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Old 6th June 2011 | 19:13
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gonebutnotforgotten
 
Joined: Aug 2005
Posts: 79
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From: London
Airbus feedback?

Where does this idea that there is no feedback on the Airbus control system come from? the side stick itself resists input via a spring so that a certain force is needed to move it through a certain deflection, and then that deflection commands (initially at least) a normal acceleration which is constant over most of the envelope in all laws except direct, as I (mere Boeing pilot) understand it. I got the following from a 1992 paper which I assume is still roughly right:

Limits:

Pitch
Max. load 10 daN
Threshold 0.5 daN
Deflection +-16 deg.
Orientation 20 deg fwd.

In non engineer units doesn't that mean you need roughly 10kg or 23 lb to demand the maximum allowed normal g of 2.5. The feedback is firstly the spring rate of the side stick, and secondly the response of the aircraft, what more should one want?

I would still like to understand why the first two stall warnings were generated before everything went pear shaped, doubtless the full BEA description will clarify that, but it would seem that when the PF took over he put in a mighty demand for no very obvious reason

Last edited by gonebutnotforgotten; 6th June 2011 at 19:15. Reason: table formatting
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