WorksheetsAerodynamics 2
Total questions: 109
Worksheet time: 55mins
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:
1.9
1.45
0.9
0.45
In a gust, which combination of speeds is applicable for the structural strength of an aeroplane in the clean configuration at MSL?
28 fps and Vd
66 fps at all speeds
66 fps and Vb
56 fps and Vc
The load factor that determines Va is the:
gust load factor at 66 fps
manoeuvring flap limit load factor
manoeuvring limit load factor
manoeuvring ultimate load factor
To maintain altitude and speed when an aeroplane is rolled into a turn the pilot must (i) . . .. . .. . .. . .the thrust: (ii) . . .. . .. . .. . .. . .the angle of attack.
(i) maintain;
(ii) increase
(i) increase;
(ii) increase
(i) increase;
(ii) maintain
(i) increase;
(ii) decrease
The data that may be obtained from a buffetonset boundary chart is:
Mmo for various masses and altitudes
Mcrit for various masses and altitudes
the low-speed and the high-speed stall Mach numbers for various masses and altitudes
the low-speed and the high-speed buffet Mach numbers for various masses and altitudes
The manoeuvring load factor positive limit for a utility category light aeroplane in the clean configuration is:
6.0
4.4
2.5
3.8
Two aeroplanes at different masses execute a 20◦ banked turn at 150 kt IAS. The heavier aeroplane will:
have a greater rate of turn than the lighter aeroplane
turn at the same radius as the lighter aeroplane
have a larger turn radius than the lighter aeroplane
have a smaller radius of turn than the lighter aeroplane
The limiting load factor for a large transport aeroplane in the manoeuvring diagram is:
2.0
4.4
6.0
2.5
Two identical aeroplanes mass 1500 kg commence a 20◦ banked turn. Aeroplane A flies at 130 kt and aeroplane B flies at 200 kt. Which of the following statements is correct?
The load factor for A is greater than the load factor for B.
The turn radius for A is greater than the turn radius for B.
The Cl for A is smaller than the Cl for B
The rate of turn for A is greater than the rate of turn for B.
Given: TAS 300 kt; Bank angle 45◦; g = 10 m/s2. The turn radius is:
2387 m
4743 m
9000 m
3354 m
The manoeuvring load factor for a large jet transport aeroplane with flaps extended is:
1.5
2.5
4.4
2.00
The buffet margin:
is always greatest after a step climb
decreases during a constant Mach number descent
is always positive below Mmo
increases during a constant IAS descent
By what percentage does Va alter when an aeroplane’s mass decreases by 19%?
10% lower
4.36% lower
It remains the same
19% lower
In straight and level flight Cl is 0.4. An increase of 1◦ of the angle of attack increases Cl by 0.09. A vertical gust changes the angle of attack by 5◦. The revised instantaneous load factor is:
2.125
1.09
2.00
3.18
Va is:
the speed that should not be exceeded in a climb
the maximum speed at which maximum upelevator deflection is permitted
the maximum speed at which rolls are permitted
the turbulence speed for transport aeroplanes
Vmo:
should be chosen between Vc and Vd
is equal to the design speed for maximum gust intensity
is the calibrated airspeed at which Mmo is reached at FL350
should not be greater than Vc
The three vertical speeds in fps for the clean configuration that determine the shape of the gust load factor diagram are:
25; 55; 75
35; 55; 66
28; 56; 66
15; 56; 65
The turn indicator shows a right turn and the slip indicator is left of the neutral position. The action required to coordinate the turn is:
decrease the right bank
increase the rate of turn
increase the right bank
increase the right rudder
The approximate total lift of an aeroplane of 50 000 N gross mass in a 45◦ banked turn is:
50 000 N
80 000 N
70 000 N
60 000 N
In a level, coordinated turn the load factor n (i) . . .. . ...and the stalling speed Vs (ii) . . .. . .. . . are:
(i) less than 1;
(ii) lower than in straight and level flight
(i) more than 1;
(ii) lower than in straight and level flight
(i) less than 1; (ii) higher than in straight and level flight
(i) more than 1; (ii) higher than in straight and level flight
Exceeding Va by a small amount may result in:
permanent structural damage if the elevator is deflected fully up
structural failure if the elevator is deflected fully up
permanent structural damage because of excessive dynamic pressure
structural failure if a turn is executed
At high altitude an aeroplane flies at a Mach number that ensures a 0.3g buffet margin. So that the buffet margin is increased to 0.4g at the same speed the pilot must:
increase the angle of attack
decrease the altitude
extend the flaps to the take-off setting
increase the altitude
If there is only one fixed value of Va it is:
the speed at which the aeroplane will stall at the manoeuvring load factor at the MTOM
the maximum speed in smooth air
the speed that ensures that the maximum manoeuvring load factor is not exceeded with unrestricted use of the elevators
the speed to be used in rough air
The bank angle to be used in a rate one turn depends on the:
TAS
mass
load factor
wind
Regarding the gust load of an aeroplane for every other factor remains constant, which of the following statements is correct:
(i) the gust load increases when the mass decreases.
