Principles Of Flight

Question 1

What is the Aerofoil section?

Answer 1

The shape of the wing from leading edge to trailing edge

Question 2

What is the curve on the wing called?

Answer 2

The Chamber

Question 3

What is the Angle of Attack?

Answer 3

The angle at which the wing meets the airflow

Question 4

How is one third of the wing’s lift produced?

Answer 4

From the Angle of Attack - due to air being pushed downwards and creating an opposite effect in that the Aerofoil is pushed up

Question 4

How is two thirds of the wing’s lift produced?

Answer 4

From the Chamber - the air has to travel a greater distance on top so travels faster and therefore the pressure on top decreases - Bernoulli’s theory

Question 5

What is the Parallelogram of forces?

Answer 5

Where opposite forces create a resultant force, that can be calculate using trigonometry

Question 6

What are the 4 forces during flight?

Answer 6

Weight, lift, drag and thrust

Question 7

What does it mean when the aircraft is in equilibrium?

Answer 7

Constant height - lift equal to weight

Constant speed - thrust equal to drag

Question 8

What are the two types of drag?

Answer 8

Induced drag

Parasite drag

Question 9

What is induced drag?

Answer 9

Air moves outwards underneath the wing, and inwards over the top.
This causes the two air streams to meat and create trailing edge vortexes

Question 10

What do trailing edge vortices turn into?

Answer 10

Wing-tip vortices due to them moving up towards each tip

Question 11

How can drag be reduced?

Answer 11

By increasing the aspect ratio - (Span/Chord)

Question 12

What are the different forms of parasite drag?

Answer 12

• Form drag
• Skin friction
• Turbulence caused from additional items on the outside of plane

Question 13

What is Total drag?

Answer 13

It includes both induced and parasite drag

Question 14

When is parasite drag at it’s lowest?

Answer 14

At low airspeeds

Question 15

When is induced drag at it’s lowest?

Answer 15

At high airspeeds

Question 16

What is the “speed squared law”

Answer 16

Form drag is proportional to the square of the speed

Question 17

What can the “Speed squared law” be applied to?

Answer 17

Airspeed and lift

Question 18

What does increasing the Angle of Attack cause?

Answer 18

And increase of lift and drag

Question 19

What is the critical angle of attack?

Answer 19

The angle at which the aircraft will stall - 15 degrees

Question 20

What is the stall in terms or air particles?

Answer 20

When the air no longer clings to the Aerofoil and breaks away and breaks the smooth airflow

Question 21

How can lift be created without thrust?

Answer 21

By adopting a nose-down attitude

Question 22

What is the best lift/drag ratio?

Answer 22

10:1

Question 23

What uses this ratio?

Answer 23

The best gliding angle

Question 24

What is the best gliding angle?

Answer 24

The airplane will travel 10 feet forward for every 1 foot of height loss
-60Knts

Question 25

What is minimum sink?

Answer 25

Flying at an airspeed just below the best gliding angle, this airspeed will keep you in the air the longest
-50Knts

Question 26

What is the best rate of climb?

Answer 26

To attain the maximum height in the minimum amount of time

-50Knts

Question 27

What is the best angle of climb?

Answer 27

The speed at which the rate of climb is at it’s best

-60Knts

Question 28

What is stability?

Answer 28

It is a condition which enables an aircraft to revert to it’s original flight path without pilot input

Question 29

What axis does the aircraft yaw on? + What does it cause?

Answer 29

Vertical + change of direction of heading

Question 30

What axis does the aircraft pitch on? + What does it cause?

Answer 30

Lateral + Nose up or down

Question 31

What axis does the aircraft roll on? + What does it cause?

Answer 31

Longitudinal + Banking

Question 32

How is stability archived in a rolling plane?

Answer 32

Dihedral, the angle at which the wing is from it’s roots