Private Pilot Flight Training and Instruction Flight Training Article Library | Back To 4VFR.COM Cruise Control Learning to trim for level flight requires that you think in terms of setting as many constants as possible for a given flight situation. First, get a constant level attitude. Using the nose/horizon reference is more difficult than using the wing. The wing level with the horizon works best with the high-wing types. Second, get a constant speed at cruise speed or lower. If you exceed cruise speed without reducing power your trim setting will set for the higher speed. You should practice reducing power to 75% power setting as cruise. 2450 rpm is a good set. Third, trim off the pressure. Is their only one way to trim? No. With experience you may just give a few flips and make a fine adjustment as required. You can even make numerous small changes. Doing it differently does not make it wrong. There is no one way to do anything in flying. Different aircraft and different trim systems require different techniques. The aim of my following suggestions is that it gets the beginner into anticipating trim movements as may be required for every change of configuration. Trim then becomes another constant. Trimming off pressure is a search for the trim position that allows the aircraft to be flown with only one finger and the thumb. Which ever one you are using to hold altitude tells you which way to move the trim. Most students tend to move the trim more than required. You might do well as a student to use half as much movement as you think is required. You are trimmed when both finger and thumb need only to lightly brush the yoke. Getting trimmed to this point makes flying enjoyable and relaxing. Unlike an automobile, a correctly trimmed airplane can be flown hands-off. Once this sense of 'feel' is acquired you will not want to fly any other way. Every pilot has a slightly different 'feel' of an aircraft so changing pilots usually involves changing trim. Every student and pilot should use trim to create opportunities to fly with rudder. Training aircraft usually have a rudder tab that has been set by prior pilots so that very little rudder is required in straight-and-level cruise. You can make slight turns using just the rudder with little difficulty. Steeper turns with the rudder will cause a loss of altitude. Much of this altitude is regained when using hard rudder to level the wings. Practice flying with just the rudder when copying the ATIS, using the sectional, or just for fun. Once an aircraft is trimmed for a particular airspeed in level flight, additional power or a reduction in power will cause the aircraft to climb and descend at that airspeed. You must exercise some yoke control and rudder to correct for any transitional oscillations. Trim remains the same. Trim is the cruise control of flying an aircraft. I very much recommend not changing trim when descending from cruise to pattern altitude. Descend by reducing power. Enter downwind at cruise speed until abeam the numbers. The deceleration in airspeed while holding altitude on downwind will allow you to trim for the approach speed while reaching the appropriate 'key' position for turning base. Written by Gene Whitt Flight Training Article Library | Back To 4VFR.COM