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Old 26th August 2011 | 19:24
  #489 (permalink)  
henra
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From: PLanet Earth
Originally Posted by rudderrudderrat
Hi Henra,


In Direct Law - I agree.
In ALT LAW - when stick free, the FBW computers would maintain the same attitude and probably apply more nose up elevator and trim in an attempt to maintain 1g during the stall.
I was indeed referring to the basic aerodynamic behaviour.
It was Elevator + Trim which enabled it to keep the Nose up.

Regarding behaviour close to the stall in Alt 2 that is an interesting one.
Assumed the control logic is a pure C* it would indeed first try to maintain 1g slowly switched to maintaining of pitch below a certain speed (should be somewhere between 210 and 230 kts for the A330 where the switch from g demand to pitch rate demand occurs).

Where I'm actually not sure is the question if that is all they do in the control logic or if they switch to another logic (eg.g AoA) below another threshold.
which points me to a kind request:
It would be great if someone with access to a level D sim for an A330 could try what happens in Alt2 if you point the Nose 10° NU and let go of the stick. Will it fly attitude right into the stall ?
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