FEATI University 2nd Aero Departmental Mock Exam (Aerodynamics) PDF

FEATI University 2nd Aero Departmental Mock Exam (Aerodynamics) Name:_________________________________________________________Date:_____________Score:_________ I. Shade the letter of the c...

FEATI University 2nd Aero Departmental Mock Exam (Aerodynamics) Name:_________________________________________________________Date:_____________Score:_________ I. Shade the letter of the correct answer. (Use #2 Pencil) 1. Wing spoilers, when used asymmetrically, are associated with (a) ailerons (c) flaps (b) rudders (d) elevator 2. If an aircraft is yawing to the left, where would you position the trim tab on the rudder? (a) center (c) left (b) right (d) down 3. With respect to differential aileron control, which of the following is true? (a) The up going Aileron moves through a smaller angle than the down going aileron. (b) The up going and down going ailerons both deflect to the same angle. (c) The down going aileron moves through a smaller angle than the up going aileron. (d) Both ailerons move at different direction all the time 4. Which part of the wing of a swept-wing aircraft stalls first? (a) root (c) leading edge (b) tip (d) trailing edge 5. Dutch roll is movement in? (a) yaw and pitch (c) yaw and dive (b) yaw and roll (d) pitch and yaw 6. Wing sweptback will? (a) increase lateral stability (c) has no effect (b) decrease lateral stability (d) increase drag 7. The stalling speed of aircraft will? (a) increase if its heavier (c) is always constant (b) decrease if its heavier (d) increase as angle of attack increases 8. An automatic slat will lift by itself when the angle of attack is? (a) low (c) both high and low (b) high (d) by a switch in cockpit 9. Which condition is the actual amount of water vapor in a mixture of air and water? (a) absolute humidity (c) dewpoint (b) relative humidity (d) precipitation point 10. The temperature to which humid air must be cooled at constant pressure to become saturated is called (a) absolute humidity (c) dewpoint (b) relative humidity (d) precipitation point 11. Flutter can be reduced by (a) horn balance (c) servo tabs (b) Mass balancing (d) trim tabs 12. Tuck under occurs when (a) Shock stall on outboard wings (c) The aircraft reaches Mcrit (b) Shock stall on inboard wings (d) when at nose heavy 13. If, after a disturbance, an aeroplane initially returns to its equilibrium state. (a) It has neutral stability (c) it has static stability and may be dynamically stable. (b) It is neutrally unstable (d) it has static stability and may not be dynamically stable. 14. If an aircraft returns to a position of equilibrium it is said to be. (a) Statically stable (c) positively stable (b) Neutrally stable (d) negatively stable 15. Which part of the rotor disc produces the most lift during forward flight? (a) Midspan portion (c) rear portion (b) Back portion (d) front portion 16. Translational drift is the tendency of the helicopter to drift (a) laterally (c) vertically (b) longitudinally (d) all of the above 17. In forward flight the relative air velocity at each blade. (a) Greatest for retreating blade (c) greatest at fastest blade (b) Equal for all blades (d) greatest at advancing blade 18. What is the swash plate on a helicopter used for in the rotor blades? (a) Control pitch (c) control flap (b) Control speed (d) control lead and lag 19. Initially downstream a normal shockwave the air flow is? (a) supersonic (c) the same (b) subsonic (d) increases 20. Tuck under can be counteracted by? (a) Trim tabs (c) aileron reversal (b) Swept back (d) mach trim 21. Critical Mach Number is defined as (a) that number at which the airflow becomes supersonic. (b) that free-stream Mach Number at which some part of the airflow over the aircraft becomes sonic. (c) the minimum Mach number at which the aircraft can go supersonic. 22. Critical Mach No. may be increased by. (a) Using higher thickness/chord ratio wing (c) increasing dihedral (b) Sweeping back wing (d) use of vortex generators 23. As an aircraft accelerates through the transonic region, the centre of pressure tends to move? (a) forward (c) rearward (b) no change (d) center 24. What produces the most lift at low speeds? (a) High camber (c) low aspect ratio (b) Low camber (d) high aspect ratio 25. Which statement is true? (a) Both Induced drag and profile drag increase with the square of the airspeed. (b) Profile drag increases with the square of the airspeed. (c) Induced drag increases with the square of the airspeed. 26. The pint wherein the Profile drag and induced drag intersects is? (a) L/D max (c) stalling speed (b) Maximum drag (d) maximum speed 27. If the wing loading of an aircraft were reduced the stalling speed would. (a) increase (c) decrease (b) not be affected (d) increase or decrease depending on the weight removed 28. For a cambered wing section, the zero lift angle of attack will be. (a) 4 degrees (c) positive (b) zero (d) negative 29. Induced downwash. (a) Reduces effective AOA of the wing (c) have no effect (b) increases effective AOA of the wing (d) R = 585 miles 30. The stalling of an aerofoil is affected by the? (a) weight (c) angle of attack (b) airspeed (d) all of the above 31. Wing tip vortices create a type of drag known as (a) Form drag (c) skin friction drag (b) Wave drag (d) induced drag 32. Geometric Pitch is the distance moved. (a) In one revolution (c) in one revolution without slip (b) In one revolution with slip (d) angle of root chord to tip chord 33. The primary purpose of a feathering propeller is to. (a) prevent further engine damage when an engine fails in flight. (b) prevent propeller damage when an engine fails in flight. (c) eliminate the drag created by a windmilling propeller when an engine fails in flight. 34. The air pressure and density at a point on the wing of a Boeing 747 are 1.10 x 105 N/m2 and 1.20 kg/m3 respectively. What is the temperature at that point? (a) 111 K (c) 152 k (b) 319 k (d) 17 k 35. The high-pressure air storage tank for a supersonic wind tunnel has a volume of I 000 ft3. If air is stored at a pressure of 30 atm and a temperature of 530" R, what is the mass of gas stored in the tank in pound mass? (a) 2248 (c) 2189 (b) 1237 (d) 1879 36. Calculate the standard atmosphere values OF Temperature at a geopotential altitude of 14 km. (a) 273 K (c) 288.8 K (b) 216.66 (d) 245 K 37. The flight test data for a given airplane refer to a level-flight maximum-velocity run made at an altitude that simultaneously corresponded to a pressure altitude of 30,000 ft and density altitude of 28,500 ft. Calculate the temperature of the air at the altitude at which the airplane was flying for the test. (a) 152 R (c) 390 R (b) 276 R (d) 154 R 38. Consider an airplane flying at some real, geometric altitude. The outside (ambient) pressure and temperature are 5.3 x 104 N/m2 and 253 K, respectively. Calculate the pressure altitude at which this aiq1lane is flying. (a) 5221 m (c) 2325 m (b) 3456 m (d) 5147 m 39. Consider a convergent duct with an inlet area A 1 = 5 m2 Air enters this duct with a velocity V1 = 10 m/s and leaves the duct exit with a velocity V2 = 30 m/s. What is the area of the duct exit? (a) 2.3 m2 (c) 1.24 m2 2 (b) 1.67 m (d) 1.97 m2 40. Consider an airfoil in a flow of air, where far ahead (upstream) of the airfoil, the pressure, velocity, and density are 2116lb/ft2, 100 mi/h, and 0.002377 slug/ft3, respectively. At a given point A on the airfoil, the pressure is 2070 lb/ft 2. What is the velocity at point A? (a) 245 fps (c) 178 fps (b) 322 fps (d) 278 fps 41. An airplane is flying at standard sea-level conditions. The temperature at a point on the wing is 250 K. What is the pressure at this point? (assume isentropic flow) (a) 345 KPa (c) 122 kPa (b) 61 kPa (d) 89 kPa 42. Consider an airfoil in a flow of air, where far ahead of the airfoil (the free