Comparison KFPLAN KF605 vs Precision Aerobatics Katana Mini Kit

— Airplane for beginners. The specificity of this type is reflected in the name itself: such models (they are also called “trainers”) are intended for initial training. This is the best option for those who have not previously dealt with radio-controlled aircraft. Usually, "coaches" have electric motors, light weight, good stability, and their design is designed, including on survivability in case of accidents and insensitivity to piloting flaws. All this allows you to confidently stay in the air even at low speeds and other critical modes, however, it makes it difficult to perform complex aerobatics. Nevertheless, such machines are quite suitable for basic aerial acrobatics; and some of them can even be equipped with interchangeable parts, allowing you to turn the “trainer” into a model for an experienced pilot.

— Glider. The main external feature of radio-controlled gliders, like their full-sized counterparts, is the large wingspan (which can be more than twice the length of the fuselage). At the same time, unlike classic gliders, these models have engines; however, such an engine, usually, continuously operates only when climbing, and after that it can be turned on periodically, for a short time — a long wing allows you to glide over long distances without using engine thrust. Gliders are not suitable for active aerial acrobatics and are intended mainly for level flight with smooth turns. Howev...er, with certain tricks on such a machine, it is also possible to perform individual elements of aerobatics.

— Mini plane. Aircraft of small size, with a wingspan of less than 400 – 450 mm. This makes them easier to transport from place to place and easier to use indoors (although you still need quite a lot of space for flying — like a gym). At the same time, compact dimensions make it difficult to use advanced features, and most models in this category belong to the entry level and have basic functionality.

— Acrobatic plane(Fan Flyer). Models originally designed for complex and aerobatics. They are distinguished by advanced high-tech equipment, are not cheap and require good piloting skills.

— Seaplane. Models equipped with a float chassis. Usually, they use the water surface for takeoff and landing, as well as full-size seaplanes; at the same time, many models allow the replacement of floats with classic wheels and can even be equipped with interchangeable chassis. According to the specifics of the application, they can be similar to both models for beginners and fan flyers (see above).

— Jet aircraft. Models that mimic the appearance of a jet aircraft. At the same time, such machines are not necessarily equipped with jet engines — most often they have the same motors as propeller models, except that the propeller role is played not by a propeller, but by an impeller hidden in the body. The latter is one of the advantages of this option in light of the fact that the moving blades are protected from contact with surrounding objects (unlike open propeller blades), which makes the device safer and less sensitive to collisions.

— " Flying wing ". Models built according to the "flying wing" aerodynamic scheme. Such a scheme assumes the absence of a pronounced fuselage, as well as separate stabilizers with elevators — only wing elements are responsible for pitch control. The purpose of such models can be both entertaining and aerobatic, depending on the design features. However, for a number of reasons, they have not received much distribution.

— Biplane. Biplanes are called aircraft with two pairs of wings, usually located one above the other. Such devices have a number of advantages over monoplanes (aircraft with one pair of wings) — in particular, a large wing area with a smaller span. However, most of these advantages are more relevant for full-size aircraft than for scale models. Therefore, in radio-controlled vehicles, the biplane scheme is mainly used to create copies of real machines (in particular, during the First World War).

— RTF (RTF). Models of this configuration ("Ready To Run", "Ready To Fly") are supplied fully equipped, with all the equipment necessary for operation — a motor, control electronics, etc. — and practically do not require preparation before the flight. This is the simplest and at the same time affordable option, however, note that most RTF models are designed for undemanding users, and even advanced devices do not always allow replacing complete parts with more high-end ones. Note that many of these devices are delivered disassembled (for more details, see "Casing"), however, their assembly is usually extremely simple and cannot be compared in terms of time and effort with Kit kits (see below).

— ARR (ARF). Models partially ready to fly ("Almost Ready to Run / Fly"). Supplied as a base (airframe) of the aircraft, usually with an engine, but without some of the necessary elements. Usually, the list of required items includes control radio equipment and a battery, and the kit may also lack a charger, servos, etc. and modify it in the future.

— Kit (set). Kits are supplied as a set of parts, from which the owner must assemble the aircraft on his own. Also, as in the case of ARF (see above), many items of equipment have to be bought on their own, and in this case, the engine is usually included in the list of necessary items. The purpose and complexity of a...ssembling "whales" can be different — from simple and unpretentious aircraft for beginners (see "Type") to professional fan flyers. Anyway, this option is intended for the most enthusiastic "techies" who are fond of not only flying, but also assembling and modifying flying machines.

