2009年12月21日月曜日

AR447事故 ピトー管変更勧告

A330、A340は8月にピトー管変更勧告を受けたようだ。
 A330-200が6月に大西洋上に墜落した事故で、フランスの事故調査
委員会に当たる調査分析事務所は、2度目の報告書を公表し、航空機の
速度計測装置(ピトー管)の耐空証明基準の改善を図るよう勧告した。

装備された仏タレス社製のピトー管が、内部で結氷したため、測定不能
になり、自動操縦装置が機能しなくなり、墜落の一因とみられていた。
海外報道では、EASAは、8月にピトー管をタレスからグッドリッチに
変更するように勧告している。
11月末に発生したA330のインシデントは、ピトー管を交換していな
かったのだろうか。
整備会社は自費で交換するしかないが、交換したのだろうか。


---速度計の耐空基準改善勧告 仏機墜落で事故調---
2009年12月18日 00時29分
http://www.tokyo-np.co.jp/s/article/2009121701001030.html

 【パリ共同】リオデジャネイロ発パリ行きエールフランスのエアバスA330―200が6月に大西洋上に墜落した事故で、フランスの事故調査委員会に当たる調査分析事務所は17日、2度目の報告書を公表し、航空機の速度計測装置(ピトー管)の耐空証明基準の改善を図るよう勧告した。
 事故原因を断定するには至っていないが、ピトー管の不具合が事故に密接に関係していたことを事実上認める報告で、同事務所は欧州航空安全局に適切な耐空証明基準を設けるための調査・研究を依頼した。
 ピトー管は進行方向に向いた管に入る空気の圧力で速度を計測する仕組みだが、事故機などが装備する仏タレス社製のピトー管では、内部で結氷し測定不能に陥る問題が起きていた。この場合、自動操縦装置が機能しなくなり、これが暴風圏を飛行中だった事故機の墜落の一因とみられた。
 報告書は「ピトー管の安全性テストで、特に高高度を飛行中に問題がみられた」と指摘。「高高度で分厚い雲の中を進む場合にも十分な耐空証明基準を設けるべきだ」としている。


---Report into Flight 447 crash shows passengers had not been told of emergency---
December 18, 2009
Charles Bremner in Paris
http://www.timesonline.co.uk/tol/news/world/europe/article6960721.ece

Death came without warning for the 216 passengers aboard the Air France Airbus that crashed into the Atlantic off Brazil last June, according to the investigators’ account published yesterday.

The latest report on Flight 447, a landmark disaster for aviation, said that no cause could yet be attributed but it confirmed that faulty speed sensors were partly to blame and once again implied possible errors by the crew.

Study of debris and 51 salvaged bodies showed that passengers had not been told of an emergency as Flight 447, with 228 aboard, hurtled towards the ocean while the pilots fought to regain control.

The cabin crew were not in their seats, no oxygen masks had deployed and life jackets were still in their wrappers. The aircraft did not lose cabin pressure, as previously thought, and it was not configured for ditching when it smashed belly-down into the water, said the report from the BEA (Bureau of Investigation and Analysis). This made clear that the crew had not prepared passengers for an emergency, pilots said.

Adding new detail to previous findings, the investigators said that 43 of the 51 bodies, which were from all parts of the cabin, showed severe fractures to spinal columns, pelvises and chests. These injuries reflected the upward shock to seated passengers of an aircraft hitting the water belly first, it said.

The investigators touched on an assumption that the two co-pilots may have been flying the aircraft rather than the veteran captain. “The captain may have been taking a rest or may have been at the controls, something that the investigation has not yet been able to determine,” they said. Long-haul captains usually rest for a period during the night-time cruise. The captain’s body was the only one of the three to have been recovered, which suggested that he was not on the flight deck, experts said.

The BEA, which is under fire from victims’ families for the slow pace of its work, said that no cause could be assigned without the “black box” flight recorders. A new deep-sea search is to start in the new year in the area where the regular Rio-Paris flight fell out of the sky.

