Not very many years ago, few people had even heard of drones. Most of those who had would probably have an idea from science fiction or techno-thrillers about what a drone was and what it might be capable of, but no real knowledge. Yet, in just a few years, drones have gone from obscurity to near-constant media attention. We hear of drone strikes and drone surveillance in the world's trouble zones, and of drones delivering packages - even pizza - in the commercial world.
A surprising number and range of users have been operating drones for some time, although the rest of the world has known little about it. Outside of the military, drones have been used for research purposes, or to monitor the environment. Commercially available drones can now be bought at quite a cheap price by private users for recreational purposes.
Yet, in truth, there is nothing really new about the idea of a remotely operated vehicle. The word 'drone' has entered the popular vocabulary, but long before this happened users were flying remote-controlled aircraft and helicopters, or racing radio-controlled cars. Remotely controlled weapons have been in use for several years - although not always with a great deal of success. It is, however, debatable whether these were, strictly speaking, drones.
What is a Drone?
One useful definition of a drone is a pilotless aircraft that can operate autonomously, i.e. one that does not require constant user control. This means that traditional radio-controlled aircraft and the like are not, in the strictest sense, drones. Nor are many underwater Remotely Operated Vehicles (ROVs), and not only because they are not aircraft. In fact, many recreational 'drones' are not really drones, as they are semi-autonomous. However, it is useful to widen the definition of a drone somewhat in order to cover a range of similar vehicles that undertake the same role using broadly the same principles.
RQ-4 GLOBAL HAWK
SPECIFICATIONS: RQ-4 GLOBAL HAWK
Length: 14.5m (47ft 6in)
Wingspan: 39.8m (130ft 6in)
Height: 4.7m (15ft 4in)
Powerplant: Rolls-Royce North American F137-RR-100 turbofan engine
Maximum takeoff weight: 14,628kg (32,250lb)
Maximum speed: 574km/h (357mph)
Range: 22,632km (14,063 miles)
Ceiling: 18,288m (60,000ft)
Endurance: More than 34 hours
Operating a UAV is a complex business, which has been described as similar to flying a plane whilst looking through a straw. In addition to piloting the vehicle, operators must control cameras, radar and other instruments, and hand-off data to other users, making the operation of a large military UAV a multi-person task.
It is quite difficult to pin down a working definition of 'drone' that does not immediately founder on the rocks of the first exception it encounters. In theory, any remote-controlled aircraft can operate like a drone, inasmuch as it can be pointed in the right direction and set to fly straight and level. During this period, the operator can let go of the controls and the aircraft will go on its way without control input.
This is not really a drone operation, however. To be such, the aircraft would need to be able to make some decisions for itself. A simple autopilot that used the aircraft's control surfaces to keep it on course might not qualify, but one that could be given a destination and fly the aircraft to it, possibly making course changes as necessary, would fit the common definition of a drone.
Some 'drones', especially those operated by the military, are primarily operated by a pilot from a ground station. They can undertake autonomous flight, but are normally under constant control. Military drones, suc