stream), the pressure, velocity, and density are 2116 lb/ft2, 500 mi/h, and 0.002377 slug/ft3, respectively. At a given point A on the airfoil, the pressure is 1497lb/ft2 What is the velocity at point A? Assume isentropic flow. For air, cp = 6006 ft ·lb/(slug)( R). (a) 2298 fps (c) 1345 fps (b) 889 fps (d) 1061 fps 43. A jet transport is flying at a standard altitude of 30,000 ft with a velocity of 550 mi/h. What is its Mach number? (a) 0.667 (c) 0.811 (b) 0.925 (d) 0.467 44. In a low-speed subsonic wind tunnel, one side of a mercury manometer is connected to the settling chamber (reservoir) and the other side is connected to the test section. The contraction ratio of the nozzle A2 / A1 equals 1/15. The reservoir pressure and temperature area p1 = 1.1 atm and T1 = 300 K, respectively. When the tunnel is running, the height difference between the two columns of mercury is 10 cm. The density of liquid mercury is 1.36 X 104 kg/m3 Calculate the airflow velocity in the test section V2. (a) 188 m/s (c) 122 m/s (b) 165 m/s (d) 144 m/s 45. The altimeter on a low-speed Cessna 150 private aircraft reads 5000 ft. By an independent measurement, the outside air temperature is 505°R. If a Pitot tube mounted on the wing tip measures a pressure of 1818 lb/ft2 What is the true velocity of the airplane? (a) 156 fps (c) 179 fps (b) 237 fps (d) 202 fps 46. Consider the flow of air over a small flat plate that is 5 cm long in the flow direction and 1 m wide. The free-stream conditions correspond to standard sea level, and the flow velocity is 120 m/s. Assuming laminar flow, calculate the boundary layer thickness at the downstream edge (the trailing edge). (a) 4.06 x 10-4 m (c) 4.88 x 10-4 m -4 (b) 3.22 x 10 m (d) 4.54 x 10-4 m 47. Consider a NACA 4412 airfoil at an angle of attack of 4°. If the free-stream Mach number of 0.7 and low speed Cl of 0.83, what is the lift coefficient? (a) 0.7 (c) 1.59 (b) 0.89 (d) 1.16 48. What atmospheric conditions will cause the true landing speed of an aircraft to be highest? (a) Low temp high humidity (c) high temp high humidity (b) Head wind low humidity (d) high temp low humidity 49. The landing speed of an aircraft is 54 m/s2. If the maximum deceleration is 3m/s2 the minimum length of runway required is. (a) 162 m (c) 360 m (b) 223 m (d) 486 m 50. The percentage of nitrogen in air is approximately. (a) 60% (c) 88% (b) 78% (d) 67%  Philippine State College of Aeronautics Piccio Garden, Villamor, Pasay City MOCK EXAMINATION AERODYNAMICS (25%) 1. At an airplane’s minimum drag speed, the ratio between induced drag and profile drag (Di/Dp) is _____ a. 1 b. 1/3 c. 1/2 d. 3 2. Which of the following is a glider? a. Zenith S-5 b. Zeppelin c. F/A – 18 d. DG 1001 3. An aircraft is stabilized in the level flight at six nautical miles per second with tailwind of 100 knots. What is the aircraft’s true airspeed? a. 300 knots b. 360 knots c. 120 knots d. 160 knots 4. An aircraft with a gross weight of 2,000 pounds was subjected to a 60-degree constant altitude bank, the total load is _____. a. 1,500 lbs. b. 4,000 lbs. c. 1,862 lbs. d. 2,820 lbs. 5. It is the sum of the gage pressure and atmospheric pressure. a. Absolute pressure b. Gage pressure c. Vacuum pressure d. Plenum pressure 6. Find the speed of sound when the barometric pressure is 8.88” Hg and the density is 0.000902 slug/ft^3. a. 2,047 ft/s b. 1,507 ft/s c. 2,064 ft/s d. 1,570 ft/s 7. Find the Reynold’s number for an airplane wing that is four feet in chord and moving at twenty miles per hour through standard atmosphere. a. 4,870,000 b. 4,580,000 c. 4,990,000 d. 4,480,000 8. Air at standard pressure and temperature has a density of 0.002377 slugs per cubic foot. What is the temperature if the air is compressed adiabatically to 2 atm? a. 172.3 R b. 172.3 F c. 519.6 R d. 288.6 K 9. In an undisturbed air stream, the pressure is 14.7 psi, the density is 0.002378 slugs per cubic foot, and the velocity is 500 feet per second. What is the velocity where the pressure is 13.5 psi? a. 632 ft/s b. 475 ft/s c. 497 ft/s d. 628 ft/s 10. Atmosphere is made of _________ of Argon. a. 20.94 percent b. 78.08 percent c. 0.001 percent d. 0.94 percent 11. A 40 mph wind is blowing against a signboard 8 feet by 10 feet in size. Atmosphere is at normal density. What is the force acting against the signboard? a. 419 lbs b. 10.4 lbs. c. 500 lbs d. 194 lbs. 12. Which of the following is not present in a subsonic wing? a. Induced Drag b. Wave Drag c. Parasite Drag d. Interference Drag 13. It refers to the varying of wing chord using a uniform airfoil section. a. Airfoil Tapering b. Planform Tapering c. Section Tapering d. Thickness Taperring 14. The force perpendicular to the chord of an airfoil is commonly referred as _________. a. lift force b. drag force c. normal force d. axial force 15. A wing is flying at an angle of attack of 2 degrees. With lift and drag coefficient equal to 0.85 and 0.005, respectively, what is the normal force coefficient? a. 0.879 b. 0.850 c. 0.819 d. 0.836 16. Which of the following is not true regarding power required? a. Power required greater at low density – altitude. b. Power required varies directly to the airspeed. c. Power required increases as the value of airspeed increases. d. Power required is always greater than power available. 17. At sea-level, an airplane’s rate of climb is 1,000 feet per min. Its absolute ceiling is 15,000 feet. How long will it take to climb to 7,000 feet if it will fly from sea level? a. 8.3 mins b. 9.5 mins c. 23.5 mins d. 10 mins 18. To ensure safety during take–off, lift-off velocity should be _____. a. 20 percent greater than stalling speed b. 30 percent greater than stalling speed c. 15 percent greater than stalling speed d. equal to the stalling speed 19. Which of the following is true regarding radius of turn during level coordinated flight? a. The greater the weight, the wider the turn will be. b. The greater the angle of bank, the wider the turn will be. c. The greater the wing area, the wider the turn will be. d. The higher the angle of attack, the wider the turn will be. 20. The control surfaces for producing or regulating roll about the longitudinal axis are the _____. a. elevators b. trim tabs c. ailerons d. rudder and flaps 21. Ailerons’ chord are commonly measured _____. a. 20 to 33 percent of the wing chord b. 15 to 30 percent of the wing chord c. 12 to 15 percent of the wing chord d. 20 to 25 percent of the wing chord 22. In a twin-engine airplane, one mounted on each wing, the torque reaction is _____. a. neutralized b. doubled c. four times less d. four times greater 23. The movable rudder usually has an area of _____. a. 50–60 percent of the horizontal stabilizer b. 40–45 percent of the total wing area c. 60–70 percent of total vertical area d. double of horizontal stabilizer or half of wing area 24. What is the consequence of having too much lateral stability? a. During crosswind, landing is extremely difficult. b. During tailwind, landing is extremely difficult. c. Tendency of sideslip will be eliminated. d. Increase of airplane’s efficiency. 25. At a point in a flow over an F-15 high performance fighter airplane, the pressure, temperature, and Mach number are 1,890 psf, 450 R and 1.5 respectively. Calculate the freestream temperature given the pressure ratio equal to 3.671. a. 652 Rankine b. 625 Rankine c. 526 Rankine d. 615 Rankine 26. Across an oblique shockwave, which of the following is true? a. Tangential component of velocity in front of and behind the wave are equal. b. Tangential component of velocity in front is greater than the velocity behind the wave. c. Tangential component of velocity behind is greater than the velocity in front the wave. d. Normal component of velocity behind is greater than the velocity in front the wave. 27. Consider a rocket burning hydrogen and oxygen; the combustion chamber pressure and temperature are 25 atm and 3,517 Kelvin, respectively. The area of the rocket nozzle throat is 0.1 square meters. The area of the exit is designed so that the exit pressure exactly equals ambient pressure at a standard altitude of 30 km. For the gas mixture assume that k = 1.22 and the molecular weight M = 16. At a standard altitude of 30 km, calculate exit Mach number a. 5.21 b. 1.00 c. 4.35 d. 3.56 28. On what instance does negative pressure coefficient occurs? a. When local velocity is higher than freestream velocity. b. When the dynamic pressure is twice the pressure difference. c. When the freestream velocity is higher than local velocity. d. When the local pressure is greater than freestream pressure. 