Atm 3 Module 2

Front 1

To understand what allows an aircraft to fly (how an airplane produces lift) we need basic knowledge of what two propositions?

Back 1

1. Bernoulli's Principle
2. Newton's Third Law of Motion

Front 2

Explain Bernoulli's Principle (Primary Source of Lift)

Back 2

the internal pressure of a fluid (liquid or gas) decreases at points where the speed of the fluid increases;
Area decreases, Velocity increases, pressure decreases;
The pressure differential around an airfoil is the primary source of lift and causes the higher pressure area below the airfoil to try to equalize pressure by pushing (lifting) the airfoil toward the lower pressure area above thus producing lift

Front 3

What is the Secondary Source of Lift?

Back 3

Newton's Third Law of Motion;
air is striking the underside of an airfoil (action) and the wing is being pushed up (reaction)

Front 4

Identify the forces affecting an aircraft in flight

Back 4

1. Lift
2. Weight
3. Thrust
4. Drag

Front 5

Name three main parts of the airfoil.

Back 5

1. Leading Edge
2. Trailing Edge
3. Chord Line

Front 6

Define Relative Wind

Back 6

The relative wind for an aircraft in flight flows in a direction parallel with and opposite to the direction of flight.

Front 7

What are 6 types of airfoils?

Back 7

1. Wing
2. Propeller
3. Helicopter Rotor
4. Horizontal Stabilizer
5. Vertical Tail Surfaces
6. Fuselage

Front 8

The three principle airfoils that produce lift on an aircraft are:

Back 8

1. Wing
2. Horizontal Tail Surfaces
3. Propeller

Front 9

Define Angle of Attack

Back 9

The angle of attack is the acute angle formed between the chord line of an airfoil and the direction of the air striking the airfoil (relative wind).

Front 10

Four key properties of the atmosphere that affect air density, and aircraft performance are:

Back 10

1. Temperature
2. Altitude
3. Pressure
4. Water Vapor (Humidity)

Front 11

Increased density altitude, such as in mountainous and high terrain areas with warm humid air, can greatly reduce aircraft performance, including:

Back 11

Longer Takeoff Roll
Longer Landing Roll
Slower Climb Rate
Reduced Engine Power Output

Front 12

An (increase/decrease) in altitude (increases/decreases) atmospheric pressure and (increases/decreases) density altitude, which has a pronounced (negative/positive) effect on flight.

Back 12

increase
decreases
increases
negative

Front 13

When the air is heated, it expands and, therefore, has (less/more) density, (increasing/decreasing) the density altitude

Back 13

less
increasing

Front 14

Water vapor (humidity) is lighter than air; consequently, humid air is lighter than dry air. Therefore, as the water content of the air increases, the air becomes (more/less) dense, (increasing/decreasing) density altitude and (increasing/decreasing) performance.

Back 14

less
increasing
decreasing

Front 15

Give two examples which indicate the conditions that affect aircraft performance

Back 15

1. Cold, Dry Day, AT Sea Level (good performance)
2. Hot, Humid Day, AT 5,000 Feet Elevation (poor performance)

Front 16

Changes in an aircraft’s attitude are described as movement about three axes. Name them.

Back 16

1. Vertical Axis (Yaw)
2. Longitudinal Axis (Roll)
3. Lateral Axis (Pitch)

Front 17

What are the primary control surfaces affecting movement about these axes and what do they control?

Back 17

1. Rudder controls Vertical Axis (Yaw)
2. Elevators control Lateral Axis (Pitch)
3. Ailerons control Longitudinal Axis (Roll)

Front 18

Air density greatly affects aircraft performance. What are three variables that determine air density?

Back 18

1. Altitude
2. Temperature
3. Humidity

Front 19

Left and right ailerons move simultaneously, but in opposite directions.
Lift (increases/decreases) on the down aileron, (increases/decreases)on the up aileron.

Back 19

increases
decreases

Front 20

What is adverse yaw?

Back 20

the tendency of the nose of the aircraft to yaw in the opposite direction of the turn (caused by the drag of the "down" aileron

Front 21

The rotor blade of a helicopter is an airfoil and functions the same as a wing on a conventional aircraft. Name the three devices that control the rotor blade

Back 21

1. Throttle
2. Collective
3. Cyclic

Front 22

Lift is created as air flows smoothly over an airfoil. A stall occurs when the_____of_____is exceeded.

Back 22

critical angle of attack

Front 23

Air stops flowing smoothly over an airfoil between___and___degrees angle of attack

Back 23

15
20

Front 24

What are the three primary causes of stalls?

Back 24

1. Insufficient Airspeed
2. Excessively Violent Flight Maneuvers
3. Severe Wind Shear