France/brazil- air France Flight 447 crash Summary



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FRANCE/BRAZIL- Air France Flight 447 crash

Summary:

Last investigations ended in May of this year, despite calls by victims’ families to continue. The black box was never recovered, despite an extensive search by French submarines. The general consensus is that the crash was the result of a technical failure—malfunctioning airspeed sensors (pilot tubes) are the most widely cited and known to have been problematic on Airbus 330s. It was also suggested that the failure of these instruments may have occurred in conjunction with, or been caused by, bad weather conditions, specifically a thunderstorm. Latter reports, however, indicate that this was unlikely. Early theories that the plane either came apart in air, or was blown-apart by a bomb, have been widely dismissed.

Most recent articles are 3,4,5 and 7.


  1. Could a Computer Glitch Have Brought Down Air France 447?

Jun. 05, 2009

http://www.time.com/time/world/article/0,8599,1902907,00.html

As the French team leading the investigation into the Air France Flight 447 crash works through the multitude of likely and less likely disaster scenarios — from the repercussions of stormy conditions to an act of terrorism — perhaps among the most difficult to assess will be possible flight computer malfunctions. Air France CEO Pierre-Henry Gourgeon noted on Monday that immediately preceding AF447's disappearance, automatic messages sent by the plane indicated "multiple technical failures." As details emerge regarding these messages, experts will struggle to understand whether they were the inevitable result of the plane's breaking up or indicators of the failures that led to the accident. (Read "What Brought Down Air France Flight 447?")

Gourgeon said the "succession of a dozen technical messages" sent by AF447 showed that "several electrical systems had broken down" immediately prior to the crash. A chronology of these messages acquired by the São Paolo daily Jornal da Tarde show that moments before the plane is believed to have plunged into the ocean, its autopilot became disengaged and the plane sustained damage to its stabilizing controls and flight systems, as well as a failure of the systems that were monitoring the aircraft's speed, altitude and direction: the ADIRU (Air Data Inertial Reference Units) and the ISIS (Integrated Standby Instruments System). These are key components in fly-by-wire systems, which use computers and wires instead of mechanics and hydraulics to control a plane's flight. (Watch TIME's video of the rescue of US Airways flight 1549.)

On Wednesday, TIME revisited an October 2008 incident in which a Qantas Airbus 330 — the same model as AF447 — unexpectedly went into a brief yet harrowing 20-second nosedive, causing multiple injuries and requiring an emergency landing. The investigation that followed blamed an ADIRU failure for the 330's uncommanded dive: one of the plane's three ADIRUs, which are designed to help the plane's flight-control computer fly the plane safely, began sending erroneous data spikes to the flight-control computer. Instead of deferring to the information of the two functioning ADIRUs as it normally should, the computer acted on the false data and sharply altered the plane's course, with near disastrous results. It was later learned that the same plane had experienced a similar occurrence in September 2006, as had three other flights. All those planes carried the same brand and model of ADIRU, as do more than one-third of the 330s and 340s in the Airbus fleet. So if this model of ADIRU has a history of failure, why does Airbus continue to fit them in its 330s and 340s?

According to Airbus spokesman Justin Dubon, any comparisons between the Qantas and Air France flights are fundamentally misleading. "One thing that has got to be clear is that there are more than one manufacturer of ADIRUs, and the ADIRU manufacturer for the Qantas case is not the same for the Air France case," he tells TIME. As reported in the aviation trade magazine Air Transport News, manufacturer Northrop Grumman makes the ADIRUs for Qantas, and Honeywell for Air France. "There are no similarities in ADIRUs between the two cases," says Dubon. (Q&A: How to survive a plane crash.)

As for the Qantas 330s and the rest of the Airbus 330 fleet, Dubon says they will continue to fly with their same ADIRUs until directed otherwise by investigative authorities. "The [Qantas] investigation is still ongoing, and we're still involved in giving technical assistance to that, but no final recommendations have been made," he says. "And obviously, when the investigators do, then we will act on those."

