126 + Interview Questions in Performance And Flight Mechanics in Aircraft Design Page 2 InterviewSolution

51.	A prop driven aircraft has propeller efficiency of 0.92 and C as 0.000745 1/m. If lift to drag ratio is 14 and weight fraction as 1.145 then, find range of the propeller driven aircraft.(a) 2340.95m(b) 2340.5miles(c) 2340km(d) 2500milesI have been asked this question by my college professor while I was bunking the class.The query is from Flight Mechanics topic in section Performance and Flight Mechanics of Aircraft Design
Answer» Right answer is (a) 2340.95m To ELABORATE: PROP RANGE = (lift to DRAG)[PROPELLER efficiency/C]ln (weight fraction) = 14[0.92/0.000745]ln (1.145) = 2340.95m.

Discussion

52.	Graphical representation of sink rate of sailplane is called ____________(a) typical speed polar(b) drag polar wing(c) lift curve of wing(d) propulsion systemsI have been asked this question in class test.This intriguing question originated from Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design
Answer» Correct choice is (a) TYPICAL speed polar To explain: The graphical REPRESENTATION of sink RATE for sailplane is called speed polar. Speed polar is also known as hodograph. Drag polar is graphical representation of drag characteristics. LIFT curve is used to provide RELATIONSHIP between lift and angle of attack.

Discussion

53.	Determine the value of turn rate. Consider glider has centripetal acceleration of 10 and velocity of 9.5.(a) 1.052(b) 9.5(c) 10(d) 2.8The question was posed to me in a job interview.Origin of the question is Flight Mechanics topic in portion Performance and Flight Mechanics of Aircraft Design
Answer» The CORRECT ANSWER is (a) 1.052 Explanation: TURN rate = centripetal acceleration/velocity = 10/9.5 = 1.052 unit.

Discussion

54.	Which of the following is not part of takeoff?(a) Ground roll(b) Transition(c) Climb(d) DescendingI got this question in an online quiz.Query is from Flight Mechanics in portion Performance and Flight Mechanics of Aircraft Design
Answer» The correct choice is (a) GROUND roll Explanation: Takeoff segment is SUBDIVIDED into number INDIVIDUAL segments or SECTIONS. These segments are ground roll, transition, climb etc. Descending is not the PART of takeoff.

Discussion

55.	The distance shown by ‘?’ in the following diagram is termed as __________(a) flare distance(b) loiter(c) cruise(d) climbThis question was posed to me during an online interview.This intriguing question originated from Flight Mechanics topic in division Performance and Flight Mechanics of Aircraft Design
Answer» Correct option is (a) flare distance To EXPLAIN: Above diagram is illustrating TYPICAL LANDING phase of the AIRCRAFT. As SHOWN in the diagram flare distance is marked by ‘?’. Aircraft will decelerate from Approach speed to touchdown speed during flare.

Discussion

56.	Following diagram represents _________(a) lift induced thrust required(b) zero lift thrust required(c) drag polar(d) lift curveThe question was asked in an online interview.I want to ask this question from Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design
Answer» RIGHT option is (a) LIFT induced thrust required Best explanation: Para below it Lift induced thrust required is shown in the diagram. Lift induced thrust required and zero lift thrust required are not EQUAL, they are two different properties. Lift curve and drag polar is USED to provide information of the lift variation and drag variation respectively.

Discussion

57.	Determine the value of fuel burned during steady climb if SFC C is 0.000029 per second, thrust is 150KN and time required is 1500s.(a) 6.525 KN(b) 100N(c) 345(d) 87.87 NThe question was asked in my homework.This question is from Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design
Answer» Correct OPTION is (a) 6.525 KN The best I can EXPLAIN: Fuel burned = SFCThrustTime = 0.0000291501500*1000 = 6.525KN.

Discussion

58.	Corner speed is defined as __________(a) velocity for maximum instantaneous turn(b) maximum lift velocity(c) maximum aerodynamic efficiency(d) minimum instantaneous turn speedThis question was addressed to me in an internship interview.This interesting question is from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design
Answer» Right ANSWER is (a) velocity for maximum instantaneous TURN The best I can explain: Velocity for maximum instantaneous turn is TERMED as corner speed. Corner speed is defined by intersection of the stall limit and the Structural limit. For a TYPICAL fighter, corner speed can vary between 300 to 350 knots.

