Aerodynamics Conceptual Questions (Mock Exams)

Which statement relates to Bernoulli`s principle?

a. For every action there is an equal and opposite reaction.

b. An additional upward force is generated as the lower surface of the wing deflects air downward.

c. Air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface.

d. Air traveling faster over the curved upper surface of an airfoil causes higher pressure on the top surface.

C

Which force is not present during gliding?

a. Thrust

b. Weight

c. Lift

d. Drag

A

Which of the following is true about the Bernoulli's Principle?

a. dynamic pressure is maximum at stagnation point

b. total pressure is zero when velocity of stream is zero

c. dynamic pressure decreases as static pressure decreases

d. dynamic pressure decreases as static pressure increases

D`

It is the difference between the geometric and effective pitch.

a. Slip

b. interference

c. efficiency

d. resultant pitch

A

On the NACA series airfoil the first digit stands for?

a. maximum thickness

b. location of camber

c. camber

d. airfoil maximum lift

C

What limits the high airspeed potential of a helicopter?

a. harmonic resonance

b. Rotor RPM limitations

c. induced drag

d. retreating blade stall

D

Speed of sound is a function of what parameter?

a. velocity

b. temperature

c. viscosity

d. none of the above

B

Which statement is correct about the Cl and angle of attack?

a. for an asymmetric aerofoil with positive camber, if angle of attack is greater than 0, Cl = 0

b. for a symmetric aerofoil, if angle of attack = 0, Cl =0

c. for a symmetric aerofoil, if angle of attack = 0, Cl is not equal to 0

d. for an asymmetric aerofoil, if angle of attack = 0, Cl =0

B

What happens to the value of lift as velocity is doubled?

a. Doubled

b. Tripled

c. Quadrupled

d. Reduced by half

C

It is well known as the asymmetric blade effect.

a. C - factor

b. Efficacy ratio

c. P - factor

d. Slipstream

C

Which of the following controls the direction of helicopter about the vertical axis?

a. Cyclic

b. Correlator

c. Collective

d. Pedals

D

Air passes a normal shock wave. Which of the following statements is correct?

a. The temperature increases

b. The pressure decreases

c. The temperature decreases

d. The velocity increases

A

When the air has passed through a normal shock wave the Mach number is

a. lower than before but still greater than 1

b. equal to 1

c. higher than before

d. less than 1

D

As altitude increases, the speed of sound?

a. The same

b. Increase

c. Decrease

d. Not greater than 1

C

What limits the high airspeed potential of a helicopter?

a. harmonic resonance

b. Rotor RPM limitations

c. induced drag

d. retreating blade stall

D

It is the effect by which the force applied only occurs 90 degrees from the point application.

a. rigidity in space

b. Translational lift

c. conservation of momentum

d. Gyroscopic precession

D

The lift- and drag forces, acting on a wing cross section

a. Depends on the pressure distribution about the wing cross section.

b. Is normal to each other at just one angle of attack.

c. Is proportional to each other, independent of angle of attack.

d. Varies linearly with the angle of attack.

A

On standard atmosphere, as temperature increases, density ______?

a. The same

b. Is constant

c. Increases

d. Decreases

D

If your aircraft has wing washout, it is designed to stall from the?

a. Bottom to top

b. Leading edge to trailing edge

c. Tip to root

d. Root to tip

D

When you lower your flaps, you:

a. Decrease wing camber

b. Decrease stall speed

c. Decrease lift

d. Decrease drag

B

When you retract your flaps, you immediately Decrease:

a. Lift

b. Drag

c. Camber

d. All of the above

D

The difference between IAS and TAS will:

a. Increase at decreasing temperature

b. Increase at increasing air density.

c. Decrease at increasing speed.

d. Decrease at decreasing altitude.

D

Is a process which is both adiabatic and reversible?

a. Isobaric

b. Isometric

c. Isentropic

d. Isochoric

C

Which of the following statements about stall speed is correct?

a. Decreasing the angle of sweep of the wing will decrease the stall speed

b. Increasing the angle sweep of the wing will decrease the stall speed

c. Use of a T-tail will decrease the stall speed

d. Increasing the anhedral of the wing will decrease the stall speed

A

The additional increase in drag at mach no.

above the critical Mach no. is due to:

a. Wave drag

b. Increase angle of attack

c. Increased interference drag

d. Increased skin friction drag

A

When the air is passing through a shock wave the static temperature will:

a. Increase

b. Decrease

c. Stay constant

d. Decrease and beyond a certain mach no. start increasing again

A

The relative thickness of an aerofoil is expressed in:

a. Camber

b. Meters

c. % camber

d. % chord

D

"A line connecting the leading- and trailing edge midway between the upper and lower surface of a aerofoil". This definition is applicable for :

a. The Mean aerodynamic chord

b. The upper camber line

c. The camber line

d. The chord line

C

Compared with an oblique shock wave at the

same Mach number a normal shock wave has a:

a. Higher expansion

b. Smaller compression

c. Smaller expansion

d. Higher compression

D

Increasing the no. of propeller blades will:

a. Decrease the torque in the propeller shaft at max power

b. Increase the max absorption of power

c. Increase the prop efficiency

d. Increase the noise level at max power

B

The critical angle of attack:

a. Decrease if the CG is moved aft

b. Changes with an increase in gross weight

c. Remains unchanged regardless of the gross weight

d. Increase if the CG is moved FWD

C

Air passes a normal shock wave. Which of the following statement is correct?

a. The temperature increases

b. The pressure decreases

c. The temperature decreases

d. The velocity increases

A

Ground effect has the following influence on the landing

a. Decreases

b. Does not change

c. Increase only if the landing flaps are fully extended

d. Increases

D

Which of the following flight phenomena can happen at Mach Numbers below the critical Mach number?

a. Mach buffet

b. Shock stall

c. Dutch roll

d. Tuck under

C

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

A

Which of the following is a glider?

a. Zenith S-5

b. Zeppelin

c. F/A - 18

d. DG 1001

C

It is the sum of the gage pressure and atmospheric pressure.

a. Absolute pressure

b. Gage pressure

c. Vacuum pressure

d. Plenum pressure

A

Atmosphere is made of _________ of Argon.

a. 20.94 percent

b. 78.08 percent

c. 0.001 percent

d. 0.94 percent

D

Which of the following is not present in a subsonic wing?

a. Induced Drag

b. Wave Drag

c. Parasite Drag

d. Interference Drag

B

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

B

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

C

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.

D

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

A

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.

A

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

C

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

A

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

B

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

C

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.

A

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.

A

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.

A

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

C

Too much angle of bank during a level turning flight may cause _____.

a. slipping

b. blanketing

c. skidding

d. porpoising

A

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

A

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

B

The distance between the wings of a biplane is properly termed as _____.

a. gap

b. decalage

c. stagger

d. cathedral

A

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

C

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.

B

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

D

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.

B

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

A

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

A

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.

C

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

C

Which of the following conditions will an aircraft experience the greatest stress?

a. Climbing flight

b. Level flight

c. Turning flight

d. Gliding flight

C

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

D

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

C

At higher altitude, stall speed will _____.

a. increase

b. decrease

c. remain constant

d. stay constant until it reaches tropopause

A

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

A

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

B

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

C

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

D

Which statement relates to Bernoulli`s principle?

a. For every action there is an equal and opposite reaction.

b. An additional upward force is generated as the lower surface of the wing deflects air downward.

c. Air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface.

d. Air traveling faster over the curved upper surface of an airfoil causes higher pressure on the top surface

C

The term `angle of attack` is defined as the angle between the

a. chord line of the wing and the relative wind.

b. airplane`s center line and the relative wind.

c. airplane`s longitudinal axis and that of the air striking the airfoil.

d. wing chord line and aircraft's longitudinal axis.

A

In what flight condition are torque effects more pronounced in a single-engine airplane?

a. Low airspeed, high power, high angle of attack.

b. Low airspeed, low power, low angle of attack.

c. High airspeed, high power, high angle of attack.

d. High airspeed, low power, high angle of attack.