But even if there are recommendations to be made, it's unlikely they will come anytime soon. According to an aviation source close to the Australian investigation, Qantas remains perplexed by the phenomenon, finding that since October 2008 that particular A330 has never suffered a repeat ADIRU failure, even when flying the same routes under similar conditions. "So it's something they need to get to the bottom of," says the industry insider, who requested anonymity. "Because it's so unpredictable — it happens one time, and then never happens again — they're still trying to work out what it is."

The Airbus 330 is not the only model to suffer ADIRU failures. An Airworthiness Directive issued by the U.S. Federal Aviation Administration last year warned airlines of instances of failure in ADIRUs aboard Airbus 319, 320 and 321 models that "could result in loss of one source of critical altitude and airspeed data and reduce the ability of the flight crew to control the airplane." Dubon says these issues are "totally unrelated ... Our safety people have informed me that is not relevant to either the Qantas case or the Air France case."

But some people have firsthand experience of ADIRU failures on Air France flights: Air France pilots. Julien Gourguechon, International Secretary General of the French Pilots Union (SNPL) and an Air France pilot of 10 years, says ADIRU failures are not foreign to him, his colleagues or other French pilots flying for other companies and the military. "For sure there are pilots from SNPL who have experienced ADIRU problems," he says. But, he adds, this is "very rare ... You don't have more fly-by-wire technical failure with them than you do with hydraulic, mechanic or engine failure." As for Flight 447, even if the plane's ADIRU did malfunction, an electrical short circuit or other problem may actually be to blame, he says. "The ADIRU is fed by a lot of sources, and the failure of one of these sources could lead to an ADIRU failure."

For now, Gourguechon finds the endless speculating exhausting. "Initially we were talking about electrical failure, yesterday we were talking about icing conditions, tomorrow we will talk about something else," he says. "ADIRU failure is as credible as very bad weather, hail, an electrical failure. I would not give priority to one scenario."

But until investigators figure out what happened — if they ever do — Gourguechon says there's little chance we'll be able to escape the realm of the hypothetical. "The biggest fear for us is that if we don't find the [flight] recorders, then all the analysis, even made by experts and professionals with all the time they need, runs the risk of being very incomplete and based on a lot of interpretation."


  1. Air France 447 crash: Autopsy strongly suggests mid air breakup

18 June 2009 @ 02:25 pm BST

http://uk.ibtimes.com/articles/20090618/air-france-447-crash-autopsy-strongly-suggests-mid-air-breakup_1.htm

The autopsy results from some of the 50 bodies recovered so far show strong signs that the Air France flight 447 broke up mid air.



The victims of the Air France 447 crash had multiple fractures in legs, hips and arms but no signs of burns or water in the lungs. This indicates that the injuries were caused before the plane hit the water.

Air investigation experts have said all of the signs from the autopsy points towards the fact that the plane broke up in mid air before crashing into the water.

A former U.S. National Transportation Safety Board official said those injuries could mean the plane broke apart in the air.

Had the plane broken up after impact, it would have suffered far greater damaged with the parts of the plane becoming fragmented. The bodies would have suffered greater damage as well.

FOR FULL COVERAGE OF THE AIR FRANCE CRASH CLICK HERE

The tail fin was recovered intact and recently, the entire galley kitchen of the aircraft was recovered from the Atlantic Ocean.

The galley kitchen (shown in the picture) was one of the largest intact pieces of the Air France 447 to have been recovered. The nature of the galley raises the point that the breakup occurred in mid air leading to the aircraft parts breaking up one after another.

A direct impact into the ocean from such a high altitude would most likely have caused a severe disintegration of the plane.

The bodies recovered so far were located in two or more different locations separated by large distance. This gives rise to the prospect that the passengers would have fallen out as different parts of the flight broke and gave way.



