Aircraft Design Mcqs - Set 1

1)   What is the initial phase of an Aircraft Design?

a. Conceptual Design
b. Preliminary Design
c. Detail Design
d. Sizing
Answer  Explanation 

ANSWER: Conceptual Design

Explanation:
Initial Phase of an Aircraft begins with the Conceptual Design. Preliminary design deals with the modelling. Detailed design is responsible for actual layout.


2)   The whole Design philosophy of an Aircraft is termed as _____

a. design wheel
b. anatomy
c. design evaluation
d. sizing
Answer  Explanation 

ANSWER: design wheel

Explanation:
The whole Design philosophy of an Aircraft is called Design Wheel. The design processes as per the design wheel are then divided into different phases of Aircraft design such as sizing.


3)   The requirements of an Aircraft will fall in ______ phase.

a. surface requirement
b. preliminary design
c. detail design
d. conceptual design
Answer  Explanation 

ANSWER: conceptual design

Explanation:
The requirements of an Aircraft is very basic question in whole process. Such basic questions are part of the conceptual design phase. Sizing and detail data will be put at later stages.


4)   Which are the phases of Aircraft Design process?

a. Conceptual Design only
b. Conceptual Design, Preliminary Design and Detail Design
c. Only Preliminary Phase
d. Only Detail Design Phase
Answer  Explanation 

ANSWER: Conceptual Design only

Explanation:
Aircraft design process can be broken into three major phases. These phases are Conceptual Design, Preliminary Design and Detail Design. Each phase deals with distinct subjects.


5)   Which of the following is a correct pair?

a. Testing major parts for fabrication – Conceptual Design
b. Testing major parts for fabrication – Detail Design
c. Testing major parts for fabrication – Preliminary Design
d. Testing major parts for fabrication – Initial Design
Answer  Explanation 

ANSWER: Testing major parts for fabrication – Detail Design

Explanation:
The Detail design is the final stage of any Aircraft. Here, we consider the actual processes for designing from fabrication to manufacturing. Conceptual and preliminary are the intermediate stages of an Aircraft design.


6)   Can we use similar design phases for an Airplane and for a Helicopter?

a. True
b. False
Answer  Explanation 

ANSWER: True

Explanation:
There are 3 phases of any Aircraft Design. These 3 phases are conceptual, preliminary and detail designing. The Airplane and Helicopter both fall into the category of Aircraft so the phases will be similar but with modification as per requirements.


7)   Which of the following is the correct pair in chronological order?

a. Detail Design-Preliminary Design-Conceptual Design
b. Conceptual Design-Preliminary Design-Detail Design
c. Conceptual Design-Detail Design-Preliminary Design
d. Preliminary Design-Detail Design-Conceptual Design
Answer  Explanation 

ANSWER: Conceptual Design-Preliminary Design-Detail Design

Explanation:
The Overall design process of an Aircraft goes through 3 distinct phases in sequence. Any Aircraft is designed based on specific criteria which are called as requirements of Aircraft. Hence, the correct pair in chronological order is Conceptual Design-Preliminary Design-Detail Design.


8)   Which of these is not part of the Conceptual Design phase?

a. Specifications and Requirements
b. Conceptual Drawing
c. First weight estimation
d. Lofting
Answer  Explanation 

ANSWER: Lofting

Explanation:
The Conceptual Design is the first phase of Design. In this phase we are concerned about-What are the requirements? What should be the Weight? Will my design fly? First-order Sizing etc.


9)   The aim of the Preliminary Design stage is to make the company ready for the full scale development.

a. True
b. False
Answer  Explanation 

ANSWER: True

Explanation:
Once, the Conceptual design stage is completed, next stage is Preliminary design. It tests and analyzes the finalized conceptual drawing. If all the parameters met the design criteria then, the final step of this stage is to make company ready for the full scale development.


10)   The main objective of the Preliminary stage is ______

a. manufacture
b. fabrication
c. first order sizing
d. lofting
Answer  Explanation 

ANSWER: lofting

Explanation:
Lofting is one of the main objectives of the preliminary design. Manufacturing and Fabrication are part of the Detail Design. First order sizing is done during the conceptual stage.


11)   What is meant by the term Lofting?

a. Specifications and Requirements
b. Conceptual Drawing
c. Mathematical modelling of the skin
d. Trade study specifications
Answer  Explanation 

ANSWER: Mathematical modelling of the skin

Explanation:
Lofting is defined as the mathematical modelling the outer layer of airframe i.e., skin of Aircraft. Lofting is nothing but defining the shape of the fuselage and overall aircraft. It is one of the main objectives of the Preliminary Design.


