Terminology regarding remotely piloted aircraft
Different international organisations use multiple terms for remotely piloted aircraft. The International Telecommunication Union, ITU, has adopted the terms UA (Unmanned Aircraft) and UACS (Unmanned Aircraft Control Station). The entire system including both UA and UACS is referred to as UAS (Unmanned Aircraft System).
However, the International Civil Aviation Organization, ICAO, refers to the same aircraft with the term RPA (Remotely Piloted Aircraft) and to the same system with the term RPAS (Remotely Piloted Aircraft System).
Other references to such aircraft are UAV (Unmanned Aerial Vehicle), drone and autonomous aerial vehicle. The European Aviation Safety Agency, EASA, has adopted the term “drone". Trafi uses the term “remotely piloted aircraft".
The names for different copters depend on the number of their rotors - a quadcopter is a 4-rotor, a hexacopter a 6-rotor and an octocopter an 8-rotor copter. Such copters are generally referred to as multicopters. Single- and double-rotor copters are traditional helicopters.