Aircraft Design - Configuration Layout Considerations Quiz(MCQ)

1 .

If an aircraft is not designed properly then __________

A)

it will have more lift

B)

it will have less drag

C)

it will have higher aerodynamic efficiency

D)

it can experience excessive flow separation

Correct Answer : it can experience excessive flow separation

Explanation : Overall aircraft design will decide whether the aircraft is streamlined or not. An inadequate and poorly designed aircraft can suffer from drag increment, excessive flow separation etc.

2 .

________ can be considered as one of the most powerful aerodynamic consideration.

A)

Only wingspan

B)

Wetted area

C)

Number of ribs

D)

Number of spars

Correct Answer : Wetted area

Explanation : Wetted area is considered as one of the most powerful aerodynamic tool. Wetted area is nothing but the actual area that will be in contact if fluid is flown over the body. Spar and ribs are structural members.

3 .

To reduce fuselage wetted area we can _______

A)

increase fineness ratio

B)

always use long fuselage

C)

lower the fineness ratio

D)

always double the fineness ratio

Correct Answer : lower the fineness ratio

Explanation : Wetted area can be used to determine the drag properties of an aircraft. Fineness ratio is nothing but the length of the fuselage divided by max diameter of the fuselage. Hence, if we lower the fineness ratio then the ratio of length to diameter will reduce which in turn reduces the wetted area.

4 .

What is the disadvantage of short and fat fuselage?

A)

Higher supersonic wave drag

B)

Lower wetted area

C)

Lower supersonic wave drag

D)

Higher incompressible wave drag

Correct Answer : Higher supersonic wave drag

Explanation : Wave drag is the supersonic phenomena. Wave drag does not exist for incompressible flow. Short and fat fuselage will offer minimization of the wetted area. This gives advantage in terms of friction properties. However, it suffers from higher wave drag at supersonic speeds.

5 .

A fuselage is designed as show in below diagram. If velocity of free stream is 120knts then, find the maximum angle marked by’?’.

A)

10° – 12°

B)

39°

C)

40°

D)

54°

Correct Answer : 10° – 12°

Explaination : Given, Free stream velocity V = 120knts. As shown in the figure fuselage has some deviation with free stream. For given speed of freestream air, a typical fuselage should be allowed up to 12.5° maximum. More than the given limit will affect the drag parameters. Hence, answer would be 10°-12°.

6 .

Determine the corrections or otherwise of the following assertion [A] and reason [R]:
Assertion [A]: Maintaining smooth longitudinal contour in fuselage will give better aerodynamic design.
Reason[R]: Longitudinal control lines are used to provide smoothness to the fuselage.

A)

Both [A] and [R] are false

B)

[A] is false but [R] is true

C)

Both [A] and [R] are true but [R] is not the correct reason for [A]

D)

Both [A] and [R] are true and [R] is the correct reason for [A]

Correct Answer : Both [A] and [R] are true but [R] is not the correct reason for [A]

Explaination : A good aerodynamic design of a fuselage will maintain smooth longitudinal contour to reduce the drag and other similar effects. This can be achieved by using longitudinal control lines. Smooth fuselage with lesser discontinuity will reduce the drag and as a result of which aerodynamic efficiency will improve. Hence, [A] and [R] both correct however, [R] is not correct reason.

7 .

Short and fat fuselage will have ________

A)

lower tail arm

B)

higher tail arm

C)

higher wetted area

D)

higher fineness ratio

Correct Answer : lower tail arm

Explanation : Tail arm is nothing but the distance between cg of tail to cg of an aircraft, typically. Short and fat fuselage will have shorter tail arm or tail moment arm. Size of the fuselage will be reduced for such case and as a result of which the tail arm will be reduced.

8 .

Why do we provide upsweep to the lower surface at aft fuselage?

A)

To increase lift

B)

To increase drag

C)

To maximize drag

D)

To reduce drag

Correct Answer : To reduce drag

Explanation : Fuselage is primary drag generating component of aircraft. A lower surface upsweep is provided to reduce drag penalty for typical aircraft. This upsweep will induce vortex flow pattern at the lower surface which can reduce the drag. However, for high speed aircraft it should be as low as possible.

9 .

What is the base area of the fuselage?

A)

Wing area

B)

Forward facing surface

C)

Fuselage cabin area only

D)

Any unfair rearward facing blunt surface

Correct Answer : Any unfair rearward facing blunt surface

Explanation : Base area is nothing but the rearward area of the fuselage. It is any unfair rearward facing blunt surface. Wing area is the product of span and chord for rectangular planform. Fuselage cabin will be located at front side of the fuselage.