12)   How Conceptual Design begins?

a. With predefined requirements or new concept
b. With Fabrication
c. With Lofting
d. With CFD tests
Answer  Explanation 

ANSWER: With predefined requirements or new concept

Explanation:
Conceptual Design is the first and foremost phase of Aircraft Design. Here, the rough design is being prepared based on certain requirements. In some cases it also initiated through new idea or concepts.


13)   Civil and military requirements are same for Conceptual Design.

a. True
b. False
Answer  Explanation 

ANSWER: False

Explanation:
Often civil and military requirements are different from each other. Civil Aircraft are designed for less controllability while military aircrafts are made less stable. Thrust requirements are also different for both.


14)   Which of these cannot be considered as design requirement of prop engine?

a. Range
b. Endurance
c. Take-off and landing
d. Turbine Temperature
Answer  Explanation 

ANSWER: Turbine Temperature

Explanation:
A typical Prop engine is reciprocating engine. Prop engine relies on the power produced through propeller. Range, take-off and landing, endurance etc. are affected by the power generated by the Prop engine. If asked for Turbo-prop then, we can include turbine as well.


15)   The drawing which represents the rough idea of the actual design is called as ______

a. conceptual sketch
b. conceptual elevation
c. conceptual digit
d. conceptual parameter
Answer  Explanation 

ANSWER: conceptual sketch

Explanation:
Based on the general requirements, design engineer makes rough calculations of different parameters during the stage of conceptual design. Based on the initial estimation of weight and performance, engineers will draw a rough sketch having all the required details. Such rough drawing is called conceptual sketch.


16)   The estimation of weight, fuel weight etc. is done by ____ process.

a. sizing
b. drawing
c. lofting
d. drafting
Answer  Explanation 

ANSWER: sizing

Explanation:
Sizing is the process to calculate some performance parameters of aircraft. Lofting is modelling of skin. Drafting and drawing are linked together.


17)   What is the function of ‘first order sizing’?

a. To provide data for initial layout
b. To crate lofting
c. To test model in Fluent
d. To provide manufacturing
Answer  Explanation 

ANSWER: To provide data for initial layout

Explanation:
During the conceptual stage we make a rough sketch called a conceptual sketch. With the help of it we can provide initial estimation of some parameters such as aerodynamics, weight etc. This initial estimation will provide data for the initial layout. Thus, it is called as first order sizing.


18)   The three view drawing which shows arrangements of parts during conceptual design is called as _____

a. lofting
b. planning
c. first order sizing
d. analyzing
Answer  Explanation 

ANSWER: planning

Explanation:
First order sizing is nothing but a three vie drawing base on initial estimated data. The three vie drawing can highlight vital information such as undercarriage location etc.


19)   If design is carried out in CAD software then what should be the scale of design?

a. Full Scale
b. Half Scale
c. Quarter Scale
d. Tenth Scale
Answer  Explanation 

ANSWER: Full Scale

Explanation:
If designer is using computer aided design software then, they are required to design the full scale model. If engineer is using pen-paper then, the appropriate scale is required to draw the drawing for example, 1/15th scale.


20)   Why do we use optimization after initial layout?

a. To provide lowest cost structure
b. To improve highest cost structure
c. To reduce effectivity
d. To lower efficiency
Answer  Explanation 

ANSWER: To provide lowest cost structure

Explanation:
Optimization techniques are used to provide the lightest and most cost effective structure. In other words, it is used to check whether my design is best for given requirements, for given cost constraints.


21)   The Configuration layout is revised after optimization and experiences number of iterations before being finalized for Preliminary Design.

a. True
b. False
Answer  Explanation 

ANSWER: True

Explanation:
If configuration layout is found to be imperfect during optimization then this layout is revised and this process is iterative. It will go to a number of iteration before it passes through the optimization stage. Once, the optimized design is prepared then it can proceed further.


22)   The subsequent step after the requirements in conceptual design phase is _____

a. design take-off gross weight
b. control
c. stability
d. lofting
Answer  Explanation 

ANSWER: design take-off gross weight

Explanation:
The Conceptual design often begins with the mission requirements of the aircraft. Once the requirements are set, next step is to estimate the design take-off gross weight. This is done due to the fact that weight will directly affect the vital performance parameters.


23)   The “Design take-off gross weight” and “maximum take-off weight” are always interchangeable.

a. True
b. False
Answer  Explanation 

ANSWER: False

Explanation:
During the conceptual design process design take-off gross weight is calculated based on requirements. Based on the mission profile we can use terms interchangeably in general. However, it is not the case for each and every mission.


