Airbus Turn Coordination

[longobard]

I've just found this nice Airbus flight laws resume (A330 in this case):

http://www.smartcockpit.com/data/pdfs/plane/airbus/A330/instructor/A_0-Flight_Laws.pdf

Note 11 states that turn coordination is avilable only with Angle of bank less than 33° (in normal and alternate law) but i cannot find any reference in the fcoms.

Does anybody have an idea on the truth of that note?

[CJ1234]

I was under the impression that turn coordination was supplied right up to the limit (67 degrees)

I do know that 33 degrees is the point at which bank angle prot comes into action in normal law, but was under the impression that turn coord was provided well beyond this.

mmm....

1234

[longobard]

i knew the same as well...

[CJ1234]

I'm going on the 320 - maybe the 330's different?

[longobard]

on that is the same

[flyprototype]

or come in case of engine failure.

[longobard]

no reference to that...

no big airbus pilot knowing that?

[Double the Drift]

Beyond 33deg the aircraft will no longer automatically hold the pitch attitude and back pressure must be applied, as in a typical aircraft... turn co-ordination is maintained all the way through.....

[K.Whyjelly]

From the A330 FCTM...............................

LATERAL CHARACTERISTICS
NORMAL CONDITIONS
When the PF performs a lateral input on the sidestick, a roll rate is ordered and naturally
obtained.
Therefore, at a bank angle of less than 33 °, with no input on the sidestick, a zero roll rate is
ordered, and the current bank angle is maintained. Consequently, the aircraft is laterally stable,
and no aileron trim is required.
However, lateral law is also a mixture of roll and yaw demand with: ‐ Automatic turn coordination ‐ Automatic yaw damping ‐ Initial yaw damper response to a major aircraft assymetry.
In addition, if the bank angle is less than 33 °, pitch compensation is provided.
If the bank angle is greater than 33 °, spiral stability is reintroduced and pitch compensation is no
longer available. This is because, in normal situations, there is no operational reason to fly with
such high bank angles for a long period of time.

Also look in FCOM 1:27:20 pg2 A319,320,321

Pitch trim is automatic both in manual mode and when the autopilot is engaged. In normal
turns (up to 33 of bank) the pilot does not have to make any pitch corrections once the turn
is established.

[catiamonkey]

Keep reading forward: picture on FCTM 2.60.3. Turn coordination up to the bank limits.

[longobard]

thanks catiamonkey, the picture explains!