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TRIM CHART
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 truer, straighter and better flying airplane.
TRIM FEATURE
MANEUVER
OBSERVATION
CORRECTION
Control Centering
Fly general circles and
Try for hands off straight
Readjust linkages so Tx
random maneuvers.
and level flight.
trims are centered.
Control Throws
Fly random maneuvers.
A) Too sensitive, jerky
If A) Change linkages to
controls.
reduce throws.
B) Not sufficient control.
If B) Increase throws.
Engine Thrust Angle*
From straight flight,
A) Airplane continues
If A) Thrust is correct.
chop throttle quickly.
level path for short
distance.
B) Airplane pitches nose up.
If B) Decrease downthrust.
C) Airplane pitches nose
If C) Increase downthrust.
down.
Center of Gravity
From level flight, roll
A) Continues in bank for
If A) Balance is good.
Longitudinal Balance
to 45º bank and
moderate distance.
neutralize controls.
B) Nose pitches up.
If B) Add nose weight.
C) Nose drops.
If C) Remove nose weight.
Yaw**
Into wind, do inside
A) Wings level throughout.
If A) Trim is correct.
loops using only elevator.
B) Yaws to right on inside,
If B) Add left aileron trim.
and left on outside loops.
C) Yaws left on inside, and
If C) Add right aileron trim.
right on outside loops.
Lateral Balance
Into wind, do tight
A) Wings are level and
If A) Trim is correct.
inside loops.
plane falls to either side.
B) Falls off to left in loops.
If B) Add weight to right
Worsens as loops tighten.
wing tip.
C) Falls off to right in loops.
If C) Add weight to left
Worsens as loops tighten.
wing tip.
Aileron Rigging
With wings level, pull
A) Climb continues along
If A) Trim is correct.
to vertical climb and
same path.
neutralize controls.
B) Nose tends to go to
If B) Raise both ailerons
inside loop.
very slightly.
C) Nose tends to go to
If C) Lower both ailerons
outside loop.
very slightly.
*Engine thrust angle and C.G. interact. Check both.
**Yaw and lateral balance produce similar symptoms. Note that the fin may be crooked. Right and left references are
from the rear of the plane, as if you were in the cockpit.
