PT2 CHP6 Aerodynamic Forces

Question 1

Describe what the forces are when an aircraft turns.

Answer 1

• Total lift = a horizontal lift component and a vertical lift component
• The opposing force of the horizontal lift component is centrifugal force (load factor/G force)
• The vector between the centrifugal force (load factor) and weight is load factor

Question 2

Which component of the force vectors causes the aircraft to turn right or left

Answer 2

Horizontal Component of Lift

Question 3

What is a coordinated turn?

Answer 3

• When making a turn, apply the correct amount of rudder to ensure the turn is coordinated (ball on turn coordinator is in the middle)
• Horizontal component of lift = centrifugal component (load factor)

Question 4

Which force vectors determine whether a turn is coordinated?

Answer 4

• If the horizontal component of lift equals the centrifugal force (load factor), then the turn will be coordinated

Question 5

In a coordinated turn, what is a standard rate turn?

Answer 5

3˚ per second

Question 6

A turn at a rate of 3˚ per second is known as what?

Answer 6

A coordinated turn

Question 7

What is a slipping turn?

Answer 7

• An uncoordinated turn
• The nose is facing to the outside (opposite) direction of the turn
• the centrifugal force (load factor) vector is shorter than the horizontal component of the lift
• the ball is on the left side of turn/slip coordinator

Question 8

An uncoordinated turn when the nose is facing to the outside (opposite) direction of the turn and results in the centrifugal force (load factor) vector to be shorter than the horizontal component of the lift is known as what?

Answer 8

A slipping turn

Question 9

How do you counteract a slipping turn?

Answer 9

Kick the rudder to the left

Question 10

By kicking the rudder to the left in a slipping turn, what will the result be?

Answer 10

This coordinate the turn

Question 11

What is skidding turn?

Answer 11

• An uncoordinated turn
• The horizontal force will be shorter than the centrifugal component (load factor)
• the nose is facing to the inside direction of the turn
• the ball is on the right side of turn/slip coordinator

Question 12

An uncoordinated turn when the horizontal force is shorter than the centrifugal component (load factor), which causes the nose is facing to the inside direction of the turn (the ball is on the right side of turn/slip coordinator), is known as what?

Answer 12

Skidding turn

Question 13

What is the danger of a skidding turn?

Answer 13

It can cause the aircraft to enter a spin

Question 14

How do you counteract a skidding turn?

Answer 14

Kick the rudder to the right

Question 15

By kicking the rudder to the right in a skidding turn, what will the result be?

Answer 15

Coordinate the turn

Question 16

Is a slipping or a skidding turn more dangerous and why?

Answer 16

A slipping turn is more dangerous because it can cause the aircraft to enter a spin

Question 17

What is Rate of Turn (ROT)?

Answer 17

The number of degrees (˚) of heading change per second that an aircraft makes

Question 18

The number of degrees (˚) of heading change per second that an aircraft makes is known as what?

Answer 18

Rate of Turn (ROT)

Question 19

What must be done to maintain the same rate of turn?

Answer 19

If the speed increases, the bank angle must be increased

Question 20

What is the Radius of Turn?

Answer 20

• The distance (radius) it takes to fly a distance based on the rate of turn
• Directly related to the rate of turn
• If bank angle is constant and speed is increased, radius of turn will increase
• If the bank angle is increased and speed is constant, radius of turn will decrease
• Remember, the steeper the turn, the more load factor is felt

Question 21

Describe the Radius of Turn if the airspeed is constant.

Answer 21

• If the airspeed is constant at 50 knots, then the bank angle will change the radius of turn.
• The steeper (narrow angle) the bank angle at a constant airspeed, shorter radius of turn
• The shallower (wide angle) the bank angle at a constant airspeed, longer radius of turn

Question 22

Describe the Radius of Turn if the bank angle is constant.

Answer 22

• If the bank angle is constant (20˚), the radius of turn will differ based on the speed.
• The slower the aircraft with a constant bank angle, will have a shallower radius of turn.
• The faster the aircraft with a constant bank angle, will have a steeper radius of turn.

Question 23

Describe the forces (RW and lift) before the plane climbs.

Answer 23

• Before the plane climbs, the relative wind (RW) is parallel and opposing the aircraft; the Lift will be perpendicular to the RW

Question 24

Describe the forces (RW and lift) to get the aircraft off the ground.

Answer 24

• More lift will be required, increase the AOA and the RW will be parallel to the nose
• For a split second the lift will increase and result in the aircraft to climb

Question 25

Describes the forces (RW and lift) once the aircraft is established in a climb.

Answer 25

- Once established in the climb, the RW is parallel to the path; the lift is perpendicular

Question 26

What is a stall?

Answer 26

A rapid decrease in lift caused by separation of the airflow from the wing's surface.

Question 27

A rapid decrease in lift caused by separation of the airflow from the wing's surface is known as what?