Discussion

59.	The highest altitude where Ps is zero is called ________(a) absolute ceiling(b) drag polar(c) geometric height(d) geometric altitudeThis question was posed to me in an international level competition.The origin of the question is Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» Right ANSWER is (a) absolute ceiling Explanation: Absolute ceiling is defined as the highest altitude at where Ps is ZERO. GEOMETRIC height or geometric altitude is based on height measured. Drag POLAR is GRAPHICAL representation of drag properties.

Discussion

60.	Determine total pressure if static pressure is 1600psf and Mach number is 1.8. Consider flow of air.(a) 9193.2 psf(b) 1000 psf(c) 3450 psf(d) 7892 psfI have been asked this question in an online quiz.I'd like to ask this question from Flight Mechanics topic in division Performance and Flight Mechanics of Aircraft Design
Answer» The CORRECT choice is (a) 9193.2 PSF To elaborate: Total pressure = STATIC pressure[1+0.2Mach NUMBERMach number]^3.5 = 1600[1+0.21.81.8]^3.5 = 16001.648^3.5 = 9193.2 psf.

Discussion

61.	An aircraft has L/D as 12 and thrust required at this value is 100N. Now if L/D has doubled then what will be the new thrust required?(a) 50N(b) 500N(c) 100 N(d) 12.5NI had been asked this question in a national level competition.This is a very interesting question from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» CORRECT option is (a) 50N Explanation: Given, 1: L/D = 12 and thrust required T1 = 100N Now, L/D is doubled. Hence, new thrust required T2 = T1(old L/D) / (New L/D) = 10012/212 = 10012/24 = 50N.

Discussion

62.	If my aircraft is in steady level flight and has thrust of 100 unit then, what will be the approximate value of time Easter if change of aircraft weight. Consider SFC as C unit.(a) -100C(b) 1000(c) 1.25(d) 5.43This question was posed to me in an interview for job.My question is from Flight Mechanics in section Performance and Flight Mechanics of Aircraft Design
Answer» Right OPTION is (a) -100C Easiest explanation: Given, thrust T = 100 unit and SFC = C unit. Now, TIME rate of change of AIRCRAFT weight = -CT = -100C = -100C.

Discussion

63.	If an aircraft is in steady level flight and weighs 2500 kg then, find lift at the given flight condition.(a) 24.525KN(b) 24525kg(c) 2500 N(d) 35000kgThe question was posed to me by my school principal while I was bunking the class.The doubt is from Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design
Answer» CORRECT option is (a) 24.525KN To explain I would SAY: Given, a steady LEVEL FLIGHT and MASS m = 2500kg Lift = mg = 25009.81=24525N = 24.525 KN.

Discussion

64.	Find the approximate value of velocity of best climb. Consider Thrust loading as 1.08, wing loading as 377 unit, CD0 as 0.025, K as 0.0075 and sea level density as 1.225 unit.(a) 98.46(b) 37.45(c) 12.1(d) 189.982The question was asked in homework.Question is taken from Flight Mechanics topic in division Performance and Flight Mechanics of Aircraft Design
Answer» Correct ANSWER is (a) 98.46 For EXPLANATION: Given, THRUST loading T = 1.08, WING loading w=377, CD0=0.025, K = 0.0075, density d=1.225 unit Velocity of best climb = \(\sqrt{\frac{w[T+\sqrt{T^2+12CD0K}]}{3dCD0}}\) = \(\sqrt{\frac{377[1.08+\sqrt{1.08^2+120.0250.0075}]}{31.2250.025}}\) = \(\sqrt{4488.092.16}\) = 98.46 unit.

Discussion

65.	A glider has aspect ratio of 20 and CD0 of 0.02. In order to attain maximum range, determine the value required aerodynamic efficiency. Take e as 1.(a) 28.02(b) 20(c) 30(d) 43This question was addressed to me in my homework.My doubt stems from Flight Mechanics topic in section Performance and Flight Mechanics of Aircraft Design
Answer» Correct ANSWER is (a) 28.02 To explain: AERODYNAMIC efficiency= 0.5(πEaspect ratio/CD0)^0.5 = 0.5(π120/0.02)^0.5 = 28.02.

