Principles Of Flight Flashcards
What is the Aerofoil section?
The shape of the wing from leading edge to trailing edge
What is the curve on the wing called?
The Chamber
What is the Angle of Attack?
The angle at which the wing meets the airflow
How is one third of the wing’s lift produced?
From the Angle of Attack - due to air being pushed downwards and creating an opposite effect in that the Aerofoil is pushed up
How is two thirds of the wing’s lift produced?
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
What is the Parallelogram of forces?
Where opposite forces create a resultant force, that can be calculate using trigonometry
What are the 4 forces during flight?
Weight, lift, drag and thrust
What does it mean when the aircraft is in equilibrium?
Constant height - lift equal to weight
Constant speed - thrust equal to drag
What are the two types of drag?
Induced drag
Parasite drag
What is induced drag?
Air moves outwards underneath the wing, and inwards over the top.
This causes the two air streams to meat and create trailing edge vortexes
What do trailing edge vortices turn into?
Wing-tip vortices due to them moving up towards each tip
How can drag be reduced?
By increasing the aspect ratio - (Span/Chord)
What are the different forms of parasite drag?
- Form drag
- Skin friction
- Turbulence caused from additional items on the outside of plane
What is Total drag?
It includes both induced and parasite drag
When is parasite drag at it’s lowest?
At low airspeeds
When is induced drag at it’s lowest?
At high airspeeds
What is the “speed squared law”
Form drag is proportional to the square of the speed
What can the “Speed squared law” be applied to?
Airspeed and lift
What does increasing the Angle of Attack cause?
And increase of lift and drag
What is the critical angle of attack?
The angle at which the aircraft will stall - 15 degrees
What is the stall in terms or air particles?
When the air no longer clings to the Aerofoil and breaks away and breaks the smooth airflow
How can lift be created without thrust?
By adopting a nose-down attitude
What is the best lift/drag ratio?
10:1
What uses this ratio?
The best gliding angle
What is the best gliding angle?
The airplane will travel 10 feet forward for every 1 foot of height loss
-60Knts
What is minimum sink?
Flying at an airspeed just below the best gliding angle, this airspeed will keep you in the air the longest
-50Knts
What is the best rate of climb?
To attain the maximum height in the minimum amount of time
-50Knts
What is the best angle of climb?
The speed at which the rate of climb is at it’s best
-60Knts
What is stability?
It is a condition which enables an aircraft to revert to it’s original flight path without pilot input
What axis does the aircraft yaw on? + What does it cause?
Vertical + change of direction of heading
What axis does the aircraft pitch on? + What does it cause?
Lateral + Nose up or down
What axis does the aircraft roll on? + What does it cause?
Longitudinal + Banking
How is stability archived in a rolling plane?
Dihedral, the angle at which the wing is from it’s roots