(ii) the gust load increases when the altitude increases.
(i) incorrect; (ii) incorrect
(i) incorrect; (ii) correct
(i) correct; (ii) incorrect
(i) correct; (ii) correct
If all other factors remain constant, which of the following has the effect of increasing the load factor?
increased aeroplane mass
decreased air density
aft CG
vertical gust
Regarding the gust load of an aeroplane if every other factor remains constant, which of the following statements is correct:
(i) the gust load increases with increased aspect ratio of the wing.
(ii) the gust load increases when the speed increases.
(i) correct; (ii) correct
(i) incorrect; (ii) correct
(i) incorrect; (ii) incorrect
(i) correct; (ii) incorrect
Is it permissible for a transport aeroplane to exceed the ‘buffet-onset Mach number?
Yes, during the approach.
Yes, to fly faster at extremely high altitudes
No
Yes
The speed limiting the right side of the gust manoeuvre envelope is:
Vmo
Vd
Vc
Vflutter
The formula to determine wing loading is:
1/Bank Angle
Mass/Lift
Lift/Mass
Mass/Wing Area
The following device is used to ensure the correct response when a jet aeroplane enters or leaves a turn:
a yaw damper
vortex generators
a dorsal fin
differential ailerons
The following device is used to ensure the correct response when a jet aeroplane enters or leaves a turn:
a yaw damper
vortex generators
a dorsal fin
roll-control spoilers
To maintain altitude and airspeed during a turn the pilot must:
increase the angle of attack
increase the angle of attack and increase the thrust
increase the thrust
decrease the radius of the turn
The percentage increase of lift, over that required in straight and level flight, required to maintain altitude during a 45◦ banked turn is:
10%
20%
41%
50%
A heavy aeroplane and a light aeroplane enter a turn at the same TAS and with the same bank angle. The radius of turn of the heavy aeroplane is . . .. . ... that of the light aeroplane.
the same as
greater than
less than
double
The radius of turn attained at a TAS of 300 kt with 45◦ of bank if g is assumed to be 10 m/s2.
3376 ft
7829 ft
9450 ft
2398 ft
The following device is used to ensure the correct response when a jet aeroplane enters or leaves a turn:
a yaw damper
vortex generators
a dorsal fin
aileron-rudder coupling
The effect that mass has on the radius of turn for the same bank angle is that:
it increases proportionately as mass increases
it decreases proportionately as mass increases
mass does not affect the radius of turn
it increases proportionately as mass decreases
To maintain a constant Mach number in a level turn the pilot has to increase:
the angle of attack and maintain the thrust setting
the angle of attack and increase the thrust
the thrust and maintain the same angle of attack
the thrust and decrease the angle of attack
In a right turn the slip indicator is left of neutral. One of the ways to coordinate the turn is to apply:
a greater rate of turn
more left rudder
more right rudder
less right bank
The manner in which a pilot can increase the rate of turn and decrease the radius of turn simultaneously is to:
increase the bank angle and increase the airspeed
decrease the bank angle and increase the airspeed
decrease the bank angle and decrease the airspeed
increase the bank angle and decrease the airspeed
In a minimum radius turn if the flap is lowered:
the aeroplane will stall
increase the turn radius provided that there is sufficient thrust to prevent the aeroplane from stalling and that Vle is not a factor
decrease the turn radius provided that there is sufficient excess thrust to maintain a safe speed and the Vfe is not a factor
increase the rate of turn but not affect the turn radius
The correct design gust value at MSL from the following is:
At Vc 56 fps
At Vd 55 fps
At Vb 26 fps
At Vd 66 fps
The relationship of Va to Vs is:
Vs1g = Va√n
Va = Vs1g√n
Va = Vs1g × n2
Va = Vs1g × n
Which of the following statements regarding Va is correct?
At speeds below Va stalling with full control deflection will damage the airframe
In normal operations Va should never be exceeded.
Full control deflection is possible without exceeding the limiting load factor up to Va.