Discussion

66.	Find the velocity required for maximum range. Consider a sailplane has wing loading of 110N/m^2 and K/CD0 of 0.35.(a) 10.3m/s(b) 10.3mph(c) 12.5mph(d) 9.2mphI have been asked this question during a job interview.My question comes from Flight Mechanics in section Performance and Flight Mechanics of Aircraft Design
Answer» Correct option is (a) 10.3m/s Easy EXPLANATION: VELOCITY = \(\sqrt{\FRAC{2wing \,LOADING\sqrt{K/CD0}}{density}}\) = \(\sqrt{\frac{2110\sqrt{0.35}}{1.225}}\) = \(\sqrt{106.24}\) = 10.3 m/s.

Discussion

67.	Which of the following is incorrect?(a) Operating envelope will give same values for all the aircraft(b) Load factor at cruise is unity(c) Lift is same as weight during cruise(d) Wing loading is not same as thrustI got this question by my college director while I was bunking the class.I'm obligated to ask this question of Flight Mechanics topic in division Performance and Flight Mechanics of Aircraft Design
Answer» Correct option is (a) OPERATING envelope will give same values for all the aircraft For explanation: LOAD FACTOR is defined as ratio of lift to weight. At cruise lift and weight both are equal. HENCE, at cruise load factor is unity. Wing loading and THRUST are two different things. Wing loading is ratio of weight by reference area.

Discussion

68.	A propeller aircraft has wing loading of 30 unit and is operating with density of 1.21 unit. Determine velocity for maximum loiter. Consider K/CD0 as 0.1.(a) 3unit(b) 5unit(c) 9unit(d) 10unitI have been asked this question by my college professor while I was bunking the class.This is a very interesting question from Flight Mechanics topic in division Performance and Flight Mechanics of Aircraft Design
Answer» RIGHT answer is (a) 3unit The best explanation: Maximum loiter VELOCITY = \(\SQRT{\FRAC{2wing \,loading\sqrt{\frac{K}{3CD0}}}{density}}\) = \(\sqrt{\frac{230\sqrt{0.1/3}}{1.21}} = \sqrt{49.58*0.1816}\) = 3 unit.

Discussion

69.	If an aircraft can slow down during turn then, it is termed as __________(a) instantaneous turn(b) non instantaneous turn(c) straight flight(d) cruise segmentI had been asked this question in an interview for internship.My doubt stems from Flight Mechanics topic in portion Performance and Flight Mechanics of Aircraft Design
Answer» The correct option is (a) instantaneous turn To elaborate: If an AIRCRAFT can slow down during turn then, it is termed as Instantaneous turn. Here, LOAD factor will be limited by maximum lift coefficient or structural strength of the aircraft. Cruise SEGMENT is PART of mission profile of an aircraft. At cruise all forces and moments are BALANCED.

Discussion

70.	Which of the following is correct in terms of fate of climb (R/C)?(a) R/C = excess power/weight(b) R/C = lift/drag(c) R/C = excess lift/drag(d) R/C = excess power/Thrust requiredThe question was asked during an online interview.The above asked question is from Flight Mechanics topic in portion Performance and Flight Mechanics of Aircraft Design
Answer» Correct choice is (a) R/C = excess power/weight The best explanation: RATE of climb is NOTHING but the vertical velocity of the AIRCRAFT. Rate of climb can be DEFINED as the ratio of excess power of the aircraft to the aircraft weight. Hence, Correct relation between rate of climb and power is as follows: R/C = excess power/weight. Where, R/C = rate of climb.

Discussion

71.	Determine the value of best glide ratio velocity. Consider velocity for minimum sink rate is 10 fps.(a) 13.15 fps(b) 20 fps(c) 11 fps(d) 34 fpsI got this question in an interview for internship.I need to ask this question from Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design
Answer» Correct option is (a) 13.15 fps For EXPLANATION I would say: GIVEN, velocity for minimum sink rate v = 10 fps Velocity for BEST glide ratio = v/0.76 = 10/0.76 = 13.15 fps.

Discussion

72.	The aircraft _____________ during a sustained turn.(a) cannot be slowed down(b) can be slowed down(c) can lower its velocity(d) can increase lofting process effortI had been asked this question during an interview.This interesting question is from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» Correct OPTION is (a) cannot be slowed down To elaborate: In sustained turn, aircraft is not allowed to SLOW down. During sustained turn aircraft cannot be slowed down or LOSE altitude during turn. In sustained turn thrust has to be equal to the DRAG. Lift is load factor times weight.

Discussion

73.	If aerodynamic efficiency of the glider is 20 then, found the value of corresponding glide angle.(a) 2.86 unit(b) 3.8(c) 5.6(d) 12.12This question was addressed to me in my homework.I would like to ask this question from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» CORRECT CHOICE is (a) 2.86 UNIT Explanation: Glide ANGLE = ARCTAN (1/Aerodynamic efficiency) = arctan (1/20) = 2.86 unit.

