Setting stab trim before engine start

[downscc 1,327]

1 hour ago, rwy23 said:

I have to say I didn't know that....but I knew they are available on yoke (left handle), but why you not suppose to move that? Any difference in set up? Would be good to know..

For your reading pleasure 777 FCOM 9.20.10 - 9.20.11; the first thing you should have noticed is the levers are labeled "ALTN PITCH TRIM,"  most all aircraft with electric trim are trimmed primarily with the switches on the stick/yoke.

If you are using P3D you don't need FSUIPC for the controller buttons, just assign the buttons directly in P3D controls UI.

[rwy23 1]

To be honest, I think I read all manuals, but I have to admit that I was concentrated on something else I was searching that I missed that thinking I knew that...but thank you for answer....

[Qavion2 39]

The Altn Switches bypass some of the safety systems on the 747-400 and have a different effect on the autopilot, depending on the autopilot mode. This is why you should normally use the control column trim switches.

[scandinavian13 5,192]

16 hours ago, rwy23 said:

I think I watched your video on YT setting the trim.

I may have been looking down in that area while setting the trim because the indicator is there, but I highly doubt you've seen a video of me working them unless it's one of those videos where I go over every option/button/switch in the plane.

[scandinavian13 5,192]

16 hours ago, rwy23 said:

I did not set buttons for that thru FSUIPC...that might be the option...

Nope. As mentioned, set it up quite literally, in the sim itself using the default sim controls screen.

[rwy23 1]

1 hour ago, scandinavian13 said:

I may have been looking down in that area while setting the trim because the indicator is there, but I highly doubt you've seen a video of me working them unless it's one of those videos where I go over every option/button/switch in the plane.

Could be not sure....You were showing start from C&D and set-up.....

Thanks Kyle

[Captain_Al 66]

14 hours ago, Qavion2 said:

The Altn Switches bypass some of the safety systems on the 747-400 and have a different effect on the autopilot, depending on the autopilot mode. This is why you should normally use the control column trim switches.

John is correct, the control column stab trim switches are Primary and should be used first. The Alternate Trim switches trim at the same rate as the control column switches, have greater forward travel compared with the control column switches, but they react different if an A/P or A/P's are engaged.

In the case of the control column switches, if you trim with a single A/P engaged, the A/P will disconnect. If you are in multiple autopilot mode below 1500 RA on a triple channel ILS approach and trim, nothing happens as the trim is inhibited if you try to trim.

If you trim using the Alternate Switches in single or multiple A/P modes, they will trim and the A/P will sense trim is coming from somewhere other than the A/P, and you will get an Unscheduled Stabilizer Trim message. Alternate also bypasses the control column cutout feature, so for all these reasons, Alternate is just that...Alternate, to be used if the Primary trim system does not trim.