Basic information about different types of flight and how the regulations apply

Unmanned aircraft come in a variety of shapes and sizes, ranging from small hand launched types, all the way up to large aircraft that could be the same size as an airliner.  Just like ‘traditional’ manned aircraft, they may be of a fixed wing design, rotary winged, or a combination of both.

Unmanned aircraft may also be referred to as:

• Drones
• Remotely Piloted Aircraft Systems (RPAS)
• Unmanned Aerial Vehicles (UAV)
• Model Aircraft
• Radio Controlled Aircraft

Regardless of the name used, they all share the common characteristic that the person responsible for piloting the aircraft is not onboard it. Just like any other aircraft however, an unmanned aircraft must always be flown in a safe manner, both with respect to other aircraft in the air and also to people and properties on the ground.

The person that owns, or is in overall charge of the unmanned aircraft is known as the UAS operator

The person that is actually flying an unmanned aircraft is known as a remote pilot

The CAA aims to enable the full and safe integration of all UAS operations into the UK’s total aviation system.

Categories of operation

UAS operations are divided into three operating categories and every flight will fall into one of these, depending on the level of risk.  The first and most essential point to address is to determine the category that your flight will be conducted under.  The three categories are:

• Open category:
  • This covers relatively simple operations that present a low risk to other people or property
  • Flights are subject to a set of basic, pre-determined rules, within which there are some further sub divisions
  • In most cases, the UAS operator needs to be registered and the remote pilot needs to pass a simple test, but apart from this there is no requirement for any authorisation from the CAA  

• Specific category:
  • This covers medium risk operations, or operations that fall outside the boundaries of the Open category
  • All flights must be conducted in accordance with an operational authorisation, that has been issued by the CAA  

• Certified category:
  • This covers high risk operations, where the overall risk requires the same approach that is taken for manned aviation in order to maintain safety
  • The UAS must be certificated, the UAS operator must be certified and the remote pilot must hold a suitable licence

Operating principles

The primary responsibility of anyone who flies any aircraft is to determine how it is being flown and the process that is being used to avoid it colliding with other aircraft, objects or people.  The same responsibility applies when flying unmanned aircraft, but because the remote pilot is not physically onboard the aircraft, it is achieved in a slightly different manner.

As a result, UAS are flown under one of two operating principles:

Within the Visual Line of Sight (VLOS) of the remote pilot

This means that the unmanned aircraft must be able to be clearly seen by the remote pilot at all times when it is airborne.  By doing this, the remote pilot is able to monitor the unmanned aircraft’s flight path and so manoeuvre it clear of anything that it may collide with.  While corrective spectacles can be used to look at the aircraft, the use of binoculars, telescopes, or any other image enhancing devices are not permitted. 

Beyond the Visual Line of Sight (BVLOS) of the remote pilot

If the remote pilot is unable to maintain direct unaided visual contact with the unmanned aircraft while it is airborne, then an alternative method of collision avoidance must be employed in order to ensure that it can still be flown safely.  

BVLOS flight will normally require either:

• a technical capability which is equivalent to the method the pilot of a manned aircraft uses to ‘see and avoid’ potential conflictions - this is referred to as a Detect and Avoid (DAA) capability
• a block of airspace to operate in which the unmanned aircraft is ‘segregated’ from other aircraft - because other aircraft are not permitted to enter this airspace block, the unmanned aircraft can operate without the risk of collision, or the need for other collision avoidance capabilities
• clear evidence that the intended operation will have ‘no aviation threat’ and that the safety of persons and objects on the ground has been properly addressed.

Further information

Further Guidance on UAS operations within UK airspace can be found in our UK guidance document CAP 722.