29. The average force exerted upon a unit area of surface by the bombardment due to random thermal motion of molecules of air or any other fluid is known as _____. a. dynamic pressure b. atmospheric pressure c. static pressure d. gage pressure 30. Too much angle of bank during a level turning flight may cause _____. a. slipping c. skidding b. blanketing d. porpoising 31. Intentional one-engine inoperative speed is a minimum speed selected by the manufacturer for intentionally rendering one engine inoperative in flight for pilot training. a. VSSE b. VON c. VNE d. VAT1 32. It refers to the demonstrated ratio of the change in height during a portion in climb in still air. a. Lapse Rate b. Climb Gradient c. Height Differential d. Height Slope 33. The distance between the wings of a biplane is properly termed as _____. a. gap c. stagger b. decalage d. cathedral 34. By changing the angle of attack of the wing, the pilot can control the airplane’s _____.  a. lift and drag b. lift and induced drag c. lift, drag, and airspeed d. induced drag 35. What is the primary function of an exhaust cone of a turbine engine? a. Align the exhaust gases to develop an efficient power. b. Collect and convert exhaust gasses into a solid high-velocity exhaust jet. c. Collect and convert exhaust gasses into a solid low-velocity exhaust vapor. d. Straighten the swirling exhaust gasses. 36. Higher induced angle of attack can be obtained by using _____. a. lower taper ratio b. larger wing area c. higher wing aspect ratio d. lower wing aspect ratio 37. Which of the following best describes the wings with higher aspect ratio? a. Lower wing–lift curve slope. b. Steeper wing–lift curve slope. c. Same wing lift–curve slope with infinite wing. d. Aspect ratio doesn’t affect wing lift–curve slope. 38. Hazardous vortex turbulence that might be encountered behind large aircraft is created only when the aircraft is _____. a. producing lift b. operating at high altitude c. using high power setting d. operating at high airspeed 39. The angle of attack of a wing directly controls _____.. a. distribution of pressure acting on the wing b. dynamics acting on the airflow of the wing c. angle of incidence of the wing d. amount of airflow below and above the wing 40. What flight condition should be expected when an aircraft leaves ground effect? a. Increase in dynamic stability. B. Decrease in induced drag and a requirement of lower angle of attack. C. Increase in induced drag and a requirement of higher angle of attack. d. Decrease in parasite drag permitting a lower angle of attack. 41. An airplane having a wingspan of 36 feet is flying at 2,500 pounds of lift. If the dynamic pressure is equal to 47.54 pounds per square foot, determine the drag due to lift. Assume the wing exercises an elliptical lift distribution. a. 32.289 lbs. b. 12.356 lbs. c. 1,500 lbs. d. 453.25 lbs. 42. Which of the following is categorized as secondary flight controls? a. Aileron, Rudders, Trim tabs b. Flaps, Aileron, Elevators c. Flaps, Spoilers, Trim tabs d. Trim tabs, Spoilers, Floating Ailerons 43. Which of the following conditions will an aircraft experience the greatest stress? a. Climbing flight b. Level flight c. Turning flight d. Gliding flight 44. A 22,240-pound airplane has an excess power of 56 kWatts at sea level and a service ceiling of 3.66 kilometers. Calculate its rate of climb at absolute ceiling. a. 30.49 inches per minute b. 100 ft. per minute c. 58.76 meters per minute  d. 0 inches per minute 45. When an airplane is at constant altitude bank, the stall speed will _____. a. remain the same as level flight condition. b. increase as the square of the load factor c. increase as the square root of the angle of bank d. decrease as the square root of the load factor 46. At higher altitude, stall speed will _____. a. increase b. decrease c. remain constant d. stay constant until it reaches tropopause 47. Rotor system which have a horizontal hinge at the base of the blades that allow flapping as they rotate. a. Semi-rigid b. Rigid c. Fully-articulated d. Horizontal flapping assembly 48. The process of producing lift with the rotor blades moving freely from a flow of air up through the rotor system. a. Feathering b. Autorotation c. Flapping d. Porpoising 49. In propeller design, which of the following condition has the highest propeller efficiency? a. Greater thrust, shorter propeller diameter, greater RPM b. Greater power, longer propeller diameter, less RPM c. Greater thrust, shorter propeller diameter, less RPM d. Greater power, longer propeller diameter, greater RPM 50. Which of the following is associated to permanent structural deformation of one or more parts of an airplane? a. Maneuvering load factor b. Gust load factor c. Ultimate load factor d. Limit load factor  Department of Aeronautical Engineering and Aircraft Maintenance Technology First Aerodynamics Mock Exam Name: ________________________________________ Date: ______________ Duration: 3 hours Rating: ___/50 Shade the letter of your answer in the answer sheet provided. Strictly no erasures. 1. At a given point on the wing of a Boeing 727, the pressure and temperature of the air are 1.9 x 10 4 N/m2 and 203 K, respectively. Calculate the density at this point. (a) 0.43 (c) 0.00063 (b) 0.35 (d) 0.00045 2. The following utilize air breathing engines except. (a) Airplanes (c) Rockets (b) Helicopters (d) Hot Air Balloon 3. A stream of air 72 sq. ft in cross section is moving horizontally at a speed of 100mph. What force is required to deflect it downward 10° without loss in speed? (a) 2854 (c) 2342 (b) 2765 (d) 2553 4. Which of the statements is true about Bernoulli’ principle? (a) Mass and energy are conserved (c) Concept is only limited for incompressible flows (b) It applies to turbulent flows (d) None of the Above 5. This is the measure of the average kinetic energy of the particles in a gas (a) Pressure (c) Specific Volume (b) Density (d) Temperature 6. Which of the following is correct about incompressible flows? (a) Variation of density is not significant (c) Applicable to supersonic vehicles (b) Flow velocity is greater than 100 m/s (d) Valid for all kinds of subsonic flows 7. Consider an airfoil in a flow at standard sea level conditions w/ the free stream velocity of 50 m/s. At the given point on airfoil the pressure is 90000Pa, calculate the velocity at this point. (a) 144.88 m/s (c) 134.88 m/s (b) 154.88 m/s (d) 124.88 m/s 8. Find the temperature at an altitude where the density is 0.623 kg/m3 in standard atmosphere. (a) 215.15K (c) 245.73K (b) 221.63K (d) 288.22K 9. It is an aircraft instrument that measures the total pressure at a point in the flow. (a) Static port (c) Altimeter (b) Pitot tube (d) Velocimeter 10. Which of the following is true about lift generation in an aircraft wing? (a) High pressure is created at the upper surface of the wing and low pressure at the lower surface (b) Equal pressures are created at the upper and lower surfaces of the wing (c) Low pressure is created at the upper surface of the wing and high pressure at the lower surface (d) Low pressure is created at the leading edge of the wing and high pressure