Technology & Engineering · Depth 3 · Introductory · 2 min read

Drones

Drones are aircraft with no pilot on board, flown remotely or autonomously. What they are, how multirotors are studied, and the basic rules.

What is a drone?

A drone, or unmanned aircraft, is any aircraft that operates, or is designed to operate, without a pilot on board. It is either piloted remotely or flies by itself (autonomously).[1] The drone together with the equipment used to control it, such as the remote controller, is called an unmanned aircraft system (UAS).[1] Under European rules, radio-controlled model aircraft count too.[1]

How do they fly?

Drones obey the same physics as any other aircraft. They need air and motion to create lift.[4] Many drones, like many new air-taxi designs, rely on several rotors rather than fixed wings. Engineers study how these rotors behave in wind tunnels. NASA’s Multirotor Test Bed, for example, measures the loads on individual rotors to improve predictions of multirotor performance and noise.[3]

How does a drone keep its balance? Follow the links to Sensors, Microcontrollers and PID Controller on the map.

Rules for flying

Rules differ from country to country, so check with your national aviation authority before you fly. This is general information, not legal advice.

In the European Union, most leisure and low-risk commercial flights fall into EASA’s open category. It has three subcategories (A1, A2 and A3) depending on how close you fly to people. Flights must stay below 120 metres above the ground.[2] Registration of drone operators has been mandatory in the EU since 31 December 2020.[1] Whether you must register depends on your drone: the lightest drones (under 250 g, without a camera) don’t require it, while heavier drone classes do.[2]

Real-life examples

  • Flying for fun in Europe

    A hobby drone flight in the EU usually falls into the open category: stay below 120 metres, and keep your distance from people depending on your drone's class.[2]

  • Tiny drones

    The lightest drones (under 250 g, without a camera) don't require the operator to register in the EU, while heavier classes do.[2]

  • Tomorrow's air taxis

    Future air taxis borrow the multirotor idea, and NASA tests their rotor designs in wind tunnels.[3]

Connected across the map

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Evidence & sources

Level 2 · Authoritative

Supported by highly reputable institutions such as government agencies, universities or standards bodies.

Why this level? Definitions and flying rules come from the EU's aviation safety agency (EASA) and NASA. Rules differ between countries and change over time, so check your local aviation authority.

This is a Knowledge Atlas editorial classification of the sources we could find, not a certificate of truth. How we evaluate knowledge

Sources

Based on 4 sources from 2 institutions: EASA, NASA.

Show all 4 sourcesHide the list
  1. AuthoritativeEuropean Union Aviation Safety Agency· Government agencyDrones (UAS): frequently asked questionsOpened and checked against this page on 28 Sept 2026
  2. AuthoritativeEuropean Union Aviation Safety Agency· Government agencyOpen Category: Low Risk, Civil DronesOpened and checked against this page on 28 Sept 2026
  3. AuthoritativeNational Aeronautics and Space Administration· Government agencyTesting Air Taxis, Drones and More with NASA’s Multirotor Test BedOpened and checked against this page on 28 Sept 2026
  4. AuthoritativeNational Aeronautics and Space Administration· Government agencyWhat is Lift?Opened and checked against this page on 28 Sept 2026