Ten days after Air France Flight 447 vanished over the south Atlantic on June 1 last year, the French nuclear submarine Emeraude joined the search for the wreck. Along with other vessels from Brazil and Europe, the Emeraude, which had sophisticated sonar equipment, swept the area of the ocean closest to the last known position of the Airbus A330.
At the time the greatest hope for pinpointing the wreckage was that somebody would detect the beeps coming from sonar beacons attached to the airplane’s black boxes. At best, these could be expected to work for only thirty days before the batteries died.
No beeps were heard, and the search was abandoned. Since then there have been two other searches, including one that continues until the end of this month.
Now it turns out that, all the time, the Emeraude had picked up the signals coming from the beacons. The crew listening for them just didn’t know that, among all the echoes and signals bouncing off the ocean floor, the most crucial information was there.
In the months that followed, French Navy technicians used new technology to analyze the audio recordings from the submarine and, early this month, identified the beeps from Flight 447. That is why the French accident investigators were able to say that the search has now been narrowed to an area of around three square miles.
But, in another twist of fate, that knowledge was acquired at the very moment when the third search lost many of its major resources, the U.S. Navy’s Anne Candies, equipped with both a remote-controlled undersea vehicle and towed sonar, which was needed for a military mission, and two more remotely operated under water vehicles from the U.S. Woods Hole oceanic research establishment, and another underwater vehicle from Germany - all required for scientific work.
The search is now left to a Norwegian ship, the Seabed Worker, with two autonomous under water vehicles. But technical problems with both have hampered the search.
Airbus and Air France each donated a further 1.5m euros to keep the operation running until June. Even though it is no longer tasked with covering a large area, the challenge is formidable. The seabed terrain is alpine, with high peaks and jagged-edged troughs, going down as far as 20,000 feet or more. The remains could be lying in a crevice where they are virtually invisible. And French officials have damped expectations by warning that the black boxes, and the wreck, may never be located.
If the search is fruitless, investigators face a test for which there is no equivalent in recent experience. The families of the 228 people lost on Flight 447 obviously want to know why this airplane failed. But so does the whole commercial aviation business. There are more than 600 A330s flying around the world and, as I have reported, there are persistent concerns about their safety record-as well as the deadly crash involving an A330 in Libya last week, which does not seem to feature anything that could have a bearing on Flight 447, there was a recent episode in Hong Kong where an A330 flown by Cathay Pacific, having sent out a distress message, landed at excessive speed and suffered damage because of a malfunction in its engine management system.
The BEA, the French accident investigation bureau, has already published two extremely thorough reports on Flight 447, based on the evidence available from retrieved wreckage found floating on the ocean and on data messages sent from the A330 in the last minutes of its life. With no black boxes and no human witnesses, the investigators are left with a finite body of circumstantial evidence which has to be subjected to rigorous reappraisal and every technical resource available.
Air France pilots have been particularly insistent on pursuing every possible clue because they know that, in the absence of a definitive cause, pilots are often the ones who end up being blamed. Blame, however, has no place in the science of air crash investigation. Cause is what matters.
Related Stories
Complete coverage of Flight 447 on Clive Alive
Previously, Clive Alive constructed a time line of the accident and suggested changes to make the A330 saferi
Leave a comment