Principles of Flying

Question 1

What are the four forces that act upon an aircraft in flight?

Answer 1

Lift, Weight, Thrust, Drag

Question 2

What are Newtons 1,2,3 Laws

Answer 2

1 - An object will continue moving in space at a constant velocity unless an external force is applied.
2 - if a force is applied to a body it will accelerate at a rate proportional to its mass and the force applied.
3 - For every action there is an equal and opposite reaction.

Question 3

Where is an aircrafts centre of gravity? (CofG)

Answer 3

The poin t about which all gravitational moments add up to zero.

Question 4

What is the equation for Newtons 2nd law?

Answer 4

f=ma

Question 5

What is Pitch, Roll and Yaw?

Answer 5

Pitch - Nose moving up or down
Roll - Rotating left or right around longitudinal centreline
Yaw - Nose moving left or right around a vertical axis through the main rotor mast.

Question 6

How does a vector differ from a line?

Answer 6

Both direction and magnitude

Question 7

What is the front tip of an aerofoil called?

Answer 7

Leading Edge

Question 8

What is the back tip of an aerofoil called?

Answer 8

Trailing Edge

Question 9

What is the centre line in aerofoil called?

Answer 9

Chord Line

Question 10

What is the cross in the middle of the thickest part called?

Answer 10

Centre of pressure

Question 11

A symmetrical aerofoil has a mean chord that is?

Answer 11

Straight

Question 12

The Angle of Attack (AoA) of an aerofoil is measured between the mean chord line and the?

Answer 12

Relative Air Flow

Question 13

In nature, energy always flows from ( ) pressure to ( ) pressure

Answer 13

High pressure to low pressure

Question 14

What is the lift equation

Answer 14

Lift=CL 1/2p v2 S

Question 15

What do the components of the lift equation mean?

Answer 15

CL - Coefficient of lift
1/2p - Density of the air
V2 - Air velocity over the aerofoil
S - Aerofoil surface area

Question 16

Will a helicopter generate the same amount of lift at 28,000ft and at sea level?

Answer 16

NO

Question 17

The ability of a wing to provide lift, increases with its ( ) until the critical ( ) is reached (It is just one answer for both)

Answer 17

Angle of Attack

Question 18

What are the two types of drag?

Answer 18

Zero lift drag (parasitic drag)
Lift dependant drag

Question 19

What are characteristics of drag

Answer 19

The total of all air resistance to an object moving through it.

Acts parallel to and opposite of the flight path

Question 20

Give three items that contribute to Induced drag (Lift dependant)

Answer 20

Surface (Skin) Friction Drag
Form Drag
Increased Angle of Attack

Question 21

Give three items that contribute to Parasitic Drag

Answer 21

Extended Landing Gear
External tanks
Ordnance/Racks

Question 22

Why is icing a hazard?

Answer 22

Increased aircraft weight
Changes the aerofoils shape
Decreases the lift being generated
Increases the drag being generated

Question 23

What two things must be present for icing to occur?

Answer 23

Visible moisture
OAT lower than 2C

Question 24

Wing tip vortices are what?

Answer 24

Two counter rotating cylindrical vortices

Question 25

What are hazards of Wake Turbulance on a following aircraft?

Answer 25

Induced Roll and Yaw Especially dangerous during take of and landing Rare but can cause structural damage

Question 26

What Gas Turbines commonly used in aviation?

Answer 26

Turbojet (F18) Turboprop (PC21) Turboshaft (Helicopter) Turbofan (Airliners)

Question 27

What is the work cycle of a gas turbine engine?

Answer 27

SUCK SQUEEZE BANG BLOW

Question 28

What are the 4 sections of a gas turbine?

Answer 28

Intake Compressor Combustion Turbine/Exhaust

Question 29

When does the spark occur in a combustion chamber?

Answer 29

Engine start

Question 30

Give an example of a conventional helicopter layout

Answer 30

MH-60R

Question 31

Why is the tail rotor required for in convential helicopters?

Answer 31

Torque reaction

Question 32

What is a teetering main rotor head?

Answer 32

Semi-Rigid rotor head (HUEY) Simple and cheap Prone to mast bumping

Question 33

What are the characteristics of a fully articulated rotor head?

Answer 33

They are extremely complex and heavy and as a result are used primarily on larger helicopters. The freedom of movement provided by mechanic hinges and bearings reduces vibration and rotational stress.

Question 34

What are the characteristics of a rigid rotor head?

Answer 34

Simple and cheap Flexible structures to allow blade movement

Question 35

The manufactured twist in rotor blades is called what?

Answer 35

Washout

Question 36

What is a defining characteristic of an assymetrical aerofoil main rotor blade?

Answer 36

Has a curved mean chord line

Question 37

Describe the main rotor disk

Answer 37

Circular area swept by main rotors

Question 38

Relative airflow vector for a rotary wing BVD is made up of what two components?

Answer 38

Rotational airflow & Induced Flow (IF)

Question 39

Induced flow is caused by what?

Answer 39

Drawing air from above the rotor

Question 40

The combination of Induced flow and rotational airflow creates what?

Answer 40

Relative airflow

Question 41

Describe the path of the rotorblades during rotation

Answer 41

Tip Path Plane

Question 42

What is the angle between the plane of rotation and the feather axis?

Answer 42

Coning angle

Question 43

Total reaction is created by what?

Answer 43

Rotor Thrust and Rotor Drag

Question 44

What is the opposing force to Rotor Drag?

Answer 44

Torque

Question 45

The cockpit flight control changes the pitch angle of each main rotor blade individually as they cycle round the rotor mast

Answer 45

Cyclic

Question 46

This cockpit flight control changes the pitch angle of all the main rotor blades at the same time

Answer 46

Collective

Question 47

What is the swashplate assembly composed of?

Answer 47

Stationary (Control ring in EC135) Rotating (Bearing Ring in EC135)

Question 48

Which swashplate is used to transfer the cyclic and collective commands to the rotor blades through the Pitch Control Links?

Answer 48

Rotating

Question 49

Which swashplates are raised/lowered when the pilot raises and lowers the collective?

Answer 49

Both

Question 50

Why are there two cyclic control rods connected to the stationary swashplate?

Answer 50

One for pitch, one for roll

Question 51

Four items that affect coning angle

Answer 51

Rotor RPM Rotor thrust produced (blade pitch) Weight of the helicopter Dynamic loading due to manoeuvering (G Force)

Question 52

To move the aircraft laterally we must tilt the...

Answer 52

Total Rotor Thrust vector

Question 53

The 90degree lag between control input and the response by the rotor is termed

Answer 53

Phase Lag

Question 54

Phase Lag can be compensated for by...

Answer 54

Advance Angle alone or, Advance Angle and Control rigging

Question 55

Flapping to equality of lift is...

Answer 55

Blade movement which equalises rotor thrust across the disc

Question 56

Due to the principle of conservation of angular momentum, when rotor blades are coned up the RPM will...

Answer 56

Increase

Question 57

Which conventional rotor head design would give a pilot the quickest response time?

Answer 57

Rigid/Semi-Rigid rotor head

Question 58

Three metrics to measure Control Power

Answer 58

Immediacy (Time delay) Rate (roll or pitch rate) Control movement required

Question 59

The cockpit flight control that allows the pilot to changethe pitch of angle of all the TAIL rotor blades collectively in order to provide heading control.

Answer 59

Yaw pedals

Question 60

Yaw pedals control pitch of the tail rotor blades to: (4 answers)

Answer 60

Counter main rotor torque Overcome frictional forces in the drive train during autorotation Provide heading control in the hover Provide yaw control (balance) in forward flight