TRIM PROBLEM FL350

[boyanpilot]

Well,I am on flight simulator since june2002,I know to fly any airplane at IFR and I now every thing,but trim is problem,when my airplane is on FL350 his nose is little up and tail is little down,I try to make some trims but it all falls uppart,I dont know how TO USE TRIM correctly when I am on the ground,climb,cruise,and landing,IF YOU KNOW HOW TO USE TRIM please help

Boyan Stanishich(20years)
Montenegro

[ashaman]

First, it's only normal for an airliner to have a little nose-up attitude in level flight. About 3~4 degrees of nose-up attitude (depending from airliner to airliner) is aerodynamically normal.

Second, you fly at FL350 in manual? Nothing wrong with it, but almost everyone (and I mean both in real world and simulation) at that flight level uses the autopilot.

[boyanpilot]

I USE AUTOPILOTS, and nose is up,I even tryed to fix it using COGcenter of gravity corrections,but its still bad,I dont know how to use it really IF YOU KNOW HOW PLEASE WRITE IT ON

THAKS A LOT

[ashaman]

If your nose-up attitude goes WAY up the 3~4 degrees then it's a problem of climbing.

It means that you climb too fast to too high a flight level in too little of time.

How you should climb varies from aircraft from aircraft, but let's say you tru to bring to FL350 a full weight 742 (Its the plane I'm more familiar with, after the Concorde ).

V1, Vr... First climbing phase it's done manually. When you clean the wings and up to 10000 feet keep yourself to about 1800 to 2200 fpm (feet per minutes) beginning at 2200 and reaching 12000 feet at 1800.

Over 12000 feet, and depending from weather too, begin to lessen the angle of climb. Remember that you are flying a FULL WEIGHT 742 (in this case)

Keep an eye on the N1 and N2 of the engines and be very attentive to keep an angle of climb that won't strain them. This will allow you to reach the first level of flight (form which you'll step-climb gradually as you burn fuel) of FL330 (NOT FL350).

From there and as (as already said) you burn fuel, you can step climb higher, to FL350, FL370, FL390...

You can't ask to a full weight liner to reach high flight levels form the start, nor can you ask said liner to reach said high flight levels like a rocket. It's a liner, not a Shuttle.

What you need is practice, practice, practice.

If you do all this no problem and still the airliner is exaggeratedly nose-uppity, it could bbe a problem with the flight dynamics of the plane (that you have not specified). Then I can only suggest you to try using some other liner and see what happens.

[boyanpilot]

WEL I AM FLYING on 744 boeing,and other,but you are right maybe I climb to fast I usally use 2500ft per minute untill I reach FL 330,and I dont know,trim shud be better used,but airplane dosnot givs it to me he do his own on trim,same happends on 737,DC 10 and 777
I really dont know what to do!

[simonmd]

2500? I'd say 1800fpm is the max you should use in any passenger heavy. How are the hosteses supposed to serve coffee at that angle?!

[ashaman]

I usally use 2500ft per minute untill I reach FL 330

Holy...

Not even the Concorde gets to FL330 (usual supersonic transition flight level) at that variometric speed.

As already said, a good way to understand if your climbing profile is good enough (without a FMC, that does all the work for you), you should watch the N1 and N2 of the engines. You have to get there without straining anything and with a good flight attitude. And when you step climb from a FL to another after you've burned some fuel, you have to step climb at 200~300 feet per minutes.

Real life pilots of airlines fly like this. Pilots of military fighter jets can maybe use the climbing speed you're using, but you'll agree that theirs are a different kind of planes.

[elite marksman]

Firstly, I normally climb at 1800 until FL200, then from there to FL300 at 1000-1500 depending on aircraft and weight, then above 300 I usually use something between 500-1000fpm, again depending on fuel load and aircraft.

Secondly, you can't trim the aircraft manually while autopilot is on. Thats what the autopilot is for, too keep you flying at the set speed, altitude, and heading.

Third, watch your artificial horizon. If you notice the AoA go above 10-12 degrees except during takeoff check your airspeed, if its really low, <210 for a clean 774, level off or even dive slightly to avoid a stall, if I remember correctly, a  clean fully loaded 774 will stall around 190kts, and if you're trying to climb above FL280 at 2500fpm your going to lose airspeed, fast.

Lastly, I kindly ask that you stop using all caps words. It gets  annoying.

[boyanpilot]

OK about caps,sorry,I will try to do as you all guys sad Thanks