at the trailing edge 11. A pitot-static tube is used to measure the airspeed at the test section of the wind tunnel. If the pressure difference across the pitot-static tube is 4 inches of water, what is the airspeed at the test section? Assume incompressible flow and standard sea level conditions. (a) 171.8 (c) 132.2 (b) 125.5 (d) 183.1 12. What qualifies a flow to be classified as subsonic? Prepared by JGGD  (a) Slower than the speed of sound (c) Slower than the speed of light (b) Faster than the speed of sound (d) Faster than the speed of light 13. A Pitot tube on an airplane flying at standard sea level reads 1.07 x 105 N/m2. What is the velocity of the airplane? BONUS (a) 70 (c) 200 (b) 152 (d) 83 14. The following statements are true about streamlines except? (a) A group of streamlines is called a streamtube (c) All streamlines are smooth (b) Bernoulli’s principle is applicable to streamlines (d) All of the above 15. It is the basis of standard altitude. (a) Absolute altitude (c) Pressure altitude (b) Geometric altitude (d) Geopotential altitude 16. Consider an airfoil in a flow of air, where far ahead of the airfoil, the pressure, velocity and density are 2116 lb/f t2 ,100 mi/h and 0. 002377 slug/ft3, respectively. At a given point A on the airfoil, the pressure is 2070 lb/ft2. What is the velocity at point A? (a) 255.4 ft/s (c) 235.4 ft/s (b) 245.4 ft/s (d) 355.4 ft/s 17. Which of the following is not true about equation of state for a perfect gas? (a) Relates pressure, temperature, density of a gas (c) Valid for hypersonic flows (b) Applicable to supersonic flows (d) Usable for gases in which intermolecular forces are weak 18. What is the relationship of area and velocity in very low velocity airflow? (a) As area increases, velocity of the fluid increases (b) As velocity increases, the area occupied by the fluid decreases (c) As area increases, the velocity remains the same (d) As velocity decreases, the area occupied by the fluid remains the same 19. The following are vector quantities except? (a) Speed (c) Displacement (b) Position (d) Velocity 20. It is the science that deals with the interaction of objects in air. (a) Hydrodynamics (c) Dynamics of Rigid Bodies (b) Thermodynamics (d) Aerodynamics 21. A flow that is both insulated and frictionless. (a) Isobaric (c) Isochoric (b) Adiabatic (d) Isentropic 22. The speed of sound is greatly a function of? (a) Density (c) Temperature (b) Pressure (d) Velocity 23. Consider a low speed subsonic with a 12/1 contraction area for the nozzle. If the flow in the test section is at standard sea level condition with a velocity of 50 mps. Calculate the height difference area in u-tube mercury manometer (density of mercury=1360 kg per cu-m) with one side connected to the nozzle inlet and the other to the test section. (a) 0.113 m (c) 0.115 m (b) 0.114 m (d) 0.116 m 24. It is the design maneuvering speed. (a) VA (c) VC (b) VB (d) VD 25. What happens to the pressure of the fluid at isothermal regions? (a) Pressure increases as height increases (c) Pressure remains the same (b) Pressure decreases as height increases (d) None of the above 26. A type of aerodynamic flow where effects of friction are held negligible. (a) Incompressible (c) Compressible (b) Inviscid (d) Viscous Prepared by JGGD 27. A uniform current of air with a speed of 100 ft per sec. flows around a circular cylinder at a distance from the cylinder where the pressure is atmospheric. What is the pressure at a point on the surface of the cylinder located that a radial line through the point makes an angle of 15° with the direction of airflow? (a) 2134.44 (c) 2125. 50 (b) 2236.43 (d) 2243. 52 28. It is the sum of indicated airspeed and position as well compressibility errors. (a) Equivalent (c) True (b) Calibrated (d) Cruising 29. Consider the isentropic flow over an airfoil. The freestream conditions are T= 245 K and P = 4.35 X 104 N/m2. At a point on the airfoil, the pressure is 3.6 x 104 N/m2. Calculate the density at this point. (a) 0.47 (c) 0.63 (b) 0.54 (d) 0.78 30. It is a flow classification that is between subsonic and supersonic. (a) Hypersonic (c) High Speed Subsonic (b) Ultrasonic (d) Transonic 31. What happens to the pressure across the shockwave? (a) increase (c) remains the same (b) decrease (d) none of the above 32. The aircraft is said to be trimmed if? (a) The moment at aerodynamic center is zero (c) The rotation at center of gravity is zero (b) The rotation at center of pressure is zero (d) The rotation at geometric center is zero 33. It is the angle between the chord line and the longitudinal axis of the aircraft. (a) Sweep angle (c) Angle of Incidence (b) Angle of Attack (d) Dihedral Angle 34. Which of the following statements is true about maximum L/D ratio? (a) can be found where Cl is at maximum (c) located where both Cl and Cd are minimum (b) can be found where Cd is minimum (d) located where both Cl and Cd are maximum 35. What happens to the value of lift as velocity is doubled? (a) lift is doubled (c) lift is quadrupled (b) lift is tripled (d) lift is reduced by half 36. The drag polar equation of an advanced light twin airplane in clean configuration can be written as: CD = 0.0358 + 0.0405CL2. Its weight is 4200 lbs. and the wing area is 155 ft2. Assuming standard sea level conditions, calculate the minimum power required. (a) 54,000 (c) 62,000 (b) 44,000 (d) 32,000 37. A glider weighs 800 lbs. and has a wing loading of 12 psf. Its drag equation is CD = 0.010 + 0.022CL2. After being launched at 1500 ft. in still air, determine the greatest distance it can cover. (a) 12 km (c) 14 km (b) 13 km (d) 15 km 38. An airplane weighs 36,000 lbs. and has a wing area of 450 ft2. The drag polar equation is CD = 0.014 + 0.05CL2. It is desired to equip this airplane with turboprop engines with available power such that a maximum speed of 602.6 mph at sea level can be reached. The available power is assumed to be independent of flight speed. Calculate the maximum the rate of climb. Neglect compressibility effects. Note: R/C is a function of power, whereas climb angle is a function of thrust. (a) 91 ft/s (c) 131 ft/s (b) 81 ft/s (d) 241 ft/s 39. Consider an aircraft with the following properties: W/S = 59.88 lbs/ft2. W = 10,000 lbs, S = 167 ft2, CLmax, = 1.5, nmax= 6, CD = 0.018 + 0.064CL2, and Tmax = 5000 lbs. Find the speed at which this condition will occur. (a) 308.22 ft/s (c) 238.33 ft/s (b) 542.0 ft/s (d) 448.6 ft/s Prepared by JGGD 40. Air enters a converging-diverging nozzle at 0.5 MPa with a negligible velocity. Assuming the flow to be isentropic, determine the pressure that will result in an exit Mach number of 1.8. (a) 0.07 (c) 0.09 (b) 0.08 (d) 0.10 41. An airfoil is in a freestream where P = 0.61 atm, ρ = 0.819 kg/m3, and V = 300 m/s. At a point on the airfoil surface, the pressure is 0.5 atm. Assuming isentropic flow, calculate the velocity at that point. (a) 2132 (c) 932 (b) 1132 (d) 832 42. Consider a normal shock wave in air where the upstream flow properties are V = 680 m/s, T = 288 K, and P = 1 atm. Calculate the pressure downstream of the shock. (a) 4.5 (c) 2.5 (b) 3.5 (d) 1.5 43. Consider the isentropic supersonic flow through a convergent-divergent nozzle with an exit-to-throat area ratio of 10.25. The reservoir pressure and temperature are 5 atm and 600 R, respectively. Calculate the temperature at the nozzle exit. (a) 240 K (c) 162 K (b) 283 K (d) 146 K 44. A slender missile is flying at Mach 1.5 at low altitude. Assume the wave generated by the nose of the missile is a Mach wave. This wave intersects the ground 559 ft behind the nose. At what altitude is the missile flying? (a) 173 (c) 373 (b) 273 (d) 473 45. Consider an oblique shock wave with β = 35° and a pressure ratio P2/P1 = 3. Calculate the upstream Mach number. (a) 1 (c) 3 (b) 2 (d) 4 46. What is the value of pressure coefficient at low speeds? (a) Cpo > Cp (c) Cpo = Cpcr (b) Cpo < Cp (d) Cpo = Cp 47. What is the relationship between drag coefficient and lift coefficient? (a) Cd = Cl2 (c) 2Cd = 2Cl (b) Cd2 = Cl (d) Cd = 2Cl 48. The location of aerodynamic center for usual subsonic airfoils can normally be found at (where c =chord) (a) near c/2 as angle of attack decreases (b) c/4 regardless of angle of attack (c) near c/4 as angle of attack decreases (d) it ranges from c/4 to c/2 regardless of angle of attack 49. Which of the following statements is true about airfoil thickness? (a) Critical Mach number increases as the thickness of the airfoil increases (b) Critical Mach number has nothing to do with airfoil thickness (c) Critical Mach number decreases as thickness decreases (d) None of the Above 50. What is the critical pressure coefficient for an airplane flying at 500 knots in air at 25°F. (a) -0.489 (c) -0.093 (b) -0.78 (d) -0.045 Prepared by JGGD Aeronautical Board Examination Review Aerodynamics 25% 4th Mock Examination 1. Calculate the density (in lb mass per cu ft.) at 28,000 ft. altitude in the standard atmosphere. a) 0.030777 c) 0.000957 b) 0.040888 d) 0.001035 2. A standard altimeter reads 8,000 ft. when the ambient temperature is 35 0F. What is the density altitude (in ft.)? a) 8,299 d) 13,86 b) 7,899 2 c) 15,32 4 3. A horizontal pipeline enlarges from a diameter of 6 in. at point A to a diameter of 12 in. at point B. The velocity at point A is 1222.309963 in/s and the pressure at A is 10 lb. per sq. in. What is the pressure at B (in lb. per sq. in.)? a) 10.08 c) 76.28 b) 73.39 d) 10.96 4. Alcohol (specific gravity = 0.80) is flowing through a horizontal pipe, which is 10 in. in diameter, with a velocity of 40 ft. per sec. and the reference fluid is H2O. At a smaller section of the pipe there is 6 lb. per sq. in. less pressure. Assuming that the flow is smooth, what is the diameter there? a) 0.66 ft. c) 0.73 ft. b) 0.54 ft. d) 0.68 ft. 5. A Venturi tube narrows down from 4 in. in diameter to 2 in. in diameter. What is the rate of flow of water (in cubic meters per second) if the pressure at the throat is 2 lb. per sq. in. less than at the larger section? a) 0.015 c) 0.011 b) 0.018 d) 0.048 6. A submarine is cruising in fresh water with its longitudinal axis 30 ft below the surface. At a speed of 15 knots, the impact pressure (in Newton per sq. meter) on its nose is _____________. a) 119,470 c) 120,540 b) 121,360 d) 118,890 7. An airplane is flying at sea level at airspeed of 280 knots. The difference between total and static pressure (in lb. per sq. ft.) is____________. a) 265 c) 105 b) 235 d) 110 8. What force (in pounds) is required to push a flat plate, 3 ft. by 2 ft., at a speed of 35 ft. per sec in a direction perpendicular to its surface? a) 25 c) 22 b) 28 d) 18 9. What area (in sq. ft.) should a wing (with maximum lift coefficient of 1.6) have so that an airplane weighing 1,800 lb. shall stall at 38 knots at sea level? a) 220 c) 215 b) 225 d) 230 10. A cylinder 3 ft. in diameter and 9 ft. long is rotating at 140 revolutions per minute in an airstream of 45 miles per hour. The total lift (in pounds) is__________________. a) 293 c) 282 b) 286 d) 297 11. The drag polar equation of an airplane is given by the relation: 2 CD = 0.055 + 0.046CL The lift coefficient for minimum thrust horsepower required is__________. a) 1.277 b) 1.560 Aeronautical Board Examination Review Aerodynamics 25% 4th Mock Examination c) 1.725 d) 1.894 12. At sea level, an airplane rate of climb is 1,070 feet per minute. Its absolute ceiling is 18,400 feet. What is the rate of climb at 12,000 feet altitude? a) 372 ft. per minute c) 394 ft. per minute b) 380 ft. per minute d) 386 ft. per minute 13. Consider an oblique shock wave with a wave angle of 30 degrees. The upstream flow velocity at sea level is 1,590 knots. Calculate the deflection angle of the flow. a) 6.72 c) 7.64 b) 7.01 d) 6.36 14. Given is a NACA 23018 airfoil with camber of 4.6 centimeters. Calculate the position of camber (in centimeters). a) 30.5 c) 33.5 b) 27 d) 34.5 15. If the Mach number of a transport plane flying at a standard altitude of 10,000 meters is 0.84, its flight speed (in meters per second) is____________. a) 233 c) 251 b) 244 d) 242 16. An expansion wave is created by a deflection angle of 10 degrees at a supersonic stream with Mach number of 2 and pressure ratio P1/P2 = 1/3. Calculate the Mach number after the wave. a) 2.71 c) 2.38 b) 2.35 d) 2.44 17. How does the best angle of climb and best rate of climb vary with increasing altitude? a) Both decrease. b) Both increase. c) Best angle of climb increases while best rate of climb decreases. d) Best angle of climb decreases while best rate of climb increases. 18. At sea level, an airplane rate of climb is 650 ft. per minute. Its service ceiling is 12,000 ft. The time to climb (in minutes) to reach an altitude of 8,500 ft. is ______________. a) 18.24 c) 19.62 b) 19.96 d) 17.53 19. The drag polar equation of an advanced light twin airplane in 2 clean configuration can be written as: CD = 0.0358 + 0.0405 CL For best range, the lift coefficient is______________. a) 0.358 c) 0.716 b) 0.405 d) 0.940 2 20. In an undisturbed airstream the pressure is 101,325 N/m , density is 1.225 kg per cubic meter, and the velocity is 150 2 meters per second. Where the pressure is 93,000 N/m , the velocity (in meters per second) is_______________. a) 191 c) 184 b) 178 d) 196 21. A plane of 3,800 lb. gross weight is turning at 175 miles per hour with an angle of bank of 50 degrees. Determine the lift (in Newton). a) 26,295 c) 27,436 b) 25,364 d) 24,527 22. Consider an oblique shock wave with a flow Mach number of 2.0 and a pressure ratio P2/P1 = 3.0 across the wave. Calculate the Mach number downstream of the wave. Aeronautical Board Examination Review Aerodynamics 25% 4th Mock Examination a) 0.94 c) 1.08 b) 1.15 d) 1.26 23. Low induced drag can be obtained by using: a) Low span loading. c) High wing loading. b) Low wing aspect d) High span loading. ratio. 24. The rate of descent is minimum when: a) Parasite drag equals the induced drag. b) Parasite drag equals one-third of induced drag. c) Parasite drag equals three times the induced drag. d) Total drag equals twice the sum of parasite drag and induced drag. 25. For optimum range, a) Parasite drag equals the induced drag. b) Parasite drag equals one-third of induced drag. c) Parasite drag equals three times the induced drag. d) Total drag equals four times the sum of parasite drag and induced drag. 26. If the thrust available exceeds the thrust required in level flight the aeroplane: a) will accelerate b) will descend if the airspeed remains constant c) decelerates if it is in the region of reversed command d) will decelerate 27. If the altitude and angle of attack remain constant, an increased mass will require: a) increased airspeed and increased power b) increased airspeed and decreased power c) decreased airspeed and increased power d) decreased airspeed and decreased power 28. In level flight, the power-required curve would move......... if the altitude is decreased: a) up and to the right c) down and to the left b) down and to the right d) up and to the left 29. To fly at a speed between V minimum drag and Vs it would require: a) increased flap c) decreased thrust b) increased thrust d) decreased flap 30. The most important aspect of the ‘backside’ of the power curve is the: a) elevator must be pulled to lower the nose b) speed is unstable c) aeroplane will not stall d) altitude cannot be maintained 31. Which of the following sets are examples of aerodynamic balancing of control surfaces? a) balance tab, horn balance and mass balance b) control surface leading-edge mass, horn balance and mass balance c) spring tab, servo-tab and power-assisted control d) servo-tab, a seal between the wing trailing edge and the control surface leading edge 32. Flutter may be caused by: a) distortion by bending and torsion of the structure causing increased vibration in the resonance frequency b) low airspeed aerodynamic wing stall c) roll-control reversal d) high-airspeed aerodynamic wing stall 33. When power-assisted controls are used for pitch control, this: a) makes trimming unnecessary b) makes aerodynamic balancing of the controls difficult c) can only function as an elevator trim tab Aeronautical Board Examination Review Aerodynamics 25% 4th Mock Examination d) ensures that partial aerodynamic forces is still felt on the control column 34. Which statement about a primary control surface controlled by a servo-tab is correct? a. The servo-tab can only be used as a trim tab. b. The control effectiveness is increased by servo-tab deflection. c. Due to the effectiveness of the servo-tab the control surface area is reduced. d. The position is indeterminate on the ground, in particular with a tailwind. 35. The purpose of a horn balance in a control system is to: a) decrease the effective longitudinal dihedral of the aeroplane b) decrease the required stick forces c) prevent flutter d) produce mass balancing 36. In comparison with a correctly balanced aeroplane during take-off, the position of the stabilizer for a nose heavy aeroplane requires: a) increased nose-down trim from a decreased stabiliser angle of incidence b) increased nose-up trim from a decreased stabiliser angle of incidence c) decreased nose-up trim from an increased stabiliser angle of incidence d) decreased nose-down trim from an increased stabiliser angle of incidence 37. If the CG is located in a forward position then the elevator deflection for a maneuver with a load factor greater than 1 will be: a) dependent on the trim position b) larger c) smaller d) unchanged 38. The lateral static stability of an aeroplane is increased by: a) Fuselage-mounted wings, dihedral, T-tail b) sweep back, under-wing-mounted engines, winglets c) high wing, sweep back, large and high vertical tail d) low wing, dihedral, elliptical wing planform 39. If the CG is aft of the CP straight and level flight can only be maintained when the horizontal tail loading is: a) zero b) downward c) upward or downward depending on elevator deflection d) upward 40. Which of the following statements regarding dihedral is correct? a) Dihedral is necessary for slip-free turns. b) The ‘effective dihedral’ component is its contribution to the static lateral stability. c) ‘Effective dihedral’ is the angle between the 1/4-chordline and the lateral axis of the aeroplane. d) Dihedral contributes to dynamic lateral stability but not to static lateral stability. 41. The effect of having the CG on the forward limit and full nose-down trim on rotation at take-off is that the: a) stick forces will decrease b) stick forces will increase c) the nose-wheel will lift off immediately d) rotation will occur earlier in the take-off ground run 42. An aeroplane that has positive static stability is dynamically.............. Aeronautical Board Examination Review Aerodynamics 25% 4th Mock Examination a) either neutral, stable or unstable b) always stable c) always unstable d) always neutral 43. An aeroplane is prone to spiral divergence if it has the following conditions: a) weak directional stability and positive lateral stability b) positive longitudinal stability c) overactive inputs from the yaw damper when recovering from Dutch roll d) positive directional stability and weak lateral stability 44. In steady horizontal flight the Cl of an aeroplane is 0.35. A one-degree increase in the AoA increases the Cl by 0.079. A vertical gust of air instantly changes the AoA by two degrees. The new load factor is: a) 1.9 c) 0.9 b) 1.45 d) 0.45 45. In a gust, which combination of speeds is applicable for the structural strength of an aeroplane in the clean configuration at Standard Sea Level? a) 28 fps and Vd b) 66 fps at all speeds c) 66 fps and Vb d) 56 fps and Vc 46. The load factor that determines Va is the: a) gust load factor at 66 fps b) manoeuvring flap limit load factor c) manoeuvring limit load factor d) manoeuvring ultimate load factor 47. Two aeroplanes at different masses execute a 20◦ banked turn at 150 kt IAS. The heavier aeroplane will: a) have a greater rate of turn than the lighter aeroplane b) turn at the same radius as the lighter aeroplane c) have a larger turn radius than the lighter aeroplane d) have a smaller radius of turn than the lighter aeroplane 48. To produce a coordinated turn when the turn and slip needle shows right and the ball is to the left it is necessary to: a) increase the bank angle to the right b) increase the rudder input to the right c) decrease the bank angle to the right d) increase the radius of turn 49. Which of the following statements is true? a) Extending flaps in severe turbulence moves the CP aft, which increases the margins to the structural limits. b) In severe turbulence, the limiting factors are the stall and the margin to the structural limitations. c) Extending flaps in severe turbulence reduces the speed and increase the margins to the structural limits. d) Extending flaps in severe turbulence reduces the stalling speed and reduces the risk of exceeding the structural limitations. 50. An aeroplane continues straight and level flight with wings level after suffering a port engine failure, which of the following statements is correct? a) turn indicator neutral; slip indicator left of neutral b) turn indicator left of neutral; slip indicator left of neutral c) turn indicator left of neutral; slip indicator neutral d) turn indicator neutral; slip indicator neutral  PHILIPPINE  STATE  COLLEGE  OF  AERONAUTICS     Piccio  Garden,  Villamor,  Pasay  City       MOCK  EXAMINATION     AERODYNAMICS     1. A   NASA   Learjet   has   a   section   of   one   wing   instrumented   with   devices   capable   of   measuring   temperature   and   pressure   at   discrete   points   on   the   wing.   If   at   one   of   these   points,   the   instruments   measure   pressure   =   10   psi   and   temperature   =   -­‐20   deg.F,  what  is  the  density  of  the  air  at  that  point?     a..001971  slug  per  cu.  Ft   b..0019017  slug  per  cu.  Ft   c..0019071  slug  per  cu.  Ft   d..0010971  slug  per  cu.  Ft   2. A  wind  tunnel  has  the  following  flow  properties  at  the  inlet:  P  =  101,000  Pa;  A  =  1   sq.m;   T   =   288   K;   V   =   200m/s   and   in   the  test   section,   A   =   0.25   sq.m   and   V   =   900   m/s.   What  is  the  mass  flow  rate  in  the  wind  tunnel?       a. 314.32  N/s   b. 256.32  lb/s   c. 244.32  kg/s     3. An  atmospheric  pressure  of  3  psig  is  equivalent  to  ___.  (in  psia)     a. 3  psia   b. 14  psia   c. 17  psia   d. 15  psia     4. Flight-­‐test   course   students   are   preparing   for   a   flight   test   sortie   in   a   light   aircraft.   They   note   that   the   altimeter   indicates   a   pressure   altitude   of   7000ft.   The   student   flight-­‐test   engineer   reads   an   air   temperature   of   65   degrees   F.   What   is   the   density   altitude  for  these  conditions?     a. 10,000  ft   b. 9,0000  ft   c. 8,000  ft   d. 7,000  ft   5. As  airspeed  decreases  in  level  flight  below  that  speed  for  maximum  lift/drag  ratio,   total  drag  of  an  airplane     a. decreases  because  of  lower  parasite  drag     b. increases  because  of  increased  parasite  drag.     c. increases  because  of  increased  induced  drag.   d. remains  the  same  regardless  of  changes  in  airspeed.   6. What  causes  an  airplane  (except  a  T  tail)  to  pitch  nose  down  when  power  is  reduced   and  controls  are  not  adjusted?     