Great Planes Giant Aeromaster Kit - GPMA0502 - Manual (Page 50)

into play here so be patient and eliminate the variables one-by-
one The maneuver is a simple loop but it must be entered with
the wings perfectly level Position the maneuver so that your
assistant can observe it end on Always loop into the wind Do
several loops see if the same symptom persists Note if the
model loses heading on the front or back side of the loop If you
lose it on the way up it s probably an aileron problem while a loss
of heading on the way back down is most likely a rudder situation
After you get the inside loops going correctly do the same
maneuver to the outside entering from an inverted position
Before you make too many dramatic changes glance at the
remainder of the chart and note the myriad combination of things
we can do just with the ailerons Each change you make will affect
all other variables'
Note that the Yaw test is the same looping sequences Here,
however we are altering rudder and ailerons instead of the
elevator halves We must repeat that many airplanes just will not
achieve adequate lateral trim without sealing the hinge gaps shut
The larger you make the loops (to a point), the more discernable
the errors will be
why a plane flies the way it does, and you'll be a better pilot for it
One thing we almost guarantee is that your planes will be more
reliable and predictable when they are properly trimmed out They
will fly more efficiently and be less prone to doing radical and
surprising things Your contest scores should improve, too.
We wish to acknowledge the Orlando, Florida, club newsletter,
from which the basics of the chart presented here were gleaned
Reprinted in part by Great Planes Model Manufacturing Company
courtesy of Scale R/C Modeler magazine, Pat Potega, Editor,
August 1983 issue
Building Notes:
The Lateral Balance test has us pulling those loops very tightly
Actually we prefer the Hammerhead as a better test for a heavy
wing Pull straight up into a vertical and watch which wing drops
A true vertical is hard to do, so make sure that your assistant is
observing from another vantage point Note that the engine torque
will affect the vertical fall off, as will rudder errors Even though we
balance the wing statically before leaving for the field, we are now
trimming it dynamically
The A i l e r o n Coupling (or rigging) is also tested by doing
Hammerheads This time however we want to observe the side
view of the model Does the plane want to tuck under a bit 9 If so,
then try trimming the ailerons down a small bit so that they will
act as flaps If the model tends to want to go over into a loop then
rig both ailerons up a few turns on the clevises Note that
drooping the ailerons will tend to cancel any washout you have in
the wing On some models the lack of washout can lead to some
nasty characteristics at low speeds
The effects noted with the Aileron Coupling tests can also be
caused by an improperly set wing incidence The better test for
this is knife edge flight If the model tends to pull upward, i e , it
swings toward a nose up direction, then reduce the wing
incidence If the model tries to go off heading toward the bottom
side of the plane, then increase incidence
Again, we reiterate that all of these controls are interactive When
you change the wing incidence, it will influence the way the
elevator trim is at a given C G Re trimming the wing will also
change the rigging on the ailerons, in effect and they may have to
be readjusted accordingly
The whole process isn't hard As a matter of fact it's rather fun —
but very time consuming It s amazing what you will learn about
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