Age
The minimum age for which this radio-controlled model is suitable. These recommendations are rather conditional, but it is still not recommended to deviate from them. "Adult" models 14+ with many adjustments, moving parts and power simply will not be able to master the baby. At the same time, models for the younger age category may not be interesting and boring for older children.
Main rotor diameter
Helicopter rotor(s) diameter. In fact, this parameter primarily determines the dimensions of the machine in the working position; this is especially true for three- and four-bladed models, where the propeller cannot be deployed along the fuselage, reducing the width of the space occupied (although the blades can be folded, which eliminates this drawback). Otherwise, the diameter of the rotor is of secondary importance: it is selected by the manufacturer in such a way as to provide features corresponding to the class of the machine, and it is worth focus primarily on the general purpose and price category of the helicopter, and not the size of the propeller.
Tail rotor diameter
The diameter of the tail rotor in machines of the classical scheme (see below). This parameter is of practical importance only in professional aircraft modeling sports, and even then quite rarely; relevant moments are described in special sources.
Number of rotor blades
The number of blades provided in the design of the main rotor of a helicopter. When calculating this number, all rotors are taken into account — this means that in the coaxial circuit models (see above), the total number for both screws is indicated. Actually, in such machines
4 blades are used as standard — 2 per screw, there is usually no need for more; but in the classical scheme, this number can be different — from
2 to
3 —
8(technically, more is possible, but in fact this is rare).
The fewer blades provided in the design, the simpler and cheaper the screw (ceteris paribus), but the faster it must rotate in order to provide the necessary lift; this puts forward corresponding requirements to the engine. However, the number of blades is usually chosen by the manufacturer in such a way as to provide the machine with flight characteristics corresponding to the price and class. Therefore, this parameter can only be of practical importance for professional models designed for complex aerobatics; You can read more about this in special sources.
Battery capacity
The capacity of the battery supplied with the electric motor model (see "Motor"). Indicated only for variants using branded batteries (see "Battery type"), measured in ampere-hours: 1 Ah corresponds to the capacity at which the battery is capable of delivering a current of 1 A for 1 hour.
The higher the battery capacity, the more time the helicopter can spend in the air, usually. However, the practical time of operation on a charge is largely determined by other characteristics of the machine — dimensions and weight, engine model and power, etc. Therefore, in most cases, this parameter plays a purely reference role, and only helicopters that do not have any significant differences in other characteristics (and even then very approximately) can only be compared in terms of battery capacity.
USB charging
Capable
of charging the helicopter battery from a standard USB port. This function is convenient primarily due to the prevalence of the USB standard: it is used in the vast majority of modern computers and laptops as a data transfer interface, and in portable electronics it is also used as a power source for charging batteries. Thus, a model with this feature can be connected for charging to computer equipment — or to any 220-to-USB network adapter. This is more convenient than using a specialized charger (which can also be lost). However the current power during such charging is relatively low, which is why it is poorly suited for powerful batteries.
Copy of the original
This category includes radio-controlled models, the design of which
copies the appearance of real-life helicopters — attack, transport, search and rescue, etc. Such a design, most often, does not affect the functionality, but it gives an additional resemblance to full-size machines. This is primarily appreciated by aviation fans, however, the use of copy models is not limited to purely aesthetic moments — they can also be useful for quite practical tasks (for example, imitation of a real helicopter when shooting a movie).
Dimensions (LxWxH)
General dimensions of the model. Note that the length and width are indicated only for the fuselage, excluding the main rotor. However, for ease of transportation, the blades are often made removable or folding.