10 .

Following diagram represents?

A)

Lowest lift design

B)

Highest area design

C)

Typical low wave drag design

D)

Highest drag design

Correct Answer : Typical low wave drag design

Explaination : Above diagram is showing typical low wave drag design of an aircraft. It is called coke-bottling. It is used to improve the wave drag properties by altering the volume distribution. It can be used to reduce drag up to 50%.

11 .

Supersonic wave drag can be reduced by using _______

A)

drag ruling

B)

area rule

C)

lift augmentation

D)

drag augmentation

Correct Answer : area rule

Explanation : R. whitcomb had developed a method to reduce the supersonic drag. The method is known as area ruling or area rule. In this method overall volume distribution of components are altered in such way that the resultant body should provide less drag.

12 .

Vortex generator is used to ________

A)

separate flow

B)

increase volume

C)

reattach separated flow

D)

increase surface area

Correct Answer : reattach separated flow

Explanation : Vortex generator is small body placed on surface to reattach the separated flow. A flow flows around the vortex generator, it curls the flow. And as a result of which flow is being forced to swirl and to flow reattaches to the surface if it has separated.

13 .

Drag divergence Mach number will increase by using _________

A)

area rule

B)

increase in drag

C)

increment in total volume

D)

drag increment at maximum area

Correct Answer : area rule

Explanation : Drag divergence Mach number is that Mach number after which drag increases drastically. Area rule can be used to lower the drag up to 50%. By using area rule properly we can improve the drag divergence Mach number.

14 .

What is the load path?

A)

Lifting path

B)

Structural elements by virtue of which opposite moments are linked

C)

Structural elements by virtue of which similar forces are connected

D)

Structural elements by virtue of which opposing forces are connected

Correct Answer : Structural elements by virtue of which opposing forces are connected

Explanation : Load path is nothing but the elements by virtue of which opposing forces are connected. Typically, a good structural arrangement will have efficient load path. By providing appropriate load path, we can improve our design based on structural considerations.

15 .

We can minimize the weight of the structural member by _______

A)

placing similar forces near to each other

B)

placing opposite forces near to each other

C)

placing opposite forces away from each other

D)

placing only upward forces near to each other

Correct Answer : placing opposite forces near to each other

Explanation : To reduce the structural weight it is required that our design should have efficient load paths through which we can effectively connect opposing forces. For a typical aircraft, two common forces to be resolved are lift and force. Hence, by locating opposite forces near to each other we can improve structural considerations of our design.

16 .

Span-loading is defined as ______

A)

wing loading

B)

thrust loading

C)

inverse of power loading

D)

distribution of weight along span as lift distribution

Correct Answer : distribution of weight along span as lift distribution

Explanation : Span-loading is the distribution of weight along span as lift is distributed. Thrust loading is the ratio of thrust and weight. Wing loading is weight per area. Power loading is weight of aircraft to the power produced.

17 .

To reduce weight of the structural member we can _______

A)

provide only shortest possible load paths

B)

provide only straightest possible load paths

C)

provide shortest and straightest possible load paths

D)

provide shortest and highly curved possible load paths

Correct Answer : provide shortest and straightest possible load paths

Explanation : In general it is required to locate opposing forces at the same location. We can reducing weight by doing so. However, it is not possible for every scenario. Hence, we need to provide some path through which we can connect these forces. These paths are load paths and by providing shortest and straightest possible load path we can reduce the weight.

18 .

Following diagram represents _________

A)

ideal span loading

B)

ideal wing loading

C)

ideal thrust loading

D)

ideal power loading

Correct Answer : ideal span loading

Explaination : Above figure is representing the distribution of lift and weight along the span. It is shown in figure that weight is distributed exactly same as lift along the span. This is ideal condition and termed as ideal span loading.

19 .

Following diagram represents ____

A)

ring frames

B)

strut braced

C)

bending beams

D)

wing box carrythrough

Correct Answer : wing box carrythrough

Explaination : Wing box carry through arrangement is shown in above diagram. These arrangement is widely used in general aviation and transport aircrafts. Here, box is continued from wing through the fuselage as can be seen in the diagram.

20 .

Following diagram represents ______

A)

strut braced

B)

ring frames

C)

bending beams

D)

hybrid strut braced

Correct Answer : ring frames

Explaination : A typical ring frames arrangement is shown in above diagram. In this type of wing carry through, large and heavy bulkheads are used. These bulkheads are used to oppose the bending. This type is mostly used by modern fighters.

21 .

