SPLIT ELEVATORS
(also Yaw and
C.G.)
Into wind, pull open
loops, using only elevator.
Repeat tests doing outside
loops to inverted entry.
A. Wings are level throughout.
B. Plane tends toward outside
when right side up, and to
inside when inverted.
C. Plane goes in on regular
loops, and out on inverted.
D. Plane goes out on both
types of loops.
E. Plane goes in on both
types of loops.
If A, trim is fine.
If B, add weight to right
wing, or add right rudder.
If C, add weight to left
wing, or add left rudder.
If D, raise right half of
elevator (or lower right).
If E, raise left half of
elevator (or lower right).
YAW
2
Into wind, do open loops,
using only elevator.
Repeat tests doing
outside loops from
inverted entry.
A. Wings are level throughout.
B. Yaws to right in both
inside and outside loops.
C. Yaws to left in both
inside and outside loops.
D. Yaws right on insides, and
left on outside loops.
E. Yaws left in insides, and
right on outside loops.
If A, trim is 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.
1. Engine thrust angle and C.G. interact. Check both.
2. Yaw and lateral balance produce similar symptoms. Note that fin may be crooked. Right and left references are from the plane's vantage point.
3. Ailerons cannot always be trimmed without sealing the hinge gap.
30
TRIM FEATURE
MANEUVERS
OBSERVATIONS
CORRECTIONS
CONTROL
Fly general circles and
Try for hands off straight and
Readjust linkages so that
CENTERING random
maneuvers,
level flight.
Tx trims are centered.
CONTROL
Random maneuvers
A. Too sensitive, jerky
If A, change linkages to
THROWS controls,
reduce
throws.
B. Not sufficient control.
If B, increase throws.
ENGINE
From straight flight,
A. Aircraft continues level If
A,
trim is okay.
THRUST chop
throttle quickly,
path for short distance.
ANGLE
B. Plane pitches nose up. If B, decrease downthrust.
C. Plane pitches nose down.
If C, increase downthrust.
CENTER OF
From level flight roll to
A. Continues in bank for
If A, trim is good.
GRAVITY
45-degree bank and
moderate distance.
LONGITUDINAL neutralize
controls. B.
Nose pitches up.
If B, add nose weight.
BALANCE
C. Nose drops.
If C, remove nose weight.
LATERAL
BALANCE
Into wind, do tight inside
loops, or make straight up
climbs into Hammerheads.
Do same from inverted
entry.
A. Wings are level and plane
falls to either side
randomly in Hammerhead.
B. Falls off to left in both
inside and outside loops.
Worsens as loops tighten.
C. Falls off to right in both
loops. Worsens as loops
tighten.
D. Falls off in opposite
directions on inside
and outside loops.
If A, trim is correct.
If B, add weight to right
wing tip.
If C, add weight to left
wing tip.
If D, change aileron trim.
3
WING
INCIDENCE
Knife edge flight.
A. Model tends to veer
in nose up direction.
B. Model veers in nose
down direction.
AILERON
RIGGING
With wings level, pull
to vertical climb and
neutralize controls.
A. Climb continues along
same path.
B. Nose tends to go to
inside loop.
C. Nose tends to go to
outside loop.
If A, trim is correct.
If B, raise both ailerons
very slightly.
If C, lower both ailerons
very slightly.
If A, reduce wing incidence.
If B, increase wing incidence.
