Wingspan
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.
Fuselage length
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.
Wing area
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.
Wing load
Model wing loading in normal flight mode. Technically, this indicator is the ratio of the weight of the aircraft to the wing area — for example, for a model weighing 1 kg and planes of 20 dm2, the load will be 1000/20=50 g/dm2.
The lower the wing loading, the easier the model is kept in the air, the less engine thrust it needs and the lower the takeoff and landing speeds will be. On the other hand, a small wing loading increases wind drift. Thus, the lowest values are found in gliders (see "Type"), the highest in fan flyers and some beginner models.
Flight weight
In this case, the flight weight means the maximum weight of the model, at which it is able to fly normally with a complete motor and battery (for ARF and Kit, see "Packages" — with recommended equipment). This parameter allows you to determine the weight margin — the amount of cargo that the model can take on board in addition to what is already included in the standard set. To calculate the maximum weight of additional cargo, you need to subtract the nominal weight (see above) from the flight weight.
In addition, the flight weight must be known when completing the ARF or Kit model with non-standard parts — so as not to overload the machine.
