AVN 2100 Stability

Question 1

An airplane ____ about the longitudinal axis.

Answer 1

Rolls

Question 2

An airplane ______ about the lateral axis.

Answer 2

Pitches

Question 3

An airplane _____ about the vertical axis

Answer 3

Yaws

Question 4

Trim and flaps are _______ control surfaces

Answer 4

Secondary

Question 5

The purpose of a trim device is to:

Answer 5

Minimize the effort of the pilot when moving a control surface or maintaining that surface in a desired position.

Question 6

Trim lessons the _____ felt by the pilot on the associated flight controls

Answer 6

Aerodynamic resistance

Question 7

The three axes of motion intersect at the ______

Answer 7

Center of gravity

Question 8

The center of gravity is the theoretical point where _______

Answer 8

The entire weight of the plane is concetrated

Question 9

The center of pressure is the ______

Answer 9

Point along the chord line of an airfoil where life is concentrated.

Question 10

The center of pressue is also known as the _______

Answer 10

Center of lift

Question 11

Stability is the ______

Answer 11

Tendency of the aircraft to return to its original condition after being dispaced

Question 12

A stable aircraft will ______ return to its original position

Answer 12

Return

Question 13

An unstable aircraft will ______ from its original position

Answer 13

Move farther away

Question 14

A neutral aircraft will ______ in its displaced position

Answer 14

Remain

Question 15

The two types of stability are :

Answer 15

Static and dynamic

Question 16

Positive Static stability is:

Answer 16

The initial tendency to return to original position

Question 17

Positive Dynamic stability is:

Answer 17

The tendency of the aircraft to return to its original position over a period of time

Question 18

With negative static stability, an aircraft tends to:

Answer 18

Initially displace farther from its original position

Question 19

Oscillations _____ in a displaced aircraft with ________

Answer 19

Negative dynamic stability

Question 20

Oscillations will remain the same in a displaced aircraft with ________

Answer 20

Neutral dynamic stability

Question 21

If an aircraft returns to its original position thorugh a series of successively smaller oscillations, it has _______

Answer 21

Positive dynamic stability

Question 22

Longitudinal stability involves _____ motion about the ______ axis

Answer 22

Pitching, lateral

Question 23

If an aircraft naturally returns to its original attitude it is

Answer 23

Longitudinally stable

Question 24

The center of pressure changes with the _____

Answer 24

Angle of attack

Question 25

The center of gravity is located _____ of the center of pressure

Answer 25

Fore or aft

Question 26

As the angle of attack increases, the center of pressure _______

Answer 26

Increases

Question 27

As the center of pressure moves further aft of the CG, the aircraft becomes _____ longitudinally stable

Answer 27

Less

Question 28

The horizontal stabilizer is mounted with a ______ angle of incidence to provide _______

Answer 28

Negative, tail down force

Question 29

When the wings angle of attack is increased, the horizontal stabilizer's angle of attack _____, thus _______ the tail down force

Answer 29

Increases, decreases, decreasing

Question 30

Decreasing the tail down force produces a _______

Answer 30

Nose down moment

Question 31

For positive longitudinal stability, when the nose goes up, tail down force should _____

Answer 31

Go down

Question 32

Longitudinal stability deponds on the _____ and its ______ from the _______

Answer 32

Size, distance, center of gravity

Question 33

The larger the ______, the _______ the longitudinal stability

Answer 33

Horizontal stabilizer, greater

Question 34

The greater the distance of the tail from the ______, the _______ the longitudinal stability

Answer 34

Center of gravity, greater

Question 35

4 characteristics of CG too far forward:

Answer 35

Higher stalling speed, more stable, slower cruise speed, not enough elevator authority

Question 36

4 characteristics of CG too for aft:

Answer 36

Lower stall speed, faster cruise speed, less stable (easier to stall and spin and harder to recover)

Question 37

Because of the effects of the propeller slipstream, reduced thrust will reduce the _____ , meaning that the nose will _____

Answer 37

Taildown force, drop

Question 38

Directional stability is stability about the _____ axis

Answer 38

Vertical

Question 39

When an aircraft yaws, the vertical stabilizer has an _____ with respect to the relative wind

Answer 39

Angle of attack

Question 40

When yawing, the induced angle of attack of the ______ produces a restorative ______

Answer 40

Fin, moment

Question 41

The farther from the ______ that the vertical stabilizer is, the greater the _______

Answer 41

Center of gravity, directional stability

Question 42

The larger the ______, the greater the ______ stability about the vertical axis

Answer 42

Vertical stabilizer, directional

Question 43

"Keel Surfaces" refer to _______

Answer 43

Side surfaces of the aircraft

Question 44

When an airplace is _____, keel surfaces are exposed to the relative wind.

Answer 44

Yawed

Question 45

The greater the area of the keel surface, the ____ it contribution to ________

Answer 45

Greater, directional stability

Question 46

Lateral stability is built into an aircraft with four things:

Answer 46

Dihedral, swept wings, high keel surfaces, low CG

Question 47

What is dihedral?

Answer 47

The angle that the wings are inclined upward from the fuselage towards the wingtips

Question 48

Dihedral increases ______ stability because the increased ______ of the low wing increases its ________

Answer 48

Lateral, angle of attack, lift

Question 49

Why do swept back wings contribute to lateral stability?

Answer 49

The lower wing exposes more of its span to the airflow when rolled

Question 50

Uneven fuel burning may result in _______

Answer 50

Lateral instability

Question 51

What is dutch roll?

Answer 51

A lateral motion that is a combination of rolling/yawing, side to side oscillations

Question 52

A series of uncoordinated turns alternately in opposite directions is:

Answer 52

Dutch roll

Question 53

The differential lift created between the two wings when turning creates a _____ differential, leading to ______

Answer 53

Drag, adverse aileron yaw

Question 54

Increased dihedral increases the tendency to ______

Answer 54

Dutch roll

Question 55

Does dutch roll resolve itself on most aircraft?

Answer 55

Yes

Question 56

Typically, dutch roll is the result of two things:

Answer 56

1. A sharp wind gust against one wing 2. A very large control input that is suddenly released

Question 57

Inputing a very large control movement and then suddenly releasing it may induce ______

Answer 57

Dutch Roll