pitch trim for TO

[Swisspilot1986]

Does anyone understand why the pitch trim in 2.9 up instead of 2.7 up? tks

[sunake]

On the FCTL page the trim is shown in units, on the PFD it's is shown in "percentage mean aerodynamic chord" I think. All in all, they both work out to be the same thing. Some companies that operate the A320 family for example, prefer to set trim using the percent method, because it eliminates incorrect trim setting errors. For example, you may accidentally set the trim 1.5 units down instead of 1.5 units UP. So using the percentage prevents that kind of error. 

[SAN738]

22 hours ago, sunake said:

On the FCTL page the trim is shown in units, on the PFD it's is shown in "percentage mean aerodynamic chord" I think. All in all, they both work out to be the same thing. Some companies that operate the A320 family for example, prefer to set trim using the percent method, because it eliminates incorrect trim setting errors. For example, you may accidentally set the trim 1.5 units down instead of 1.5 units UP. So using the percentage prevents that kind of error. 

I think he is asking why (assuming it's automatically set), are they 0.1% off?

[Swisspilot1986]

Sunake has well answered my question. But you're right, too. I didn't notice this difference of 0.1% firstly.