Top Flite Nobler - Manual (Page 8)

35 Sand flaps and drill for flap horn (note offset — see plan). Install flaps
and hinge temporarily to wing
36 Mount three servos Make all pushrods as shown on plan Hinge rudder
and elevator Check all controls for free movement
37. Remove engine, R/C gear, landing gear main struts and all control surfaces
This model may be covered with Super MonoKote (follow instructions on
enclosed leaflet closely) or alternatively may be covered and finished using
silk and dope Hinge all control surfaces permanently after covering
38. Install fuel tank receiver, battery, wheels, engine and spinner, and cockpit
canopy Check CG (see plan for correct position) and if necessary move equip-
ment fore or aft to get CG correct
FLYING
With a good 35 to 45-size engine the airspeed is a relatively constant 70
to 80 mph Automatic speed control is an advantage during maneuvering This
is achieved by propeller selection, airfoil, and flying weight of under 6 lbs
The planform of the plan, wing shape with swept leading edge and fuselage
profile provide excellent yaw stability and accurate roll response
The stunt flaps, which will be described later, contribute excellent lateral
stability
A nearly symmetrical plane and neutral stability coupled with efficient or
large control surfaces produce the Nobler s maneuverability The rudder and
elevator are unusually large for a model airplane The ailerons are reflexing
trailing edge sections with sealed hinge gap giving rapid accurate linear response
with little drag Normal control surface movements are ailerons ± 10 degrees,
elevator ± 15 degrees, and rudder ± 30 degrees The coupled flaps move ±
5 degrees
For many years control line planes have had mechanically coupled flaps
and elevators to give them smoother flight and more lift in sharp corners The
same advantages apply w i t h RC planes Control line models used equal coupled
flap and elevator movement, while the RC models should have much less flap
movement than elevator movement This is because of the inferior power/weight
ratio of RC models compared to CL models, and the consequent necessity to hold
down the drag to maintain flying speed
A radio controled model gains other advantages with flaps For example,
with more pitch axis power, we can have a more forward CG location for groovier
flying When deflected downward, the centersection of the wing is operating at
a higher angle of attack than the wing tips ensuring against tip stalling during
high g maneuvers or low speeds With the additional lift of the flaps the plane
needs less rotation about its pitch axis for a given response, thereby causing
less drag speed changes, and showing a smoother flight path The symmetrical
airfoil is, therefore, infinitely variable to obtain optimum performance
When landing or taking off, the flaps allow slower and more stable flight.
Even in gusty or windy weather, the Nobler seems to fly as if on rails The
flaps keep the wings extra stable because the wing tips are flying at a lower
angle of attack while the other features keep it tracking accurately Even though
the flaps are not sharply deflected, they provide a tremendous amount of additional
lift, even at low speeds
The technique of using flaps coupled with the elevator function is relatively
new to RC flying A detailed investigation of the performance with the flaps
and without the flaps has been made At the 1969 DCRC Symposium, Fred Marks
and Ed Sweeney presented a paper describing the technique showing the results of
tests and experiments with several airplanes To make their findings meaningful,
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