Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PPL > Theory of Flight > Flashcards

Theory of Flight Flashcards

1
Q

What are the 3 axis of the plane ?

A

Yaw (Vertical ), Roll (Longitudinal), Pitch (Lateral )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the definition of the Weight ?

A

The Downward forces toward the centre of the earth as a result of gravity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the defintion of the Drag ?

A

Drag is the resistance an airplane experiences in moving forward to the air.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the definition of the Lift ?

A

The force upwards which sustain the airplane in flight.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the definition of the Thrust ?

A

The force exerted by the engine and its propeller(s) which pushes air backward with the object of causing a reaction, or thrust in the forward direction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does an aircraft fly ?

A

According to bernouilli’s principle, as the wing moves through the air, a pressure force appears on the lower camber and a suction force appears on the upper camber. The sum of this two forces are producing the principal lifting agent. As a consequence of this phenomenon, the air mass is accelerated downward, which produces a reaction force upward, contributing further to the total lift.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the angle of attack ?

A

The angle between the chord and the relative airflow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is an angle of incidence ?

A

The design angle between the chord and the longitudinal plane of the aircraft.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the difference between parasite drag and induced drag ?

A

Parasite drag is due to surfaces that does not generate lift ( 3 types : form, friction and interference )
Induced drag is due to the surfaces that generate lift.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the ground effect ?

A

The ground effect is like an air cushion at the ground level ( due to the reduction of induced drag near the ground )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why the Frise and Differential Ailerons are used ?

A

They are used to reduce the difference of drag between the left wing and the right wing during a turn..

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are vortex generators ?

A

Vortex generators are small plates standing on edge in a raw spanwise along the wing. They tend to prevent or delay the breakaway of the boundary layer by re-energizing it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the effects of the asymmetric thrust, the slipstream and the precession on the airplane ?

A

This generate a nose left tendency that have to be counteracted with the rudder.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the Longitudinal Stability ? and what are the main contributors in the design of an airplane ?

A

Pitch Stability ( The tail stabilizer and an appropriate position of the CoG provide a good Longitudinal Stability )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the Lateral Stability ? and what are the main contributors in the design of an airplane ?

A

Roll Stability ( Keel effect, Dihedral and Sweepback designs provide a good Lateral Stability )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the Directional Stability ? and what are the main contributors in the design of an airplane ?

A

Normal Stability ( Keel effect and Sweepback design contribute to Normal Stability )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Name 5 factors that affect stalls and a very brief description of them.

A

The weight ( with a higher weight the stall speed is increased )
The center of gravity ( if positioned aft, that will decrease the stall speed but dangerously affects the stability )
Turns ( With the increase of the load factor that increases the stall speed )
Turbulences (It that changes the relative airflow with the aircraft )
Contaminants on the wing ( Dirt, Ice, Snow, Rain will alter the lifting characteristics of the airfoil and therefore the stall speed wil increase )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the main differences between Spiral dive and the Spin ?

A

The Spin is stalled whereas the Spiral dive no.
The Airspeed , Vertical Speed and Rate of Turn are constant in a spin. All these parameters are increasing during a Spiral dive .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the Mach Number ?

A

It is the ratio between the speed of a body and the speed of sound in the air surrounding the body.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Name 4 types of profile ?

A

Symmetrical, Semi-Symmetrical , Flat Bottom, Under-Camber.

21
Q

What is the aspect ratio ?

A

The ratio between the span and the average chord of the wing.

22
Q

What is the trim tab made for ?

Anti servo tab ?

A

Trim tab :To remove the pressure on the pitch control and maintain attitude during flight.
Antiservo tab : Used to increase the pressure on the controls. it can be used as a trim also.

23
Q

What are the Ancillary controls ?

A

Carburetor heating, Flaps, Trim, Throttle, Mixture.

24
Q

What is the Coanda effect ?

A

It states that the air viscosity is not very high but sufficient for the air molecules to stick to a hard surface.

25
Q

What is Adverse yaw ?

A

The adverse yaw is the tendency of a plane to yaw on the opposite side of a roll. It is due to the differential of lift (and drag ) between the two wings. The high wing in a level turn generates more lift hence more induced drag.

26
Q

What is the Dynamic Stability ?

A

It is the overall tendency of an airplane to return to it’s original position, following a series of damped out oscillation.

27
Q

What is the Static Stability ?

A

It is the initial tendency of an airplane, when disturbed, to return to the original position.

28
Q

What is the purpose of the wing fences and wash in wash out design ?

A

The wing fences and wash in wash out design of the wing enalbe the tip of the wing to stall later than the wing root then allowing a better controllability of the airplane until the effective stall.

29
Q

What are the 4 phases of the spin ?