Following diagram represents ______

A)

ring frames

B)

strut braced

C)

bending beams

D)

hybrid strut braced

Correct Answer : bending beams

Explaination : Bending beam arrangement is shown in above diagram. This type is combination of the wing box and ring frames wing carry through arrangement. Strut braced will rely upon strut and used in slower transport aircraft typically.

22 .

A typical large airliner has outer diameter of 20in. find the approximate value of diameter for passenger compartment.

A)

12in

B)

20in

C)

24in

D)

34in

Correct Answer : 12in

Explanation : Given external diameter = 20in. Radius = 20/2 = 10in.
Approximate radius of passenger compartment = external radius – structural thickness
= 10-4 = 6in
Hence, diameter = 2*6 = 12in.

23 .

A wing has chord of 1m. Find the appropriate range of the front spar position from l.e.

A)

3.2

B)

1.2

C)

0.9m-1.5m

D)

0.2m-0.3m

Correct Answer :

Explanation : Given chord c = 1m.
Typical range of front spar location = 20% to 30% of chord = 20% of 1 to 30% of 1 = 0.2*1 to 0.3*1 = 0.2m-0.3m.

24 .

To decrease the weight of a typical commercial fuselage, stringers should be ______

A)

only straight

B)

straight and uninterrupted

C)

straight and curved

D)

interrupted at every point

Correct Answer : straight and uninterrupted

Explanation : A typical transport fuselage will have more numbers of stringers attached to its structure. Stringers are short and light structural elements. They are distributed around fuselage circumference. Stringers should be straight and uninterrupted to minimize the weight as possible and as per our requirement.

25 .

Fuselage bending loads are carried by _______

A)

ribs

B)

tail

C)

nelson

D)

keelson

Correct Answer : keelson

Explanation : Keelson is a large beam placed at fuselage bottom. Keelson is structural element through which bending loads are carried out. Tail is after section of the aircraft which has primary purpose to provide stability and control.

26 .

Longerons are used to oppose _______

A)

drag

B)

bending

C)

expansion only

D)

contraction only

Correct Answer : bending

Explanation : Longerons are structural members of an aircraft. They are heavy and used to prevent the bending. Longerons are fewer in numbers and primarily opposes the loads which can result in the bending stress and can cause the bending of structure. Their placement should be considered while designing the aircraft.

27 .

RADAR stands for ________

A)

radio detection and ranging

B)

radio defense and rigging

C)

radio detection and rigging

D)

radio determination and ranging

Correct Answer : radio detection and ranging

Explanation : RADAR stands for ‘radio detection and ranging’. It is used to detect the aircraft. Radar can be monostatic radar or bistatic based on location of transmitter and receiver. Radar is one of the primary sensors in modern aircrafts.

28 .

Typical radar system consists of _________

A)

Only TX

B)

Only Rx

C)

TX and Rx

D)

Does not require TX or Rx

Correct Answer : TX and Rx

Explanation : A typical radar system consists of 2 main primary components; 1. Transmitter TX and 2. Receiver Rx. Transmitter is used to transmit the electromagnetic waves whereas receiver will receive any incoming waves.

29 .

A typical radar is located at 4 meter distance from an object. If radar transmits signal from that position then, signal strength S will be ________

A)

proportional to (1/4?)

B)

proportional to (1/4?)

C)

proportional to 4

D)

proportional to 1/4

Correct Answer : proportional to (1/4?)

Explaination : Given, Distance d =4m.
Since, no other parameters have mentioned we will directly use the relation between strength and the distance to find required relation.
Typically, radar strength is proportional to (1/distance?) = (1/4?).

30 .

RCS stands for ________

A)

radar cone shape

B)

radio conic shape

C)

radar cross section

D)

radio cruise and stall

Correct Answer : radar cross section

Explanation : RCS is acronym of ‘radar cross section’. RCS of an aircraft will directly impact the radar detectability of the aircraft. RCS is usually measured in decibel square meters or dBsm.

31 .

Following diagram represents ____

A)

Surface current scattering

B)

Lift vectors

C)

Capturing area of surface

D)

Surface current explosion

Correct Answer : Surface current scattering

Explaination : Above figure is illustrating the concept of surface current scattering. As shown in the figure, some radar energy is incoming to the surface. As radar energy passes through the surface some edge scattering can be observed as shown by the diagram. This scattering effect can affect the radar detection.

32 .

As a designer, we want to improve radar detectability of our aircraft. Where should we locate our warheads to achieve this goal?

A)

At wingtip

B)

Below wing

C)

Inside fuselage

D)

Outside fuselage

Correct Answer : Inside fuselage

Explanation : Inside fuselage will eliminate rcs of warheads as they are no longer in the range of radar signals. Locating warheads on wingtips, outside fuselage or below wings will provide some surface area through which signal can be returned. Hence, it will not improve detectability as an inside fuselage position.

