Editors picks

Do we still need to find black boxes?

19 March 2010
By David Thorpe Ieng MIET
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Investigators probing the June 2009 crash of an Air France flight in the Atlantic Ocean still do not know what brought the plane down, who was at the controls when it crashed, or what the pilots did in the moments leading up to the disaster, according to the latest report.

Flight 447 - an Airbus A330 - went down in stormy weather in the Atlantic Ocean on 1 June 2009, while flying from Rio de Janeiro, Brazil, to Charles de Gaulle Airport in Paris, France. All 228 people on board were killed. Most of the bodies were never recovered. The plane hit the water belly first, essentially intact, studies of the debris and the bodies that have been recovered show that oxygen masks were not deployed, indicating that the cabin did lose pressurise.

Automated messages sent from the plane in the minutes before the crash showed there were problems measuring airspeed, the investigators said, but that alone was not enough to cause the disaster. Large parts of the plane -- including the flight data recorder and cockpit voice recorder -- have never been found, leaving investigators without key pieces of the puzzle.

Investigators have been trying to begin a new search for the recorders, but are being hampered by bad weather.

The area where the plane went down is far out in the Atlantic -- two to four days for ships from the nearest ports in Brazil or Senegal in West Africa. The underwater terrain is rough, with great variations in depth - that is, underwater mountains and valleys - over short distances, the report says

.The new search should involve air-accident investigators from the United Kingdom, Germany, Brazil, Russia, the United States and France, as well as the US Navy. Jean-Paul Troadec, director of the French investigation bureau, told reporters that the new search, about 1,000 kilometres (600 miles) from Brazil's northeast coast, will involve sonar and robot submarines and is planned to last for 60 days.

Communications with civil aircraft
Before it crashed, Flight 447 sent out 24 automated error messages that suggested the plane may have been flying at the wrong speed through the thunderstorms. This poses a wider question: why do aeronautic communication channels carry such limited information, with an aircraft’s fly-by-wire data being assigned to the black box, and speech channels for ground control to talk to the flight crew not always being available? The question of why automated error messages from the aircraft did not include its exact location must be an important point for France's air accident investigation agency to follow up.

Mobile phones can send data as text messages throughout the world, but once aircraft are in the air we appear to still be in the “Biggles era”. Yet a combination of geostationary satellites and existing ground stations should surely make it possible to be in real-time contact with every airliner in the air. It can only be a matter of cost and the requirement for aircraft manufacturers to agree a common standard for such data transmission that has left us in this position. It is unreasonable to expect that a flight crew will fully understand the complex technology of every type of modern airliner they fly, or the fly-by-wire data each aircraft system produces. A real-time data link to the ground would enable specialists to analyse in-flight problems as they happened.

Such datalinks could also help combat terrorism. If ground control had-real time flight data from all aircraft, any deviation from a planned route or change of altitude could set alarm bells ringing on the ground.

Energy saving
Air traffic controllers use computers to allocate landing slots at busy international airports. Advance knowledge of the real-time position of all the flights heading for an airport would help this process as flight crews could then be asked to slightly increase or decrease their speed of flight to arrive in a particular time slot. Perhaps the time and fuel wasted circling an airport to obtain a landing slot would then be a thing of the past.

A wake-up call
Present-day aeronautic communications engineers should do more to improve air-to-ground communications for civil aircraft. NASA gave us a strong lead with the Apollo 13 mission, proving that, if you have an in-flight problem, help from the ground can make the difference between disaster and a happy ending. Forty years later it seems absurd that support communications were better on a single trip to the moon than they are today for the thousands of flights that cross the Atlantic Ocean every year.

During the 1980s David Thorpe was the product manager for the BT-designed Touchdown Communications Command System. This system was deployed by the US Air Force and several civil airlines to improve their operational communications. The airlines deploying this system included BA(Heathrow), Qantas(Sidney) and Air France(Paris).

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After publication of the main article featured here, I subsequently e-mailed the CAA asking them to consider my article. I was delighted to receive the following response:

Dear Mr Thorpe,

Thank you for your e-mail regarding real time communication with aircraft and recording of flight data. In terms of your original enquiry, the CAA understands and shares your concerns and you may find the following helpful.

As a result of both AF447 and previous, similar, accidents, the UK CAA and the UK Air Accident Investigation Branch (AAIB), together with regulators, accident investigators and equipment manufacturers all over the World have been actively working together to find means to improve both of the issues you raise. This has resulted in a number of worldwide initiatives that have either already been put in place (via the International Civil Aviation Organisation (ICAO) and National Aviation Authorities), or are being actively investigated as I write.

In addition, in response to the issues identified by AF447, BEA (the French air accident investigators) formed a working group to address a number of issues, in particular, the best means to get flight recorder data back to the ground in real time. This work has resulted in a number of flight recorder related recommendations being made to the European Aviation Safety Agency (EASA), which are currently being discussed with the active support of both CAA and AAIB, together with regulatory, accident investigation and manufacturing representatives from Europe and the United States. The result of these discussions is likely to be new regulations and/or technical standards that address better/faster transmission of flight recorder to the ground.

In summary, the concerns you raise are shared by aviation regulators all over the World and we are working with industry to resolve them. This does, of necessity, require a lot of work over an extended time frame to be sure that what we eventually decide on really will make an improvement to the overall safety of flight, when all the other factors that affect safety are taken in to consideration. As this work does take a lot time, it isn’t always obvious to anyone outside the aviation regulation community that it is actually happening and we do appreciate that this can lead to an impression of inactivity but please be assured the Civil Aviation Authority take safety very seriously and that we are working hard to resolve these and other, related, issues.

We would like to thank you for taking the time to write to us and your interest in this subject.

Yours sincerely

Louise Unsworth

Civil Aviation Authority

Aviation House

Gatwick Airport South

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