Exam 4 Review

Question 1

Movement around the longitudinal axis is called:

Answer 1

Roll

Question 2

Movement around the lateral axis is called:

Answer 2

Pitch

Question 3

Movement around the vertical axis is called:

Answer 3

Yaw

Question 4

What is Dynamic Stability?

Answer 4

An objects tendency to return to its previously undistrubed state OVER TIME

Question 5

What is Static Stability?

Answer 5

INITIAL tendency of an object to return to its previously undisturbed state

Question 6

What is a Phugoid?

Answer 6

• Aircraft motion where attitude, pitch and airspeed vary widely
• Interchangeable between Kinetic and Potential Energy
• *Tail Stalls Out**

Question 7

Explain Dutch Roll

Answer 7

Coupled lateral/directional oscillation that is “Out of Phase”

Question 8

Name 2 types of stability that increase when we sweep the wings back

Answer 8

1. Side Slip

2. Static

Question 9

What is the Rate equation?

Answer 9

Rate (deg per sec) = 1091(tan BA)/V

Question 10

What is the Radius equation?

Answer 10

Radius (feet) = V^2/11.26(tan BA)

Question 11

What is the Load Factor equation?

Answer 11

n (Gs) = 1/(cos BA)

Question 12

_____ static stability leads to ALL dynamic stability.

Answer 12

POSITIVE static leads to ALL dynamics

Question 13

If an a/c’s controls are bumped and the plane returns back to its OG state, it has what kind of stability?

Answer 13

POSITIVE STATIC

Question 14

If an a/c’s controls are bumped and the plane remains steady in the new position, it has what kind of stability?

Answer 14

NEUTRAL STATIC

Question 15

If an a/c’s controls are bumped and the plane continues away from its OG state, it has what kind of stability?

Answer 15

NEGATIVE STATIC

Question 16

If an a/c’s controls are bumped and the planes displacement reduces over time back to its OG state, it has what kind of stability?

Answer 16

POSITIVE DYNAMIC

Question 17

If an a/c’s controls are bumped and the planes displacement remains constant over time, it has what kind of stability?

Answer 17

NEUTRAL DYNAMIC

Question 18

If an a/c’s controls are bumped and the planes displacement increases over time away from its OG state, it has what kind of stability?

Answer 18

NEGATIVE DYNAMIC

Question 19

What are 2 causes of ROLL due to YAW?

Answer 19

1. Speed difference of wings

2. Rolling moment on the vertical tail

Question 20

What do we call YAW due to ROLL?

Answer 20

Adverse Yaw

Question 21

What results when an a/c BANKS w/o a turn?

Answer 21

1. Side Slip

2. Keel effect?

Question 22

When we trim the elevator, what are we trimming to maintain?

Answer 22

Airspeed

Question 23

How is LATERAL stability achieved?

Answer 23

1. Dihedral
2. Keel Effect
3. Sweepback

Question 24

What gives stability around the VERTICAL axis?

Answer 24

Vertical tail (Fin and Rudder)

Question 25

What gives stability around the LONGITUDINAL axis?

Answer 25

1. CG 2. Horizontal Stabilizer (Pitch stability) - Stability around the lateral axis

Question 26

What gives movement around the vertical axis?

Answer 26

Rudder

Question 27

What gives movement around the longitudinal axis?

Answer 27

Ailerons

Question 28

What gives movement around the lateral axis?

Answer 28

Elevator

Question 29

List 6 things that give longitudinal stability?

Answer 29

1. CG 2. Weight 3. Lift 4. Tail 5. Canard 6. Pitch stability

Question 30

Why do manufacturers add a Dorsal Fin to an airplane?

Answer 30

- Gives SIDE FORCE to have nose chase into the Relative Wind | - Helps to get out of spins

Question 31

You're in a 43 degree bank angle, IAS is 137 knots and the plane weighs 6,300 lbs. Find load factor, rate of turn and radius of turn!

Answer 31

Load Factor = 1.37 Gs Rate = 7.43 degrees per second Radius = 1,787.5 ft

Question 32

When would an a/c become "Out of Phase"

Answer 32

During a Dutch Roll

Question 33

What does Dihedral help with?

Answer 33

Lateral Stability

Question 34

What do Sweepback wing help with?

Answer 34

Lateral Stability when banking

Question 35

What IS dihedral? How does it work?

Answer 35

- The upward angle of an a/c's wings from the fuselage | - Lower wing flying at a higher AOA, increases lateral stability when banking

Question 36

What is Keel Effect?

Answer 36

The result of sideforce-generating surfaces being above/below the CG in an a/c

Question 37

4 ways lateral stability is designed into a/c

Answer 37

1. Dihedral 2 sweepback 3. Keel 4. Vertical wing placement