33 .

RCS of flat surface can be reduced by _____

A)

increasing flat side length

B)

provide more rcs to flat side

C)

using twice length of the flat side

D)

providing some slope to flat surface

Correct Answer : providing some slope to flat surface

Explanation : Flat surfaces offer highest rcs possible. Now, to reduce it we can provide some slope to flat side of the surface. This will reduce the amount of EMW being returned by the flat side. If we increase the flat side length then, it will not reduce rcs of the flat surface.

34 .

RCS is the measure of _________

A)

lift generated

B)

how much weight is required

C)

radio cruise and stall properties

D)

the amount of EM energy is being returned by an object

Correct Answer : the amount of EM energy is being returned by an object

Explanation : RCS will directly affect radar detectability of the aircraft. It is the measure of how much EM energy is being returned by an object. If RCS is more then, the object will return more amount of the EM energy and vice-versa.

35 .

RCS can be altered by _________

A)

altering the look angle

B)

altering the drag force

C)

altering the ram cruise and stall

D)

altering the tail moment arm only

Correct Answer : altering the look angle

Explanation : RCS is based on the look angle. By altering look angle we can alter the rcs of an object. Tail moment arm will affect the stability not the rcs in general. RCS is also reduced by using stealth technology.

36 .

Which of the following will not affect the radar detectability of an aircraft?

A)

Look angle

B)

Drag magnitude

C)

Flat surface

D)

Stealth properties

Correct Answer : Drag magnitude

Explanation : Radar detectability is directly affected by how much EM energy is being returned by an object. It is also affected by RCS or radar cross section. RCS depends upon look angle, flat surface, stealth technology etc. Drag magnitude will not affect radar detection.

37 .

To improve IR detection of engine, we can __________

A)

show nozzle at IR sensor

B)

use higher exhaust temperature

C)

nozzle does not affect the IR detection

D)

hide the nozzle from expected location of an IR sensor

Correct Answer : hide the nozzle from expected location of an IR sensor

Explanation : Emissions of hot parts can be reduced by lowering their temperature. We can hide nozzle from the IR detector itself. As a result we can improve the IR detectability.

38 .

Which of the following is one of the countermeasures for IR detection?

A)

Decoy

B)

Temperature increase

C)

Not mixing plume with outside air

D)

Engine exhaust temperature increase

Correct Answer : Decoy

Explanation : A decoy is an off-board system. Decoy is a countermeasure that is ejected from and separated away from the aircraft. Decoy will try to lure the missile track away from the aircraft.

39 .

Plume emissions can be reduced by _______

A)

increasing plume temperature

B)

quickly mixing exhaust with outside air

C)

increasing exhaust temperature

D)

increasing engine outlet temperature

Correct Answer : quickly mixing exhaust with outside air

Explanation : Plume emissions can be reduced by quickly mixing the exhaust of engine with outside air. Emissions from hot parts are reduced by cooling them. Increase in temperature will increase emissions and as a result, it will increase IR detection as well.

40 .

A military aircraft can use _____ as a countermeasure for IR detection.

A)

lift

B)

glares

C)

flares

D)

engine temperature increase

Correct Answer : flares

Explanation : If we increase engine exhaust temperature then, it will increase the IR detection. As a countermeasure for IR detection, most of military a/c are using flares. Flares are used to generate fake IR signatures.

41 .

An aircraft does not emit any IR radiation.

A)

True

B)

False

C)

Can Not Say

D)

None of the above

Correct Answer : False

Explanation : IR is an electromagnetic wave. An infrared radiation is not visible to a human named eye. Any bay which has warmth will generate infrared radiation. Aircraft will emit infrared radiation.

42 .

In general, an IR detector will respond to?

A)

Irradiance

B)

RCS

C)

Rotational fluid

D)

Rotational force

Correct Answer : Irradiance

Explanation : Typically, all it detector will respond to irradiance. Irradiance is area density of the power. Hence, an infrared detector will respond to the density of the radiant power. RCS is measure of radar detection.

43 .

What is an IR signature of an aircraft?

A)

Only refraction

B)

Only reflections

C)

Sum of some emissions only

D)

Total of detectable emissions and reflections

Correct Answer : Total of detectable emissions and reflections

Explanation : Total of detectable and reflections can be called as an IR signature. This signature is used for tracking and detecting the aircraft. An aircraft’s IR signature is complex mixture of reflections and emission of various components.

44 .

Which of the following is primarily responsible for an IR signature?

