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Fly By Wire w/ bad IRS results in another Airbus upset

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Aug 2005, Malaysian Air B777 incident.

It is written about in an October 2008 issue of Aviation Week and Space Tech.

Basically, hardware is certified. Software is not.
 
I'll stick with cables & pulleys, thanks.

How does that make a difference?

The next gen 737 gets information from the ADIRU's or whatever they call them on that thing. You thinking the autopilot couldn't command "bad" control movements?

Besides, cable and pulleys caused a few bad 73 crashes.
 
The next gen 737 gets information from the ADIRU's or whatever they call them on that thing. You thinking the autopilot couldn't command "bad" control movements?

Sure it could, but it's not the same thing. When you see it malfunction and hit the AP disconnect on a Boeing, you're actually disconnecting the computer. That's not the case on a fly-by-wire airplane like the Airbus.
 
Sure it could, but it's not the same thing. When you see it malfunction and hit the AP disconnect on a Boeing, you're actually disconnecting the computer. That's not the case on a fly-by-wire airplane like the Airbus.

Well, not sure how you read that into the report? How did they gain control of the a/c? Not having anymore data to go by, they may well have disconnected the autopilot and flown manually.

Yes, on the Boeing you disconnect the auto pilot computer, however, if you were in cruise, autopilot engaged and the autopilot decided to command an abrupt pitch down, as it did in this case, the result might well have been the same.

Certainly, having spent a fair amount of time with Fifi, there is nothing in the system that should command such an abrupt pitch over, certainly not the envelope protection, secondly, the max pitchover you can generate through the stick, shoving it full forward is minus 1G. Appears this was a bit more than that.

Fifi is, perhaps unfairly, considered a very "strange" bird because of the FBW, but she is just an airplane and one with a proven safety record.

(Donning flamesuit, standing by for torching by the cable and pulley crowd)
 
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Well, not sure how you read that into the report? How did they gain control of the a/c? Not having anymore data to go by, they may well have disconnected the autopilot and flown manually.

They did disconnect and fly manually. The report is a bit vague, but it can be read that two minutes after the first fault, and with the AP off, the flight control computers commanded another significant hard over. Yikes!
 
I don't think even the protection modes will command a "negative G" pushover. Anyone know?

Maybe the computer doesn't "think" it's doing a negative-g pushover if it's that messed up to begin with.
 
They did disconnect and fly manually. The report is a bit vague, but it can be read that two minutes after the first fault, and with the AP off, the flight control computers commanded another significant hard over. Yikes!

You are correct, my bad :(

However, I will stand by my comment wrt. Airbus safety and FBW.
 

Thanks for pointing out my editing shortcomings :)

7 total computers, 2 of which are FACs, short for Flight Augmentation Computers. Turning those two off will disable a lot of the protections but still allow you to fly in Alternate Law.

I just saw a bit on a crash of the X 31 in a flight test program. Seems someone forgot to connect the pitot heat, leading to airspeed readout loss at altitude. Not a good thing in a FBW experimental bird. Test pilot punched out, plane went in flat spin free fall. Ouch!
 

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