WT 787 needs a lot of ND trim after TO

[BWBriscoe 118]

Using the WT 787-X on takeoff I find I need to add a lot of nose down trim to maintain the VNAV course (the nose keeps wanting to raise). Is this normal and realistic? All weights, CG and TO trim are correctly set (using simbrief and imported into the aircraft using the weights and fuel settings page).

[Noel 4,563]

1 hour ago, BWBriscoe said:

Using the WT 787-X on takeoff I find I need to add a lot of nose down trim to maintain the VNAV course (the nose keeps wanting to raise). Is this normal and realistic? All weights, CG and TO trim are correctly set (using simbrief and imported into the aircraft using the weights and fuel settings page).

I never could reliably use autopilot for VNAV takeoffs (after the suggested 400' AGL) and gave up recently even using derate of 2 and climb of 2 as well--the bloody thing wants to shoot up, trim and full on push forward of the yoke hardly cut it.  I use A Pilot's Life and Self Loading Cargo which don't tolerate the extreme climb rate w/ penalties so recently started to hand fly until all's stable or longer, then flip AP VNAV on and all's well now.

[MattNischan 3,868]

2 hours ago, BWBriscoe said:

Using the WT 787-X on takeoff I find I need to add a lot of nose down trim to maintain the VNAV course

Generally, during the takeoff phase, you would pitch for V2+10 or V2+20 until the acceleration height, and then you'd flatten it out to 240 or your next speed constraint. So, you wouldn't necessarily be trying to target the VNAV path until after that. The FBW system is targeting a speed much closer to that, so if you're trying to follow the VNAV path and accelerating far beyond V2, then you'll need to lay on the ND trim button to increase the FBW targeted trim speed.

[BWBriscoe 118]

All I'm doing is flying the FMC created TOGA and eventually VNAV path and following the FD and speed bugs.

[Noel 4,563]

1 hour ago, BWBriscoe said:

All I'm doing is flying the FMC created TOGA

That, is what I never could make work.  I hope someone has a solution or describes a method that works really well.  

[MattNischan 3,868]

2 hours ago, BWBriscoe said:

All I'm doing is flying the FMC created TOGA

What speed (or range of speeds) is the aircraft at while you fly the TOGA pitch reference?

[Boeing_Driver 76]

I’m not absolutely certain, but I think there is a bug that freezes the trim immediately after takeoff.

[TrevorS 54]

Watched a video some time back where the person complained about the same problem. What he does is to before takeoff, press the AP button. This will give you a red warning. Ignore it  (don't cancel it) and continue with the takeoff. Works like a charm. I have tried it on a few takeoffs now and its like magic. The 787 is now a pleasure to fly. Give it a try.

[miguelpp 25]

That preocedure can be done in real life?

Best.

Miquel.

[fluffyflops 1,865]

17 hours ago, TrevorS said:

Watched a video some time back where the person complained about the same problem. What he does is to before takeoff, press the AP button. This will give you a red warning. Ignore it  (don't cancel it) and continue with the takeoff. Works like a charm. I have tried it on a few takeoffs now and its like magic. The 787 is now a pleasure to fly. Give it a try.

thanks for this.