Chapter 1: Introduction

Question 1

Main Helicopter Advantages

Answer 1

• Vertical takeoff/landing
• Ability to hove for extended periods
• Unique handling properties under low airspeed conditions

Question 2

Types of Rotors(comprises Rotor Systems):

Main Rotor

Answer 2

• mounted horizontally to a vertical mast to provide vertical lift. Rotates counter-clockwise(US) Clockwise(EU)

Question 3

Types of Rotors(comprises Rotor Systems):

Tail Rotor

Answer 3

• mounted vertically to provide horizontal/ anti-torque lift

Question 4

Types of Rotors(comprises Rotor Systems):

Tandem Rotor

Answer 4

• Aka Dual Rotor
• two large twin counter-rotating horizontal rotor system/assemblies for heavy weight machines

Question 5

Types of Rotors(comprises Rotor Systems):

Coaxial Rotor

Answer 5

• pair of counter-rotating rotors mounted on same mast one above each other.

Question 6

What is the Make Up of a Main Rotor System?

Answer 6

• Mast: hollow cynlindrical metal shaft extending up from/driven from transmisson
• Hub: attachment point for rotor blades at top of mast
• Rotor Blades

Question 7

Rotor System Classifications

Answer 7

• Semi rigid:
• Rigid
• Fully articulated explanations in chapter 4

Question 8

What is the Make Up of a Anti-Torique(tail) Rotor System?

Answer 8

• Drive shaft: powered by main transmission and a gearbox mounted at end of tail boom
• Gearbox: provides angled drive for the tail rotor
• Tail rotor blades
• Pitch change links: adjusted to set the angle of incidence

Question 9

Purpose of Anti Torque(Tail) Rotor System

Answer 9

• Newton’s 3rd law: every action has an equal and opposite reaction: creation of torque
• With a single main rotor helicopter, the creation of torque as the engine turns the rotor creates a torque effect that causes the body of the helicopter to turn in the opposite direction of the rotor.
• Tail rotor system creates anti torque to combat this by pushing or puling against the tail

Question 10

Basic Helicopter Controls:

Cyclic

Answer 10

• varies the pitch of the rotor blades throughout each revolution of the main rotor system to create unequal lift(thrust)
• Tilts the rotor disc in a particular direction resulting in helicopter moving in that direction(i.e. cyclic pushed forward pushes rotor disc forward and creates forward thrust)
• can be joystick or teetering bar control system.

Question 11

Basic Helicopter Controls:

**Collective **

Answer 11

• Changes pitch angle of all main rotor blades collectively. All blades change equally, increasing/decreasing total lift or thrust
• Result is increase or decrease in altitude or airspeed.
• Variable friction control to prevent inadvertent movement
• Aka collective pitch control

Question 12

Basic Helicopter Controls:

Anti-Torque Pedals

Answer 12

• Control direction in which nose is pointed.
• Pedal input changes pitch of tail rotor blades
• Increases/reduces thrust produced by tail rotor and causes nose to yaw in direction of applied pedal.

Question 13

Basic Helicopter Controls:

Throttle

Answer 13

• controls power produced by engine connected to rotor via transmission
• Purpose: maintain enough engine power to keep rotor rpm within allowable range to keep rotor producing enough lift for flight
• Twist grip mounted on collective

Question 14

Two Types of Flying

Answer 14

• Hover: more challenging b/c helicopter generates its own gusty air acting against the fuselage.
  
  • Requires constant inputs + corrections to keep.
  • Cyclic used to eliminate drift in horizontal direction(control forward/back/left/right)
  • Collective used to maintain altitude
  • Pedals control nose heading.
• Forward flight