Uncategorized

Jul 4, 2012

AF447 report: Will it cause an Airbus v Boeing fan boy brawl, or something sensible?

The final report by the French air safety investigator, BEA,  into the crash of Air France flight AF447 on 1 June, 2009, into the mid Atlantic on a flight between Rio de Janeiro and Pa

Ben Sandilands — Editor of Plane Talking

Ben Sandilands

Editor of Plane Talking

The final report by the French air safety investigator, BEA,  into the crash of Air France flight AF447 on 1 June, 2009, into the mid Atlantic on a flight between Rio de Janeiro and Paris, with the loss of all 228 people on board, will be released tomorrow night eastern Australian time. Although the flight data and cockpit voice recorders were eventually retrieved and read from the wreckage field on an 'abyssal plain' on the ocean floor, together with more wreckage and many bodies, and much has been revealed in the course of two earlier interim reports by the Bureau d'Enquêtes et d'Analyses the final report is expected to answer some controversial questions, yet provoke more arguments.

Why did two relatively junior Air France pilots fly what at impact was a mechanically fully functional jet into the ocean?

How and why did the pilot at the controls (the pilot flying) put the A330-200 into a steep climb followed by a high altitude stall, which then persisted until it slammed belly first and nose elevated into the ocean with all its control surfaces and engines operational?

Free Trial

Proudly annoying those in power since 2000.

Sign up for a FREE 21-day trial to keep reading and get the best of Crikey straight to your inbox

By starting a free trial, you agree to accept Crikey’s terms and conditions

3 comments

Leave a comment

3 thoughts on “AF447 report: Will it cause an Airbus v Boeing fan boy brawl, or something sensible?

  1. LongTimeObserver

    I’ll take Door #2 and Sensible, but be prepared for the fanboi brawl…

  2. John Thomas

    One of the facts that airline management fail to realise or acknowledge is that flying is a skill learnt through experience. This does not fit with most airlines operating models where in response to the looming pilot shortage the high experience employment requirements were dropped in favour of other avenues to crew aircraft.

  3. Worrierqueen

    It wil be interesting to see the report and who they blame. No doubt it will be the pilots and the pitots but it would do the industry a disservice to stop there. There are problems with training, computerisation and the whole design of the airbus itself.

    The pilot left to have a nap when he knew they were entering very turbulent weather. He appointed the junior of the two first officers to take over the plane while he was away but allowed the senior co-pilot to occupy his (the pilot’s seat) which is the seat of the PF (pilot flying). Thus the lines of control were tangled from the start.

    Then there were the problems with the computer when the pitot tubes blocked up. There was no direct angle of attack (the angle between the wings and the airflow) indicator in the cockpit, although it could be derived by the primary flight display. However in the case of AF447, the crew were getting lots of bad data and incorrect warnings and didn’t know which instruments they could trust and which they couldn’t.

    They were told an A330 couldn’t stall but this was only true when the computers were in primary law mode. When the pilots pitots bunged up and the data the computers were getting conflicted, they immediately switched to alternate law that allowed the pilots complete control to stall the plane. Furthermore the computers only provided the stall warning until the angle of attack reached 40 degrees (it should be 13 to 18 degrees) at which point the computers then decided the data must be wrong and switched the stall warning off. Thus when the pilots did attempt to lower the nose of the plane to pick up speed and the angle of attack went to less than 40 degrees, the stall warning started up again, leading the pilots to conclude they were in an overspeed stall ruather than an underspeed stall (they were so close to coffin corner it was difficult to choose between them), so would pull back the stick again and the stall warning would stop.

    Next the A300 is designed to operate to minimise G forces in the plane rather than minimise stall chance (since this is theoretically impossible anyway at least in normal law) and the best way for this was to maintain the plane nose up which the horizontal stabiliser continued to do short of active pilot interference (although there is no evidence AF447 was in a deep stall that could not have been corrected with correct pilot input).

    And this leads to the final design flaw of the A330. instead of the old fashioned stick or steering wheel used in older planes, the A330 and later designs uses a joystick arrangement like in a home computer console. These are to each side of the pilot and co-pilot and thus one can’t be seen from the other’s position. So the junior pilot who appears to have been piloting the plane from the co-pilot seat was constantly pulling back the joystick keeping the nose up and this could be seen by neither the senior co-pilot or the captain when he returned.

    And finally finally, in the older planes, when the pilot pulled one way on the control column, and his co-pilot pulled the other, it tried to do both (strongest winning), giving instant feedback that the pilot and co-pilot were in conflict over the controls. In the A330, the computer simply splits the diferrence. Thus when the senior co-pilot said he was taking over control and pushed his stick forward to push the nose down, the junior co-pilot was still pushing his back and the computer just split the difference doing nothing at all, and worst of all not telling anyone in the cockpit what it had done (or not done).

    There’s a lot more to go in this debate yet and it looks as if our computers are becoming so complex, pilots simply are not capable of working successfully with them in all situations.

Share this article with a friend

Just fill out the fields below and we'll send your friend a link to this article along with a message from you.

Your details

Your friend's details

Sending...