Brainscape's Knowledge GenomeTM

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


See full index

Mod 11: Systems > 11.1.1 - Aerodynamics and Flight Controls > Flashcards

11.1.1 - Aerodynamics and Flight Controls Flashcards

1
Q

Name thr Primary Flight Controls

A

Ailerons

Rudder

Elevator

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

Which control surface is used to control an aircraft longitudinally about the lateral axis?

A

Elevator

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

What is the purpose of a variable incidence stabiliser?

A

Angle of Incidence is the angle between chord line of wing and longitudinal axis of aircraft.

variable incidence stabiliser​ means that the full stabiliser can be moved to change the angle of incidence.

It is usually for the horizontal stabiliser and the elevator is still part of it.

Used for trimming purposes

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

What is a canard?

A

Any aircraft that has the equivalent of two lifting surfaces, instead of the conventional horizontal stabiliser that provides a down load, can be classified as a canard.

The canard is the forward surface, and frequently is also a control surface.

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

Where does an aircraft get it directional control from?

A

Directional control is achieved by the rudder.

Directional control about the vertical axis

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

What is a Ruddervator?

A

V-Tailfin

The two fixed surfaces act as both horizontal and vertical stabilisers, while also the movable surfaces are connected through a mixing-type linkage that allows in and out movement of the control wheel to move both surfaces together

The rudder pedals move the surfaces differentially.

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

What are the 2 ways of controlling spoilers?

A
  1. Arm the spoilers with the lever (cockpit)
  2. When flaps retracted, the side stick will move them to roll the aircraft instead of the ailerons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the purpose of a slot?

A

To improve the airflow conditions at high angles of attack and slow speeds

A slot is fixed

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

What effect does extending the slats/flaps have on angle of attack?

A

Changes the chord line decreasing angle of attack

(approx normal 16/17 degree to 25 degree)

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

Briefly explain ‘‘Adverse Yaw’’

A

The movement of the nose in the wrong direction at the beginning of a turn is called adverse yaw

Adverse yaw is the natural and undesirable tendency for an aircraft to yaw in the opposite direction of a roll. It is caused by the difference in lift and drag of each wing

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

Describe breifly the purpose of a stall strip (stall wedge) and its operation

A

It is extremely important that an aircraft wing stall progressively from the root out to the tip, so the ailerons will be effective throughout the stall.

If a wing does not naturually have this stall progression characteristic (washout), it is possible to place stall wedges on the leading edge of the wing in the root area.

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

Explain the operation of a Servo Tab

  • How operated
  • Movement relative to control surface
  • Purpose
A

A Servo tab is integrated into the flight control

It moves in the Opposite direction to the control surface

Assists or provides the force for moving a primary flight control. Aerodynamically positions control surfaces that require too much force to move manually.

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

What are anti-servo tabs (anti-balance tabs)?

A

Moves in the same direction as the control surface

Increases force needed by pilot to change flight control position. De-sensitizes flight controls.

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

What is the purpose of a spoiler mixer?

A

Takes 2 inputs

  1. aileron
  2. (spoiler) lever position in cockpit

determines what overall spoiler position should be

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

Explain how a vortex generator operates?

A

Small Venturi like system on top of wing at transition phase.

Vortex generator re-energises airflow to keep laminar flow for longer

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

What is the purpose of a trim tab?

(how Controlled?

What direction relative to control surface?

also purpose)

A

It is independently controlled linkage system set from the cockpit

Moves in the opposite direction as the control surface deflection

Reduces the force needed to move a primary control surface (Allows for ‘‘hands off’’ flight)

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

What will happen to control surface whose CG is behind the hinge line during flight?

A

Control surface will move ‘arse-down’

Will pivot it down where the CG is (will create a tendency about the hinge line)

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

The aileron that moves upwards travels a _____ distance than the aileron that moves downward.

A

Greater

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

Large transport aircraft have two ailerons on each wing. For high-speed flight the _____ aileron is locked in place and does not move

A

outer

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

When the ailerons of a large transport airplane are deflected, the flight spoilers on the wing with the ____ (up or down) aileron extend automatically.

A

Up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Flight spoilers may be extended the same amount on each wing to act as ______

A

Speed brakes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The movable control surfaces on a V-tail airplane act as both elevators and rudders. These surfaces are called ______

A

Ruddervators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

In a conventional airplane using horizontal stabilator and elevators mounted on the tail, the normal aerodynamic force acts _____ (Upward or downward)

A

Downward

24
Q

A canard surface has an angle of incidence that causes it to stall ____(Before or after) the main wing stalls

A

before

The angle of incidence of the canard is greater than that of the main wing, so it will stall first

25
Q

The type of wing flap that produces the greatest amount of increase in lift with the minimum change in drag is the _____ flap

A

Fowler

26
Q

A leading edge flap _____ (increases or decreases) the camber of the wing

A

increases

27
Q

Slats extend from the leading edge of the wing to ______ (increase or decrease) the wing camber

A

increase

28
Q

A trim tab ______ (does or does not) move relative to the control surface on which it is installed as the surface is moved in flight

