Landing - GREAT PLANES RV-4 Instruction Manual

trims to maintain straight and level flight. After flying around
for a while and while still at a safe altitude with plenty of fuel,
practice slow flight and execute practice landing approaches
by reducing the throttle to see how the model handles at
slower speeds. Add power to see how she climbs as well.
Continue to fly around, executing various maneuvers and
making mental notes (or having your assistant write them
down) of what trim or C.G. changes may be required to fine
tune the model so it flies the way you like. Mind your fuel
level, but use this first flight to become familiar with your
model before landing.
CAUTION (THIS APPLIES TO ALL R/C AIRPLANES): If,
while flying, you notice any unusual sounds, such as a
low-pitched "buzz," this may indicate control surface
flutter. Because flutter can quickly destroy components of
your airplane, any time you detect flutter you must
immediately cut the throttle and land the airplane! Check
all servo grommets for deterioration (this may indicate
which surface fluttered) and make sure all pushrod
linkages are secure and free of play. If the control surface
fluttered once, it probably will flutter again under similar
circumstances unless you can eliminate the free-play or
flexing in the linkages. Here are some things which can
cause flutter: Excessive hinge gap; Not mounting control
horns solidly; Poor fit of the clevis pin in a horn; Side-play
of pushrod in guide tube caused by tight bends; Poor fit of
Z-bend in a servo arm; Insufficient glue used when gluing
in the elevator joiner wire; Excessive play or backlash in
servo gears; and insecure servo mounting.

Landing

To initiate a landing approach, lower the throttle while on the
downwind leg. Allow the nose of the model to pitch
downward to gradually bleed off altitude. Continue to lose
altitude, but maintain airspeed by keeping the nose down as
you turn onto the crosswind leg. Make your final turn toward
the runway (into the wind) keeping the nose down to
maintain airspeed and control. Level the attitude when the
model reaches the runway threshold, modulating the throttle
as necessary to maintain your glide path and airspeed. If
you are going to overshoot, smoothly advance the throttle
(always ready on the right rudder to counteract torque) and
climb out to make another attempt. When you're ready to
make your landing flare and the model is a foot or so off the
deck, smoothly increase up elevator until it gently touches
down. Once the model is on the runway and has lost flying
speed, hold up elevator to place the tail on the ground,
regaining tail wheel control.
If you have installed the functional flaps the landing
approach is very similar. Lower the throttle while on the
downwind leg. Then, lower the flaps approximately 1/2"
[13mm]. The nose will most likely pitch up slightly. When it
does, continue lowering the throttle until the nose levels.
Continue to lose altitude as you turn onto the downwind leg.
Line up with the runway, allowing the nose to come down but
maintaining airspeed and control. Fly the airplane to two or
three feet above the runway and then drop the throttle to
idle. Add elevator to flare the airplane to touchdown.
One final note about flying your model. Have a goal or flight
plan in mind for every flight. This can be learning a new
maneuver(s), improving a maneuver(s) you already know, or
learning how the model behaves in certain conditions (such
as on high or low rates). This is not necessarily to improve
your skills (though it is never a bad idea!), but more
importantly so you do not surprise yourself by impulsively
attempting a maneuver and suddenly finding that you've run
out of time, altitude or airspeed. Every maneuver should be
deliberate, not impulsive. For example, if you're going to do
a loop, check your altitude, mind the wind direction
(anticipating rudder corrections that will be required to
maintain heading), remember to throttle back at the top and
make certain you are on the desired rates (high/low rates).
A flight plan greatly reduces the chances of crashing your
model just because of poor planning and impulsive moves.
Remember to think.
Have a ball! But always stay in control and fly in a
safe manner.
GOOD LUCK AND GREAT FLYING!
51