The report partly blamed the speed sensors, known as Pitot tubes. Automatic data messages from the stricken aircraft showed within hours of the June 1 crash that the airliner had lost Pitot data while flying in a storm. This in turn led to a loss of automated flight controls. “It was an inconsistency in the measurements that initiated the disconnection of the various control systems: autopilot, autothrust and flight director,” the BEA said.

The consensus among Air France pilots and aviation experts is that the technology failure led to the airliner entering a high-altitude aerodynamic stall from which the crew were unable to recover.

The BEA recommended international measures to raise standards for speed data systems at high altitude. Also, not enough is known about the weather at high cruising levels, it said. It also called for better flight data recorders and new links to report parameters in “real time” by satellite.

The investigators angered the unions by implying again that the pilots of the A330 Airbus may have failed to follow standard procedures for retaining control of an aircraft with a faulty flight system. The agency studied 32 incidents of pitot failure since 2003 and noted that the crew in each of them had kept control by following Airbus methods. It also said that the three pilots on AF 447 had just completed refresher training in handling speed anomalies and that there had been no failure in the attitude instruments - modern artificial horizons - which are vital to piloting airliners.

Air France’s main union said that the BEA was seeking to help Airbus and the airline by shifting blame to dead pilots rather than questioning the systems of the highly automated airliner. “The only established fact in this investigation is the false speed data,” said Eric Derivry, an Air France captain and official with the National Airline Pilots’ Union (SNPL). “We are not saying that pilots never make mistakes, but the BEA is pointing the finger to create the impression that the pilots were not up to handling the plane,” he told The Times.

Gerard Arnoux, head of the Union of Air France Pilots (SPAF), told The Times that the pilots do not understand why the investigators are reluctant to conclude that the aircraft was in a deep aerodynamic stall "which it was obviously in". The Bureau was trying to implicate the pilots without any evidence, he said. "There is nothing to justify saying that our colleagues did not behave correctly." It suits everyone to point the finger at them.

He also questioned why the investigators had not highlighted the lack of reliable weather information on the flight decks of modern airliners. With satellite pictures that are freely available, the crew would never have become entangled in severe weather, he said.


---Air France crash report set for release---
December 17, 2009 -- Updated 0642 GMT (1442 HKT)
http://edition.cnn.com/2009/WORLD/europe/12/16/airfrance.report/

(CNN) -- Investigators probing the June crash of an Air France flight off Brazil will release their second interim report Thursday with a press briefing, officials said.

France's Investigation and Analysis Bureau will hold the briefing Thursday afternoon, the bureau said in a statement.

Flight 447 -- an Airbus A330 -- went down in stormy weather in the Atlantic Ocean on June 1 while flying from Rio de Janeiro, Brazil, to Charles de Gaulle Airport in Paris, France. All 228 people on board were killed.

Large parts of the plane, including both flight data recorders, have never been found, despite an extensive search operation that included a French navy submarine.

Investigators said earlier this week they were planning to resume the search for the data recorders, according to Agence France-Presse. Jean-Paul Troadec, director of the investigation bureau, told reporters that the new search, about 1,000 kilometers (600 miles) off Brazil's northeast coast, will begin in February. The new underwater sweeps will last a maximum three months and involve sonar and robot submarines, he said.

Troadec was in Rio de Janeiro to speak to the relatives of the 58 Brazilians who were on board, AFP reported Sunday. "We tried to convince the families that we are conducting the investigation with the full intention of getting to the truth," he said.

The upcoming report contained "no surprises" but did set out "new details, notably in terms of safety recommendations," he said.

Tests have already brought into question the performance of pitot tubes, which are used to measure the pressure exerted on the plane as it flies through the air, and are part of a system used to determine air speed.

Before it crashed, Flight 447 sent out 24 automated error messages that suggested the plane may have been flying too fast or too slow through the thunderstorms, officials have said.

The European Aviation Safety Agency (EASA) issued a directive in late August requiring airlines to replace pitot tubes manufactured by Thales Avionics on Airbus A330s and A340s. It said airlines should replace them with other Thales tubes and those manufactured by Goodrich.

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