The Basic Trainer


Quite often a person has an interest in model airplanes and visits a local flying field just to observe. He sees all types of airplanes from trainers to pattern planes to scale World War II fighter planes. His interest is piqued by all the fabulous looking models. He thinks, "I have to have one of those Mustangs." He immediately sets out trying to find a P-51 model to begin his modeling hobby. This is a serious mistake. Many hours of training and practice are involved before a beginner has the ability to handle the more advanced models. A beginner must realize the dedication that is required to gain the ability to fly the type of model that initially spawned his interest. He must begin the hobby with a basic trainer and progress through different levels of models until his goal is reached.

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.


Parts of a Trainer

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.

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BEST TRAINERS
Click on model name or supplier for additional information
NAME SUPPLIER DESCRIPTION
Stick 40+ Balsa USA The most basic trainer kit available, inexpensive, easy to build, easy to fly, almost indestructable
Kadet LT40 SIG Mfg.. Inc. Very good quality trainer kit, relatively easy to build, easy to fly, excellent performance
Eagle II Carl Goldberg Very good quality trainer kit, relatively easy to build, very easy to fly, good performance
Aerostar 40 Midwest Very good quality trainer kit, relatively easy to build, easy to fly, very good performance
Telemaster 40 Hobby Lobby Very good quality trainer kit, relatively easy to build, easy to fly, good performance
PT40 Mk II Great Planes Very good quality trainer kit, relatively easy to build, easy to fly, very good performance
AviStar 40 Mk II Hobbico Good quality ARF trainer, easy to assemble, easy to fly, excellent performance
Trainer 40 Thunder Tiger Good quality ARF trainer, easy to assemble, easy to fly, excellent performance
Trainer 40 Tower Hobbies Good quality ARF trainer, easy to assemble, easy to fly, very good performance

Most if not all of the models listed have been reviewed by one of the major model magazines. A beginner can get information from these reviews that may help in deciding which model to buy and the areas of assembly that need special attention. Regardless of the amount of advice that the beginner gets from experienced modelers, the final decision is the beginner's. The choice of a model is an individual choice and all the pro's and con's must be weighed. Each person must decide which model is pleasing in appearance and performance and which one will meet his needs. The final consideration should be that the model should be considered disposable. Many trainers are destined for the junk pile when it has served its purpose.