How are rotor blades mounted on a helicopter?

A helicopter rotor blade is usually mounted on a set of hinges which allow three angular degrees of freedom. A typical arrangement of the hinges is shown in Fig. 1. The flapping motion is defined as an up and down rotation, through an angle β, in a plane which contains both the blade and the shaft.

Which is part of the helicopter engineering handbook?

The Helicopter Engineering Handbook forms a part of the Engineering Design. This volume, Preliminary Design, is Part One of a three-part Engineering Design Handbook titled Helicopter Engineering. design, Qualification Assurance, this part is intended to set forth explicit design standards…

Which is the most important component of a helicopter?

Helicopter Main Rotor Design The main rotor is the most important and complex component of a helicopter. Main rotor design balances many contradictory goals and constraints. Examples include minimizing cost, maximizing performance, and keeping vibration and noise below thresholds.

Why are rotor speeds important in a helicopter?

Larger rotor speeds also reduce torque (per unit power), facilitating cheaper, lighter drive systems. Rotor speed is constrained on the high and low side by several other factors.

What do you call a helicopter rotor with drag hinges?

Rotors fitted to the helicopter rotorhead with both flapping and drag hinges are known as fully articulated since the combination of the two constitutes the equivalent of a universal joint. Rotors with flapping hinges only are termed semi-articulated.

How does a helicopter maintain a constant rotor speed?

The vast majority of helicopters maintain a constant rotor speed (RPM) during flight, leaving the angle of attack of the blades as the sole means of adjusting thrust from the rotor. The swash plate is two concentric disks or plates. One plate rotates with the mast, connected by idle links, while the other does not rotate.

How is the rate of descent of a helicopter controlled?

The primary ways to control the rate of descent are with airspeed and rotor rpm. Higher or lower airspeed is obtained with the cyclic pitch control just as in normal powered flight. In theory, a pilot has a choice in the angle of descent, varying, from straight vertical to maximum horizontal range (which is the minimum angle of descent).