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There
are certain criteria that a trainer should have in order to be satisfactory for
a beginner.
1.
High Wing
- A high wing model is inherently more stable than a low wing model due to
pendulum effect. Since the weight of the model is below the wing, the fuselage
tends to swing downward like a pendulum in order to equalize forces.
2.
Flat Bottom Wing
- The wing cross section should have a virtually flat bottom. This type of cross
section has more gentle flight characteristics that are necessary for a
beginner.
3.
Dihedral
- The wing should have some dihedral. This means that the tips of the wings are
higher than the center. The effect of the dihedral is to try to equalize forces
and keep the wings level or to return the wings to a level orientation.
4.
High Aspect
Ratio - The ratio of
the wing length or span should be at least 5 1/2 times the width or chord. This
will reduce the rate at which the model responds to command input allowing more
time for a beginner to react.
5.
Constant Chord
- The width of the wing should be the same from the center or root to the end or
tip. This distributes the weight of the airplane evenly over the entire surface
of the wing.
6.
Low Wing Loading
- The weight of the model divided by the area of the wing should not exceed 19
oz./sq. ft. This reduces the speed required to maintain an acceptable rate that
the model descends when the power is reduced resulting in a lower landing speed.
7.
Moderate Size
- Most trainers are for engine sizes between .15 and .60. The smaller ones are
more susceptible to the effects of wind and normally the wing loading is higher
simply because of the weight of the radio equipment. The larger sizes are easier
to fly and easier to see but are more difficult to transport. Most trainers are
for .40 size engines. These trainers have been widely accepted as the optimum
size.
8.
Structurally
Sound - A trainer must
be able to take the abuses imposed by a beginner. This is especially true for
hard landings. It must be able to withstand minor crashes with minimal damage.
It should be relatively easy to repair.
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A
trainer that meets these guidelines will give the beginner excellent service
without the frustration that can occur with an inappropriate model. With proper
instruction, the beginner can progress quickly to his solo flight and on to the
novice stage and still get years of sport flying from the trainer.
There
are several trainers on the market that meet and far exceed the guidelines.
These range from the most basic kit to beautiful Almost Ready to Fly (ARF)
models complete with engine and radio. There are a lot of considerations when
choosing a trainer but the two most basic are time and money.
A
trainer built from a kit has the advantage of being less expensive in some
cases. It gives the builder the pleasure of building, the option of color and
trim scheme, and the knowledge of the structure to perform repairs. The biggest
disadvantage is the time required to construct the model when the beginner would
rather be learning to fly. Another disadvantage in some cases is the emotional
attachment the builder develops having spent many hours on his creation.
The
big advantage of the ARF models is that they can be assembled in about an hour
and the beginner can be ready to start his flying lessons. The disadvantages are
the unknown structure and
the fixed color scheme. Most ARF models perform as well as any kit built model
on the market. Any beginner who purchases an ARF model should get an experienced
modeler to check the model before the maiden (first) flight.
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top
Aileron -
The
moveable portion of the wing which causes a change about the roll axis, some
beginners call it a "flap" but that's another control surface used to slow
down a planes' descent.
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Cowling -
The
part of the fuselage which covers the engine, this is not a necessary part and
is not included on most trainers. Most trainers have exposed engines with
"cheeks" on either side of the engine.
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Engine -
A 2 or
4 cycle reciprocating machine or electric motor which provides the motivational power
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Elevator -
The
moveable portion of the horizontal stabilizer which causes a change about the
pitch axis (up or down) back to top
Fin -
Properly
known as vertical stabilizer which provides stabilization about the yaw axis
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Fuselage -
The
main body of an aircraft, it usually houses the electronics and pushrods that
move the control surfaces
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Landing Gear
-
The supporting structure of an aircraft including landing gear
struts and wheels, on most trainers the front wheel actually steers the plane
(on the ground) back to
top
Propeller (Prop)
-
The combination of blades which provide thrust
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Rudder -
The
moveable portion of the vertical stabilizer which causes change about the yaw
axis back to top
Spinner -
Covering
over the prop hub. This is good for using electric starters, simply push onto
the spinner and press the button to motivate the engine to life back to
top
Stabilizer -
Properly
known as horizontal stabilizer which provides stabilization about the pitch axis
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Wing -
The
horizontal surfaces which provide the lifting forces
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