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Jack1985
24th Aug 2012, 09:49
Hi everyone! I'm just confused with another Airbus issue,

In the 737NG series trim is set manually, But yesterday I learned that the Airbus automatically sets trim for take-off. What I was precisely told was an aircraft taking off in CONF 3 sets the following;

FMGC -> PERF -> TAKE OFF -> FLAPS/THS = 3/0

Is this correct? And if not and say the aircraft needed a take off trim of 2.6DN how would it be set in the FMGC e.g. what would be put in the FLAPS/THS option?

Very much appreciated, Thanks! :)

hetfield
24th Aug 2012, 10:37
FMGC -> PERF -> TAKE OFF -> FLAPS/THS = 3/0As far as I remember, that's only a reminder without function.

TO trim setting is achieved with FMGC input ZFWCG/ZFW.

Maz11
24th Aug 2012, 11:00
The Airbus does not set takeoff trim automatically, we have to set it. The value we enter in the Takeoff performance page is only there as a reminder.

TO trim setting is achieved with FMGC input ZFWCG/ZFW.
Not exactly correct as that is the ZFW trim setting, not the TOCG.

The TOCG we have calculated by either using the Loadsheet (if you're in the dark ages) or the LPC is indeed entered like you say on the Takeoff Performance page, and in your example if you wanted 2.6DN and a Flap 3 takeoff you would put 3/2.6DN in the FMGC.

As I said though this is only a reminder, so after engine start we would set 2.6DN using the trim wheel.

nitpicker330
24th Aug 2012, 13:41
The newest A330's in our fleet set the stab trim automatically during start.

This from FCOM 1

The THS is automatically set at 4 UP (inside the green band). Before departure, as soon as the three hydraulic systems are available, the THS is automatically set to the takeoff value, calculated by the PRIM, according to the ZFWCG entered in the MCDU and the fuel distribution

Fly3
24th Aug 2012, 13:52
On the A340 the trim is set automatically during engine start.

hetfield
24th Aug 2012, 14:34
On the A340 the trim is set automatically during engine start.

Yeah, sorry now I know why I mixed it up with 320.

Toooo long ago;)

Jack1985
25th Aug 2012, 06:59
Thanks for the replies everyone! :ok:

The Airbus does not set takeoff trim automatically, we have to set it. The value we enter in the Takeoff performance page is only there as a reminder.

Yeah that's what I originally thought, thanks! :)