Discussion

74.	If a glider needs to be flown at maximum range then, at which value of CL we should fly this glider? Consider CD0/K is 2.8.(a) 1.67(b) 3.2(c) 5.6(d) 2.5I had been asked this question in class test.Query is from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» RIGHT OPTION is (a) 1.67 The BEST EXPLANATION: CL = [CD0/K] ^0.5 = 2.8^0.5 = 1.67.

Discussion

75.	Which of the following is required condition of thrust required minimum?(a) CL = (CD0/K)^0.5(b) CL = (CD0)0.21(c) CL = (CD0/K)1.5(d) CL = 0.5The question was posed to me in an interview for internship.The question is from Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design
Answer» Right choice is (a) CL = (CD0/K)^0.5 To elaborate: At cruise Thrust required is same as drag PRODUCED by the AIRCRAFT. Now, to operate the aircraft at Thrust required minimum then, aircraft should be operated with CERTAIN value of lift coefficient. Such value can be determined by using following relation: CL = (CD0/K)^0.5 Where, CL is minimum Thrust required lift coefficient, CD0 is PARASITE drag coefficient and K is induced drag CONSTANT.

Discussion

76.	During level turning operation my aircraft has load factor of 2. Find the required bank angle for this level turning operation.(a) 60°(b) 60rad(c) 120rad(d) 2.1radThis question was addressed to me in an interview for job.My query is from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design
Answer» The correct CHOICE is (a) 60° The explanation: BANK angle = arccosine (1/load FACTOR) = arccosine (1/2) = arccosine 0.5 = 60°.

Discussion

77.	Final velocity at the end of the landing phase will be ____________(a) zero(b) same as Approach speed(c) touchdown speed(d) same as climb rateI had been asked this question during an online exam.The origin of the question is Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design
Answer» Correct answer is (a) zero The best EXPLANATION: FINAL velocity at the end of the aircraft landing phase will be zero. It is not EQUAL to approach speed. Touchdown speed is achieved during FLARE segment. Rate of climb is VERTICAL velocity of the aircraft.

Discussion

78.	Following diagram represents __________(a) zero specific power Contour(b) zero lift(c) zero drag(d) drag at zero liftThis question was addressed to me in my homework.I need to ask this question from Flight Mechanics in section Performance and Flight Mechanics of Aircraft Design
Answer» Right answer is (a) zero specific power CONTOUR For explanation: Above diagram is ILLUSTRATING the concept of zero specific power Contour. As shown in the diagram, zero specific power Contours are plotted for different values of load factor. This chart is ONE of the major tools for EVALUATION of new fighters.

Discussion

79.	If power required at sea level altitude is 2005W then, determine power required at altitude at which density ratio is 0.9.(a) 2.113KW(b) 211115W(c) 2354W(d) 500WI got this question during an internship interview.I'm obligated to ask this question of Flight Mechanics in section Performance and Flight Mechanics of Aircraft Design
Answer» CORRECT OPTION is (a) 2.113KW To elaborate: POWER at altitude = Sea-level power[1/density ratio]^0.5 = 2005[1/0.9]^0.5 = 2113.45W = 2.113KW.

Discussion

80.	Following diagram represents _____________(a) sustained turn rate envelope(b) instantaneous turn rate(c) power required diagram at 3 km(d) lift curve for wingThis question was addressed to me during an interview.I'd like to ask this question from Flight Mechanics topic in section Performance and Flight Mechanics of Aircraft Design
Answer» The correct answer is (a) sustained TURN RATE envelope Explanation: Above DIAGRAM is ILLUSTRATING the concept of turn rate. Typical sustained turn rate at an altitude is shown in the diagram. Above diagram is illustrating the concept of Sustained turn rate envelope.

Discussion

81.	Term marked by ’?’ in the following diagram is called __________(a) corner speed(b) dive speed(c) cruise speed(d) free stream velocityI got this question in a national level competition.I'd like to ask this question from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design
Answer» Correct answer is (a) corner speed The best explanation: Above diagram is SHOWING a typical relationship between turn rate and velocity. Above diagram is illustrating the concept of corner speed. Corner speed is velocity required for maximum INSTANTANEOUS turn. Cruise speed of an aircraft is speed required to ATTAIN cruise CONDITION or steady LEVEL flight.

