What does trim do on an airplane?

Question

Also when I play Flight Simulator X I dont really know how to trim. In the First Lesson it says to hit end 3x does that automatically trim the plane to the airspeed you are at at the point you hit END 3x? Also when you trim the airplane in FSX does it mean it will fly straight and level? Please help!! Thanks

Answer 1

Can't help you much with the FSX part, but trim itself is a way to help the pilot fly the airplane without having to maintain pressure on the controls. when you trim the elevators for example, you are positioning the elevator in a different position that where they usually are, thus either keeping the aircraft either levled, nose up or nose low without having to continuosly having to hold the yoke in that position manualy.

Answer 2

"Trim" implies the usage of trim tabs. These are devices that provide mechanical force to maintain a control surface deflection without any effort from the pilot.

When you trim an airplane with respect to a certain control surface (mostly the elevator) it will ascertain a certain deflection for that control surface. If that particular deflection means that the airplane will fly straight and level, then sure it will.

Answer 3

To make it simple, it takes the pressure off the controls.

Say you have a low tire on one side of your car and the car is pulling to one side or the road is slanted. You have to keep pressure on the wheel to keep it straight.

OK, with trim you would be able to relieve that pressure and the car would drive straight hands off.

Same with and A/C you normally trim for a hands off situation. Or you could trim for a decent or climb.

In a climb it is very tiring to keep back pressure on the controls for 10-20 minutes so the trim relieves the pressure.

Answer 4

In a REAL airplane you have to keep constantly applying pressure to the control yoke to keep the airplane in a particular 'atitude' (turning, climbing, decending or level flight). Trim allows you to maintain that particular attitude without applying pressure. In some sense it allows you to 'fine-tune' the aircraft to keep flying how you want it to.

In FS, it doesnt quite work the same way because you don't have a force being applied against you via the control yoke. It still makes sense to use it as a 'fine-tuning' tool however.  You can use it to get the airplane to keep flying straight and level once you have obtained that attitude manually. Remember, however, that in FS (and in teh real world) you have wind variations that will affect flight, so if you arent using autopilot, you will still need to continue some manual inputs.

Answer 5

I assume you're talking about pitch trim. Laws of nature want that when a plane is traveling faster, it's nose will want to come up (I'm not talking about sonic effects here, that occurs on higher airspeeds than what I'm talking about). When a plane is traveling slower, the nose will want to come down. That means that when flying slow, a pilot has to maintain continues back pressure, and when flying fast, he should continuously push on the yoke to fly level (or a climb or descent with constant airspeed) . Because that involves a lot of unnecessary physical activity that could have been used for more important things like drinking coffee, aircraft have little tabs on their elevator. That tab is called the trim tab and it can be moved up or down by the pilot. By moving the tab upwards, the elevator on the tail will be moved down. By moving the tab downwards, the elevator will be moved up. So instead of having the pilot push the elevator down or up at different airspeeds, you can have the trim keep the elevator down or up. That means that a pilot does not have to use force to control the pitch of an aircraft. (A lot of military and passenger aircraft use stabilizers instead of elevators with a trim tab. Those stabilizers can be moved by using the trim and by using the yoke. So instead of moving a little tab that pushes the elevator into the position you want, you can move the entire elevator with the trim. But it does the same thing as those trim tabs)

In flight simulator when you trim the aircraft it will fly straight and level if you put the aircraft in a straight and level flight and then release the yoke. You MUST maintain the same airspeed then, because when you will go faster the nose will come up, and when you will go slower the nose will come down again. A certain trim setting only applies with one airspeed.