The Art of the Helicopter John Watkinson - Karatunov.net

Introduction to rotorcraft 9
for the model building enthusiast. As will be seen in Chapter 9, such models have
become highly sophisticated even though, like their full-sized counterparts, they remain
expensive to build and operate.
Conceptually somewhere between the model and the full-size helicopter is the UAV
(unmanned autonomous vehicle). These machines are designed to perform surveillance
tasks, typically carrying cameras and other sensors. As electronic and sensing devices
have become smaller, useful equipment can be carried aloft at much lower cost if there
is no need to carry a pilot. Unlike the model, which needs actively to be controlled by
the pilot on the ground at all times, the UAV carries enough navigational equipment,
automatic stabilization systems and processing power to be self-contained. Also unlike
the hobbyist’s machines, UAVs must be built and operated to professional standards.
1.3 Types of rotorcraft
The definition of a rotorcraft is quite general, embracing any flying machine that
produces lift from rotors turning in a plane that is normally close to the horizontal.
This definition does not concern itself with the proportion of the machine’s weight
carried by the rotors, or whether that proportion changes at different stages of flight.
Figure 1.10 shows the main classes of rotorcraft that will be defined here.
T
(a) W
(b)
(c)
D
T
P D
W
Fig. 1.10 The main classes of rotorcraft.The conventional single main rotor machine predominates.See text
for details.
P
W
T
D