A)

Fuel tank

B)

Passenger

C)

Engine exhaust

D)

Cabin crew

Correct Answer : Engine exhaust

Explanation : Primary sources for IR detection in an aircraft is engine exhaust. Passenger, cabin crew and fuel tank will play minor role as compared to the engine exhaust. Engine exhaust consists of hot gases and emissions.

45 .

An aircraft is flying with Mach 2.0. Calculate recovery temperature if ambient temperature is 305K. Assume recovery factor is 0.85.

A)

512.4K

B)

400°C

C)

253.2K

D)

100°C

Correct Answer : 512.4K

Explanation : Given, Mach number = 2.0, ambient temperature T1 = 305K
Assuming the recover factor as 0.85 and for such case,
Recovery temperature T2 = T1*(1+0.17*M²)
T2 = 305*(1+0.17*2*2) = 305*1.68 = 512.4K.

46 .

If my aircraft has luminance of 10 unit and is designed to operate in background which has luminance of 8 unit then, what will be the approximate value of contrast?

A)

0.25 unit

B)

1.25

C)

5.25unit

D)

5.26

Correct Answer : 0.25 unit

Explaination : Given, luminance of A/C L₁=10unit, luminance of background L₂ = 8unit.
Approximate contras value C = |L₁-L₂|/L₂ = |10-8|/8 = 2/8 = 0.25 unit.

47 .

An observer is observing in an aircraft from distance of 2400 feet. If size of the aircraft can be given as 24000 feet then, what will be the simplified value of visual angle in minutes of arc? Consider all simplified environment and ideal conditions.

A)

34

B)

343

C)

3438

D)

34380

Correct Answer : 34380

Explaination : Given, distance d = 2400 feet, length l=24000 ft.
Visual angles in minutes of arcs = 3438*l/d = 3438*24000/2400 = 34380.

48 .

Higher contrast between different parts of aircraft will __________

A)

increase detectability

B)

decrease

C)

increases twice times always

D)

always decreases by two units

Correct Answer : increase detectability

Explanation : Contrast between two parts of an aircraft will increase visual detectability. Higher contrast makes it easy to be seen visually. We can reduce contrast so that we can improve visual detection of the aircraft.

49 .

Visual detection is based on?

A)

Only size

B)

Only weight

C)

Only color

D)

A/C size, color, etc

Correct Answer : A/C size, color, etc

Explanation : Visual detection is affected by size, color etc. How much wider or longer or big is my aircraft? Will affect its visual detection. Color of my aircraft with respect to background will affect visual detection as well.

50 .

In order to reduce background contrast, we can provide _________

A)

camouflage pattern

B)

red color pattern only

C)

always use black color

D)

always use red and black pattern

Correct Answer : camouflage pattern

Explaination : By using a red color pattern we are making our aircraft to look more vibrant which will increase its chances of detection. Camouflage patterns can be used in order to reduce background contrast.

51 .

For ground background, camouflage paint scheme consists _________

A)

black and red

B)

mottled white

C)

mottled grey green

D)

yellow and red only

Correct Answer : mottled grey green

Explanation : For ground background, camouflage paint pattern consists of mottled grey green typically. Apart from this, grey-brown combination is also used as camouflage paint for ground background.

52 .

Camouflage patterns for sky background will include ________

A)

clean red

B)

dirty blue-grey

C)

clean pink

D)

dirty red always

Correct Answer : dirty blue-grey

Explanation : For sky background, camouflage paint pattern consists of dirty blue-grey typically. Apart from this, grey-brown combination is also used as camouflage paint for the ground background.

53 .

A. Typical aircraft will have lighter colors at lower surface.
R. The background lookup angle is sky.

A)

[A] is false but [R] is true

B)

Both [A] and [R] are false

C)

Both [A] and [R] are true and [R] is the correct reason for [A]

D)

Both [A] and [R] are true but [R] is not the correct reason for [A]

Correct Answer : Both [A] and [R] are true and [R] is the correct reason for [A]

Explaination : An aircraft will be spending major time in the sky. Hence, it is required to use lighter colors at lower surface as the background lookup angle is sky. It will reduce the contrast of an aircraft with respect to sky and will improve visual detection.

54 .

How to reduce engine noise?

A)

By using chevron nozzle

B)

By using high velocity jet

C)

Using small diameter and high velocity jet

D)

Higher exhaust jet with less diameter of exhaust

Correct Answer : By using chevron nozzle

Explanation : Chevron nozzle is used to reduce the engine exhaust aural signatures. Chevron nozzle accompanies saw tooth pattern at the trailing edge. High velocity jet will produce more noise due to air shear layer effects.

55 .