The wing span is the distance from one extreme point of the wing to the other (in other words, the distance between the left and right tips). For biplanes (see "Type") with wings of different sizes, the largest span is indicated.

Long(relative to the fuselage) wings provide more lift and make it easier to fly in gliding mode (for example, with a failed engine). In addition, the aircraft is more stable — but also less agile. Another disadvantage of a long wing is its high drag, which requires a lot of engine power and makes it difficult to accelerate to high speeds. In light of all this, aerobatic models (both fanflyers and beginners, see "Type") typically have relatively small wingspans.

The total length of the aircraft fuselage. By itself, it mainly determines the dimensions and "weight category" of the machine, and comparing this parameter with the wingspan (see above), one can evaluate some features of the use and controllability of the device.

The total area of the wing (carrying surface) of the aircraft. This parameter is auxiliary and is used in fact for rather specific purposes — in particular, to calculate the wing load (see below), if it is not specified or the model has been modified, to select an aftermarket motor for the model, etc.

The number of screws installed in this model.

In real aircraft, several propellers (and engines) are usually provided in order to provide the necessary thrust. However, in the case of radio-controlled models, this can also be achieved with a single screw, despite the fact that a multi-screw circuit significantly complicates and increases the cost of the device. Therefore, variants with multiple propellers are rare, usually this design is used in models that copy real multi-engine machines. However, there are exceptions — for example, a four-engine device that externally copies an airplane, but flies on the principle of a quadcopter.

The capacity of the battery supplied with the aircraft.

Theoretically, the higher the battery capacity, the more energy it can store and the longer the battery life can be. However, theoretically, battery life also depends on the power (read — energy consumption) of the engine, and in fact, it also depends on the flight style, the intensity of manoeuvring and other situational factors. Therefore, it is worth focus not so much on the battery capacity as on more practical parameters — first of all, the same operating time stated in the specifications.

At the same time, capacity data can be useful in some calculations — for example, when estimating the battery life of a larger battery. With an increase in capacity, battery life, usually, grows proportionally: for example, if a 1.5 Ah battery gave 15 minutes of flight, then with a 3 Ah battery this figure can reach 30 minutes. However note that more capacious batteries weigh more; this is especially noticeable with a small weight of the aircraft.

Rated voltage of the battery supplied with the aircraft.

This parameter is selected by the manufacturers to provide the required motor and servo performance. Therefore, when buying and regular use, you can not pay special attention to it. In fact, voltage data is needed primarily when looking for a spare or replacement battery.

The type of battery supplied with or recommended for use with the model.

— Ni-Mh. Nickel-metal hydride batteries have a combination of reliability, good capacity, resistance to temperature extremes and low cost. In addition, they are almost not subject to the “memory effect” (drop in capacity when charging a battery that is not completely discharged). On the other hand, in most characteristics, such batteries are inferior to lithium-ion and lithium-polymer ones, and therefore are used relatively rarely, mainly in inexpensive models.

— Li-pol. Lithium-polymer batteries are a further development of lithium-ion and have quite advanced characteristics. Of these, it is worth mentioning, in particular, the high charge density (that is, good capacity with small size and weight, which is especially important for flying equipment), as well as the absence of a “memory effect”. Such batteries are much more expensive than nickel-metal hydride ones, but this disadvantage is more than offset by advantages. Thanks to all this, most modern radio-controlled aircraft use lithium-polymer batteries.

— AA. "AA" is not a battery manufacturing technology, but a size known to many as ordinary "finger-type" batteries. In this standard size, both batteries and disposable cells can be produced, and both of them are on the market in many varieties that differ in quality, capacity and price. Another difference between the AA elements and the options described above is...that they are initially removable and allow for quick replacement. “Finger” elements are sold almost everywhere, in addition, the user has a choice: regularly buy inexpensive disposable elements or fork out once for batteries, but no longer worry about additional costs. On the other hand, the power of such a power supply is small, and it is suitable only for small models with the simplest functionality — in more solid equipment, it is more rational to use specialized batteries. Also note that even in the RTR package (see above), batteries are most often not included in the kit.