A trainer is a specific type of model aircraft that is designed to be stable in flight. This means that it has an inherent ability to correct itself and overcome the rotational forces applied so that it regains straight and level flight. Most trainers are designed to that they remain stable in slow flight so that they are easy to land.

The Basic Trainer diagram shows the components of a common trainer.

Aileron - The moveable portion of the wing which causes a change about the roll axis

Cowling - The part of the fuselage which covers the engine

Engine - A 2 - cycle reciprocating machine which provides the motivational power

Elevator - The moveable portion of the horizontal stabilizer which causes a change about the pitch axis

Fin - Properly known as vertical stabilizer which provides stabilization about the yaw axis

Fuselage - The main body of an aircraft

Landing Gear - The supporting structure of an aircraft including landing gear struts and wheels

Propeller (Prop) - The combination of blades which provide thrust

Rudder - The moveable portion of the vertical stablizer which causes change about the yaw axis

Spinner - Covering over the prop hub

Stabilizer - Properly known as horizontal stabilizer which provides stabilization about the pitch axis

Wing - The horizontal surfaces which provide the lifting forces

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.

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 a matter of a few hours and the beginner can be ready to start his flying lessons. The disadvantages are the cost, the unknown structure that is sometimes weak, and the fixed color scheme. Most ARF models perform as well or almost 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 assembly is started. An experienced modeler can point out areas that may need to be reglued or reinforced.

There are several models that are widely accepted as being the best in the field although there is disagreement as to which is the "All Time Best". The list is not an all inclusive but includes those which are most widely accepted. Some of the trainers are also available in .20 and .60 size but the .40 is the most widely accepted.

• Kadet LT40 - SIG Mfg. Inc.
• Kadet Senior - SIG Mfg. Inc.
• Eagle II - Goldberg Models
• Aerostar 40 - Midwest Products.
• Telemaster 40 - Hobby Lobby

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