1. Introduction

A ready-to-fly kit is a radio controlled aircraft that is fully built with no assembly required. It includes a transmitter and a receiver.

In fact, the definition of rotors are different from that of propellers. The airplane often uses propellers to produce thrust, whereas the helicopters use rotors to produce lift. Unlike the airplane propeller (often fixed blade pitch angle), the blade pitch angle of the rotor of the helicopter is controlled by swashplate. From the definition, it should be said that multicopters are often mounted with propellers rather than rotors [5, pp. 79–85], because the propellers of multicopters often have fixed blade pitch angles. However, the terms “quadrotor” and “multirotor” are widely used in the world. Therefore, the two terms “rotor” and “propeller” are not distinguished in this book strictly. But the term “propeller” is preferred.

Refer to http://​ardupilot.​org for details.

If the blades are spinning counterclockwise, then the airframe will start to rotate clockwise due to the torque reaction. This is due to Newton’s Third Law, which states that every action has an equal and opposite torque reaction. Therefore, most helicopters, namely the single rotor helicopter, have a small rotor placed vertically at the tail to compensate for the opposite reaction. Since a quadcopter has four propellers, the sum of the opposite torque reaction of four propellers can be zero, which is also used to control the yaw of a quadcopter.

Altitude hold mode is considered. In fact, in most cases, the altitude will be held as same as possible.

Left stick operates upward-and-downward and yaw movements, and right stick operates forward-and-backward and leftward-and-rightward movements. This mode is commonly used in North America and other parts of the world including China. This is one RC transmitter mode, which can be changed to other modes.

Airworthiness is the measure of an aircraft’s suitability for safe flight. Certification of airworthiness is initially conferred by a certificate of airworthiness from a national aviation authority and is maintained by performing the required maintenance actions.

A smartphone device is an electronic device, generally connected to other devices or networks via different wireless protocols such as Bluetooth, NFC, Wi-fi, and 3G that can operate to some extent interactively and autonomously.

TED is a nonprofit devoted to “ideas worth spreading”—through http://​www.​TED.​com, the annual conferences, the annual TED Prize, and local TEDx events.

http://​www.​engineeringvilla​ge.​com.

http://​www.​webofknowledge.​com.

A failsafe is that, in the event of a specific type of failure, responds in a way that will cause no harm, or at least a minimum of harm, to other devices or to personnel.