Organisations operating aircraft, and their pilots.
SESAR Concept of Operations Step 1 Edition 2013 (Ed. 01.02.00)
In the ATM operational concept, three classifications of airspace users are considered:
a) ICAO-compliant manned flight operations (the largest segment by far)
b) ICAO non-compliant manned flight operations; and
c) flight operations of unmanned aerial vehicles (UAVs).
ICAO-compliant manned flight operations are those conducted in accordance with ICAO provisions (e.g. SARPs, PANS). ICAO-compliant airspace users include:
a) all civil aircraft operators (i.e. those engaged in commercial air transport (passenger, mail and cargo services)), aerial work, air taxi operators, business aviation, private air transport, sporting and recreational aviation etc., and
b) the portion of States’ users operating State aircraft using civil air traffic rules.
ICAO non-compliant manned flight operations are those conducted by State aircraft which cannot comply for operational or technical reasons.
Flight operations of unmanned aerial vehicles (UAVs), a growing segment of airspace users, include both civil and military applications of UAV technology. In certain situations, UAV technology is seen as a more cost-effective solution than the use of conventional aeroplanes or helicopters.
Lexicon Release 2015.1