  1. Revealed: The truth behind the Air France disaster that killed 228 people

11:23 PM on 28th May 2010

http://www.dailymail.co.uk/news/article-1282367/Air-France-crash-The-truth-disaster-killed-228-people.html?ito=feeds-newsxml

Airbus A330-200: A new documentary claims that technical failures with air speed indicators might have led to the crash

What had gone wrong? An awful five days later, the shattered wreckage of Flight 447 was discovered, floating in the Atlantic 750 miles off the coast of Brazil. All 228 passengers and crew were dead.

Despite a £24 million search operation, the all-important black boxes could not be recovered.

No one was able to explain what had happened. To the anger of relatives, French investigators will not make a final report on the disaster until the black boxes are found.

But now, for the first time, the story behind this devastating air disaster can be told. A BBC2 documentary, Lost: The Mystery Of Flight 447, to be screened tomorrow night, has brought together leading aviation experts to conduct a forensic investigation into the crash.

Amazingly, they have been able to pinpoint exactly what happened on that fateful night, even though the aircraft left barely a trace when it crashed.

Furthermore, they are able to answer the question: could it happen again?

Tony Cable worked for the UK Air Accidents Investigation Branch for 32 years. He was the senior investigator on the fatal Concorde crash in Paris ten years ago, and on the Lockerbie bombing.

'The normal way of investigating an accident is to look at the crash site. In this case, though, there's only a small amount of floating wreckage,' he says.

'The flight data and cockpit voice recorders are clearly at the bottom of the ocean with the rest of the wreckage - a very, very big handicap to the investigation.'

How, then, did the team begin? First, they eliminated the possibility of a terrorist attack.

'The possibilities that immediately come to mind would be a bomb or a structural break-up,' says Cable.

He drafted in John Cox, one of the world's leading aviation safety consultants, and they pieced together the recovered aircraft parts to find out what forces acted on them in the last moments of flight.

This method was used to solve the mystery of TWA flight 800, which crashed off the coast of New York in 1996. By examining fragments of that fuselage, experts determined that faulty wiring had caused a fuel explosion.

Engineer Jim Wildey is a veteran of that investigation. Looking at the recovered parts from Flight 447, he made the first major breakthrough: the plane showed signs of a highspeed impact with the water.

'The nose cone has been flattened, crushed and torn,' he says. 'This is a very clear sign that this piece was on the airplane when it hit the water.'

A floor section from the cargo compartment also revealed that the plane was level at the point of impact, and hit the water at speed.



It appears, then, that flight 447 didn't explode in mid-air; it simply fell out of the sky. But if there was no explosion, what did happen?

The A330 is a jewel in the crown of European aerospace giant, Airbus. It had previously been considered extremely safe, with 700 in service around the world and not a single passenger fatality before Flight 447.

The plane uses a state-of-the-art fly-by-wire computerised control system, where mechanical levers are replaced by electronics. When the autopilot is switched on, the plane flies itself.

'Ninety-nine per cent of the time when you're sitting as a passenger flying at 35,000 feet, the autopilot is flying the aeroplane,' says Captain Martin Alder, former chairman of the British Airline Pilots' Flights Safety Group.

Using Air Traffic Control transcripts, Cable has been able to piece together the last devastating moments in the cockpit.

He believes that flight 447 would have been on autopilot as it headed out over the Atlantic, with Captain Marc Dubois, 58, and his co-pilot standing by. Three hours out from Rio de Janeiro, Flight 447 was still on track.

The last crew conversation with on-ground controllers was routine. The co-pilot called out the plane's position using the internationally recognised phonic alphabet: 'Charlie Papa Hotel Quebec.'

But at 1.35am, all radio communications ceased. But for another 35 minutes, Flight 447's computer continued to send out automatic position reports by satellite to the Air France base at Charles de Gaulle airport.

A last reading showed a location at 2.10am, 70 miles from where the wreckage was discovered.

