how to trim properly
 

Its not about game use, i know the keys/axis etc. The elevetor trim i know how to use properly(or i think i know). My question is, in planes that have rudder and aileron trim, how do i know the amount of trim to apply from eatch one? Look at the slip ball? Torque that afects our aircraft is mainly from 4 forces:
Reactive force( blades hiting the air, more intense at low speed, high engine rotation)-shold correct with rudder trim or aileron trim? ( i think aileron)

Spiraling sleepstream, this air hits the plane in one side of the tail, and i think should be corrected with rudder trim.

Giroscopic prececion, aplies strenght 90 degrees from aplied force. i think aileron trim here, but since it is only noted on changes of engine rotation, i think no need to trim.

P factor, at high angles of atack the diferent forces aplied on uper and down blades are diferent and produce more Yaw. i gess no need to trim here, we dont fly alway on high angle of atack.

And of corse there is te weight balance, but dont think it applies here in the sim, (ex having a fat copilot...)

And how about planes with no aileron trim, how do i know the amount of rudder trim so that the plane flies as fast as possible?

The slip or ball indicator is what I go by. I'm not sure if this is the only indicator you use but it's mostly the thing that I use along with a little bit of seat of the pants kind of feel for the aircraft. I don't tend to win at air races but I'm rarely last so I must be doing something right :)

Its not just about speed.

Correct trim also effects your shooting. If the ball is not centered your shots will be hitting off to one side rather than where the cross hairs are lined up.

I had never thaught of that mr Galway, and of couse it afects shooting! Thx for the post, and thanks also to mr Icefire. So, if ball is centred it should be ok, if ball centred and it is still roling we should aply aileron trim, correct?
Of course that for each engine rotacion, pitch angle, airspeed etc, the trim should change, so what do we adjust before combat? Or we must change also rudder trim in combat, just as we do to the elevator? (well... just use pedals to correct and shut up!) :D

I've read spitfires came pre-trimmed as far as roll and elevator go, they were all test flown and if they rolled one way, they would bend the ailerons correspondingly with a tool abit like a tuning fork, them there were re tested and only when the tester ( I can't rember his name or which book I read these facts in) would release the plane for service.
Alot of BOB pilots used a touch of rudder trim either way so they didn't fly straight and were therefor harder to shoot down.
you can always center your bubble when shooting.

edit
 

It was Alex Henshaw, cheif test pilot and Castle Bromley, the book was SPITFIRE, a complte fighting history, and yes, I have read it all!
They also trimmed elevator in the same manner.
So your spit SHOULD be trimmed, as for the yellow nose basterds, well, they're for shooting at, not flying ;)

You winding yourself up too much...
Just trim for maximum speed (at current throttle, ect).. this is the simplest and best indicator of correct trim.
;)

Unless I've reached a cruise speed and altitude it would be rare for me not to be trimming the aircraft. I hate to have an out of trim aircraft so I suppose it borders on obsession but I do think it's very important.

There are several things to keep in mind. Some aircraft only truly feel "trimmed out" at certain speeds and throttle settings. The Yaks and the Tempest for example (vastly different aircraft but with similar characteristics here) tend to be happiest at around 80% throttle, 350kph (ish) and a fair bit of rudder and elevator trim. The Tempest cruise speed is a tad bit higher but you get the idea.

I don't know if it's just me but I find the P-51 to be a complete PITA to fly, it seems to require constant fiddling with trim with the slightest change in speed.

Hello Guys !!!

The correct use of rudder trimm is based on the ball. Keep the ball centered for each phase of flight and you are doing well.

Aileron trimm on real world aircraft is used only for fuel inbalance. So for IL2 aircraft you can use aileron trimm to keep a straight flight path when your wings are damaged, producing more lift in one side than another.

Elevator trimm is used to keep a constant flight path and to reduce the pilot workload.

Remember, when your aircraft is correctly trimmed, you can fly hands free keeping the heading, altitude and bank.