Progress 1 Flashcards
When the angle of attack of a symmetrical aerofoil is increased, the centre of pressure will?
Select one:
c. Remain unaffected
d. Move toward the leading edge
c. Remain unaffected
Rétt eða rangt? The thickness/chord ratio is expressed as a percentage of the chord
Rétt
Rétt eða rangt? It is easier for air to flow over a well rounded leading edge radius than a sharp leading edge.
Rétt
A stall warning device must be set to operate at a speed about _% above the stalling speed
5-10%
A typical stalling angle of attack for a wing without sweepback is? _°.
16
A wing of constant thickness which is not swept back?
d. will stall evenly across the span
e. could drop a wing at the stall due to the lack of any particular stall inducing characteristics
e. could drop a wing at the stall due to the lack of any particular stall inducing characteristics
Þú hefur þyngdina 100 og átt að finna stall hraða m.v. þyngdina 220 (stall hraði nú er 50). Hvernig reiknar þú þetta?
Gamli stall hraði * sqrt(nýja þyngd/gamla þyngd)
If the aircraft weight is increased without change of C of G position, the stalling angle of attack will?
remain the same
In a developed spin?
a. the angle of attack of both wings will be positive
b. the angle of attack of both wings will be negative
c. the angle of attack of one wing will be positive and the other will be negative
d. the down going wing will be stalled and the up going wing will not be stalled
a. the angle of attack of both wings will be positive
Slots increase the stalling angle of attack by?
a. Increasing leading edge camber
b. delaying separation
b. delaying separation
The input data to a stall warning device (e.g. stick shaker) system is?
a. angle of attack only.
b. angle of attack, and in some systems rate of change of angle of attack
b. angle of attack, and in some systems rate of change of angle of attack
To recover from a spin, the elevators should be?
b. moved down to reduce the angle of attack
c. set to neutral
b. moved down to reduce the angle of attack
Vortex generators are used:
b. to reduce boundary layer separation
c. to induce a root stall
b. to reduce boundary layer separation
An aircraft has a L/D ratio of 15:1 at 50 kts in calm air. What would the L/D ratio be with a direct headwind of 25 kts?
15:1
Hvaða drag eykst ef þú minnkar flughraða? (EAK)
induced drag
Aspect ratio of a wing is defined as the ratio of the? __ to the ___
wingspan, mean chord
At a given True Air Speed, what effect will increased air density have on the lift and drag of an aircraft?
Lift increases, drag also increases.
In theory, if the airspeed of an airplane is doubled while in level flight, parasite drag will become?
four time greater
On a wing, the force of lift acts perpendicular to, and the force of drag acts parallel to the?
a. flightpath.
b. longitudinal axis.
c. chord line.
d. longitudinal datum
a. flightpath.
That portion of the aircraft’s total drag created by the production of lift is called?
a. induced drag, and is greatly affected by changes in airspeed
b. induced drag, and is not affected by changes in airspeed
a. induced drag, and is greatly affected by changes in airspeed
The best L/D ratio of an aircraft occurs when parasite drag is equal to ___.
induced drag
The resistance, or skin friction, due to the viscosity of the air as it passes along the surface of a wing is a type of? a. induced drag. b. form drag. c. parasite drag d. interference drag.
c. parasite drag
When gross weight is increased, induced drag increases more/less than parasite drag.
induced drag increases more
Which relationship is correct when comparing drag and airspeed?
a. Parasite drag varies inversely as the square of the airspeed
b. Induced drag increases as the square of the airspeed.
c. Parasite drag increases as the square of the lift coefficient divided by the aspect ratio
d. Induced drag varies inversely as the square of the airspeed.
d. Induced drag varies inversely as the square of the airspeed.
