PPRuNe Forums - View Single Post - How safe is (airbus) fly by wire? Airbus A330/340 and A320 family emergency AD
Old 20th Dec 2012, 08:26
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737Jock
 
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The OEB does identify the warning signs to look for PRIOR to activation of the ALPHA PROT. So we should realise "what is going on". Admittedly, switching off ADRs is not very comforting.
I was Saying that the system is giving no feedback on what it is doing. In other words there is no feedback given that alpha prot is active. No Ecam, no message on PFD, no feedback through sidestick. If the system would drive the sidestick to the FWD stop and you can't pull hard enough to make the nose come up you know what is going on.

The OEB's identifies warning signs after an A330 nearly fell from the sky... So I conclude that it is NOT that easy to realise what is going on. And even the original solution of turning all ADR's off was based on a wrong diagnosis, although it fixed the problem by returning control to the pilots.

But why does airbus design a protection that cannot be overrided by the pilots through simple sidestick input/ possibly holding the AP disconnect button to get full control and deactivate the protection.

It's also worth pointing out that in the situation described in the EAD and OP, Alpha Prot will not suddenly order a fistful of control input.
How would you call a gradual and continouos nose-down input that cannot be overrided by the sidestick? Half a fist full?

It's clear that you have zero understanding of what is going on. A pilot is trained to intervene through control-inputs, initial pilot training is the basis for this.
The airbus system, thinks it is superior and does not allow the pilot to override protections that are not always correct.
In short the system is designed to create a struggle for control between pilot and FBW system, that can only be resolved by turning off ADR's.

Last edited by 737Jock; 20th Dec 2012 at 09:14.
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