By directing the exhaust away from the ground we can __________

A)

increase noise

B)

reduce the aural signature

C)

increase the aural signature

D)

noise is not dependent on the direction of exhaust

Correct Answer : reduce the aural signature

Explanation : By redirecting exhaust stacks away from the ground we can reduce the aural signature. We can reduce aural signatures by using mufflers or by providing proper insulation as well.

56 .

To reduce aural signatures of engine exhaust, we can use _____

A)

lofting

B)

drafting

C)

insulating material

D)

non-insulating material

Correct Answer : insulating material

Explanation : We can use insulating materials to reduce the aural signatures. Lofting is mathematical modeling. Drafting is based on drawing.

57 .

Noise produced by an aircraft is called _______

A)

ir beam

B)

signal beam

C)

aurora beam

D)

aural signature

Correct Answer : aural signature

Explanation : The noise generated by an aircraft is called the aural signature of the aircraft. Aural signature or noise is very important for civil as well as military grade aircraft. Some aircraft suffers retirement due to much higher aural signatures.

58 .

Primary cause of aircraft noise is ______

A)

lift

B)

engine exhaust

C)

cabin

D)

fuselage

Correct Answer : engine exhaust

Explanation : Aircraft noise is primarily generated due to the engine exhaust. The fuselage, cabin noise are less as compared to the engine exhaust. Lift is an aerodynamic force.

59 .

Small diameter and high velocity jet will produce _______

A)

more noise

B)

less noise

C)

less aural signature

D)

independent of diameter and velocity

Correct Answer : more noise

Explanation : in a typical aircraft, engine is primary component which generates higher aural signatures. Small diameter and high exhaust will generate more noise due to the effect of air shear layers.

60 .

Arrange in the correct order of noise produced by engine type.

A)

Turbojet > turbofan > reciprocating engine

B)

Turbojet < turbofan < reciprocating engine

C)

Turbojet > turbofan = reciprocating engine

D)

Turbojet > turbofan < reciprocating engine

Correct Answer : Turbojet > turbofan > reciprocating engine

Explaination : Engine exhaust aural signatures will be affected by type of engine used. A large diameter propeller with limited tip speed will generate less noise as compare to high speed turbojets. Turbofan aural signature is less than that of the turbojet but greater than the reciprocating engine. Hence, the correct order will be Turbojet > turbofan > reciprocating engine.

61 .

To reduce piston exhaust noise __________

A)

we can use more mufflers

B)

reduce lift always

C)

mufflers can be used only

D)

increase jet speed always

Correct Answer : we can use more mufflers

Explanation : Noise by a piston engine exhaust can be reduced in a number of ways. One of them is by adopting mufflers. Apart from muffler, we can redirect the exhaust in such way that the resulting noise will be much lesser.

62 .

In order to improve vulnerability consideration, we can use ________

A)

high lift device

B)

vortex generator

C)

we cannot improve it

D)

redundant components

Correct Answer : redundant components

Explanation : Redundant components in simple words are additional components which can be used at the time of emergencies or failure of the component. For example, redundant of hydraulic system, electric system, etc. can improve survivability. Hence, by using redundant component we can improve the vulnerability of our design.

63 .

We can improve vulnerability by ______

A)

placing fuel tanks on the engine

B)

placing fuel tanks at any location

C)

placing fuel tanks inside the engine

D)

avoiding fuel tanks near to the engine

Correct Answer : avoiding fuel tanks near to the engine

Explanation : Fuel tank location can affect the vulnerability of an aircraft. Fuel tanks can catch fire much quickly. Hence, to improve vulnerability it is advised to avoid placing fuel tanks near or above the engine or inside the engine.

64 .

FMEA stands for?

A)

Failure mass and effect analysis

B)

Failure modes and effect analogy

C)

Failure modes and effect analysis

D)

Failure mass and effective analogy

Correct Answer : Failure modes and effect analysis

Explanation : FMEA stands for ‘Failure modes and effect analysis ’. Determination of FMEA is one of the most important step for evaluation of vulnerability of an aircraft. This step is done at later stage during conceptual design.

65 .

Vulnerability of an aircraft is ability of the aircraft _________

A)

to an IR detection

B)

to sustain damage, continue flying and return to base

C)

to the radar detection

D)

to get damaged and failed

Correct Answer : to sustain damage, continue flying and return to base

Explanation : Vulnerability is the ability of an aircraft which concerns whether the aircraft can sustain damage and continue to fly in order to return to the base. An aircraft can be damaged in number of ways such as through gun.

66 .