Answer 27

A stall

Question 28

Is lift still generated when the aircraft stalls?

Answer 28

Yes, just not enough to sustain flight

Question 29

When can a stall occur?

Answer 29

At any pitch attitude or speed

Question 30

When does a stall occur?

Answer 30

When the critical angle of attack is reach?

Question 31

What is the critical angle of attack?

Answer 31

The angle at which at which if exceeded, the airfoil cannot produce enough lift to sustain flight

Question 32

What occurs when CLmax is reached and why?

Answer 32

The aircraft stalls because the critical angle of attacked was reached

Question 33

What is laminar airflow?

Answer 33

The flow of air over the airflow, which relates to the ability to stick. The better the laminar flow, the better the air will flow and vice versa

Question 34

As the angle of attack increases, how does that affect laminar airflow?

Answer 34

There is less laminar airflow

Question 35

Which part of the aircraft is designed for stalls and why?

Answer 35

Wings are designed to stall at the root in order to main aileron control due to stalls creating a nose-down tendency

Question 36

Why is it important to recognize a potential stall?

Answer 36

In order to PREVENT it from happening

Question 37

What are stall warnings?

Answer 37

A system that is installed to recognize when the angle of attack is close to critical (some aircraft have stick shakers and others have stall horns)

Question 38

What is one sign of the controls when close to a stall?

Answer 38

The controls will feel "mushy", they won't have the same reaction when flight at higher speeds)

Question 39

What are the possible signs of a stall?

Answer 39

- High pitch (vision, wont be able to see the ground) - Engine sound (hearing, at a high pitch or slow speed, quiet engine) - Buffer/shaking (feel, the aircraft will shake)

Question 40

What is the key to recovering from a stall?

Answer 40

- Reducing the angle of attack from the critical angle of attack - Push on the controls to reduce the angle of attack and add power as necessary

Question 41

What are two types of stalls for training?

Answer 41

Power-on and Power-off

Question 42

When is a power-on stall?

Answer 42

Simulates a nose-high attitude during a high-power maneuver (TO/GA, apply full power, pitch too much, results in slow airspeed and start to stall)

Question 43

A nose-high attitude during a high-power maneuver simulates what?

Answer 43

A power-on stall

Question 44

What is a power-off stall?

Answer 44

Simulates stretching a glide after the engine has failed, or low on the approach to landing

Question 45

Stretching a glide after the engine has failed, or low on the approach to landing simulates what?

Answer 45

A power-off stall

Question 46

What is a spin?

Answer 46

An aggravated stall that occurs when the aircraft is stalled in a yawed condition i. The aircraft will continue to climb, reach the critical angle of attack, stall while in a yawed position, then fall forward nose down and spin

Question 47

An aggravated stall that occurs when the aircraft is stalled in a yawed condition is known as what?

Answer 47

A spin

Question 48

Why does a spin occur?

Answer 48

The outboard wing is less stalled than the inboard wing

Question 49

What is the process to recover from a stall?

Answer 49

- The nose will pitch up due to the stall - Pus the nose down

Question 50

What is the process to recover from a spin?

Answer 50

- Reduce power to idle (due to gaining a lot of speed because of the forward nose-down attitude) - Ailerons to neural - Apply full opposite rudder against the rotation (due to the rudder being used the wrong way) - Apply positive, brisk, and straight forward elevator - Neutralize the rudder after spin rotation stops - Apply back elevator pressure to return to level flight (NEVER practice a spin in an aircraft not approved for spins or practice spins alone)

Question 51

What are load factors measure in?

Answer 51

Gs (acceleration of gravity

Question 52

How many Gs is an object at rest?

Answer 52

1G

Question 53

When are G forces generated?

Answer 53

- when the aircraft turns i. aircraft are designed to withstand a certain amount of positive (felt when being pushed into your seat, then pull back) and negative (push on the control abruptly, then start to life off the seat) G forces

Question 54

What may be a result of too many G forces?

Answer 54

It can lead to overland and structure damage/failure

Question 55

How is the stall speed affected by an increase in load factor and why?

Answer 55

- In straight/level flight, lift = weight - When a turn is initiated, we must make sure to have the same amount of lift as in straight/level, which lift is split into horizontal and vertical components - To generate more lift, pull back on the controls, which will increase the angel of attack (AOA), but also increase it closer to the critical angle of attack (CAOA) - Along with lift increase, the centrifugal forces will increase Stall speed is increased, which will result in stalling the airplane sooner - The critical angle of attacked is reach much sooner than at a lower angle of attack, gives the aircraft less time to slow down. This causes the aircraft a faster speed than normal.

Question 56

What are the categories and load factor limits?

Answer 56

- Normal, 3.8 to -1.52G (exceeding the limits may result in bending a part of the aircraft) - Utility (mild acrobatic and sport), 4.4 to -1.76G - Acrobatic, 6.0 to -3.00G