiliary equipment. We are renowned for our state-of-the-art products, performance reliability and efficient solutions. 2ff7e9595c
Comments