Manoeuvring the aeroplane at speeds in excess of Va will permanently damage the airframe.
The positive limiting load factor for large jet transport aeroplanes at Vb is:
1.0
1.5
1.75
2.5
Va is the speed to be used as the maximum:
turbulence speed for transport aeroplanes
climbing speed for transport aeroplanes
speed at which maximum nose-up-elevator deflection is permitted
descending speed for transport aeroplanes
The effect on Va of a mass decrease of 19% is a decrease of:
10%
19%
5%
4.4%
The limiting load factor for a light utility aeroplane is:
4.4
5.0
2.5
2.0
If the maximum cruise altitude limited by the minimum load factor is exceeded:
the load factor may be exceeded if turbulence is encountered
the load factor may be exceeded if a sudden turn is made
Mach buffet will be immediately experienced
Mach buffet may be induced by turbulence
The positive limiting load factor for large jet transport aeroplanes with flaps extended is:
1.5
2.0
2.5
4.4
Va is the speed at which:
a gust factor of 56 fps is determined
an aeroplane should fly in turbulence
the maximum cruise ceiling is determined
full elevator deflection is possible without exceeding the load limits
The following values can be determined from the buffet-onset boundary chart:
Mcrit at various altitudes and masses
the stalling speed for various altitudes and masses
the low-speed and the high-speed buffet at various altitudes and masses
all of (a), (b) and (c) above
The manoeuvre diagram right limitation is the speed:
Vd
Vmo
Vc
Va
Which of the following actions would increase the buffet margin?
Increase the Mach number
Decrease the Mach number.
Increase the altitude with the same Mach number.
Decrease the altitude with the same Mach number
Mach buffet margin:
decreases with decreased altitude at constant Mach number
is constant at Mmo
improves using the cruise climb technique
increases with decreased altitude at a constant IAS
The load factor in straight and level flight is altered by:
rearward movement of the CG
a vertical gust
increased mass
increased air density
Vmo is:
greater than Vc
between Vc and Vd
less than Vc
less than Vd
The maximum acceptable cruising altitude is limited by the minimum acceptable load factor because exceeding that altitude:
turbulence may induce Mach buffet
turbulence may exceed the load factor limit
a sudden bank may exceed the load factor limit
Mach buffet will occur immediately
To produce a coordinated turn when the turn and slip needle shows right and the ball is to the left it is necessary to:
increase the bank angle to the right
increase the rudder input to the right
decrease the bank angle to the right
increase the radius of turn
Which of the following statements is true?
Extending flaps in severe turbulence moves the CP aft, which increases the margins to the structural limits.
In severe turbulence, the limiting factors are the stall and the margin to the structural limitations.
Extending flaps in severe turbulence reduces the speed and increase the margins to the structural limits.
Extending flaps in severe turbulence reduces the stalling speed and reduces the risk of exceeding the structural limitations.
The Cl of an aeroplane in straight and level flight is 0.42. A 1◦ increase of the angle of attack increase the Cl by 0.1. A vertical gust increases the angle of attack by 3◦. The instantaneous load factor is:
1.49
2.49
1.71
0.74
An aeroplane continues straight and level flight with wings level after suffering a port engine failure, which of the following statements is correct?
turn indicator neutral; slip indicator left of neutral
turn indicator left of neutral; slip indicator left of neutral
turn indicator left of neutral; slip indicator neutral
turn indicator neutral; slip indicator neutral
In what way is the longitudinal stability affected by the degree of positive camber of an aerofoil?
Positive, because the CP moves aft as the AoA increases
Negative, because the lift vector slopes forward as the AoA increases.
Positive, because the lift vector slopes backward as the AoA increases.
No effect, because the camber of the aerofoil produces a constant pitch-down moment coefficient independent of the AoA.
One of the factors that limits the maximum aft position of the CG is:
minimum value of the stick force per ‘g.’
maximum longitudinal stability of the aeroplane
maximum elevator deflection
too small an effect of the controls of an aeroplane
The aft movement of the CP during acceleration through the transonic flight regime will:
decrease the static lateral stability
increase the static longitudinal stability
decrease the longitudinal stability
increase the static lateral stability
How does the exterior appearance of an aeroplane change when it is trimmed for a speed increase?
The elevator is deflected further upward by a downward deflection of the trim tab.
The elevator is deflected further downward by a movable horizontal stabiliser.
The exterior appearance of the aeroplane will not change.
Elevator deflection is increased further downward by the upward deflection of the trim tab.
