User's Instructions

Aircraft
(ACRO)
Section
– 61 –
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
backer 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 back;
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.