POF - Stability

Question 1

true or false: airplane that is inherently stable will require less effort to control

Answer 1

true

Question 2

characteristic of an airplane in flight that causes to return to a condition of equilibrium or steady flight after it is disturbed

Answer 2

stability

Question 3

initial stability tendency to return to the position from which it was displaced is termed

Answer 3

positive static stability

Question 4

stability tendency made through a series of small oscillations

Answer 4

positive dynamic stability

Question 5

characteristic of an airplane that permits to maneuver easily and withstand the stress resulting from it

Answer 5

maneuverability

Question 6

capability of an airplane to respond to control inputs especially on attitude and flight path.

Answer 6

controlability

Question 7

three axes of flight and movement

Answer 7

longitudinal - roll
lateral - pitch
vertical - yaw

Question 8

common reference point of the three axes and the theoretical point where the entire weight of the airplane is concentrated

Answer 8

center of gravity

Question 9

a. controls the roll movement
b. controls the pitch movement
c. controls the yaw movement

Answer 9

a. aileron
b. elevator
c. rudder

Question 10

longitudinal stability involves which motion or axis

Answer 10

pitching motion or lateral axis

Question 11

point along the wing chord line where lift is concentrated (center of lift)

Answer 11

center of pressure

Question 12

true or false: to achieve longitudinal stability, most planes are designed slightly nose heavy

Answer 12

true

Question 13

when the CG is within the approved range, the airplane is:

Answer 13

controllable and its longitudinal stability is satisfactory

Question 14

true or false: if CG is too far forward, elevator effectiveness will be insufficient to lift the nose,

Answer 14

true

Question 15

true or false: if CG is too far aft, elevator shall not be effective and may be difficulty to recover from a stall or spin.

Answer 15

true

Question 16

true or false: always follow the POH loading recommendation or guidelines.

Question 17

downward force used to counteract nose-down tendencies due to CG

Answer 17

tail-down force (horizontal stabilizer)

Question 18

true or false: downwash from the propeller and wings passing over the horizontal stabilizer influence longitudinal stability

Answer 18

true

Question 19

results to a nose down pitching tendency due to the reduction of downwash from the wings and the propeller which reduce elevator effectiveness.

Answer 19

reduction of power

Question 20

will decrease downwash on the horizontal stabilizer from the wings and propeller slipstream which causes the nose to pitch down

Answer 20

power reduction

Question 21

determined where propeller is mounted and the general direction which thrust act

Answer 21

thrust line

Question 22

lateral stability involves which motion or axis

Answer 22

rolling or longitudinal axis

Question 23

design features that influence lateral stability:

Answer 23

weight distribution, dihedral, sweepback, and keel effect.

Question 24

true or false: you have no control of design features for lateral stability but you can control the distribution of weight to improve it.

Answer 24

true

Question 25

most common design for lateral stability. refers to the upward angle of the airplane's wings with respect to the horizontal.

Answer 25

dihedral

Question 26

involves lateral stability in which wings are angled backward from the wing root to the wing tips.

Answer 26

sweepback

Question 27

steadying influence exerted by the side area of the fuselage and the vertical stabilizer

Answer 27

keel effect

Question 28

directional stability involves which motion or axis

Answer 28

yaw or vertical axis

Question 29

interaction of lateral and directional stability in which a combination of rolling and yawing oscillations caused by either your control input or by wind gusts.

Answer 29

dutch roll

Question 30

interaction of lateral and directional stability which is associated with airplanes that have strong directional stability in comparison with lateral stability

Answer 30

spiral in instability

Question 31

true or false: if air speed is low, the required angle of attack to maintain lift may exceed which may cause a stall

Answer 31

true

Question 32

type of stall with low power conditions

Answer 32

power-off stall

Question 33

type of stall with high power condition

Answer 33

power-on stall

Question 34

type of stall which involves higher than the normal speed

Answer 34

accelerated stall

Question 35

type of stall when the pilot tries to compensate for overshooting a runway during a turn from base to final while on landing approach

Answer 35

crossed-control stall

Question 36

signs of stall

Answer 36

mushy feeling in flight control, less control effectiveness, stall warning

Question 37

steps how to recover from a stall

Answer 37

decrease angle of attack, increase power via throttle, adjust power as required upon recovery

Question 38

aggravated stall which results in the airplane descending in a helical or corkscrew path

Answer 38

spin

Question 39

to enter a spin, an airplane must first be ___

Answer 39

stalled

Question 40

true or false: although both wings are stalled, one wing is stalled more than the other

Answer 40

true

Question 41

type of spin where roll and yaw are in the same direction

Answer 41

erect spin

Question 42

type of spin where roll and yaw are in opposite direction

Answer 42

inverted spin

Question 43

type of spin which involves only the yaw

Answer 43

yaw

Question 44

spin recover (PARE)

Answer 44

power - idle aileron - neutral rudder - opposite direction of spin elevator forward

Question 45

first stage of spin from the time the plane stalls and rotation starts

Answer 45

incipient spin

Question 46

second stage of spin which is after the incipient spin where the actual spin occurs

Answer 46

fully developed spin

Question 47

third stage of the spin where anti spin procedures have been executed

Answer 47

recovery

Question 48

most aircrafts are designed to display both___ and ___ stability

Answer 48

positive static and positive dynamic stability

Question 49

common point of longitudinal, lateral, and vertical axis

Answer 49

center of gravity

Question 50

longitudinal stability is associated with the relationship of

Answer 50

center of pressure and center of gravity, power change, and the design of the horizontal stabilizer

Question 51

lateral stability involves what factors

Answer 51

wing dihedral, sweepback, keel effect, and weight distribution

Question 52

Directional stability or stability of the vertical axis is maintained by

Answer 52

vertical tail

Question 53

most likely to occur on aircraft with weak directional stability and strong lateral stability

Answer 53

dutch roll

Question 54

a spin will not develop until both wings are __

Answer 54

stalled

Question 55

in relation to center of gravity, which direction would the center of pressure normally move as angle of attack is increased on a cambered wing

Answer 55

forward

Question 56

what factors affect longitudinal stability of an airplane at high power settings and low air speed

Answer 56

On many training aircraft, an increase in thrust increases the pitching moment and nose heaviness due to the placement of the thrustline of the aircraft. This helps counteract the longitudinally destabilizing effect of increased downwash that results from an increase in power and extension of high lift devices.

Question 57

why are high wing aircrafts normally designed with less dihedral than low wing aircraft

Answer 57

Upwash passing around the fuselage just ahead of the wing tends to roll a high wing aircraft toward the upright position, contributing to lateral stability. In a low wing airplane, the downwash around the fuselage tends to be laterally destabilizing since it tends to increase the roll. The amount of dihedral is adjusted to compensate for the effects of fuselage upwash and downwash resulting in a greater requirement for dihedral in a low wing airplane than in a high wing configuration.

Question 58

Does propwash result from high power setting increase or decrease the contribution of wing dihedral to the lateral stability of an airplane

Answer 58

decrease

Question 59

true or false: when landing in gusty winds, airspeed should be increased above normal to help guard against a stall

Answer 59

true