Hi,

 

This is driving me nuts. There must be a technique for this that I'm missing.

 

I'm unable to trim the aircraft out for level flight. I understand it is "trim for speed", but without a reference for the speed target, it is very hard to trim out for level flight and on-speed.

 

I always end up either with a slight climb or descent (by slight I mean around 200-300 ft/min!!!!!!!), or a few knots fast/slow.

 

What is the secret to trimming this thing out? It's driving me crazy.

 

Is there a way to see the speed target? Obviously the system knows what it is?! It also makes flying the ILS tricky as it is either descending too fast or not fast enough, and thus deviates from the glide path.

 

I can nail the speed with the power - that's not a problem. The problem is the blasted trim!

 

Best regards,

Robin.

Yes, I'm finding it quite tricky to get in trim as well, the NGX was very easy, but it didn't have FBW. Are you supposed to use the trim in flight in the 777 or is it like Airbus in that regard? Anyone have any tips on how to trim it?

 

Regards,

Ró.

(my response assumes you are piloting manually) I don't know about the 777 specifically but in conventional aircraft once you have the aircraft trimmed for the speed you want you maintain level flight with slight adjustments in power. So if you are climbing reduce power until she evens out, if she is descending increase power a bit.

How do you set the trim on the 777?

How do you set the trim on the 777?

 

Same way as in other things? Trim buttons assigned to your yoke/joystick or the numpad 1/7 keys.

 

The tricky thing is to get it to stay in trim. I'v found it ok while flying an approach, mostly ok on takeoff, and I must admit to not doing too much 'at cruise' handflying so far.

The trim characteristic will be the same as conventional aircraft. The 777 trim gets the same results indirectly with out primarily moving the stab. The trim will appear normal to the pilot as he uses the switches as he would earlier aircraft. Behind the scenes the systems trims the aircraft in a different way. To the pilot, he would notice that control input is not needed during banks up to 30 degrees, flap/gear changes, thrust changes, and speed brake application. Other than that, the aircraft trim will appear normal.

Hi,

 

I'll try ignoring vertical speed and instead trim to neutral stick then make final adjustments with power. I have already tried this, but maybe I was not aggressive enough with the power? It seemed slow to react to thrust changes, and so I ended up with thrust induced pitch oscillations.

 

Regarding cruise flight, not sure how it compares to the real thing (tendency is FS is not sensitive enough at cruise) but from manual descriptions, the simulation nails it. It states with increase in airspeed, control inputs get stiffer - this definitely feels to be happening.

 

Manually flying at cruise is a bit easier due to reduced control sensitivity. It's lower altitudes where the system is more sensitive that seems more problematic.

 

Best regards,

Robin.

Actually, trim is quite different in the FBW system on this bird than a traditional one.  In the air, it's basically fully automated. There's no way to directly command the stabilizer in the air on a 777 (in normal mode)...all you're doing is telling the FBW system what you want the trim speed to be. The FBW system will then move the elevators and stabilizer as needed to trim to that speed. There's no need to retrim for thrust/configuration changes, since you haven't changed the commanded trim speed

"I wonder where that quote came from," he said quietly to himself...

 

haha

I always end up either with a slight climb or descent (by slight I mean around 200-300 ft/min!!!!!!!), or a few knots fast/slow.

Same here!

 

I can't remember correct but I think PMDG would look in to that!

 

Robert

The fly-by-wire in regard to trim is wrong.

 

PMDG have confirmed this and made the necessary changes. See the bug tracking thread.