Aft movement of the CG will:
increase the elevator-up effectiveness
decrease the elevator-down effectiveness
not affect the elevator effectiveness
change the elevator effectiveness depending on the wing location
During the landing of a low-winged jet aeroplane, maximum elevator-up deflection is usually required when the flaps are (i) . . . . . . . . . and the CG is (ii) . . . . . .
(i) up; (ii) fully aft
(i) fully down; (ii) fully forward
(i) up; (ii) fully forward
(i) fully down; (ii) fully aft
The effect that a ventral fin has on the static stability of an aeroplane is longitudinal (i) . . . . . . ; lateral (ii) . . . . . . . . . ; directional (iii) . . . . . . . . . .
(i) none; (ii) negative; (iii) positive
(i) positive; (ii) negative; (iii) negative
(i) negative; (ii) positive; (iii) positive
(i) none; (ii) positive; (iii) negative
Sensitivity for a spiral dive will occur when:
the Dutch-roll tendency is too strongly suppressed by the yaw damper
the static directional stability is positive and the static lateral stability is relatively weak
the static directional stability is negative and the static lateral stability is positive
the static lateral and directional stability are both negative
The effect of heavy tropical rain on the aerodynamic characteristics of an aeroplane are to (i) . . . . . . . . .. Clmax and to (ii) . . . . . . . . .. Drag:
(i) decrease; (ii) increase
(i) decrease; (ii) decrease
(i) increase; (ii) increase
(i) increase; (ii) decrease
In straight and level flight the value of manoeuvre stability is 150 N/g. To achieve a load factor of 2.5 the increase of stick force necessary is:
450 N
150 N
225 N
375 N
The effect that the use of trim to accommodate a speed decrease has on the appearance of the aeroplane is:
the elevator is deflected further downward by a trimmable horizontal stabiliser
that it has no effect
the elevator is deflected downward by an upward deflected trim tab
the elevator is deflected further upward by a downward deflected trim tab
The CG of a stable aeroplane is located:
at the neutral point
between the aft limit and the neutral point
ahead of the neutral point by a sufficient margin
aft of the neutral point
In a sideslip to the right, an aeroplane that has static directional stability, initially the:
nose tends to move to the right
right wing drops
nose will maintain its direction
nose tends to move to the left
With the CG fixed in a position forward of the neutral point if a speed change causes a departure from the trimmed attitude; which of the following statements is correct regarding the stick-force stability?
Increased speed generates pull forces.
Nose-up trim decreases the stick-force stability.
Stick-force stability is not affected by trim.
An increase of 10 kt has more effect on stick force at low speed than it does at high speed.
Static longitudinal stability is created by:
the wing surface area being greater than the horizontal tail surface area
a large trim-speed range
the CG being located ahead of the neutral point
the CG being located ahead of the wing leading edge
An aeroplane is in a sideslip at a constant speed and angle that increases the geometric dihedral of the wing. Which of the following statements is correct?
the required lateral control force increases
the required lateral control force decreases
the required lateral control force does not change
the stick force per g decreases
The lateral static stability is decreased by:
increased wing span
anhedral
dihedral
a high wing
A statically unstable aeroplane is:
sometimes dynamically stable
sometimes dynamically unstable
never dynamically stable
always dynamically stable
An aeroplane that has positive static stability
is always dynamically unstable
may be dynamically stable, neutral or unstable
is always dynamically stablecan never be dynamically stable
can never be dynamically stable
The effect that a positive wing sweep has on directional static stability is that it has:
a destabilising dihedral effect
a negative dihedral effect
a stabilising effect
no effect
The most forward allowable position of the CG is limited by:
engine thrust and location
trim system and trim-tab surface area
wing surface area and stabilise surface area
elevator capability and elevator control forces
The (i) stick-force stability and (ii) the manoeuvre stability are positively affected by:
(i) a forward CG position; (ii) a forward CG position
(i) a forward CG position; (ii) a nose-up trim position
(i) an aft CG position; (ii) an aft CG position
(i) a nose-up trim position; (ii) a nose-up trim position
The greatest positive contribution to the longitudinal static stability is provided by:
the horizontal tailplane
the engine
the fuselage
the wing
The effect a more aft position of the CG has on the aeroplane’s longitudinal static stability (i) . . . . . . . . . . . . and the required deflection of the pitch control (ii) . . . . . . . . . . is:
(i) smaller; (ii) smaller
(i) larger; (ii) smaller
(i) larger; (ii) larger
(i) smaller; (ii) larger
A CG located beyond the aft limit leads to:
a too high pulling force during rotation for take-off
an increasing static longitudinal stability
a better recovery performance from a stall
an unacceptably low value of the manoeuvre stability (stick force per g)
Which of the following statements regarding stick force per g is correct?
An unacceptable value of stick force per g can only be corrected by electronic devices (stability augmentation):
If the slope of the Fe-n line becomes negative, it is not a problem for the control of an aeroplane.
The stick force per g must have both an upper and a lower limit in order to ensure acceptable control characteristics.
the stick force per g increases when the CG is moved aft.
If the CG is located in a forward position then the elevator deflection for a manoeuvre with a load factor greater than 1 will be:
dependent on the trim position
larger
smaller
unchanged
The lateral static stability of an aeroplane is increased by:
Fuselage-mounted wings, dihedral, T-tail
sweep back, under-wing-mounted engines, winglets
high wing, sweep back, large and high vertical tail
low wing, dihedral, elliptical wing planform
If the CG is aft of the CP straight and level flight can only be maintained when the horizontal tail loading is:
zero
downward
upward or downward depending on elevator deflection
upward
The manoeuvrability of an aeroplane is best when the:
flaps are extended
CG is on the aft limit of the CG envelope
speed is low
CG is on the forward limit of the CG envelope
The most important problem of ice accretion on an aeroplane during flight is the:
reduced Clmax
increased mass
increased drag
blocked control surfaces
The vertical load on the tailplane when the CG is forward of the CP is:
zero because in steady flight all loads are in equilibrium
downward because it is always negative regardless of the position of the CG
downward
upward
Positive static stability of an aeroplane means that once it has been displaced the:
tendency will be to move with an oscillating motion of decreasing amplitude
tendency will be to move with an oscillating motion of increasing amplitude
initial tendency to move is towards its position of equilibrium
initial tendency to move is away from its position of equilibrium
Which of the following statements is correct regarding lateral static stability and directional static stability?
Static directional stability is improved by installing more powerful engines.
An aeroplane with greater static directional stability than static lateral stability is prone to spiral instability.
The effects of static lateral stability and static directional stability are independent of each other because they are rotations about different axes.
An aeroplane with greater static directional stability than static lateral stability is prone to Dutch roll.
When the CG is at the aft limit of the CG envelope its relationship to the neutral point is:
forward of the neutral point
aft of the neutral point
at the neutral point
above the neutral point
The effect of the movement of the CG (i) on the down-force on the tail (ii) and on the stalling speed (iii) is:
(i) rearward; (ii) reduced; (iii) Vs increased
(i) forward; (ii) reduced; (iii) Vs increased
(i) rearward; (ii) increased; (iii) Vs decreased
(i) rearward; (ii) reduced; (iii) Vs decreased
The effect of the movement of the CG (i) on stability (ii) and control effectiveness (iii) is:
(i) rearward; (ii) decreased; (iii) reduced
(i) rearward; (ii) decreased; (iii) increased
(i) forward; (ii) decreased; (iii) increased
(i) forward; (ii) increased; (iii) reduced
With the CG at the forward limit of the envelope the effect on Vs (i) and stall angle (ii) is:
(i) increases; (ii) remains constant
(i) increases; (ii) increases
(i) decreases; (ii) remains constant
(i) decreases; (ii) decreases
The aft limit of the CG envelope relative to the manoeuvre point is that it is:
at the manoeuvre point
aft of the manoeuvre point
always ahead of it
furthest from it under a turn of 2g
Rearward movement of the CG:
increase spiral instability
creates a tendency to ‘Dutch roll
increase the elevator stick-force gradient
increase the value of the minimum control speed
An aeroplane that is statically unstable:
is always dynamically stable
can never be dynamically stable
is only dynamically stable at high airspeeds
may or may not be dynamically stable dependent on type
Longitudinal static stability is provided by the:
fuselage
engines
horizontal stabiliser
wings
If the total moment of an aeroplane is not zero it will rotate about the:
CP
neutral point
CG
aerodynamic centre
The position of the CG that produces the greatest stability is:
on the forward limit of the envelope
on the aft limit of the envelope
aft of the neutral point
just forward of the neutral point
For take-off if the CG is towards the forward limit the effect is:
the stick force required at rotation is increased
Vmcg is decreased
the stick force required at rotation is decreased
the stick force at rotation is unaffected
In trimmed level flight an acceleration of 10 kt has the effect on stick-force stability is:
greater at high speeds
greater at low airspeeds
not affected by speed changes
the same at all speeds
