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After you have test flown and done the initial trim changes to the aircraft, use the Trim Chart below 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 a
straighter and truer flying airplane.
TRIM FEATURE
MANEUVER
OBSERVATION
CORRECTION
Control Centering
Fly general circles and
Try for hands off straight and
Readjust linkages so the transmitter
random maneuvers
level flight
trim levers are centered
Control Throws
Fly random maneuvers
A) Too sensitive, jerky controls
If A) Adjust linkages to reduce
B) Not sufficient control
control throws
If B) Adjust linkages to increase
control throws
Engine Thrust Angle*
From straight and level
A) Airplane continues in a level
If A) Engine thrust angle is correct
flight, chop the throttle
path for a short distance
quickly
B) Airplane pitches nose up
If B) Decrease down-thrust
C) Airplane pitches nose down
If C) Increase down-thrust
Center of Gravity and
From level flight, roll to
A) Airplane continues in the bank
If A) Trim settings are good
Longitudinal Balance
a 45º bank and neutralize
for a moderate distance
the controls
B) The nose pitches up
If B) Add nose weight
C) The nose drops
If C) Remove nose weight
Yaw**
Into the wind, do inside
A) Wings are level throughout
If A) Trim settings are good
loops using only elevator.
B) Yaws to right in both inside
If B) Add left rudder trim
Repeat test doing outside
and outside loops
loops from an inverted
C) Yaws to left in both inside
If C) Add right rudder trim
entry
and outside loops
D) Yaws to the right on inside
If D) Add left aileron trim
loops and yaws to the left on
outside loops
E) Yaws to the left on inside
If E) Add right aileron trim
loops and yaws to the right on
outside loops
Lateral Balance
Into the wind, do tight
A) Wing are level and plane falls
If A) Trim settings are good
inside loops
to either side
B) Falls off to the left in loops.
If B) Add weight to right wing tip
Worsens as loops tighten
C) Fall off to the right in loops.
If C) Add weight to left wing tip
Worsens as loops tighten
Aileron Rigging
Wing the wings level pull
A) Climb continues along the
If A) Trim settings are good
to a vertical climb and
same path
neutralize the controls
B) Nose tends to go toward an
If B) Raise both ailerons very slightly
inside loop
C) Nose tends to go toward an
If C) Lower both ailerons very slightly
outside loop
TRIM CHART
*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.