Discussion

82.	Determine static pressure if external flow dynamic pressure is 1800psf and flow has Mach number of 2.(a) 642.857psf(b) 1000psf(c) 2400 psf(d) 4673 psfI got this question in unit test.This interesting question is from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» The CORRECT answer is (a) 642.857psf The EXPLANATION: Static PRESSURE = DYNAMIC pressure / (0.7Mach number^2) = 1800 / (0.72^2) = 642.857 psf.

Discussion

83.	Consider external flow dynamic pressure as 2000psf and static pressure as 800psf. find the approximate value of Mach number.(a) 1.9(b) 5(c) 4.5(d) 2.78The question was asked in exam.My enquiry is from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design
Answer» CORRECT answer is (a) 1.9 Explanation: Mach NUMBER = (dynamic pressure / (0.7STATIC pressure))^0.5 = (2000 / (0.7800))^0.5 = 3.571^0.5 = 1.88 = 1.9.

Discussion

84.	An aircraft is designed to be in steady level flight with weight of 1500N and CL of 1.0. Determine at which speed we need to design this aircraft so that it can achieve this requirement. Consider density as 1.2 kg/m^3 and reference area as 2m^2.(a) 35.35m/s(b) 56m/min(c) 56m/s(d) 70km/sThis question was addressed to me during an interview for a job.This question is from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» Right option is (a) 35.35m/s Easy EXPLANATION: Given, STEADY level flight. Weight W=1500N, CL=1.0, density = 1.2kg/m^3, reference area S=2m^2. Now, velocity is given by, V = \(\sqrt{\FRAC{2W}{densitySCL}}\) = \(\sqrt{\frac{21500}{1.21.02}}\)= 35.35m/s.

Discussion

85.	A jet engine is designed to operate at endurance of 12hrs. If weight fraction is 1.6 and jet engine has tsfc C as 0.00021 per second then, find at which lift to drag ratio that can satisfy above criteria.(a) 19.3(b) 18(c) 12(d) 12.6The question was asked in homework.This intriguing question originated from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design
Answer» The CORRECT answer is (a) 19.3 To explain: Lift to drag RATIO = EnduranceC/LN (weight FRACTION) = 123600*0.00021 / ln 1.6 = 9.072/0.47 = 19.3.

Discussion

86.	What do you mean by rate of climb?(a) Vertical velocity of an aircraft(b) Lift of an aircraft(c) Thrust required(d) Drag polarThe question was posed to me in an interview for job.My question is based upon Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» CORRECT answer is (a) Vertical VELOCITY of an aircraft To explain I would say: Rate of climb is nothing but the vertical velocity of aircraft. It is the CLIMBING rate of an aircraft. LIFT is an aerodynamic force which holds the aircraft in the air. Weight is the force ACTING due to gravity. Thrust is propulsive force.

Discussion

87.	Falling diagram represents _________(a) operating envelope(b) lift curve(c) tire sizing(d) empty weight diagramThe question was asked by my college professor while I was bunking the class.My question comes from Flight Mechanics topic in division Performance and Flight Mechanics of Aircraft Design
Answer» RIGHT choice is (a) operating envelope The explanation: Operating envelope is SHOWN in the above DIAGRAM. Above diagram is typically used for fighter aircraft. Fighter operating envelope is one of the COMPLEX type of diagram. Lift curve is used to PROVIDE relationship between lift and angle of attack.

Discussion

88.	An aircraft is in sustained turn with thrust loading of 0.8 and aerodynamic efficiency of 6. Determine the approximate value of maximum load factor.(a) 4.8(b) 3(c) 1(d) 12I had been asked this question in an online interview.This interesting question is from Flight Mechanics in section Performance and Flight Mechanics of Aircraft Design
Answer» Correct option is (a) 4.8 To ELABORATE: Maximum load FACTOR = thrust loadingAERODYNAMIC efficiency=0.86 = 4.8.

Discussion

89.	Sink rate can be used to ____________(a) determine the time a glider may remain in the air(b) determine and estimate takeoff gross weight(c) estimate only wing loading(d) calculate weight to thrust ratioI got this question in an interview for internship.Question is from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» Right answer is (a) determine the time a glider may REMAIN in the air To ELABORATE: The time a glider may remain in the air can be determined by using the sink rate. Sink rate is the product of AIRCRAFT velocity and sine of the glide ANGLE. It is the VERTICAL velocity.