So what brought down the plane? Looking through meteorological data, the team discovered that there was a thunderstorm in the area at the time. But why would experienced pilots fly into a storm?



'The idea that a pilot would fly through a thunderstorm - no, absolutely not,' says aviation safety expert John Cox.

Several other flights that night took the same route as Flight 447, but the pilots made detours of up to 90 miles to avoid the storm system, which towered to an altitude of 50,000ft.

The investigating team believes that a smaller storm in front of the larger weather front confused the flight's radar system, so that the crew did not see the thunderstorm coming.

It meant they had no choice but to ride out the turbulence. The pilot would have slowed down the engines - the standard method for flying through such conditions.

At 2.10am - the plane's last known position - it appears that Flight 447 entered a rapidly developing storm system that its radar detected too late. A little more than four minutes later, everyone on board was dead.

So what happened in those critical intervening minutes? Just after 2.10am, the flight computer sent a torrent of automatic fault messages to Air France in Paris.

Called by one pilot 'the last will and testament of the aircraft', these messages show that Flight 447 suffered 24 critical faults in just four minutes and 16 seconds.

The first message showed that the autopilot had switched itself off, so the pilot had to take manual control. Then the systems controlling air speed and altitude failed.

In the cockpit, instrumental display screens would have gone blank, and flight-control computers would have died. One by one, the most critical safety features in the cockpit failed.

'It must have been a very busy and confusing situation on the flight deck,' says Cable.

It is a harrowing image, indeed. The cockpit would have filled with a multitude of audio and visual alarms, while the pilots desperately fought a losing battle to control the aircraft and keep it in the air as it was buffeted by a gigantic thunderstorm.

A final, ominous warning was sent by the plane to Paris: the Advisory Cabin Vertical Speed message, which means that the aircraft was descending at a high rate.

This last, terrifying message came just before Flight 447 and its passengers hit the water at hundreds of miles an hour. But what could have caused all the vital automatic systems to malfunction at once?

It appears that the three pitot tubes (speed sensors) failed simultaneously. It could be that they were unable to cope with the storm conditions facing Flight 447.

Accident investigators believe that super-cooled water in the clouds - well below freezing, but too pure to turn into ice - could have disabled the pitot probes.

Cable has discovered that since 2003, there have been 36 incidents involving frozen pitot tube on A330s or the similar A340s.

Indeed, in 2007, Airbus recommended a refit of all A330s with upgraded pitots. Flight 447 had not yet been refitted.



With no airspeed data, Flight 447's automatic systems would have collapsed one by one - which is exactly what happened.

It seems that in total darkness, and in the midst of a storm, the crew were forced to retake manual control of the plane.

John Cox explains how the pilots would have been bombarded with confusing information, saying: 'That crew faced an almost unheard of series of failures, one right behind the other.'

The most immediate danger was that the airplane would stall, which would lead to a sudden, uncontrollable descent (it had already slowed suddenly to cope with the turbulence).



Cox says: 'There is a good possibility that at some point in the last four minutes, it did stall.'

An unlucky series of events caused the accident, then, culminating in the automated systems failing and engines stalling.

Used to flying with high levels of automation, it seems the pilots did not have the skills to recover the situation.

Tragically, from the way the airline hit the water - nose up, with wings level - it appears that the crew may have come close to saving their passengers' lives.

It is likely they were recovering the situation but ran out of time, and suffered a second, and this time terminal, stall.

More than that, we will probably never know.

The airplane's black boxes, recording the last moments in the cockpit, stopped transmitting location signals after one month. Efforts to find them using imaging sonar continue.

So could such a tragedy happen again? Cable certainly believes that Flight 447 raises some vital issues for airlines.

'It has raised the question about whether the situation is actually being made worse by the increase in automation, whereby crews don't get a great deal of opportunity to manually fly the aircraft,' he says.

Airbus has also been criticised for not yet replacing all pitot probes in its fleet. In the face of new evidence, it maintains that even if they fail, pilots should be able to operate the plane.