A

What is one purpose of wing flaps?

a. To enable the pilot to make steeper approaches to a landing without increasing the airspeed.

b. To relieve the pilot of maintaining continuous pressure on the controls.

c. To decrease wing area to vary the lift.

d. to reduce landing roll

A

Which force is not present during gliding?

a. lift

b. drag

c. Thrust

d. Weight

C

When a fluid travels through a tube which contains a venturi, at the point of the restriction, the fluid:

a. slows down

b. create vacuum

c. reduce pressure

d. heats up

C

Lift is proportional to speed. Which of the following would give the same lift as low airspeed and high angle of attack?

a. low airspeed and low AOA

b. High airspeed and high AOA

c. high airspeed and low AOA

d. low airspeed and high AOA

C

The aspect ratio of a wing is calculated by:

a. wing area divided by wing span

b. wing span divided by wing thickness

c. wing span divided by chord

d. wing area divided by wing chord

C

The center of pressure of a wing is the point where:

a. point of rotation

b. resultant forces of lift an drag acts

c. aircraft is balanced

d. most lift is created

B

When the angle of attack of a wing is increased the center of pressure moves:

a. forward

b. backward

c. constant

d. everywhere

A

At the point of a wing stall:

a. Lift increases, drag decreases

b. Lift decreases, drag increases

c. Lift increases, drag increases

d. Lift decreases, drag decreases

B

Induced drag can be reduced by:

a. Shiny surfaces

b. High aspect ratio wings

c. Fewer (or thinner) lines or wires

d. Flying at minimum sink

B

Parasitic drag has the property of:

a. Squaring with speed

b. Doubling with speed

c. squaring with lift

d. Doubling with lift

A

Lowering temperature and/or pressure has the following effect on the altitude reading on an altimeter:

a. The indicated height is lower than actual height.

b. The indicated height is higher than actual height

c. The indicated height is accurate

d. The altimeter is completely inaccurate

B

The speed of sound in the atmosphere changes with?

a. pressure

b. visibility

c. temperature

d. humidity

C

It is line from the leading edge up to the trailing of the airfoil that is equidistant from the lower and upper surface.

a. Chord

b. thickness line

c. mean camber line

d. camber

C

When a blade flaps up, its CG will shift closer to the hub giving the blade a tendency to?

a. speed up

b. slow down

c. stop

d. has no effect

A

The primary purpose of a tail rotor system is?

a. maintain flight heading

b. counteract effect of torque

c. assist in turns

d. stabilize helicopters longitudinal axis

B

At zero angle of attack, a symmetrical wing section will produce?

a. positive lift

b. negative lift

c. zero lift

d. positive or negative depending on camber thickness

C

Which of the following is true about the Bernoulli's Principle?

a. dynamic pressure is maximum at stagnation point

b. total pressure is zero when velocity of stream is zero

c. dynamic pressure decreases as static pressure decreases

d. dynamic pressure decreases as static pressure increases

D

Which of the following is true about boundary layer?

a. turbulent boundary layer is thinner

b. turbulent will separate more quickly than laminar

c. turbulent has more kinetic energy than laminar

d. turbulent gives more skin friction

C

It is the mass of helicopter divided by area of rotor blades.

a. solidity

b. wing loading

c. blade loading

d. disc loading

D

The maximum glide distance of an aircraft is obtained when?

a. induced drag equals lift

b. parasite and induced drag are equal

c. parasite is greater than induced drag

d. parasite drag equals lift

B

During climb the rate of climb is dependent on?

a. thrust available

b. excess thrust

c. excess power

d. thrust required

C

At service ceiling the rate of climb of the aircraft is equal to?

a. zero

b.100 fps

c. 200 fps

d. 100 fpm

D

The critical angle of attack?

a. changes with location of CG

b. changes with gross weight

c. depends on velocity

d. remains unchanged regardless of gross weight

D

Which airplane design has the highest probability of super stall?

a. V tail

b. swept wing

c. canard

d. T Tail

D

Which of the following is the disadvantage of increasing propeller blades.

a. higher tip speed

b. less power absorbed by the propeller

c. increase noise

d. decrease propeller efficiency

D