A

does not

29
Q

A balance tab moves in the _______ (same or opposite) direction as the control surface on which it is mounted

A

opposite

30
Q

The type of tab that is controlled from the cockpit to produce an aerodynamic force that moves the primary control surface is called a/an _____ tab

A

servo

(The cockpit control is attached to the servo tab so that it moves in the direction opposite that desired for the primary surface. Deflection of the servo tab produces an aerodynamic force that deflects the primary surface, which in turn rotates the airplane about the desired axis

31
Q

A servo tab moves in the _____ (same or opposite) direction as the control surface on which it is mounted

A

opposite

32
Q

A spring tab automatically deflects when the control forces are _____ (high or low)

A

high

A spring tab is used on high-performance airplanes that, under high-speed conditions, develop aerodynamic forces so great that assistance is needed to help the pilot move the controls

33
Q

An anti-servo (anti-balance) tab moves in the ______ (same or opposite) direction as the control surface on which it is mounted

A

same

34
Q

What is a stabilator? (pitch control)

-location of pivot point

A

This is a single piece horizontal surface that pivots about a point approximately one third of the way back from the leading edge.

A stabilator does not replace elevator, it just gives the ability of trim

35
Q

The rudder is used only at the ______ of the turn to overcome the adverse yaw

A

beginning

(differential aileron is used to combat A.Y primarily)

36
Q

Many large jet transport aircrafts have two ailerons on each wing and flight spoilers to assist in roll control.

The _______ ailerons are locked in their faired or streamline, position when the ____ _____ ___ are up

A

outboard

trailing edge flaps

37
Q

Describe what flight spoilers do when ailerons are deflected.

A

When the ailerons are deflected, the flight spoilers on the wing with the up-aileron automatically extend to decrease the lift on the wing that is moving down and to produce additional parasite drag to overcome any adverse yaw

38
Q

The movement of the nose in the wrong direction at the beginning of a turn is called ____ ___

A

adverse yaw

39
Q

What happens to the CG (Centre of Gravity) during flight?

A

During flight , the centre of gravity will move slowly in the direction of the nose of the aircraft, as a result of fuel consumption.

40
Q

On which axis do the following control surfaces act?

(a) Rudder
(b) Elevator
(c) Aileron

A

(a) Rudder is about the vertical (normal) axis
(b) Elevator is about the lateral axis
(c) Aileron is about the longitudinal axis

41
Q

What are flight control trim systems used for?

A

A trim tab is controlled from the cockpit and used to alter the camber of the surface and create an aerodynamic force that will hold the control surface deflected.

Allow for ‘‘hands off’’ flying

42
Q

What kind of high lift devices are used on modern jet airliner aircraft?

A

Slats

Leading edge flaps (Kreugor flaps)

Trailing Edge flaps

43
Q

Explain the relationship between high lift devices and the angle of attack

A

High lift devices increase the angle of attack at which an aircraft will stall (16/17 ^ -> 25^) while flying at low speeds

44
Q

Explain the function of:

(a) Servo tab
(b) Trim tab

A

(a) The servo tab assists or provides the force for moving a primary flight control
(b) The trim tab reduces the force needed to move a primary control surface

45
Q

What type of actuators are included in the cable trim systems?

A

electrical actuators

46
Q

The following situations require trimming from what control surface:

  • A change of position of the centre of gravity and the centre of pressure
  • When there is an uneven thrust of the engines
  • When there is a fuel imbalance
A
  • Adjustible stabiliser (Stabilator)
  • Rudder
  • Aileron
47
Q

Roll trimming is usually a result of ______ ______

A

Fuel imbalance

48
Q

In modern passenger aircraft, an ____ ______ is installed in the cable system between the pedals and the _____ ______ of the steering units

A

Electric actuator

Control valves

49
Q

The purpose of slats may be as much to _____ _____ at low speeds by curing any tendencies towards ____ ____ ____ as it is to augment the lift coefficient

A

improve control

wing tip stalling

50
Q

Whenever the slat is open, at even moderate angles of attack, the _____ ____ can penetrate further aft along the chord thus reducing the thickening effect and delaying ______ and resulting in a stronger _____ ______ than that obtained from a wing without slats.

A

Boundary layer

Separation

Pressure distribution

51
Q

What is the approximate stall angle with slats extended?

A

25 degrees

(Normal stall angle is 16/17 degrees)

52
Q

What type of flap setting is used for take off?

A

For take-off, an intermediate flap setting is used.

53
Q

What type of aircraft is the plain flap used on?

A

The plain flap is only used on low speed aircraft.

54
Q

Why are stall strips used?

A

It is extremely important that an aircraft wing stall progressively from the root out to the tip, so the ailerons will be effective thoughout the stall

55
Q

An artificial feel system gives the pilot resistance that is proportional to the flight loads on the surfaces.

The control forces are too great for the pilot to manually move the surfaces, so, in the event of a hydraulic system failure

They are controlled with ___ tabs

A

Servo

Mod 11: Systems (37 decks)

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