Air traffic is possibly one of the most and best regulated and controlled of all human activities.
Although it may seem obvious, the airspace is everything in the open air or, in other words, everything between the earth's surface (land or water) and the limits of the atmosphere. This is the space which, with a few exceptions, is intended for the flight of aircraft of any kind.
In the context of each country, as well as at the supranational level, there are organisations that are responsible for legislating and ensuring safety in that space. At any given time of the day there are tens of thousands of aircraft flying, from private drones to large commercial aircraft. Even if it is a private estate, a garden or a private compound, airspace is public and therefore the competence of the national agency concerned.
In the specific case of RPAS or model aircraft, it may happen that they fly in completely enclosed environments (indoor halls or stadiums). In such cases, State aviation safety agencies do not have legislative or sanctioning powers, but rather the responsibility lies with the owner of the enclosure. However, in the case of an uncovered enclosure or an enclosure with a retractable roof, competence lies with the relevant official body.
There are three types of airspace: controlled, uncontrolled and special use airspace. The type of airspace is defined in each case depending on the movement of aircraft, the purpose of the operations being carried out and the level of safety required.
The International Civil Aviation Organisation, ICAO, classifies airspace into seven types, named with letters ranging from A to G.
Class A, B, C, D and E airspaces are controlled type. This is defined as flights where aircraft are subject to air traffic control provided by control units (area control centres, approach units and control towers). The typology of flights according to classes is as follows:
Class A. Only instrument (IFR) flights are permitted, all flights are provided with air traffic control service, and are separated from each other.
Class B. Instrument (IFR) and visual (VFR) flights are permitted, all flights are provided with air traffic control service and are separated from each other.
C-Class. IFR and VFR flights are permitted, all flights are provided with air traffic control service and IFR flights are separated from other IFR flights and VFR flights. VFR flights are separated from IFR flights and receive traffic information regarding other VFR flights.
Class D. IFR and VFR flights are permitted and all flights are provided with air traffic control service, IFR flights are separated from other IFR flights and receive traffic information in respect of VFR flights, VFR flights receive traffic information in respect of all other flights.
E-Class. IFR and VFR flights are permitted, IFR flights are provided with air traffic control service and are separated from other IFR flights. All flights receive traffic information as far as practicable. Class E shall not be used for control areas (ICAO recommendation).
The classes F and G correspond to uncontrolled airspace and this is where, according to current legislation in most countries, RPAS can fly. In these cases, an ATC authorisation is not required.
Although it may seem a little complicated, let's stick with the fact that air traffic is possibly one of the most and best regulated and monitored activities of all human endeavours. The aim is always the same: that security is always maintained at its highest level.
