# Aerodynamics & Flight Controls Examination

Here are questions about the applied aerodynamic lessons part 4.

The reduction of induced drag can be accomplished by (2Pt)
A. Wings with high AR
B. Flying at Vmax
C. Increasing delta angle
D. Improvement of aircraft longitudinal axis

VA or maneuvering speed is:

A. The speed at which a heavy transport aircraft should fly in turbulence.
B. The maximum speed at which rolls are allowed.
C. The maximum speed at which maximum elevator deflection up is allowed.
D. The speed that should not be exceeded in the climb.

Consider an oblique shock wave with β = 35 deg and pressure ratio
of P2/P1=3. What is the upstream mach number? (2Pt)
A. 3.21
B. 2.87
C. 4.1
D. 2.42

A plane of 3,800 lbs gross weight is turning at 175 miles per
hour with an angle of bank of 50 degrees. The centrifugal force is (2Pt)
A. 18,625 N
B. 20,144 N
C. 22,560 N
D. 21,342 N

NACA 4412 was used in the construction of the airfoil. Determine
the chord (in) if the camber equals 9.12 cm. (2Pt)
A. 89.76
B. 228
C. 22.8
D. 29.92

What is the movement of the center of pressure when the
wingtips of a sweptwing airplane are shock-stalled first? (2Pt)
A. inward and aft
B. outward and aft
C. outward and forward
D. inward and forward

Two identical aeroplanes A and B are flying horizontal steady
turns. Further data are:
Condition A W= 1500 kg Bank= 20 deg TAS= 130 kt
Condition B W= 1500 kg Bank= 20 deg TAS= 200 kt
Which of the following statements is correct? (2Pt)
B. The rate of turn A is larger than the rate of Turn
C. The load factor for A is larger than the load factor for
D. The lift coefficient A is smaller than the lift coefficient

As a rough rule, by what percent of the IAS should we add for
every 1000ft altitude gain to get the TAS? (2Pt)
A. 0.03
B. 0.02
C. 0.04
D. 0.05

The maximum altitude above sea level at which a given
airplane would be able to maintain horizontal flight under air conditions (2Pt)
A. Both A and C
B. Climb Ceiling
C. Service Ceiling
D. Absolute Ceiling

Why must the angle of attack be increased during a turn to maintain altitude? (2Pt)
A. Compensate for increase in drag
B. Compensate for loss of vertical component of lift

The true airspeed (TAS) is _. (2Pt)
A. higher than the speed of the undisturbed airstream about the aeroplane.
B. lower than the speed of the undisturbed airstream about the aeroplane.

C. lower than the indicated airspeed (IAS) at ISA conditions and altitudes below sea level.

The term angle of attack is defined as the angle between the
(2Pt)
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

The speed VNE is (2Pt)
A. the maximum speed, above which flaps should not be extended
B. the maximum airspeed at which maneuvers approaching the stall may be carried out
C. the maximum airspeed at which an aircraft may be flown

An elliptical planform wing has a span of 12 m and a chord of 2
m. What is the induced drag coefficient when the lift coefficient is 0.8? (2Pt)
A. 0.86
B. 0.068
C. 0.43
D. 0.034

To be able to predict compressibility effects, you have to
determine the (2Pt)
A. TAS
B. EAS
C. Mach Number
D. IAS

Air at an altitude of 10 km is compressed adiabatically to
101325 Pa. What is the temperature after compression? (2Pt)
A. 287.5 K
B. 542.17 K
C. 285.7 K
D. 327.88 K

Regarding curved deflecting angles, what happens to the vertical
component of force as the angle of deflection increases? Assuming that all the other
parameters remain constant. (2Pt)
A. No relationship
B. Increases
C. Decreases
D. Remains the same

Where on the surface of a typical aerofoil will flow separation
normally start at high angles of attack? (2Pt)
B. lower side trailing edge
D. upper side trailing edge

An airplane whose absolute ceiling is 14,200 ft climbs at 650
ft/min. at sea level. How long will it take to climb from sea level to service ceiling?