A terrifying technical disaster, then, and one that led to a very human tragedy.

Alexander Bjoroy's parents held a memorial service for him last year, paying tribute to their son, saying: 'The world was his home. Alexander embraced other cultures and respected them greatly.

'He loved to travel and see and experience new places and people. We were very fortunate to share so many marvellous experiences together in his short life.'

The body of Swedish national Christine Schnabl was one of 51 recovered, but her five-year-old son Philipe was never found. She was not wearing a life jacket - it seems there was no time.

Her husband, Fernando, is preparing an album of pictures and cuttings to give to their daughter Celine when she is old enough to understand. One day, he hopes, he will be able to give her more answers.

For now, however, he simply tells her that her mother and brother have gone to a 'good place in the sky'.



  1. One year on, families of Air France victims seek answers

June 1, 2010

http://edition.cnn.com/2010/WORLD/europe/05/31/france.brazil.crash.anniversary/index.html

(CNN) -- On the one-year anniversary marking the crash of Air France Flight 447, which killed 228 people when it fell into the Atlantic Ocean, victims' families will push for more thorough searches and more evidence, a family activist said Monday.

The Airbus A330-200 crashed into the ocean as it headed from Brazil to France, in one of Air France's worst tragedies.

A series of ceremonies will take place in Paris on Tuesday; a Mass was held Monday in Rio de Janeiro.

Brazilian businessman Martin Van Sluys, who has traveled the same Rio de Janeiro-Paris route numerous times to meet with French officials, said he will not give up his fight for a comprehensive report that can explain the causes behind the crash that cost the life of his sister.

"I keep thinking to myself as I travel in these planes, this could be me one day, this could be my son. There are so many planes flying around that could have the same issues," said Van Sluys, who acts as spokesman for families of the crash victims.

According to Brazil's air force, on May 31, 2009, the crew of AF Flight 447 made their last contact with Brazil's Atlantic Control Center (ACC) at 22:33 GMT, informing the center of the plane's position as it crossed the Atlantic.

Soon after, Brazil's air control contacted Dakar's control center in North Africa and reported that AF 447 was entering an area on its route known for constant bands of severe turbulence, officials said.

There was no further contact with the plane.

In the months following the crash, investigators moved through three separate phases of the incident probe.

In May, France' air investigation agency, BEA, announced the end of the third phase of its investigation without citing a specific cause of the crash. The plane's "black box" flight recorder remains missing in the ocean, according to Air France.

"We have demanded a fourth phase," said Van Sluys.

If financially-troubled Air France commits to a fourth search phase that would cost the company millions of euros in personnel time and resources, company officials may come close to meeting some of the victims' demands, Van Sluys said.

"My objective is to see a final report with concrete evidence," said Van Sluys. "We know how costly the truth could be to some of the interest groups behind these investigations, from the manufacturers to the suppliers."

"But what keeps me going if this had happened to me, my sister, who was a journalist and never accepted injustice, would have done this for me," he said.


  1. Air France Crash Investigator Examines Airbus Emergency Drill

June 24, 2010, 5:22 AM EDT

http://www.businessweek.com/news/2010-06-24/air-france-crash-investigator-examines-airbus-emergency-drill.html

June 24 (Bloomberg) -- The Air France Flight 447 crash inquiry is reviewing pilot instructions issued by Airbus SAS for dealing with instrument failures of the kind implicated in the accident, according to the lead investigator.



France’s BEA air-accident investigation bureau is examining the directive to climb in response to the loss of airspeed data, Alain Bouillard said in an interview. Air France said it has restricted use of the procedure in thin air at high altitudes on concern that it may increase the risk of a mid-air stall.

The emergency maneuver “can lead to a reduction in speed” when carried out at cruising level, Air France safety chief Etienne Lichtenberger said in an interview. “The risk of a low- speed stall is significant at high altitude, so it’s not a good idea to reduce speed.” Airbus said it stands by the guidance.

