Private Pilot Flight Training and Instruction Flight Training Article Library | Back To 4VFR.COM Trim Exercises (Instructor Notes) To teach the effectiveness of trim try the following exercise. The instructor should demonstrate how to hold the nose in one fixed position while the student varies the trim wheel for several turns in each direction. From level cruise, have the student lock his left elbow on the door. First the instructor varies the trim up and down while the student holds the nose in a fixed position against all pressure. Then let the student move the trim. This clearly shows the control pressures as affected by trim. The function of trim on control pressure should be shown on initial climb-out on the very first lesson. Skill in moving the trim and keeping track of these movements is an essential skill for what is to follow. An additional exercise, once some skill in leveling off is acquired, is to have the student trim the plane for level flight. Then watch the nose attitude change as the arms are held forward or back over the head. Show the student that, in a correctly trimmed aircraft, even head movement will have an effect. This is a good reason not to keep sectionals where you must look down to read them. Move the sectionals up to panel level. Further, if the plane is placed into a 30 degree bank with about 2/3 if a trim down (direction of wheel movement) the aircraft maintain both bank and altitude. These are good confidence maneuvers and illustrations of the aircraft stability and should be used to encourage the student to maintain a light, trim sensitive, touch on the controls. The student should be trained to keep track of trim turns, the indicator position, and verbalize trim movements. The next element in maintaining speed is knowing where the trim is, in the first place, and knowing how much movement is required for each power setting. From a hands-off trimmed climb at 60 knots, the C-150 will be level with a full finger-tip trim turn of the trim wheel bottom to top. The C-172 takes one and a third turns. If you pinch the wheel you will always come up short. Some fine adjustment may be needed for hands-off level flight but you will be very close. To initiate the speed reduction required at the numbers for landing, the trim is moved with full finger-tip turns top to bottom three times while holding heading and altitude. The C-150 is now hands off at 60 knots and the C-172 is hands off at 70 knots. Because of patent laws the nose gear geometry of different manufacturers was forced to develop different mechanisms for flaps, gear, and trim. Pipers trim differently, the addition of flaps changes attitude and airspeed without requiring much trim change. Cessnas require trim change for changes in airspeed and flaps. The same factors exist in both cases.It is the interrelationships between the factors that require pilots to adapt their skill to the design requirements. The finger tip technique that works so well on the Cessna must be changed to the pinch and flip, palm roll, and electric assist of the Piper. In my mind, the greatest skill difference in making manufacturer type transition lies in the use of trim. Written by Gene Whitt Flight Training Article Library | Back To 4VFR.COM