MODEL AIRCRAFT TRIMMING FOR SPORT FLYERS.

New model.

Model set-up. Wind at zero to 5 kts.  
  1. Servo output arms/pushrods set at 90 degrees.
  2. Pushrods/horns set at 90 degrees.
  3. With the radio switched on and the Tx trims at zero, adjust the elevator so that it is in line with stabiliser, clamp if necessary and adjust pushrods.
  4. High/low wing models = some engine down thrust may be set.
  5. Balance at forward point accurately. Eventually this may be adjusted aft to suit individual flyers.
  6. Pre T/O. Transmitter trims to zero.
  7. T/O.  If climb angle is extremely high control model flight path by elevator to safe angle, land and    increase down thrust. If climb angle is extremely shallow control by elevator, land and reduce down thrust.
  8. Continue to adjust thrust line until a comfortable climb angle is achieved without the use of elevator inputs.
  9. T/O and climb to circuit height and fly cross wind adjusting throttle to obtain straight and level flight without elevator inputs. This will be your cruise/throttle setting for S&L flight.
  10. When correctly trimmed the model should fly S&L with all trims at zero at cruise throttle setting To fly faster or slower in S&L flight, adjust throttle up or down and make necessary trim changes on digital trim levers. ie....for a throttle increase adjust trims nose down and vice versa.
  11. As well as the climb out angle being comfortable the glide path at engine idle should now also be comfortable.
  12. The distance away from touch down point will vary with headwind. With high headwind the descent will be steeper so begin the descent closer in and vice versa for a low/zero headwind. During the descent do not use elevator but add or subtract some engine power to adjust the descent to give you the touch down point for which you are aiming. Keep the wings level and the model aligned with the R/W.
  13. The foregoing only applies to sport models as dedicated aerobatic models need a different trimming technique.
Mike White