Hi,

 

I hope there is someone who could explain this too me. I did several take offs with a takeoff weight at about 300t with flaps set to 15 and a derated thrust setting with the 300ER. Depending on balance FMC gave me a Trim setting of 6.5 - 7.0

 

When hitting Vr I didn't need too much input tu pull the nose up! As soon as the nose gear lifts up I do not need any input in the controls achieve my climb out angle. But from then on the nose wants to rise, rise and even rise. To compensate this I need to push the yoke forward quite a lot and I tried to trim her back to release some yoke pressure. 

Heres a video of a take off from a guy, who seems to have quite the same issues. (

Rotate at 0:55)

 

I have to say, that I never had any problems on climb out with the 77L before SP1. But now this feels strange to me! Is anyone encountering those problems too?

 

Thanks in advance

Mike

Yes, same problem for me, i was about to ask  this, too !

 

Lars

Me too.

And I don't have any clue yet what this odd and certainly wrong behavior might cause.

Maybe it is hardware-related?

 

Robert

It's not a problem - they were too low before according to the pilots and seems that is correct. You just need to be much more gentle on rotation. When I first used the higher trim settings I thought I had a tail strike - just get some technique with your hardware and the 777.

 

The 777 really does not require much back pressure on takeoff. Clearly see this on a video here:

 

 

 

The 777 really does not require much back pressure on takeoff. Clearly see this on a video here:

 

 

Back pressure for rotation isn't the issue. The issue is forward pressure on climbout. You can clearly see in that video there that the pilot doesn't push the column forward much, if at all. Whereas I'm having to push all the way forward to follow the flight director, and trimming doesn't alleviate this.

Maybe this from introduction manual?

 

 

FSX’s flight dynamics engine unfortunately has an issue with this type of 

configuration that will cause the airplane to still feel like it’s out of trim in 

the nose down direction immediately after takeoff even with the takeoff 

trim set on the numbers. When the FBW system engages at 100 feet, 

there can be a noticeable pitch up motion – this is simply the system

compensating and correcting for the FSX issue and not any sort of 

“autotrim” happening. If you find this effect annoying, you can add an 

extra unit or two of trim to the calculated one at low weights / aft CGs.

Even in the real world, anywhere within the green band is acceptable for 

takeoff, so this isn’t completely out of the realm of realistic anyway. 

Maybe this from introduction manual?

 

That's what I came in here to say.  Thanks for taking it a step further and actually pasting the information here.

I found that whatever your cargo load is, putting 46% in the rear works good for me on the - 300 for CG values. Don't know if this correct or not. So if you had 30,000lb of cargo you would enter 16200/13800 in the FMC. No issue on trim, nose up type issues. I got this figure from hitting full payload and seeing the max numbers for the cargo hold. At the max allowed it is right around a 54%/46% percentage split. So I try and keep that percentage split for whatever load I have.

Why are you comparing 777-200 with 777-300?

Both have different characteristics and feel to it..you just have to be gentle with her..

Back pressure for rotation isn't the issue. The issue is forward pressure on climbout. You can clearly see in that video there that the pilot doesn't push the column forward much, if at all. Whereas I'm having to push all the way forward to follow the flight director, and trimming doesn't alleviate this.

 

I saw some of this yesterday and brought it up internally. Not sure if it's being looked at but I agree it shouldn't do that.