The switch leaves Air France at odds with the drill still applied by other airlines. In its preliminary findings, the BEA blamed erroneous airspeed data for system failures logged by automated transmissions from the A330 airliner en route to Paris from Rio de Janeiro, minutes before it plunged into the mid- Atlantic on June 1, 2009, killing all 228 people on board.

The Airbus maneuver instructs pilots to climb at a five- degree pitch attitude -- the aircraft’s angle above horizontal -- when airspeed readings become unreliable anywhere above 10,000 feet (3,048 meters). Only later in the procedure are they told to check whether it’s safe to level off.

‘Hard to Fathom’

When cruising at or above 35,000 feet, Flight 447’s last known altitude, pulling up the nose and climbing is an inappropriate response to speed-sensor failures, according to pilots and independent experts.

“It’s hard to fathom why they would suggest that,” said Hans Weber, president of Tecop International Inc., an aviation consulting firm based in San Diego, who has given safety advise to the U.S. Federal Aviation Administration and companies including Airbus parent European Aeronautic, Defence & Space Co.

“If you’re at high altitude and you carry on climbing at five degrees for too long you will lose control of the aircraft,” Weber, a physicist by training, said in an interview. “It’s what pilots call the coffin corner -- you’re quickly running out of lift in the thinner air.”

The BEA is “looking at the pertinence of these procedures” and may suggest a review even if the plane’s flight recorders, which might indicate what caused the crash, aren’t found, Bouillard said in the June 18 telephone interview. “It’s one line of inquiry -- but it’s still too early to say whether anything needs to be improved or changed.”

‘Piloting Sense’

Cedric Maniez, a pilot who flies A330s for Air France, said knowing when to follow the Airbus drill was a “matter of good piloting sense.”



When airspeed data is lost at high altitude, “you don’t touch the pitch attitude, you just try to keep it level with constant thrust,” Maniez said. “Unfortunately there’s no way of knowing what happened aboard Flight 447 or to what extent the unsuitability of this emergency maneuver might have played a role.

Three search operations have failed to recover the black- box flight recorders.

Jeremie Teahan, a spokesman for the European Aviation Safety Agency, which certified the maneuver and reviewed it again after the crash, said the authority has “not found any issues with the Airbus procedures for the time being.”

Airbus spokesman Stefan Schaffrath said in an e-mail that “strict adherence to these approved procedures remains the best way to manage unreliable airspeed situations.”

New Instructions

Four days after the crash, Air France gave its pilots new instructions that contradict the Airbus procedure for coping with airspeed-data loss.

When the problem occurs at safe cruising altitude, pilots should “maintain the same pitch attitude and engine thrust,” according to the June 5, 2009, memo signed by Lichtenburger and three other executives. Crews should then troubleshoot “without carrying out the emergency maneuver.”

Most pilots realize that there is no need to climb when already at cruising altitude, Lichtenberger said. Air France issued the memo because it nonetheless “felt there was a risk that pilots might follow the Airbus procedure to the letter.”



Air France also raised the issue with Airbus and EASA officials after its own tests showed that maintaining the five- degree configuration could slow an A330 from 270 knots to 230 knots in about two minutes, Lichtenberger said. “That means you’re getting closer to stalling speed.”

Stall Warnings

With an estimated mass of 205 metric tons at the time of the crash, the Airbus A330 would have had a stalling speed of about 170 knots, data from the manufacturer show.

According to the final radio transmissions, the failure of Flight 447’s airspeed sensors, or Pitot tubes, caused the autopilot to shut down about four minutes before a rapid loss of altitude, recorded in the final message. Debris analysis and post-mortems of the 50 bodies show that the plane hit the water belly-first in a near-vertical plunge, investigators say.

The BEA has documented 13 other cases of high-altitude airspeed-data loss, of which nine resulted in stall warnings. Some of the crews -- all of which managed to overcome the problem -- had begun and then abandoned the emergency climb maneuver when the alarm sounded, Bouillard said.