A

The Entry ( The pilot stalls the plane while in uncoordinated flight )

The Incipient ( With one wing more stalled than the other the other, the rotation starts )

The Developed (The aircraft’s rotation rate, airspeed, and vertical speed are stabilized )

The Recovery ( After appropriate control inputs, the airplane is no longer stalled )

30
Q

What is the Cl coefficient of a Standard wing no flaps ?

A

Cl 1.09

31
Q

What is the Cl coefficient of a wing with Fowler flaps ( 45 down ) and slat ?

A

Cl 2.75

32
Q

What is the Maximum ceiling ?

A

Altitude at which the power is insufficient to maintain altitude.

33
Q

What is the Service ceiling ?

A

Altitude at which aircraft can still climb at 100 ft/ min.

34
Q

What is Maximum camber ? Maximum thickness ?

A

Maximum camber is at the location where the difference in distance between the chord line and the mean chamber line is at a maximum.

Maximum thickness is at the location where the distance between the top and bottom of the aerofoil is at a maximum.

35
Q

What is NACA code ?

NACA4311 ?

A

1st digit = max camber as percentage of the chord. (Max 5 %)
2nd digit = Position of the max camber relative to the chord (in tens of percents %), measured from the leading edge.
Last 2 digits = max thickness as percentage of the chord.

If the last 2 digits are 0 wings are symmetric.

NACA4311 = max camber 4% of the chord at 30 % of the chord from leading edge , max thickness 11% of the chord.

36
Q

What are spoilers ?

A
  • Spoilers can be seen as speed brakes which allows the aircraft to descend without gaining speed.
  • Spoilers are also used to reduce the ground roll after landing, by destroying lift and transferring weight to the wheels, therefore improving braking effectiveness.
37
Q

What are common devices using Mechanical linkages ?
Fluid pressure ?
Electrically driven power ?

A 
Mechanical linkages :
•	Stick and rudder
•	Manual flaps
•	Emergency landing gear
Fluid pressure :
•	Brakes
•	Variable pitch propeller
•	Landing gear
Electrically driven power : 
•	Some landing gear
•	Flaps
38
Q

What are the Fix trims ?

A

Small surfaces mounted on the trailing edges of ailerons and rudder to compensate for adverse yaw and roll caused by propeller and engine torque ( adjusted at the manufacture can be readjusted only by a maintenance engineer ).

39
Q

What are Control balance surfaces ?

What are Dynamic balance surfaces ?

A

Control balance surfaces :
Lead weight added to reduce fluttering of controls at high speed.
Dynamic balance surfaces :
Control surface extending beyond attachment points the air striking this extension helps to lighten the required inputs.

40
Q

How does the center of lift move according to the angle of attack ?

A

When the angle of attack increases the center of lift moves forward until the critical angle of attack ( about 15° to 17° generally ) is reached then it moves backward.

41
Q

What is Dutch roll ?

A

For an aircraft which has a strong lateral stability but weak directional stability, if it is disturbed in yaw, the yawing moment will generate a roll moment. Because of the difference of stability, the moments soon get out of phase and feed each other.

42
Q

What is Spiral instability ?

A

For an aircraft which has a strong directional but weak lateral stability , if it is disturbed in roll, it will continue to roll in the same direction and the increased angle of bank leads to more yaw and roll making the nose dropping. If the pilot doesn’t counteract the aircraft will enter a spiral dive.

43
Q

How does the Rate of turn change according to the velocity and the angle of bank ?

A

As Velocity increases the Rate decreases.

As Angle of bank incrases the Rate increases.

44
Q

How does the Radius of turn change according to the velocity and the angle of bank ?

A

As Velocity increases the Radius increases.

As Angle of bank incrases the Radius decreases.

45
Q

What are Stall strips ?

A

Triangular shaped strips are installed on the inner leading edge to provoke the stall of the inner section of the wing, before the critical angle is reached.

46
Q

What are the 5 types of airplane construction ?

A
  • Metal frame, metal covered (main strength in the skin )
  • Metal frame, metal covered ( main strength in the frame )
  • Metal frame , fabric (tissue) covered
  • Composite
  • Wooden frame, fabric covered or plywood covered ( mostly in antique planes )
47
Q

What is the Wing loading ? Power loading ? Dead load and Live load ?

A

Wing loading : The gross weight of the airplane divided by the area of the lifting surfaces
(lb/square feet).

Power loading : The gross weight of the airplane divided by the horsepower of the engine(s) (lb / hp).

Dead load : Weight of a plane standing on the ground.

Live load : The additional loading, in flight, due to acceleration.

48
Q

What is Dynamic pressure ? Static pressure ?

A

Dynamic pressure is the kinetic energy per unit of a volume of a fluid.
Static pressure is pressure at a nominated point in a fluid.

49
Q

What is the fineness ratio ?

A

Chord /Max thickness

A good range is a ratio of 4 to 1 depending on the range of speed.

PPL (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions