Anúncios
1
On a swept wing aeroplane at low airspeed, the "pitch up" phenomenon:
Is caused by extension of trailing edge lift augmentation devices
is caused by boundary layer fences mounted on the wings.
Never occurs, since a swept wing is a 'remedy' to pitch up
is caused by wingtip stall.
2
Which one of the following statements about the lift-to-drag ratio in straight and level flight is correct?
At the highest value of the lift / drag ratio the total drag is lowest.
The highest value of the lift / drag ratio is reached when the lift is equal to the aircraft weight
The lift / drag ratio always increases as the lift decreases
The highest value of the lift / drag ratio is reached when the lift is zero
3
Induced drag is created by the:
separation of the boundary layer over the wing.
propeller wash blowing across the wing.
interference of the air stream between wing and fuselage.
spanwise flow pattern resulting in the tip vortices.
4
Positive static stability of an aeroplane means that following a disturbance from the equilibrium condition:
the tendency is to move with an oscillatory motion of increasing amplitude.
the initial tendency is to diverge further from its equilibrium condition.
the initial tendency is to return towards its equilibrium condition
the tendency is to move with an oscillatory motion of decreasing amplitude.
5
Which statement on dynamic longitudinal stability of a conventional aeroplane is correct?
Damping of the phugoid is normally very weak.
Speed remains constant during one period of the phugoid
Damping of the short period oscillation is normally very weak.
Period time of the phugoid is normally 5 s.
6
When the cg position is moved forward, the elevator deflection for a manoeuvre with a given load factor greater than 1 will be:
dependent on trim position
smaller
larger
unchanged
7
Which combination of design features is known to be responsible for deep stall?
Swept back wings and a T-tail.
Straight wings and aft fuselage mounted engines.
Swept back wings and wing mounted engines.
Straight wings and a T-tail.
8
After take-off the slats (when installed) are always retracted later than the flaps. Why?
Because SLATS EXTENDED gives a large decrease in stall speed with relatively
less drag.
Because SLATS EXTENDED provides a better view from the cockpit than FLAPS
EXTENDED.
Because VMCA with SLATS EXTENDED is more favourable compared with the
FLAPS EXTENDED situation
Because FLAPS EXTENDED gives a large decrease in stall speed with relatively
less drag
9
Given an aeroplane with a propeller turning clockwise as seen from behind, the torque effect during the take off run will tend to:
roll the aeroplane to the left.
pitch the aeroplane nose up.
roll the aeroplane to the right.
pitch the aeroplane nose down.
10
The type of stall that has the largest associated angle of attack is:
a deep stall
a shock stall
an accelerated stall.
a low speed stall.
11
The effects of very heavy rain (tropical rain) on the aerodynamic characteristics of an aeroplane are:
decrease of CLmax and increase of drag.
increase of CLmax and increase of drag.
increase of CLmax and decrease of drag.
decrease of CLmax and decrease of drag
12
The speed of sound is determined only by:
density
humidity
pressure
temperature
13
A laminar boundary layer is a layer, in which:
no velocity components exist, normal to the surface.
the velocity is constant
the temperature varies constantly
the vortices are weak
14
The lift force, acting on an aerofoil: (no flow separation)
is maximum at an angle of attack of 2 degrees.
is mainly caused by suction on the upperside of the aerofoil.
is mainly caused by overpressure at the underside of the aerofoil.
increases, proportional to the angle of attack until 40 degrees.
15
The induced drag:
increases as the lift coefficient increases.
increases as the magnitude of the tip vortices decreases.
has no relation to the lift coefficient
increases as the aspect ratio increases.
16
The critical angle of attack:
decreases if the CG is moved af
changes with an increase in gross weight
increases if the CG is moved forward.
remains unchanged regardless of gross weight
17
The relationship between induced drag and the aspect ratio is:
an increase in the aspect ratio increases the induced drag.
there is no relationship.
induced drag = 1.3 aspect ratio value
a decrease in the aspect ratio increases the induced drag.
18
The induced angle of attack is:
the angle by which the relative airflow is deflected due to downwash
caused by the fuselage and is greatest at the wing root
the angle by which the flow over the wing is deflected when landing flaps are set.
the angle between the local flow at the wing and the horizontal tail.
19
Slat or flap asymmetry occurring after either extension or retraction, may have an effect on controllability since:
slat asymmetry causes a yawing moment, whereas flap asymmetry causes a large
rolling moment.
slat asymmetry causes a large rolling moment, whereas flap asymmetry causes a
large yawing moment
slat and flap asymmetry both cause a large rolling moment
slat and flap asymmetry both cause a large yawing moment.
20
Which of the following situations leads to a decreasing stall speed (IAS)?
increasing air density.
decreasing weight.
increasing load factor.
increasing altitude.