________ is key parameter for vulnerability.

A)

IR

B)

RCS

C)

Visual area

D)

Vulnerable area

Correct Answer : Vulnerable area

Explanation : Vulnerable area is key parameter of a vulnerability. It is the product of probability of an aircraft component to be hit and the projected area of that component. RCS concerns with radar detection. IR concerns with IR detectability.

67 .

Positioning of the propeller should be such that __________

A)

blade will not strike anyone if they fly off

B)

it is always near to cabin

C)

the blades will strike the engine

D)

blade should fly off during flight

Correct Answer : blade will not strike anyone if they fly off

Explanation : As a crashworthiness consideration, positioning of the propeller should be such that the blades will not strike anyone in case of failure or emergency. Hence, as a designer it is our primary role to ensure not only performer but also safety of passengers as well.

68 .

If an aircraft has three components which can be considered as vulnerable components then, evaluate total vulnerable area. Given area of component 1, 2 and 3 are 5ft², 4ft² and 80ft² respectively with Pk as 1, 0.5 and 0.3 for component 1, 2 and 3 respectively.

A)

4ft

B)

10ft²

C)

31ft²31ft²

D)

50ft²

Correct Answer : 31ft²31ft²

Explaination : Given, part 1: area a₁=5ft², pk₁=1
Part 2: area a₂=4ft², pk₂=0.5
Part 2: area a₃=80ft², pk₃=0.3
Total vulnerable area = a₁*pk₁ + a₂*pk₂ + a₃*pk₃ = 5*1 + 4*0.5 + 80*0.3 = 5+2+24 = 31ft²

69 .

What do you mean by crashworthiness?

A)

Vulnerability to radar detection

B)

Special aerodynamic lift improvement

C)

Capability of an aircraft to stay in cruise

D)

Capability of structure to protect against impacts and crash loads

Correct Answer : Capability of structure to protect against impacts and crash loads

Explanation : Capability of structure to protect against impacts and crash loads can be termed as crashworthiness design. Whether the aircraft will stay in cruise or not this will be decided by operating environment.

70 .

Following diagram represents _________

A)

Scarfed firewall reduces scooping

B)

RCS exposed only

C)

Wetted area only

D)

Scarfed firewall increases scooping

Correct Answer : Scarfed firewall reduces scooping

Explaination : The above diagram is representing the effect of scarfed firewall. As shown it reduces the scooping. RCS is measurement of radar detection. Wetted area will affect aerodynamics of design.

71 .

Following diagram represents _____

A)

crash load decrement

B)

wing loading concept

C)

increment in crash load due to firewall scooping

D)

firewall scooping has decreased crashworthiness

Correct Answer : increment in crash load due to firewall scooping

Explaination : Above diagram is showing scooping effect. As shown in the figure, because of the scooping crash loads has increased. Wing loading will be used to size the aircraft. Based on mission and type of aircraft we can size our design by using wing loading concepts.

72 .

Location of landing gear should be such that _______

A)

with less crashworthiness

B)

they wouldn’t rip open fuel tanks at the time of crash

C)

they would rip open fuel tanks

D)

they must rip open fuel tank during crash

Correct Answer : they wouldn’t rip open fuel tanks at the time of crash

Explanation : Gears should be placed such that they would not rip open fuel tank at the time of crash. Location should be selected by considering crashworthiness as well. If location is not adequate then, it will damage to crashworthiness properties of our design.

73 .

To reduce production cost there should be _____

A)

more forging

B)

commonality of parts

C)

decrease commonality of parts

D)

increment in forge and labour requirements

Correct Answer : commonality of parts

Explanation : Commonality of parts will reduce the production cost. An increase in forgings will increase cost. Forge and labour requirements will increase the cost as well.

74 .

Following diagram represents ____

A)

poor production break design

B)

best production brake design

C)

preferred production break design

D)

structural cut out as per production cost concern

Correct Answer : poor production break design

Explaination : A good designer will consider the location of sub-assembly breaks. They will try to avoid placing components across these breaks. If it is not considered then, it will cause problems during production such as shown in the above figure. Here, the landing gear is across production break.

75 .

Aircraft production cost is related to __________

A)

size only

B)

weight only

C)

material only

D)

weight, size, material, etc

Correct Answer : weight, size, material, etc

Explanation : Aircraft production cost is based on its weight, material used, its size and volume etc. Production cost is affected by number of processes, sub-assembly etc. Only weight is not responsible for cost.

76 .

Aircraft production cost can be reduced by using _______

A)

flat wrap surfaces

B)

non-flat surface

C)

more forging processes

D)

welding only on non-flat surfaces

Correct Answer : flat wrap surfaces

Explanation : Flat wrap surface is used to reduce the effort and cost of the structure. In flat wrapping, we can directly wrap a sheet on our surface. This can significantly lower the aircraft production cost.

