Aero 1: Basic Theory & Lift

Question 1

Vector

Answer 1

A quantity that expresses both magnitude and direction

Question 2

Air Density

Answer 2

The total mass of air particles per unit volume

Question 3

Moment

Answer 3

A rotational force around a point or axis

Question 4

Steady Airflow

Answer 4

Airflow in which at every point in the moving air mass has constant pressure, density, temperature and velocity

Remember:
Train (temperature)
Passengers (pressure)
Don’t (density)
Vocalize (velocity)

Question 5

Mean Camber Line

Answer 5

A line halfway between the upper and lower surface of an airfoil from leading edge to trailing edge

Question 6

Chord

Answer 6

A measure of the chord line from the leading edge to the trailing edge of an airfoil

Question 7

Camber

Answer 7

Max distance between the mean camber line and the chordline

Question 8

Wingspan (b)

Answer 8

The length of a wing, measured from wingtip to wingtip

Question 9

Wing Area (S)

Answer 9

The surface area of a wing from wingtip to wingtip

Question 10

Chordwise Flow

Answer 10

Airflow perpendicular to the leading edge of an airfoil (along the chord of an airfoil)

Question 11

Spanwise Flow

Answer 11

Airflow that travels the span of the wing, parallel to the leading edge, normally from root to tip

Question 12

Pitch Attitude (θ)

Answer 12

The angle between the longitudinal axis of the airplane and the horizon

Question 13

Flight Path

Answer 13

The path described by an airplane’s center of gravity as it moves through an air mass

Question 14

Relative Wind

Answer 14

The airflow experienced by the aircraft as it flies through the air

(Always opposite direction of flight path which is dependent on center of gravity)

Question 15

Angle of Attack (AOA)

Answer 15

The angle between the relative wind and the chord line of the airfoil

Question 16

Angle of Incidence

Answer 16

The angle between the airplane’s longitudinal axis and the chord line of its wing

Question 17

Center of Gravity

Answer 17

The point at which the weight of an object is considered to be concentrated

Question 18

Aerodynamic Center

Answer 18

The point along the chord line of an airfoil where all changes in aerodynamic force effectively take place

Question 19

Max Coefficient of Lift (Cʟmᴀx)

Answer 19

The max value for the coefficient of lift as the AOA increases

Question 20

What are the different types of airspeeds?

Answer 20

Indicated Airspeed
Calibrated Airspeed
Equivalent Airspeed
True Airspeed
Groundspeed

Question 21

Indicated Airspeed

Answer 21

The instrument indication for the amount of dynamic pressure that the aircraft is creating during some given flight condition

Question 22

Calibrated Airspeed

Answer 22

IAS corrected for instrument/position error

Question 23

Equivalent Airspeed

Answer 23

The true airspeed at sea level on a standard day that produces the same dynamic pressure as the actual aircraft condition

(CAS corrected for compressibility)

Question 24

True Airspeed

Answer 24

The velocity of an aircraft with respect to the air mass in which it is traveling in

(EAS corrected for density)

Question 25

Groundspeed

Answer 25

An aircraft’s actual speed over ground

Question 26

What are the requirements for an aircraft to be in equilibrium flight?

Answer 26

The sum of all forces (drag, thrust, lift, and weight) and moments acting around the center of gravity equal zero

Question 27

What is the relationship between temperature and altitude?

Answer 27

As altitude increases, temperature decreases.

Question 28

What is the standard lapse rate?

Answer 28

A decrease in 2°C for every 1000ft in altitude up to 36,000 ft

Question 29

What is the relationship between humidity and air density?

Answer 29

As humidity increases, air density decreases.

More humidity means more water molecules that take up space in the air.

Question 30

What is the longitudinal axis? What is movement around this axis called?

Answer 30

The longitudinal axis passes from the nose to the tail of the aircraft.

Roll

Question 31

What is the lateral axis? What is movement around this axis called?

Answer 31

The lateral axis passes from wingtip to wingtip.

Pitch

Question 32

What is the vertical axis? What is movement around this axis called?

Answer 32

The vertical axis passes vertically through the center of gravity of the airplane.

Yaw

Question 33

What are the two forces that are considered aerodynamic forces?

Answer 33

Lift and drag

Question 34

What affecting factors of coefficient of lift can the pilot control?

Answer 34

Angle of attack
Camber

Question 35

What does Bernoulli’s Equation say?

Answer 35

P(total) = P(dynamic) + P(static)

Question 36

What is the relationship between area and velocity in the context of the Continuity Equation?

Answer 36

Area and velocity are inversely proportional.

This means that if area decreases, then velocity must increase on that same side to remain equivalent to the other side of the equation.

A1V1=A2V2

Question 37

General Gas Law (formula)

Answer 37

P=ρRT

Question 38

What are the requirements for an aircraft to be in trimmed flight?

Answer 38

The sum of the moments acting around the center of gravity equal zero

Question 39

Where is the aerodynamic center usually located?

Answer 39

25% aft of the leading edge

Where the max thickness of an airfoil is

Question 40

Lift Equation

Answer 40

L = 1/2pV²SCₗ

Question 41

What factors of lift can the pilot control?

Answer 41

Velocity
Angle of attack
Camber

Question 42

What happens when flaps are lowered?

Answer 42

• Cʟmᴀx increase
• Cʟmᴀx AOA decreases