24)   Design take-off gross weight includes ______

a. only fuel weight
b. only crew weight
c. only payload weight
d. crew, payload and fuel weights
Answer  Explanation 

ANSWER: crew, payload and fuel weights

Explanation:
Design take-off gross weight is total weight of the aircraft to be designed. It is the combination of all possible weights of an aircraft. Hence, from the given options, it is easy to say that it includes every type of weight.


25)   Avionics systems are an example of ____ weight.

a. empty
b. crew
c. passenger
d. payload
Answer  Explanation 

ANSWER: empty

Explanation:
Crew weight is the weight of all crew members. Passenger weight includes the weight of the passenger. Empty weight will include avionics, subsystems, power plant etc…


26)   Take-off gross weight of an aircraft is summation of _____

a. empty and payload weight
b. fuel, payload, crew, empty and miscellaneous weight
c. fuel and crew weight
d. only passenger and crew weight
Answer  Explanation 

ANSWER: empty and payload weight

Explanation:
Typically, take-off gross weight is the maximum possible weight of aircraft during take-off. It includes weight of crew, passenger, fuel, empty and some miscellaneous weight.


27)   In general, the fuel weight is represented by a fraction of total take-off weight.

a. True
b. False
Answer  Explanation 

ANSWER: True

Explanation:
For given Aircraft, we know the typical values for crew and payload. However, we do not know fuel weight as well as empty weight. Hence, they are represented in terms of the fraction of total take-off weight. This can simplify the calculation.


28)   A general aviation aircraft is flying with crew load of 115lb, payload of 220lb and fuel weight of 100lb. Find out the design take-off gross weight of the aircraft, given 95lb empty weight.

a. 530lb
b. 241lb
c. 435lb
d. 500lb
Answer  Explanation 

ANSWER: 530lb

Explanation:
Given,
Crew load = 115lb
Payload weight = 220lb
Fuel weight = 100lb
Empty weight = 95lb
Now, the design take – off gross weight is given by,
W0 = Wcrew + Wpayload + Wfuel + Wempty
W0 = 115+220+100+95
So, W0 = 530lb.


29)   A jet airliner aircraft is flying with crew load of 150kg, payload of 520lb and fuel weight of 500lb. Find out the empty weight if design take-off gross weight of the aircraft is given 1525lb.

a. 79kg
b. 79lb
c. 170lb
d. 355lb
Answer  Explanation 

ANSWER: 79kg

Explanation:
Given,
Design take-off gross weight, W0 = 1525lb
Crew load = 150kg = 150*2.205lb = 330.693lb
Payload weight = 520lb, fuel weight = 500lb
Now the design take – off gross weight is given by,
W0 = Wcrew + Wpayload + Wfuel + Wempty
1525 = 330.693 + 520 + 500 + Wempty
So, Wempty = 174.307lb = 79 kg.


30)   Cessna 172R has total gross weight of the 1110.98kg with fuel capacity of 210 kg and weight of crew and passenger is 125kg. Find out empty weight fraction.

a. 775.98kg
b. 69.84kg
c. 0.6984
d. 0.6984lb
Answer  Explanation 

ANSWER: 0.6984

Explanation:
Given,
Design take-off gross weight, W0 = 1110.98kg
Crew and payload weight = 125kg
Fuel weight = 210kg.
Here, first we need to find the empty weight and then we can find empty weight fraction.
Now the design take – off gross weight is given by,
W0 = Wcrew + Wpayload + Wfuel + Wempty
1110.98 = 125 + 210 + Wempty
So, Wempty = 775.98kg
Hence, empty weight fraction = (Wempty / W0) = 775.98/1110.98 = 0.6984.


31)   A Jet transport aircraft is flying with crew load of 175kg, payload of 1400kg and fuel weight of 500kg. Find out Fuel to empty weight fraction, if design take-off gross weight of the aircraft is 5600lb.

a. 1.076
b. 0.1831
c. 0.196
d. 0.1418
Answer  Explanation 

ANSWER: 1.076

Explanation:
Given,
Design take-off gross weight, W0 = 5600lb = 2539.6825kg
Crew load = 175kg
Payload weight = 1400kg, fuel weight = 500kg
Now the design take – off gross weight is given by,
W0 = Wcrew + Wpayload + Wfuel + Wempty
2539.682 = 175+ 1400 + 500 + Wempty
So, Wempty = 464.682kg
Fuel weight fraction = Wfuel / W0
Empty weight fraction = Wempty / W0
Now fuel to empty weight fraction = Wfuel / Wempty = 500/464.682 = 1.076.