The BEA has also called for further study of atmospheric ice crystals that may be capable of disabling Pitot tubes for longer periods and at higher altitudes than previously thought possible.

“When Airbus wrote the instructions they were probably of a mind that the emergency would occur well below cruising altitude,” Tecop’s Weber said. “There tends to be an assumption that the chances of encountering real atmospheric problems are very much reduced at high altitudes.”



  1. Report into Flight 447 crash shows passengers had not been told of emergency

December 18, 2009

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.



  1. Air France crash may have had maintenance problems

25 Apr 2010

http://www.telegraph.co.uk/news/worldnews/europe/france/7632542/Air-France-crash-may-have-had-maintenance-problems.html

According to a preliminary report into the loss of flight AF 447 last June, specialists removed nine "pitot tubes" out of a total of 84 seized from Air France and found that some were either slightly or highly degraded.

The finding could mean that the probes were not cleaned often enough, said the Liberation newspaper, which has seen a copy of the report.

In December, the French air accident investigation agency BEA said that the jet's speed probes, made by Thales, the French firm, gave faulty readings and were "one of the factors" in the crash but "not the sole cause".

Airbus and US and European air authorities ordered airlines to replace the tubes on A330 and A340 aircraft made by Thales with a different model produced by US firm Goodrich.

Air France said in a statement that the BEA enquiry "showed that Air France scrupulously respected all the procedures set out by the manufacturers and the authorities".

It said it had not seen the report cited by Libération.

One lawyer representing families of the victims said the new report "doesn't show much new", and that the "only authority" they would rely on was the investigating judges.

However, Gérard Arnoux, head of the UFPL-CFTC pilot's union, questioned the impartiality of the BEA. "They are stuck in the same obsessive refusal to acknowledge that the probes are the prime cause of the accident," he said.

The crash of AF 447, an Airbus A330, occurred on June 1, as the plane was flying from Rio de Janeiro to Paris. It was Air France's worst ever disaster.

French authorities said last month they had resumed the search for the black box recorders of the passenger jet.



  1. Missing Air France jet suffered systems failure

08/06/2009

http://www.expatica.com/fr/news/french-news/Missing-Air-France-jet-suffered-systems-failure_53364.html

Paris – French crash investigators said on Saturday that the Air France jet which plunged into the Atlantic had speed monitors that had often failed on other planes and were due to be replaced.

The head of the air accident investigation agency said the missing Rio to Paris flight, which crashed on Monday with the loss of all 228 people on board, had suffered multiple systems failures in its final moments.

Automatic error messages broadcast by the A330 jet just prior to the crash showed that its autopilot had cut out after it received conflicting speed readings, BEA director Paul-Louis Arslanian told reporters.

"There is a programme of replacement, of improvement," he said, adding that planes that have not yet had the replacement are not necessarily dangerous, and that in other cases pilots had been able to regain control.

On Friday, Airbus urged all pilots of its jets to review a warning issued in July 2001 on the procedures to follow if speed indicators give conflicting readings and force the autopilot to cut out.

Investigators seeking clues to what had caused flight AF 447 to crash so suddenly have so far had to rely on the automatic messages as salvage crews have been unable to locate the wreckage in deep Atlantic waters.

Brazilian air force spotters believe they have identified floating debris, but no surafce vessel has been able to recover any, and a French nuclear sub and a research ship equipped with mini-submarines are steaming to the scene.

Early speculation as to the cause of the accident focused on foul weather, as the jet was flying through a thunderstorm, but Arslanian said the conditions had not been exceptional for the region.

He also played down the idea that a terrorist bomb might have destroyed the plane, saying that the 24 error messages showed the onboard electronic systems including the autopilot had shut down one by one.



But he did not formally rule out an attack: "Really, that would be truly astonishing, but that's not to say it is 100 percent impossible."

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