25
To test for _
Test Procedure
Observations
Adjustments
9. Aileron
differential
Method 1: fly model toward you
& pull into a vertical climb
before it reaches you.
Neutralize controls, then half-
roll the model.
Method 2: fly model on normal
pass and do three or more
rolls
Method 3: fly the model straight
and level and gently rock the
aileron stick back and forth
A. No heading changes
B. Heading change opposite to roll
command (i.e. heading veers left
after right roll)
C. Heading change in direction of
roll command
A. Roll axis on model centerline
B. Roll axis off to same side of
model as roll command (i.e. right
roll, roll axis off right wing tip)
C. Roll axis off to opposite side of
model as roll command
A. Model flies straight ahead
without yawing
B. Model yaws away from roll
command (i.e. right roll, yaw left)
C. Model yaws towards roll
command (i.e. right roll, yaw
right)
A. Differential
settings OK
B. Increase
differential
C. Decrease
differential
A. Differential
settings OK
B. Increase
differential
C. Decrease
differential
A. Differential
settings OK
B. Increase
differential
C. Decrease
differential
10.
Dihedral
Method 1: Fly the model on
normal pass and roll into knife-
edge flight; maintain flight with
top rudder (do this test in both
left & right knife-edge flight)
Method 2: Apply rudder in level
flight
A. Model has no tendency to roll
B. Model rolls in direction of
applied rudder
C. Model rolls in opposite direction
in both tests
A. Dihedral OK
B1. Reduce dihedral
B2. Use mixer to
produce aileron
opposing rudder
travel (start with
10%)
C1. Increase dihedral
C2. Mix ailerons with
rudder direction
10%
11. Elevator
alignment
(for models
with
independent
elevator
halves)
Fly the model as in Test 6 and
pull up into an inside loop. Roll
it inverted and repeat the above
by pushing it up into an outside
loop.
A. No rolling tendency when
elevator applied
B. Model rolls in same direction in
both tests — halves misaligned.
C. Model rolls opposite directions
in both tests. One elevator half
has more throw than the other
(model rolls to side with most
throw).
A. Elevators in
correct alignment
B. Either raise one
half, or lower the
other
C. Reduce throw on
one side, or
increase throw on
the other.
12.
Pitching in
knife-edge
flight
Fly the model as in Test 10
A. There is no pitch up or down
B. The nose pitches up (the model
climbs laterally)
C. Nose pitches down (model dives
laterally)
A. No adjustment
needed
B. Alternate cures:
1) move CG aft;
2) increase
incidence;
3) droop ailerons;
4) mix down elevator
with rudder
C. Reverse ‘B’ above
*Trim tab is 3/16” x 3/4” x 4” trailing edge stock, placed just in front of aileron on bottom, pointed end forward.