32)   What is the typical range for empty weight fraction?

a. 0.3-0.7
b. 0.1-0.125
c. 0.14-0.28
d. 0.25-0.27
Answer  Explanation 

ANSWER: 0.3-0.7

Explanation:
Empty weight fraction has typical range from 0.3-0.7 according to historical guidelines. Higher empty weight fraction indicates more weight. The range given is based on typical guideline and hence in some cases it can go beyond 0.7 as well.


33)   Which of the following is the correct pair?

a. Empty weight fraction is similar to gross weight of the aircraft
b. Empty weight fraction is inversely proportion to gross weight of the aircraft
c. Empty weight fraction is directly proportion to gross weight of the aircraft
d. Empty weight fraction is not related with the gross weight of the aircraft
Answer  Explanation 

ANSWER: Empty weight fraction is inversely proportion to gross weight of the aircraft

Explanation:
Empty weight fraction is nothing but empty weight divided by gross weight of the aircraft. Higher gross weight aircraft has lesser empty weight fraction.


34)   Which of the following pair is correct based on the empty weight fraction?

a. Flying boat-0.77, Jet trainer-0.65
b. Flying boat-0.65, Jet trainer-0.77
c. Flying boat-0.45, Jet trainer-0.65
d. Flying boat-0.3, Jet trainer-1.0
Answer  Explanation 

ANSWER: Flying boat-0.77, Jet trainer-0.65

Explanation:
Here, we need to think logically. The flying boat has more empty weight than the typical jet trainer aircraft. A flying boat needs to carry additional load of boat hull compare to a typical jet trainer aircraft.


35)   A military Aircraft should be designed to have ______

a. lowest possible empty weight fraction
b. highest possible empty weight fraction
c. empty weight fraction higher than 0.89
d. empty weight fraction unity
Answer  Explanation 

ANSWER: lowest possible empty weight fraction

Explanation:
One of the most important and crucial requirements of military aircraft is minimum possible weight. The lower the weight lesser the drag and lesser the thrust requirement. Hence, a military aircraft should as lightest as possible.


36)   Determine the corrections or otherwise of the following assertion [A] and reason [R]:
Assertion [A]: Flying boats have higher values of empty weight fraction than that of the military aircraft.
Reason[R]: Military aircraft has to be lighter in weight.


a. Both [A] and [R] are true and [R] is the correct reason for [A]
b. Both [A] and [R] are true but [R] is not the correct reason for [A]
c. [A] is true but [R] is false
d. [A] is false but [R] is true
Answer  Explanation 

ANSWER: [A] is false but [R] is true

Explanation:
Military aircraft has to be lighter in weight is true. Flying boats are heavier than that of the typical military aircraft. The reason behind it is that flying boat has to carry extra weight of hull. Hence, [A] and [R] both correct but [R] is not the correct reason for given assertion.


37)   Which of the following is true?

a. Lowest possible empty weight fraction in practice is zero
b. F-35 aircraft has the highest possible empty weight fraction
c. Empty weight fraction will be different for different type of aircrafts
d. Empty weight fraction is always same for each aircraft
Answer  Explanation 

ANSWER: Empty weight fraction will be different for different type of aircrafts

Explanation:
Empty weight is weight of the power plant, avionics, sub-system of aircraft etc. Hence, in practical it cannot be zero. F-35 is a military class aircraft which is not designed to have highest possible empty weight fraction. Empty weight fraction is not constant. For, different aircraft, it will be different according to their requirements.


38)   Variable sweep wings have higher empty weight fraction than that of the fixed sweep wing.

a. True
b. False
Answer  Explanation 

ANSWER: True

Explanation:
Variable sweep will require more effort and structural breaks than fixed sweep. Structural break will increase weight. For, variable sweep, variable sweep constant is 1.04 and for fixed sweep it is 1.0.


39)   Aircraft fuel weight does not include reserved fuel fraction.

a. True
b. False
Answer  Explanation 

ANSWER: False

Explanation:
The total fuel carried by aircraft consists of usable fuel and reserved fuel. Useable fuel is provided for completing a particular mission. Reserved fuel is for an emergency.


40)   Total fuel weight of aircraft is ______

a. mission fuel only
b. sum of mission fuel, reserve fuel and trapped fuel
c. sum of trapped and mission fuel
d. reserved fuel only
Answer  Explanation 

ANSWER: sum of mission fuel, reserve fuel and trapped fuel

Explanation:
The fuel weight of aircraft is sum of useable mission fuel, reserved fuel and trapped fuel. Mission fuel is the actual useable fuel for the respective mission. Trapped fuel is unusable fuel which has been trapped in supply lines or which cannot be used.