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After you have test-flown and done the initial trim changes to the airplane, use this trimming chart to begin trimming your airplane.
Following and adhering to this chart will result in the ability to diagnose trim problems and correct those problems using the simple
adjustments shown below. Making these observations and related corrections will result in an airplane that tracks straighter and
flies truer.
TRIM FEATURE MANEUVER OBSERVATION CORRECTION
Control Centering Fly general circles and random
maneuvers
Try for hands off straight and level flight Readjust linkages so the transmitter
trim levers are centered
Control Throws Fly random maneuvers A) Controls are too sensitive or
airplane feels "jerky"
B) Controls are not sensitive enough
or airplane feels "mushy"
If A) Adjust linkages to reduce
control throws
If B) Adjust linkages to increase
control throws
Engine Thrust Angle* From straight and level flight, quickly
chop the throttle for a short distance
A) Airplane continues in a level attitude
for a short distance
B) Airplane pitches nose up
C) Airplane pitches nose down
If A) Engine thrust angle is correct
If B) Decrease engine down thrust
If C) Increase engine down thrust
Center of Gravity From level flight, roll to a 45º bank and
neutralize the controls
A) Airplane continues in the bank for
a short distance
B) Nose pitches up
C) Nose pitches down
If A) Center of gravity is correct
If B) Add nose weight
If C) Remove nose weight or add tail
weight
Yaw** Into the wind, perform inside loops
using only elevator. Repeat test
performing outside loops from an
inverted entry
A) Wing is level throughout
B) Airplane yaws to right in both inside
and outside loops
C) Airplane yaws to left in both inside
and outside loops
D) Airplane yaws to the right in inside
loops and yaws to the left in
outside loops
E) Airplane yaws to the left in inside
loops and yaws to the right in
outside loops
If A) Trim settings are correct
If B) Add left rudder trim
If C) Add right rudder trim
If D) Add left aileron trim
If E) Add right aileron trim
Lateral Balance** Into the wind, perform tight inside loops
using only elevator
A) Wing is level and airplane falls
to either side
B) Airplane falls off to the left.
Worsens as loops tighten
C) Airplane falls off to the right.
Worsens as loops tighten
If A) Lateral balance is correct
If B) Add weight to right wing tip
If C) Add weight to left wing tip
Aileron Control System With the wing level, pull to a vertical
climb and neutralize the controls
A) Climb continues along the same
path
B) Nose tends to go toward an inside
loop
C) Nose tends to go toward an outside
loop
If A) Trim settings are correct
If B) Raise both ailerons very slightly
If C) Lower both ailerons very slightly
*Engine thrust angle and center of gravity interact. Check both.
**Yaw and lateral balance produce similar symptoms. Note that the fin may be crooked. Make certain both elevator halves are even with
each other and that they both produce the same amount of control deflection throughout the complete deflection range. Right and left
references are as if you were in the cockpit.
SECTION 27: MAGIC FORMULA 3D ARF FLIGHT-TRIMMING CHART
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