Discussion

90.	Consider turning gliding flight. Turn rate is given as 0.2 unit and velocity of flight is 10 unit. Find the value of turn radius.(a) 50(b) 100(c) 2(d) 8I have been asked this question in a job interview.This interesting question is from Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design
Answer» Correct ANSWER is (a) 50 The EXPLANATION: Turn RADIUS = velocity/turn rate = 10/0.2 = 50 UNIT.

Discussion

91.	Determine the value of drag at which we can have minimum power if given reference area is 10m^2 and zero lift drag coefficient is 0.5. Consider q as 120Pa.(a) 2400N(b) 1.25(c) 9.85(d) 4500 KNThe question was asked during an online interview.Asked question is from Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design
Answer» Correct option is (a) 2400N The explanation is: DRAG at minimum power = Qarea[4ZERO lift drag coefficient] = 1201040.5 = 2400N.

Discussion

92.	Ratio of vertical distance travelled to the horizontal distance travelled is known as __________(a) climb gradient(b) lift curve slope(c) power required(d) thrust lossI got this question in unit test.Asked question is from Flight Mechanics topic in section Performance and Flight Mechanics of Aircraft Design
Answer» Right choice is (a) climb gradient For explanation I WOULD say: Ratio of vertical DISTANCE travelled to the horizontal distance travelled is known as Climb gradient. Lift curve SLOPE is change lift coefficient to the change in angle of ATTACK. Power required is product of THRUST required and velocity of the aircraft.

Discussion

93.	Total energy of an aircraft is defined as ____________(a) sum of the potential and kinetic energy(b) total kinetic energy only(c) total potential energy only(d) product of kinetic and potential energyThis question was addressed to me in an online quiz.The question is from Flight Mechanics topic in section Performance and Flight Mechanics of Aircraft Design
Answer» Correct choice is (a) SUM of the potential and kinetic energy To explain I WOULD SAY: At any given point in time, the total energy of the aircraft or energy state of an aircraft is the sum of the potential energy and kinetic energy. Kinetic energy is EQUAL to half of product of MASS and square of velocity.

Discussion

94.	Following diagram represents _________(a) turn rate and specific power relations(b) turn radius only(c) power loading vs height(d) altitude effects on thrustThe question was posed to me in final exam.This intriguing question comes from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design
Answer» The CORRECT choice is (a) turn rate and specific power RELATIONS For explanation: Typical turn rate and specific power relations can be OBSERVED in the DIAGRAM. Power loading is defined as the ratio of weight of the aircraft to the aircraft power. It is used to provide INFORMATION about performance of the aircraft.

Discussion

95.	Find the range of glider which has L/D of 13.6 and is descending from 5km.(a) 68km(b) 12 m(c) 12 inch(d) 68 mThe question was asked in a job interview.The doubt is from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design
Answer» RIGHT answer is (a) 68KM Easiest EXPLANATION: Range = altitudeL/D = 513.6 = 68km.

Discussion

96.	If a Maneuver requires specific power of 1200 unit then, find the approximate value of fuel specific energy. Given thrust as 1000 unit and tsfc of 0.00042 unit.(a) 2857.14 unit(b) 1568.45 unit(c) 4500 unit(d) 6789 unitThe question was asked during an interview for a job.This question is from Flight Mechanics topic in division Performance and Flight Mechanics of Aircraft Design
Answer» The correct choice is (a) 2857.14 unit For EXPLANATION I would SAY: Fuel SPECIFIC ENERGY = specific POWER / (thrusttsfc) = 1200/10000.00042 = 2857.14 unit.

Discussion

97.	If our design has takeoff velocity of 120 knots then, at which value of stall speed we should design our aircraft?(a) 109.08knots(b) 110 knots(c) 150 knots(d) 125 knotsThis question was addressed to me by my college director while I was bunking the class.I need to ask this question from Flight Mechanics topic in division Performance and Flight Mechanics of Aircraft Design
Answer» CORRECT answer is (a) 109.08knots To ELABORATE: STALL speed = 0.909Takeoff speed = 0.909120 = 109.08 knots.