77 .

_______ are one of the most expensive type of structure in general.

A)

Lifting only

B)

Non-lifting only

C)

Forging

D)

Only high speed bodies

Correct Answer : Forging

Explanation : Forgings are considered as most expensive type of structure. Whenever a high load is passing through small area might require forgings. Forgings are used in wing-sweep pivots, landing gear struts etc.

78 .

To simplify routing requirements we can provide ________

A)

routing tunnels

B)

structural break

C)

reducing lift at cruise

D)

increasing cruise weight

Correct Answer : routing tunnels

Explanation : To simplify the routing we can provide a routing tunnel. Structural break or cut out is based on structural requirements. Cruise lift has no direct effect for given problem of routing.

79 .

Following diagram represents ______

A)

avionics only

B)

typical routing tunnel

C)

typical non-routing

D)

non routing member

Correct Answer : typical routing tunnel

Explaination : Above figure is showing a typical routing tunnel. An external type is shown in above figure. As shown it is running along the a/c spine. Routing tunnel will help to simplify the complexity of routing.

80 .

What is Maintainability?

A)

Vulnerability

B)

RCS detection

C)

The ease with which the aircraft can be fixed

D)

The ease with which the aircraft can sustain damage

Correct Answer : The ease with which the aircraft can be fixed

Explanation : Maintainability is defined as the ease with which the aircraft can be repaired or fixed. Vulnerability is related to damage taken. RCS detection is nothing but radar detection.

81 .

R&M are measured in?

A)

RCS of system

B)

Maintenance man-hours per flight hour

C)

Vulnerable area

D)

Maintenance and research

Correct Answer : Maintenance man-hours per flight hour

Explanation : Reliability and maintainability or R&M are often used together. It is measured in Maintenance man-hours per flight hour (MMH/FH). MMH/FH varies with the type of aircraft. For small aircraft, it is typically less than 1.

82 .

What is the Major Key parameter of maintainability?

A)

RCS

B)

Survival

C)

Vulnerability

D)

Accessibility

Correct Answer : Accessibility

Explanation : Maintainability will be affected by accessibility. Survival is characteristic of vulnerability consideration. RCS is a term used in radar detection. Vulnerability is based on combat damage.

83 .

Engine access doors should be such that?

A)

They don’t allow maintenance at all

B)

Only tiny part of engine is exposed during maintenance

C)

No provision is made for them; we need to dissemble the whole engine

D)

They allow most of the engine to be exposed for maintenance

Correct Answer : They allow most of the engine to be exposed for maintenance

Explanation : Engine doors should be such that they allow most of the engine to get exposed during maintenance. This will reduce the effort of removing other components. Therefore, it will improve maintainability considerations of the engine.

84 .

What is preventive maintenance?

A)

Maintenance done before breakdown of component

B)

Unscheduled maintenance

C)

Same as corrective maintenance

D)

Not a valid type of maintenance

Correct Answer : Maintenance done before breakdown of component

Explanation : When maintenance is done at given pre-defined period of time, before breakdown then it is called preventive maintenance. It has goal to reduce breakdown of components. Unscheduled is not done at pre-defined time.

85 .

What is corrective maintenance?

A)

Scheduled maintenance

B)

Pre break down maintenance

C)

Maintenance of equipment after failure or break down

D)

Maintenance before break down

Correct Answer : Maintenance of equipment after failure or break down

Explanation : Corrective maintenance is done after breakdown or failure. Maintenance done before breakdown is called preventive maintenance. Scheduled maintenance is similar to preventive.

86 .

Which of the following can be considered as the worst feature of an aircraft in terms of maintainability?

A)

Easily reachable parts

B)

Requirements of removing number of major structural elements

C)

Easily accessible parts

D)

More accessibility is provided for components

Correct Answer : Requirements of removing number of major structural elements

Explanation : Easily accessible and reachable parts are primary requirement of maintainability considerations. Accessibility directly affects the effort and maintainability of an aircraft. If a design requires removal of major structural elements to access the component then, it is considered as the worst design based on maintainability.

87 .

What is the goal of preventive maintenance?

A)

Increase equipment failure

B)

To reduce breakdowns of critical equipment

C)

To increase breakdowns of critical equipment

D)

Not to provide maintenance at a given period of time

Correct Answer : To reduce breakdowns of critical equipment

Explanation : Maintenance can be divided into different types. Preventive is one of the type of maintenance. It is done with the goal of reducing critical equipment breakdown. It is done periodically and very well planned.