In the UK the Civil Aviation Authority (CAA) is the National Aviation Authority who oversees and regulates all aspects of civil aviation.
Below you can find the CAA publications that are relevant to drones.
Cap 393 – The Air Navigation Order (ANO)
All Small Unmanned Aircraft Systems (SUAS) and Small Unmanned Aircrafts (SUA) are subject to the rules and regulations outlined in CAP 393, the Air Navigation Order (ANO). All SUAS’s with a Maximum Take Off Mass (MTOM) of less than 150kg are regulated by the CAA.
There are currently two articles in CAP 393 which are directly relevant to the operation of a SUAS in the UK. These are article 94 and article 95.
Article 94 – Small Unmanned Aircraft
(1) A person must not cause or permit any article or animal (whether or not attached to a parachute) to be dropped from a small unmanned aircraft so as to endanger persons or property.
(2) The person in charge of a small unmanned aircraft may only fly the aircraft if reasonably satisfied that the flight can safely be made.
(3) The person in charge of a small unmanned aircraft must maintain direct, unaided visual contact with the aircraft sufficient to monitor its flight path in relation to other aircraft, persons, vehicles, vessels and structures for the purpose of avoiding collisions.
(4) The person in charge of a small unmanned aircraft which has a mass of more than 7kg excluding its fuel but including any articles or equipment installed in or attached to the aircraft at the commencement of its flight, must not fly the aircraft—
(a) in Class A, C, D or E airspace unless the permission of the appropriate air traffic control unit has been obtained;
(b) within an aerodrome traffic zone during the notified hours of watch of the air traffic control unit (if any) at that aerodrome unless the permission of any such air traffic control unit has been obtained; or
(c) at a height of more than 400 feet above the surface unless it is flying in airspace described in sub-paragraph (a) or (b) and in accordance with the requirements for that airspace.
(5) The person in charge of a small unmanned aircraft must not fly the aircraft for the purposes of commercial operations except in accordance with a permission granted by the CAA.
Article 95
(1) The person in charge of a small unmanned surveillance aircraft must not fly the aircraft in any of the circumstances described in paragraph (2) except in accordance with a permission issued by the CAA.
(2) The circumstances referred to in paragraph (1) are—
(a) over or within 150 metres of any congested area;
(b) over or within 150 metres of an organised open-air assembly of more than 1,000 persons;
(c) within 50 metres of any vessel, vehicle or structure which is not under the control of the person in charge of the aircraft; or
(d) subject to paragraphs (3) and (4), within 50 metres of any person.
(3) Subject to paragraph (4), during take-off or landing, a small unmanned surveillance aircraft must not be flown within 30 metres of any person.
(4) Paragraphs (2)(d) and (3) do not apply to the person in charge of the small unmanned surveillance aircraft or a person under the control of the person in charge of the aircraft.
(5) In this article, “a small unmanned surveillance aircraft” means a small unmanned aircraft which is equipped to undertake any form of surveillance or data acquisition.
CAP 722 – Unmanned Aircraft System Operations in UK Airspace
CAP 722 is intended to assist those who are involved in all aspects of the development of Unmanned Aircraft System (UAS) to identify the route to certification, outline the methods by which permission for aerial work may be obtained and ensure that all requirements are met by the UAS industry.
The document highlights the safety requirements that have to be met before a UAS is allowed to operate in the UK.