Discussion

98.	Following diagram represents ____________(a) typical landing analysis segments(b) takeoff phase(c) climbing(d) takeoff ground rollI have been asked this question in a job interview.My query is from Flight Mechanics in portion Performance and Flight Mechanics of Aircraft Design
Answer» Right option is (a) TYPICAL LANDING analysis segments Explanation: Above diagram is showing typical landing phase of an aircraft. As shown in the diagram landing phase is subdivided into NUMBER of segments such as flare DISTANCE, Approach distance etc. Takeoff ground roll is a segment of takeoff phase. Takeoff phase includes ground roll, transition, CLIMB etc.

Discussion

99.	Determine the value of FAR field length. Consider approach of 100 ft., flare of 120 feet and ground roll of 600ft.(a) 1366.12(b) 109(c) 600(d) 700I have been asked this question in quiz.The query is from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design
Answer» RIGHT choice is (a) 1366.12 The EXPLANATION: FAR field length = 1.666(approach + FLARE + ground ROLL) = 1.666(100 + 120 + 600) = 1366.12.

Discussion

100.	If load factor of level turning flight is found to be 1.2 and flight speed is 120m/s then, determine turn rate.(a) 3.107 degree/s(b) 1.2 rad/s(c) 0.03 rad per second(d) 1.2The question was posed to me by my college director while I was bunking the class.I would like to ask this question from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design
Answer» Right answer is (a) 3.107 degree/s The explanation: GIVEN, load factor n=1.2, FLIGHT SPEED V=120m/s Turn rate = \(\FRAC{g\sqrt{n^2-1}}{v}\) = \(\frac{9.81\sqrt{1.2^2-1}}{120}\) = 0.054 rad/s = 3.107 degree/s.

Discussion

Explore topic-wise InterviewSolutions in .

Determine the value of turn rate. Consider glider has centripetal acceleration of 10 and velocity of 9.5.(a) 1.052(b) 9.5(c) 10(d) 2.8The question was posed to me in a job interview.Origin of the question is Flight Mechanics topic in portion Performance and Flight Mechanics of Aircraft Design

Which of the following is not part of takeoff?(a) Ground roll(b) Transition(c) Climb(d) DescendingI got this question in an online quiz.Query is from Flight Mechanics in portion Performance and Flight Mechanics of Aircraft Design

Following diagram represents _________(a) lift induced thrust required(b) zero lift thrust required(c) drag polar(d) lift curveThe question was asked in an online interview.I want to ask this question from Flight Mechanics in chapter Performance and Flight Mechanics of Aircraft Design

If a glider needs to be flown at maximum range then, at which value of CL we should fly this glider? Consider CD0/K is 2.8.(a) 1.67(b) 3.2(c) 5.6(d) 2.5I had been asked this question in class test.Query is from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design

Following diagram represents __________(a) zero specific power Contour(b) zero lift(c) zero drag(d) drag at zero liftThis question was addressed to me in my homework.I need to ask this question from Flight Mechanics in section Performance and Flight Mechanics of Aircraft Design

Determine static pressure if external flow dynamic pressure is 1800psf and flow has Mach number of 2.(a) 642.857psf(b) 1000psf(c) 2400 psf(d) 4673 psfI got this question in unit test.This interesting question is from Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design

Consider external flow dynamic pressure as 2000psf and static pressure as 800psf. find the approximate value of Mach number.(a) 1.9(b) 5(c) 4.5(d) 2.78The question was asked in exam.My enquiry is from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design

What do you mean by rate of climb?(a) Vertical velocity of an aircraft(b) Lift of an aircraft(c) Thrust required(d) Drag polarThe question was posed to me in an interview for job.My question is based upon Flight Mechanics in division Performance and Flight Mechanics of Aircraft Design

Falling diagram represents _________(a) operating envelope(b) lift curve(c) tire sizing(d) empty weight diagramThe question was asked by my college professor while I was bunking the class.My question comes from Flight Mechanics topic in division Performance and Flight Mechanics of Aircraft Design

Find the range of glider which has L/D of 13.6 and is descending from 5km.(a) 68km(b) 12 m(c) 12 inch(d) 68 mThe question was asked in a job interview.The doubt is from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design

Following diagram represents ____________(a) typical landing analysis segments(b) takeoff phase(c) climbing(d) takeoff ground rollI have been asked this question in a job interview.My query is from Flight Mechanics in portion Performance and Flight Mechanics of Aircraft Design

Determine the value of FAR field length. Consider approach of 100 ft., flare of 120 feet and ground roll of 600ft.(a) 1366.12(b) 109(c) 600(d) 700I have been asked this question in quiz.The query is from Flight Mechanics topic in chapter Performance and Flight Mechanics of Aircraft Design