Trim setting?
Thread Starter
Joined: Dec 2010
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From: Ireland
Trim setting?
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!
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!
Joined: Jun 2006
Posts: 83
Likes: 19
From: Sandcastle 2
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.
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.
TO trim setting is achieved with FMGC input ZFWCG/ZFW.
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.
Joined: Jun 2009
Posts: 2,167
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From: Australia
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
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
Last edited by nitpicker330; 24th August 2012 at 12:45.
Thread Starter
Joined: Dec 2010
Posts: 1,168
Likes: 0
From: Ireland
Thanks for the replies everyone! 
Yeah that's what I originally thought, thanks!
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.
