propellers ocr

8/16/2019 Propellers OCR

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ropellers

1ZI

22)

Question 314 in database)

On take off the directional control of a nose-wheel aircraft will be affected by:

a) gyroscopic and asymmetric blade effect.


The angle of attack of a fixed pitch prop:

a) is lower in the t8 Re off run than in flight.

b) is optimum in t l i Q . 9 ~ : G - _ - : 1 GS

c) is optimum in stabilised cruise flight.

d) decreases with decrease in speed at constant engine RPM.

The correct answer is c


Which of the following will increase the angle of attack of a fixed pitch propeller blade?

a) Increased TAS and increased RPM.


The advantage of a constant speed propeller over a fixed pitch propeller is:

a) higher maximu available.

b) higher maximum etrlCiency

G-1

GS

c) more blade suiface area available.

d

nearly maximum efficiency over wide speed range.

The correct answer is d


2/6

Question 53 (in database)

A propeller blade

is

twisted along its length

in

order

10

:

a) give a progressively increasing blade angle from

roollo

tip.

b) give a progressively increasing pitch from root 10 tip.

c) m p n s t

decreasing linear speed of the blade

,

d) maintain the optima

An

gle of-Atta

The correct answer is d.

1 ;-1


As an aircraft with a variable-pitch, constanl-speed propeller accelerates along the runway:

a)

th

e angle of at

t CJ<

will decrease and the engine RPM remain constant

b) the blade pitch a ~ e i n c r e a

r

i ~ . r i n g a constant angle of attack

and

RPM.

c) Ihe angle of altack will remain constant and the engine RPM will increase.

d)

th

e linear velocity of the propeller tip will gradually decrease.

The correct answer is b.

Question

308 in

database)

If

an

aircraft with a fixed pitch propeller reduces speed the engine RPM will also reduce if the

throttle

is

not moved; this

is

because:

a) the increase

in

blade angle of attack increases propeller torque, thereby imposing a greater

load on the engine.

b d , d 1 0 ' th

,;,

;otak, d 009;06 pow ,

c) the windmill effect is lessen

l1

= l

GS

d) the angle of attack of the propeller blades has decreased.

The correct answer is a. •

Question

361 in

database)

Propeller blade angle of attack is the angle between the chord and the:

a) direction of axis of the propeller.

b) aeroplane heading.

c) relative

,;0,0;

.


3/6


On take off the directional control of a tail-wheel aircraft will be affected :

a) gyroscopic

an

lf a symmetric blade effect.

"

b) slipstream and tor :lue effect

G

_

1

GS

c) all the phenomena at Opt ions a) and b).

d none of the phenomena at Options a) and b).

The correct answer is c.


What is the purpose of increasing the number of propeller blades?

a) To reduce noise.

b) To improve absorption.

c) To increase

f f i c i e n c y

of

the variable pitch mechanism.

i.

d To enable a Ion

e u n d e r r

t t e d .

The correct answer IS b.

lJ


During the take off roll , what affect does torque have on an aircraft with a clockwise rotating

propeller?

a) Weight on

l e l f

decreased, weight on right wheel incra sed.

,

b) Weight on left whee I n c r e a s ~ ~ right wheel remains constant.

c) Weight on left wheel increased, weight on right wheel decreased.

d Weight on right wheel increased, weight on left whee decreased.



On the take off roll a nose-wheel aircraft has less tendency to swing than a tail-wheel aircraft

because:

a) the pilot has a better view.

b) the effect of" ~ l I e r torque is cancelled out y the slipstream effect.

c) it does not su ff

er

fr

Of l gyroscopic and aSY fnetric blade effect.

d the propeller normally

r o t a t

~ n

~ ~ ~ s i t e

direction.



4/6

Question 365

(in

database)

Which of the following definitions of propeller parameters

is

correct?

a)

Blade Angle

is

the angle between chord line and propeller axis.

b)

Critical tip e propeller speed at which ..there

is

a risk of the flow separating at some

part of the propeller.

. 'i._

..

~

c) Blade angle of attack

is

the Mgr

J

~ chord line and propeller vertical axis

d) Geometric propeller pitch

is

the theoretical dis

tan ce

nvelled forwa

rd y

the propeller

in

one

rotation.

The correct answer

is

d.


T

he

angle of attack of a fixed pitch propeller designed for cruising flight, measured at

its

reference station,

is

:

a) optim

um in

steady cruising flight only.

b) increases

c r e s e

in

TAS.

c) decreases

w

c r e s e in

RPM.

d will always be positive

in

a

rf6;;e

T q ~

The correct answer

is

a.

Question

57

(in database)

In a single·engine, propeller-driven aircraft, the torque reaction of a clockv.ise rotating propeller

(as seen from the pilot s seat) will tend to cause:

a) left roll

and

~ w during

take

off.

,

,

b)

left roll

and

left uring

A G S

c) right roll and right yaw during take off.

d) left y w and right mll during

take

o

ff

.

T

he

correct answer

is b.


A fixed pitch propeller with a coarse blade angle would ensure

an

economic relatively high

cruising speed. Why are such propellers not fitted to the average light aircraft?

a) Because the reduction

in

take o

ff

performance would not be acceptable.

b) Because it too noisy.

c) Because fuel

c:

Dptio .

the

climb

an

d the descent-wo

ul

d

6e

uneconomical.

d None of the above.

The correct answer

is

a.

G-1AGS


5/6


Blade angle from the hub to the tip of a propeller blade in order to maintain an

optimal rom hub to tip.

a) increases

,

b) decreases

eometric l GS

c) increases effective Pitch

d) decreases angle of Attack

The correct answer is d.


Why does the blade angle of a propeller decrease from root to tip?

a) To compensate for the change in geometric cross section.

b) To provide increased thrust at root.

c) Cross-sectionalSegment increases from tip to root.

.

,

d) To compensate

for

the increased{v

A'ff

ty

of

the blade tip.

T

he

correct answer is d. I :J

-


What would

be

the gyroscopic effect of a clockwise rotating propeller (viewed from the pilot s

seat) on a single-engine, tail-wheel aircraft

as

it raises

its

tail during the take off run?

,

b) The aircraft would yaw to GS

c) The aircraft would roll to the right.

d) The aircraft would roll to the left.

The correct answer

is b


A propeller blade

is

twisted from root to tip:

a) to provide maximum thrust at the root.

b) to

provide maximum thrust at the tip.

c) because the

J l g l e

of attack of the segment

is

dependent on segment movement

in

the

plane of rotation and the aircra true air speed.

d) because the local angle of

l ~ W S s g m

t

Is

dependent on segment movement in the

plane of rotation and the segment velocity.

The correct answer

is

d.


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propellers ocr

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