B. 41 min

How does the exterior view of an aircraft change, when the trim is
used during a speed decrease? (2Pt)
A. The elevator is deflected further downwards by means of an upwards deflected trimtab
B. Elevator deflected downwards by means of a trimmable horizontal stabilizer
C. Nothing changes in exterior view
D. The elevator is deflected upwards by means of a downwards deflected trimtab

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. (2Pt)
A. 5.21
B. 3.56
C. 1
D. 4.35

An expansion wave is created by a deflection angle of 10
degrees at a supersonic stream with Mach number of 2 and pressure of 2,160 lbs sq
ft. After the wave, the pressure is 1,192 per sq ft and the Mach number is (2Pt)
A. 2.16
B. 2.25
C. 2.07
D. 2.38

What is the free stream Mach number which produces first
evidence of local sonic flow? (2Pt)
A. Supersonic Mach Number
B. Critical Mach Number
C. Upon reaching Mach 1
D. Transonic Mach Number

To produce the same lift while in ground effect, the airplane
requires __. (2Pt)
A. a lower angle of attack
B. more thrust
C. the same angle of attack
D. a greater angle of attack

At which configuration can we fly the fastest speed? (2Pt)
A. Low angles of attack
B. Highest possible trim
C. During deployment of flaps
D. High angles of attack

The flow across a shockwave, whether it is a normal or an
oblique compression type is __. (2Pt)
A. Only isobaric
B. Only isentropic

To cover the greatest distance when gliding the gliding speed
must be (2Pt)
A. the one that gives the highest L/D ratio
B. near to the stalling speed
C. about 30% faster than VMD
D. as high as possible within VNE limits

A large Consider a convergent duct with an inlet area A1 = 5
m^2 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? (2Pt)
A. 1.67 m^2
B. 1.97 m^2
C. 1.24 m^2
D. 2.3 m^2

If air at sea level in standard atmosphere has a temperature of
288 K and a pressure of 101.3 kilonewtons per square meter, the air pressure in
kilonewtons per square meter at an altitude of 10,000 meters is _. (2Pt)
A. 27
B. 25.2
C. 26.3
D. 25.8

A cloth bag contains 1,000 cubic feet of air, the temperature
being 59 deg F and the pressure 29.92 in. What is the volume if the pressure is
increased to 40.0 in. and the temperature decreased to 0 deg F? (2Pt)
A. 663 ft^3
B. 436 ft^3
C. 450 ft^3
D. 336 ft^3

In a 45° banked turn, what is the load factor? (2Pt)
A. 1.32
B. 1.41
C. 1.25
D. 1.64

The standard rate of climb of service ceiling is (2Pt)
A. 100 feet per second
B. None of the above
C. 90 feet per second
D. 80 feet per second

Solve for the approximate speed of sound in air at which h is
the average altitude in the Troposphere. (2Pt)
A. 600 knots
B. 620 knots
C. 550 knots
D. 570 knots

What weight can an airplane have to fly level with a Clark Y
wing 250 sq. ft. in area, at 4 deg angle of attack and airspeed of 100 miles per hour
at sea-level?
Clark Y Airfoil Data
a Cl
-4 .2
2 .5
3 .55
5 .75 (2Pt)
A. 4230
B. 470
C. 469
D. 4120

The left wing may be set at a very slightly greater angle of
incidence, or in a biplane by tightening the rigging the left wing may be warped or
twisted to have slightly greater camber. The latter is called (2Pt)
A. Bi-wing Angle of Attack
B. Turnover Angle
C. Wash In
D. Incidence

What is the expected duration of an individual microburst?
(2Pt)
A. For as long as 1 hour
B. One microburst may continue for as long as 2 to 4 hours
C. Two minutes with maximum winds lasting approximately 1 minute
D. Seldom longer than 15 minutes from the time the burst strikes the ground until dissipation

At sea level, a propeller-driven airplane has a rate of climb of
650 ft per minute. Its service ceiling is 12,000 ft. The time to climb to reach an
altitude is 8,500 ft is _ minutes. (2Pt)
A. 19.62
B. 17.63
C. 18.24
D. 19.96

To ensure some degree of longitudinal stability in flight, the
position of the CG (2Pt)
A. must be forward of the Neutral Point
B. must always coincide with the aircraft
C. must not be forward of the aft CG limit
D. must be aft of the Neutral Point

When you lower your flaps, stall speed _. (2Pt)
A. decrease then increases
B. decrease

For an airplane weighing 4,000 lb, the excess horsepower at
sea-level is 60 hp, at 10,000-ft altitude there is 17 excess horsepower. What is service
ceiling? (2Pt)
A. 459 fpm
B. 745 fpm
C. 495 fpm
D. 547 fpm

The lift coefficient for the airfoil section on a wing __. (2Pt)
A. Is constant always
B. Is same for the entire wing
C. Is equal to the aerodynamic twist
D. Depends on local lift slope for airfoil

The helicopter?s vertical flight can only be achieved by
controlling the (2Pt)
A. Propeller RPM
B. Collective
C. Cyclic
D. Collective and Cyclic

An airplane weighs 3,000 lb. and has a landing speed of 50
miles per hour. What is landing speed with 500 lb. additional load?

C. 78 ft/s

When the air is passing through a shock wave the static
temperature will (2Pt)
A. Decrease
B. Stay Constant
C. Increase