The Australian Navy Carrier rules ensure than models are kept as technically relatively simple as possible. The scale requirement is also very straightforward: a model must be recognisable as a particular carrier aircraft and full bonus points are awarded for scale models. Models must have only the minimum systems that enable them to undertake the basic Carrier functions of high speed, low speed and arrested landing and are therefore permitted only an arrester hook and speed control system in addition to the normal elevator controls. Moveable flaps and rudder are the only additional control surfaces permitted.

Because of the scoring system’s emphasis is on high and slow speed and also a successful ‘arrested’ landing, a model which will fly and handle well during all flight phases is invariably the best type to use. Not only will this type produce higher flight scores, a model with a good slow speed capability will also mean that accurate arrested landings are most easily achieved by the novice pilot.

All models require the usual 2-line elevator control system for normal C/L flight. To obtain fast and slow speed flight, most Carrier Deck models use conventional R/C throttled glow motors with a variety of proper speed control systems, most of which are derived from the same basic design.

Only when the model is twin-engine can the simplest ‘speed control’ system of all be used, in which one motor - usually the outboard - is allowed to run out of fuel before the slow flight starts!

There are a number of different types of proper speed control system that can be used to operate an R/C engine. The simplest is undoubtedly an independent third control line running from control handle to model and directly connected to the engine’s throttle by a system of cranks. As this single line can only be pulled in one direction, such a system will require spring loading to obtain movement in the opposite direction. Whilst simple, this has the disadvantage that pulling too hard can reduce or even completely remove elevator line tension.

A far more satisfactory system is the 3-line arrangement first developed in the US as the ‘J.Roberts’ Flight Control System’ and now more widely used, and imitated, than any other. The J.Roberts’ system uses a special bellcrank in the model and a matching mechanism within the control handle to give fully balanced and compensated control movements. The system provides full throttle control at the same time as full elevator control whilst maintaining equal tension in all 3 lines, and also allows the throttle to be set and left in any position.

Although this very successful commercial system is readily available, it is not inexpensive. This has given rise to a number of variations on the theme which not only are often just as effective, they can usually be manufactured easily by the average aeromodeller and at very moderate costs indeed. See the appropriate section for information on the J.Roberts’ system, plus diagrams of all the common imitations and full instructions for the manufacture of each.

Modern electronics have also been used to provide multi-function control via 2 control lines! Sometimes known as closed loop telemetry, it is essentially normal radio control but sent ‘down the wires’ instead of through the air. Some R/C systems can even provide it without modification: special plug-in points actually bypass the unwanted radio frequency circuits so that transmitter and receiver can be connected directly to each end of a normal 2-line C/L system (though, of course, the wires must be insulated) and this will give as many control functions as the system has channels!

Whilst very sophisticated and particularly popular with C/L scale modellers, it is nevertheless very complex and expensive, and rarely used in Carrier. The mechanical 3-line J.Roberts’ system and its derivatives are unhesitatingly recommended as the best systems and it is assumed from here on that this is what the Carrier model builder and flier will be using. Navy Carrier requires models that fly well at low speeds. Such models are generally characterised by large wing areas, thick wing sections, lifting aerofoils and low wing loadings - or some combination thereof.

These requirements can be very easily satisfied! Conventional aerobatic designs or even stunt trainers often make excellent Carrier Deck models by virtue of their relatively large, thick sectioned wings, light weight and good flying qualities. Such model designs often need no more than the provision of a throttle control system, local undercarriage strengthening to cope with heavy deck landing impacts and the addition of strong arrester hook mounts. It is therefore perfectly possible - and has already been successfully achieved on a number of occasions - to modify an existing model in this way.

In fact, if you are unsure about committing yourself, modification of a suitable but redundant old model is undoubtedly the quickest and easiest way to see if you’ll like flying the class.

Navy Carrier is a challenging event which is a balance of good, reliable equipment and flying skill. Reliability during slow flight is at least as important as high-speed performance making modern throttled controlled R/C engines competitive.