Great Planes Shoestring GP/EP ARF - GPMA1328 - Manual (Page 29)

29
Fuel Mixture Adjustments
A fully cowled engine may run at a higher temperature than
an un-cowled engine. For this reason, the fuel mixture should
be richened so the engine runs at about 200 rpm below
peak speed. By running the engine slightly rich, you will help
prevent dead-stick landings caused by overheating.
Takeoff
Before you get ready to takeoff, see how the model handles
on the ground by doing a few practice runs at low speeds
on the runway. Hold “up” elevator to keep the tail wheel on
the ground. If necessary, adjust the tail wheel so the model
will roll straight down the runway. If you need to calm your
nerves before the maiden fl ight, shut the engine down and
bring the model back into the pits. Top off the fuel, then check
all fasteners and control linkages for peace of mind.
Remember to takeoff into the wind. When you’re ready,
point the model straight down the runway, hold a bit of
up elevator to keep the tail on the ground to maintain tail
wheel steering, then gradually advance the throttle. As the
model gains speed decrease up elevator, allowing the tail
to come off the ground. One of the most important things to
remember with a tail dragger is to always be ready to apply
right rudder to counteract engine torque. Gain as much
speed as your runway and fl ying site will practically allow
before gently applying up elevator, lifting the model into the
air. At this moment it is likely that you will need to apply more
right rudder to counteract engine torque. Be smooth on the
elevator stick, allowing the model to establish a gentle climb
to a safe altitude before turning into the traffi c pattern.
Flight
For reassurance and to keep an eye on other traffi c, it is a
good idea to have an assistant on the fl ight line with you. Tell
him to remind you to throttle back once the plane gets to a
comfortable altitude. While full throttle is usually desirable for
takeoff, most models fl y more smoothly at reduced speeds.
Take it easy with the Shoestring for the fi rst few fl ights,
gradually getting acquainted with it as you gain confi dence.
Adjust the trims to maintain straight and level fl ight. If you
have powered the airplane with a .46 engine, you will fi nd
the plane fast, but not so fast to get yourself in trouble. If you
have powered it with a .55 engine, the airplane becomes very
fast so be sure to get fully acquainted with how it performs
before attempting complex maneuvers that could get you
into trouble. After fl ying around for a while and while still at
a safe altitude with plenty of fuel, practice slow fl ight and
execute practice landing approaches by reducing the throttle
to see how the model handles at slower speeds. Add power
to see how the model climbs as well. Continue to fl y 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 fi ne tune the model so it fl ies the
way you like. Mind your fuel level, but use this fi rst fl ight to
become familiar with your model before landing.
Landing
The Shoestring has a clean, racing airframe. Because of this,
you will fi nd that it takes longer to slow the plane for landing
than some other airplanes you have fl own. Be prepared for
this and don’t be surprised if you have to go around and
set up for your landing a second time. 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 fi nal 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 fl are 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 fl ying speed, hold up elevator to
place the tail on the ground, regaining tail wheel control.
One fi nal note about fl ying your model. Have a goal or fl ight
plan in mind for every fl ight. 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 fi nding 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 fl ight 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 fl y in a safe manner.
GOOD LUCK AND GREAT FLYING!