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May 30, 2006
On A Wing And A Prayer
Remember the wild ride on Malaysia Airlines flight MH124 to Perth last August?
As a Malaysia Airlines jetliner cruised from Perth, Australia, to Kuala Lumpur, Malaysia, one evening last August, it suddenly took on a mind of its own and zoomed 3,000 feet upward.The captain disconnected the autopilot and pointed the Boeing 777's nose down to avoid stalling, but was jerked into a steep dive. He throttled back sharply on both engines, trying to slow the plane. Instead, the jet raced into another climb. The crew eventually regained control and manually flew their 177 passengers safely back to Australia.
Investigators quickly discovered the reason for the plane's roller-coaster ride 38,000 feet above the Indian Ocean. A defective software program had provided incorrect data about the aircraft's speed and acceleration, confusing flight computers. The computers had also failed, at first, to respond to the pilot's commands. Within weeks Boeing Co. warned airlines world-wide to install a fix provided by Honeywell International Inc., which makes the flight computers and supplied the faulty software. [Wall Street Journal; subscription required]
The captain did good. MAS is in the clear. The manufacturers have fixed the problem.
All's well? Not exactly:
Specialists say the biggest problems in aviation software don't stem from bugs in the code of a single program but rather from the interaction between two different parts of a plane's computer system. In extreme cases, foul-ups can lead to sudden loss of control, sometimes not showing up until years after aircraft are introduced into service.Malaysia Airlines Flight 124 is a case in point. Boeing's 777 jets started service in 1995 and had never experienced a similar emergency before. According to Boeing and Honeywell, the source of the problem was a revised computer program that had recently been installed on all 777s to fix a minor navigation flaw.
Honeywell and Boeing didn't know that the new program had a defect: It simultaneously told the autopilot that the plane was flying dangerously slow and much too fast. Investigators are still trying to figure out what circumstances triggered the program to give the conflicting data.
Fly by wire? More like hanging by a thread.
I've always found flying fun, but now, I'm not so sure.
Posted by aisehman at May 30, 2006 05:46 PM
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Comments
In Taiwan, ROC, ex-air force generals flying China Airlines Boeing planes refused to fly new fly-by-wire avionics because they refused to upgrade their knowledge so Boeing had to sell them planes based on old mechanical hydraulics system. Maybe it's a bit safer but useless on pilot's error.
Posted by: thienshingvui at June 1, 2006 10:09 AM
I think that adage actually went something like this… “Fly by wire..die by fire”.
I'm not sure if not wanting to fly newer airplanes with more sophisticated avionics equipment had anything to do with the pilots in question not trusting them. I think it had more to do with reluctance to accept the technology itself.
The learning curve is huge, the amount of information a pilot has to glean through is enormous. Safety wise, this technology was introduced to eliminate or reduce pilot induced errors.
Unfortunately, like the bugs you find on your Windows® based pc...they rear their ugly heads on airplane avionics equipment too.
Posted by: taintedcell at June 1, 2006 08:02 PM