I own a horse and motorcycle. I don't like to ride the horse very much.

Skyhigh

 

Pretty much every individual who knocks an Airbus has never flown one and knows very little to nothing about it.

 

So you're saying you're incapable of doing this while you're flying?

 

Good thing about the Airbus - it'll let you fly all you want... As long as you're not in one of its 'protections' (high-speed protection, low-speed protection, load factor...) 99.9% of the time it's great.

Bad thing about the Airbus - when in one of its protection 'modes' it won't let you fly. At least not without some very distinct limitations. From what I've read online (Airbus FBW experience only here, no Boeing FBW) this is the difference between Airbus & Boeing FBW philosophy.

I think the AF447 guys paid the ultimate price finding this out. I say 'think' because it's only a theory, but I bring it up because the conversation tends to misplace the blame on lack of 'stick & rudder' skills. I'm certainly not married to this theory but maybe some more discussion, and input from those more versed in Airbus FBW technology, could lead to a better understanding of the airplane & what happened. I'll explain.

When their pitot tubes froze up, 2 of the 3 may have iced over at roughly the same time/pressure/altitude. An iced over pitot tube makes the AS operate like an altimeter. The computer would think nothing of it until they flew into more/less dense air & then it would have a comparator error & eliminate the outlier (in this case the only one that was functioning properly).

If this actually was the case they wouldn't even have gotten an 'IAS DISCREPANCY' warning, because the 2 remaining, though incorrect, indications would have matched one another. It would even have continued in 'Normal Law' without at least a Double ADR failure. Perfect storm brewing.

If they flew into lower pressure, towards the storms dominating the area they were flying through, the airspeed would rise. If they could have caught this before the airspeed rose into the 'high-speed protection' regime they could have disconnected the autopilot, applied the 'unreliable airspeed' procedure and flown out of it. Stick & rudder - at this point the airplane would have let them do that.

If they didn't catch it before VMO+6/MMO, High-Speed Protection would have activated. A few things would have happened, most pertinently: the FBW would "apply a permanent nose-up order to aid recovery to normal flight conditions" and the Autopilot would have kicked off.

The Autopilot would have handed them an airplane that would do nothing but pitch up. FUBAR.

The only way they could have gotten out of High-Speed Protection would have been to recover the airspeed, which in this case would mean, roughly, descending below the pressure altitude at which the pitot tubes froze over. They obviously did eventually but by this time it seems they were thoroughly perplexed, stalled & out of control.

I honestly don't know if this theory actually even holds water but I'd love to know what really happened out there that night. The accusation that they were unable "to fly straight and level for two to three minutes on instruments..." lead me to making this post because I think there's potential for a more worthy discussion.

 

The Boeing will let you drive into the tree. The Airbus looks out for its own self preservation.

Nothing wrong with the Airbus. I just like the motorcycle better.

Skyhigh

 

Yup. But dont worry im only flying 76 of your passengers at a time.

 

What happens when the software is flawed? Has happened with the 777 and the Airbus. Incorrect programming/algorithm causing false data to be sent (and accepted by) the flight control computers. Now all bets are off. In the case of the Airbus it caused two uncommanded dives, injuring 60. In the 777 it caused a low speed and high speed warning at the same time.

 

I'm not worried. They've never been my passengers.

 

So will the Airbus. Trust me. It's been demonstrated.

 

What happens when the PF stalls the plane, then yanks through the stick pusher? What happens when a crew takes off on the wrong runway which is half the distance they need? What happens when crews land on a taxiway instead of the runway? What happens when the rudder on 737's continues to hardover rolling the airplane out of control and into the ground?

Stuff happens. Even a cables & pullies airplane doesn't fully protect you from failure.