Is there a 'rule of thumb' standard for the amount of down trim -upward push- (percentage wise) to use during takeoff? I am assuming the elevator trim on aircraft that have them is designed in size proportional to the size of the horizontal stabilizer. I notice in FSX that if this is off it can make a drastic difference in your takeoff roll :-jumpy Gary

You would need somebody with a better technical knowledge than me, to give a defentitive answer to this question. But my feeling is that there would be no hard and fast rule, for the reason that differant aircraft would require differant trim even down to the exact same aircraft type when they would have differant freight/passenger/fuel loadings.Best and Warm RegardsAdrian Wainer

Elevator or stabiliser trim depends on the aircraft. When I learned to fly many years ago I foud that the Cessna 172s at the time needed up trim (half a turn on the wheel IIRC) or they would be hard to break ground and a fairly heavy heave back to get off. On other aircraft I've flown including my own homebuilt (RANS S7) you don't need any. Jet aircraft operating at high subsonic mach numbers tend to have an all moving stabiliser with no separate elevator or trim tab so the tailplane angle of incidence is changed to effect trim. Many aircraft have a take off marking on their trimming device which helps you set it up for take off. John

Thanks Guys,I will play around with the different aircraft and make notes in my individual aircraft log as to the amount of trim required for takeoff under different load and temperature conditions. Where this really comes into play for me is at airports with runways that are just long enough to get airborne for the aircraft in question. This can be a fun challenge to work on and informative, aerodynamic wise. I have the amount of flap settings to use just about right, again depending on the aircraft if any are needed.Gary

Is there a way to "center" the trim wheels? I always seem to get caught with too much or too less and can't get it back to zero trim to start off fresh.

Sort of, there are keys for Aileron centre and Rudder Centre (you'll find the keys in FSX button settings). I couldn't find any Elevator Centre. I have my elevator trim on thumb wheel which has a detent at the neutral position. You can also use the elevator trim indicator to centre the elevator trim. Most aircraft load up with the elevator trim centred IIRC. Good luck with learning you trim settings. I once flew my own RW aircraft for an hour an an half on just elevator trim and rudder and I was doing figure of eights (over some cow paddocks) for much of the time. I wouldn't try that with any aircraft though.Remember you only crash when you hit the ground so keep away from it.Repeat after me:There is nothing more useless than:Fuel in the hangarRunway behind you andAltitude above you. :-)John

Hello Gary:Just a suggestion for many aircraft as you "play around with the different aircraft." There are a few that will require back pressure on the wheel or stick for lift off and climbout regardless or you will run out of runway but for many aircraft you can find an elevator trim spot for takeoff where the aircraft will rotate and takeoff by itself, handsoff (i.e. Eaglesoft Citation X, B52 etc). Takes a bit of experimenting to find the spot, but worth it IMHO.Good luck:RTH

>Is there a 'rule of thumb' standard for the amount of down>trim -upward push- (percentage wise) to use during takeoff? I>am assuming the elevator trim on aircraft that have them is>designed in size proportional to the size of the horizontal>stabilizer. I notice in FSX that if this is off it can make a>drastic difference in your takeoff roll :-jumpy >>GaryVaries with aircraft.Your aircraft add-on check list might show this setting.