a. the  CG  shifts  forward  when  thrust  and  drag  are  reduced     b. the  downwash  on  the  elevators  from  the  propeller  slipstream  is  reduced  and   elevator  effectiveness  is  reduced     c. when  thrust  is  reduced  to  less  than  weight,  lift  is  also  reduced  and  the  wings   can  no  longer  support  the  weight     d. the  CG  shifts  aft  when  thrust  and  drag  are  reduced   7. From  the  polar  diagram  of  the  entire  airplane  one  can  read:   a. the  minimum  lift-­‐drag  ratio  and  the  minimum  drag.   b. the  maximum  lift-­‐drag  ratio  and  lift  coefficient.   c. the  minimum  drag  and  the  maximum  lift.   d. the  minimum  drag  coefficient  and  the  maximum  lift.   8. The  critical  value  of  the  pressure  coefficient  for  an  airplane  flying  at  500  knots  in  air   at  25OF  is          ________.   a. –0.417   b. –0.534    PHILIPPINE  STATE  COLLEGE  OF  AERONAUTICS     Piccio  Garden,  Villamor,  Pasay  City     c. –0.325   d. –0.494   9. Why  should  flight  speeds  above  VNE  be  avoided?   a. excessive  induced  drag  will  result  in  structural  failure     b. a  high  speed  stall  is  most  likely  to  occur     c. ccontrol   effectiveness   is   so   impaired   that   the   aircraft   becomes   uncontrollable.     d. design  limit  load  factors  may  be  exceeded,  if  gusts  are  encountered   10. Given  is  a  NACA  4415  airfoil  with  apposition  of  camber  of  40  centimeters.  Calculate   its  maximum  thickness.             a.  40  millimeters   b. 100  millimeters   c. 150  millimeters   d. 50  millimeters   11. The  horizontal  dashed  line  from  point  C  to  point  E  represents  the     a. ultimate  load  factor   b. airspeed  range  for  normal  operations     c. positive  limit  load  factor     d. airspeed  range  for  turbulent  operations           12. The  speed  for  minimum  glide  angle  occurs  at  a  certain  angle  of  attack.  Which  are  the   following  aerodynamic  coefficient(s)?       CL a. ( ) MAX   CD b. C L MAX   CL c. ( ) 2 MAX     C D 3 CL d. ( 2 ) MAX   CD 13. In  Figure  4-­‐9,  The  value  of  the  angle  of  attack  corresponding  to  CLMAX  is  called:   a. Maximum  angle  of  attack.   b. Minimum  angle  of  attack.   c. Critical  angle  of  attack.   d. Best  angle  of  attack.    PHILIPPINE  STATE  COLLEGE  OF  AERONAUTICS     Piccio  Garden,  Villamor,  Pasay  City                                   14. The  drag  polar  equation  of  an  airplane  is  given  by  the  relation:                                CD  =  0.025  +  0.046CL2              For  minimum  dag  the  induced  drag  coefficient  is  equal  to_____  .   a. 0.008     b. 0.075   c. 0.050   d. 0.025   15. Consider  an  oblique  shock  wave  with  a  wave  angle  of  30  degrees.  The  upstream  flow   velocity  at  sea  level  is  1,590  knots.  The  deflection  angle  of  the  flow  is  _______________.     a. 6.62  degrees   b. 6.72  degrees   c. 6.82  degrees   d. 6.52  degrees   16. A   Venturi   tube   narrows   down   from   4   in.   in   diameter   to   2   in.   in   diameter.   The   pressure   at   the   throat   is   2   lb   per   sq   in.   less   than   at   the   larger   section?   The   rate   of   flow  of  water  is  _______________.   a. 0.523  cu  ft  per  sec.   b. 0.406  cu  ft  per  sec.   c. 0.312  cu  ft  per  sec.   d. 0.388  cu  ft  per  sec.     17. Rate  of  descent  can  be  minimized  when  the  ________________________________.   a. parasite  drag  equals  the  induced  drag   b. parasite  drag  equals  one-­‐third  of  induced  drag   c. parasite  drag  equals  three  times  the  induced  drag   d. parasite  drag  is  greater  than  the  induced  drag     18. Consider   an   oblique   shock   wave   with   a   wave   angle   of   35   degrees   and   pressure   ratio   across  the  wave  of  3.0.  The  deflection  angle  of  the  flow  is  _____________.   a. 15.24  degrees   b. 14.33  degrees   c. 16.63  degrees   d. 17.56  degrees   19. An   airplane   is   flying   at   a   density   altitude   of   4.5   kilometers   at   an   ambient   temperature  of  39o  C.  If  the  wing  chord  is  1.83  meters  and  the  equivalent  airspeed  is   103  meters  per  second,  the  overall  Reynolds  Number  is  ________________.   a. 11,424,362   b. 10,628,467   c. 13,256,352   d. 9,664,786     20. The  lift/drag  ratio  is  obtained:   a. By  dividing  CL  by  the  CD.   b. By  dividing  the  CD  by  the  CL.   c. By  dividing  the  angle  of  attack  by  the  CL.   d. By  dividing  the  angle  of  attack  by  the  CD.      PHILIPPINE  STATE  COLLEGE  OF  AERONAUTICS     Piccio  Garden,  Villamor,  Pasay  City     21. An   F-­‐15   supersonic   fighter   aircraft   is   in   a   rapid   climb.   At   the   instant   it   passes   through   a   standard   altitude   of   25,000   ft.,   its   time   rate   of   change   of   altitude   is   500   ft/s,  which  by  definition  is  the  rate  of  climb.  Corresponding  to  this  rate  of  climb  at   25,  000  ft.,  is  a  time  rate  of  change  of  ambient  pressure.  Calculate  this  rate  of  change   of  pressure  in  units  of  pounds  per  square  foot  per  second.   a. 1717  lb/ft2  sec   b. 1617  lb/ft2  sec   c. 1817  lb/ft2  sec   d. 1718  lb/ft2  sec   22. Consider  a  flying  wing  (such  as  the  Northtrop  YB-­‐49  of  the  early  1950s)  with  a  wing   area  of  206  m2,  an  aspect  ratio  of  10,  span  effectiveness  factor  of  0.95,  and  a  NACA   4412  airfoil.  The  weight  of  the  airplane  is  7.5  x105  N.  If  the  density  altitude  is  3  km.   and  the  flight  velocity  is  100  m/s,  calculate  the  total  drag  on  the  aircraft.   a. 2.35  x  104  N   b. 2.23  x  104  N   c. 2.33  x  104  N   d. 2.53  x  104  N   23. A  high-­‐speed  subsonic  Boeing  777  airliner  is  flying  at  a  pressure  altitude  of  12  km.  A   pitot   tube   on   the   vertical   tail   measures   a   pressure   of   2.96   x   104   N/m2.   At   what   Mach   number  is  the  airplane  flying?   a. 0.708   b. 0.801   c. 0.089   d. 0.616   24. Consider   the   flow   of   air   through   a   supersonic   nozzle.   The   reservoir   pressure   and   temperature   are   5   atm   and   500   K,   respectively.   If   the   Mach   number   at   the   nozzle   exit  is  3,  calculate  the  exit  pressure,  temperature,  and  density.   a. 1.37  x  104  Pa   b. 1.73  x  104  Pa   c. 1.30  x  104  Pa   d. 1.33  x  104  Pa   25. Temperature   a. 175.5  K   b. 157.6  K   c. 168.7  K   d. 178.6  K   26. Density   a. 0.267  kg/m3   b. 0.762  kg/m3   c. 0.672  kg/m3   d. 0.327  kg/m3   27.  If  the  aircraft  is  operated  in  steady  flight  at  maximum  lift/drag  ratio,  the  total  drag   is:   a. minimum   b. maximum   c. below  maximum   d. above  minimum   28.    It  is  equal  to  the  limit  load  multiplied  by  the  factor  of  safety.   a. Ultimate  load   b. Maximum  load   c. Gust  load   d. Safe  load            PHILIPPINE  STATE  COLLEGE  OF  AERONAUTICS     Piccio  Garden,  Villamor,  Pasay  City     29.    Lift-­‐off   velocity   is   typically   how   many   percent   higher   than   the   stalling   velocity   to   ensure  a  margin  of  safety  during  take-­‐off?   a. 30%   b. 20%   c. 10%   d. 40%   30.    A  gyroscopic  instrument  which  provides  details  for  roll  rate,  and  movements  about   roll  and  yaw  axis.   a. Attitude  indicator   b. Heading  indicator   c. Turn  indicator   d. VOR   31. A  compass  turning  indicator,  when  heading  north,     a. Lags  or  initially  turns  in  the  opposite  direction   b. Indicates  the  right  direction  but  with  acceleration   c. Indicates  correct  heading   d. All  of  the  above   32. It  is  the  best  rate  of  climb  speed  and  is  used  to  gain  most  altitude  in  a  given  period  of   time.   a. Vy   b. Vx   c. Vno   d. Vs   33. Power  required  is  a  function  of   a. Powerplant   b. Aerodynamic  design  &  weight   c. Altitude   d. Alternator     34. It  includes  the  effect  of  variation  of  parasite  drag  with  lift   a. Oswalds   b. Reynold’s  number   c. Load  factor   d. Mach  number   35. A   pitot   tube   is   mounted   in   the   test   section   of   a   high   speed   subsonic   wind   tunnel.   The   pressure  and  temperature  of  the  airflow  are  1  atm  and  270  K,  respectively.  If  the  flow   velocity  is  250  m/s,  what  is  the  pressure  measured  by  the  pitot  tube?   5   2   a. 1.53  x  10 N/m   5   2   b. 1.48  x  10 N/m   5   2   c. 1.55  x  10 N/m   5   2 d. 1.42  x  10 N/m   36. The  maximum  lift  to  drag  ratio  of  the  World  War  I  Sopwith  Camel  was  7.7.  If  the  aircraft   is  in  flight  at  5000  ft  when  the  engine  fails,  how  far  can  it  glide  in  terms  of  distance   measured  along  the  ground?   a. 629 miles   b. 700 miles   c. 719 miles   d. 729 miles.   37. Consider an airplane with a parasite drag coefficient of 0.025, an aspect ratio of 6.72, and an Oswald efficiency factor of 0.9. Calculate the value of (L/D)max a. 13.78 b. 14.78 c. 13.55 d. 14.55  PHILIPPINE  STATE  COLLEGE  OF  AERONAUTICS     Piccio  Garden,  Villamor,  Pasay  City     38. Find R.N. for an airplane wing 4 ft chord, moving at 150 mph. Air is 40 C; barometer 21 in Hg a. 4,500,000 b. 4,300,000 c. 3,400,000 d. 5,300,000 39. A  Fairchild  monoplane  weighs  2,550  lb;  its  wing  span  is  36  ft,  4in.  At  5000  ft  altitude,   what  is  the  induced  drag  at  an  airspeed  of  122  mph?   a. 67.9  lb     b. 47.8  lb     c. 55.9  lb     d. 40.9  lb   40. An  airplane  is  making  a  turn  of  1/8  mile  radius  at  a  speed  of  225  mph.  What  is  the  load   factor?     a. 5.0     b. 5.5   c. 5.9   d. 5.2   41. Is  the  portion  of  parasite  drag  generated  by  the  aircraft  due  to  its  shape  and  airflow   around  it?     a. Interference  drag   b. Form  drag   c. Skin  friction  drag   d. Shape  drag   42. Is  the  velocity  of  the  air  far  upstream  of  the  airfoil?     a. Stream  velocity   b. Relative  velocity   c. Free  stream  velocity   d. Indicated  velocity   43. The  initial  tendency  of  the  aircraft  to  remain  in  a  new  condition  after  its  equilibrium  is   disturbed.     a. Neutral  Static  Stability   b. Positive  Dynamic  Stability   c. Neutral  Dynamic  Stability   d. Positive  Static  Stability   44. The  layer  of  air  over  the  wing’s  surface  that  is  slowed  down  or  stopped  by  viscosity.     a. Compression  Wave   b. Laminar  boundary  layer  flow   c. Boundary  Layer   d. Turbulent  Boundary  Layer   45. Is  a  condition  in  which  the  aircraft  tires  ride  on  a  thin  sheet  if  water  rather  than  on  the   runway’s  surface.     a. Static  Hydroplaning   b. Dynamic  Hydroplaning   c. Hydroplaning   d. Potential  Hydroplaning   46. Maximum  endurance  for  a  propeller-­‐driven  airplane  occurs  when  the  airplane  is  flying   at  ________  power  required.     a. Maximum   b. Minimum   c. Stable   d. Medium        PHILIPPINE  STATE  COLLEGE  OF  AERONAUTICS     Piccio  Garden,  Villamor,  Pasay  City     47. Lift-­‐off  speed  will  be  anywhere  from  __________  times  the  stall  speed  or  minimum  control   speed.     a. 1.00  to  1.25   b. 1.08  to  1.25   c. 1.05  to  1.25   d. 1.03  to  1.25   48. Limit  load  factor  for  normal  category  aircraft.     a. 4.4  to  -­‐1.76   b. 3.9  to  -­‐1.52   c. 3.8  to  -­‐1.52   d. 6.0  to  -­‐3.00.   49. Air  circulation  around  an  airfoil  occurs  when  the  front  stagnation  point  is  below  the   leading  edge  and  the  aft  stagnation  point  is  _____  the  trailing  edge.     a. Beyond   b. Above   c. Below   d. Within     50. A  standard  pressure  lapse  rate  is  one  which  pressure  decreases  at  a  rate  approximately   1  inHg  per  1,000  feet  of  altitude  gain  to  ________.     a. 10,000  feet   b. 35,000  feet   c. 11,000  feet   d. 40,000  feet            PhilSCA MOCK EXAMINATION 2015 ANSWER KEYS SUBJECT: AERODYNAMICS SUBJECT: POWERPLANT SUBJECT: AIRLAWS, ECONOMICS, MANAGEMENT 1. C 1. C AND ETHICS 2. C 2. B 3. C 3. C 1. A 4. B 4. C 2. A 5. C 5. C 3. B 6. B 6. C 4. C 7. B 7. B 5. A 8. D 8. C 6. B 9. D 9. C 7. A 10. C 10. B 8. B 11. C 11. B 9. C 12. A 12. B 10. C 13. C 13. B 11. B 14. B 14. B 12. B 15. B 15. A 13. C 16. D 16. A 14. D 17. B 17. A 15. D 18. C 18. A 16. D 19. D 19. A 17. A 20. A 20. A 18. A 21. A 21. A 19. A 22. D 22. A 20. D 23. B 23. B 21. D 24. A 24. A 22. D 25. D 25. C 23. A 26. A 26. B 24. A 27. A 27. B 25. B 28. A 28. C 26. B 29. B 29. D 27. A 30. C 30. A 28. B 31. A 31. A 29. B 32. A 32. C 30. A 33. B 33. A 31. B 34. A 34. A 32. C 35. B 35. B 33. C 36. D 36. C 34. C 37. A 37. B 35. A 38. C 38. C 36. D 39. C 39. A 37. B 40. D 40. B 38. B 41. B 41. A 39. B 42. C 42. A 40. A 43. A 43. B 41. B 44. C 44. B 42. C 45. B 45. A 43. C 46. B 46. A 44. B 47. C 47. B 45. D 48. C 48. B 46. A 49. A 49. B 47. D 50. A 50. A 48. C 49. C 50. A  PhilSCA MOCK EXAMINATION 2015 ANSWER KEYS SUBJECT: AIRCRAFT SUBJECT: AIRFRAME STRUCTURES AND DESIGN 1. B 1. B 2. B 2. C 3. A 3. B 4. A 4. C 5. C 5. A 6. A 6. B 7. A 7. B 8. C 8. A 9. A 9. B 10. C 10. A 11. B 11. A 12. A 12. B 13. B 13. B 14. C 14. A 15. B 15. B 16. A 16. A 17. A 17. C 18. C 18. C 19. B 19. C 20. A 20. C 21. C 21. A 22. A 22. B 23. B 23. A 24. B 24. C 25. B 25. C 26. A 26. C 27. A 27. A 28. B 28. C 29. B 29. A 30. B 30. B 31. C 31. A 32. A 32. C 33. B 33. C 34. A 34. C 35. C 35. A 36. A 36. A 37. B 37. A 38. B 38. C 39. B 39. A 40. A 40. C 41. A 41. A 42. B 42. C 43. B 43. C 44. B 44. C 45. A 45. C 46. B 46. A 47. A 47. B 48. C 48. B 49. A 49. B 50. A 50. B PhilSCA MOCK EXAMINATION 2015 ANSWER KEYS  Feati University Helios St. Sta. Cruz Metro Manila Feati Aeronautical Engineering Board Review Program Computational Aerodynamics Mock Board Exam Directions: Write the letter of the correct answer on the space provided before the number. 1. Consider an airplane flying at a pressure altitude of 33,500 ft and a density altitude of 32,000 ft. Calculate the outside air temperature. a. 378 R c. 368 R b. 380 R d. 370 R 2. An F-15 supersonic fighter aircraft is in rapid climb. At the instant it passes through a standard altitude of 25,000 ft, its time rate of change of altitude is 500 ft/s, which by definition is the rate of climb. Corresponding to this rate of climb at 25,000 ft is a time rate of change of ambient pressure. Calculate this rate of change of pressure in units of lb/ (ft2) (s). a. -16.16 lb/ft2 s c. -20.25 lb/ft2 s 2 b. -17.17 lb/ft s d. -19.88 lb/ft2 s 3. An airplane is flying at a velocity of 130 mi/h at a standard altitude of 5000 ft. At a point on the wing, the pressure is 1750.0 lb/ft2. Calculate the velocity at that point, assuming incompressible flow. a. 220.5 fps c. 216.8 fps b. 218.9 fps d. 212.8 fps 4. A supersonic transport is flying at a velocity of 1500 mi/h at a standard altitude of 50,000 ft. The temperature at a point in the flow over the wing is 793.32R. Calculate the flow velocity at that point. a. 6.9 fps c. 7.9 fps b. 6.3 fps d. 7.2 fps 5. Consider a low speed subsonic wind tunnel with a nozzle contraction ratio of 1:20. One side of the mercury manometer is connected to the settling chamber, and the other side to the test section. The pressure and temperature in the test section are 1 atm and 300 K, respectively. What is the height difference between the two columns of mercury when the test section velocity is 80 m/s? a. 3.8 cm c. 2.8 cm b. 3.2 cm d. 2.0 cm 6. A pitot tube is mounted in the test section of a low speed subsonic wind tunnel. The flow in the test section has a velocity, static pressure, and temperature of 150 mi/h, 1 atm, and 70 F, respectively. Calculate the pressure measured by the pitot tube. a. 2172 lb/ft2 c. 2072 lb/ft2 2 b. 3172 lb/ft d. 3072 lb/ft2 7. The altimeter on a low