Brainscape's Knowledge GenomeTM

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


See full index

CPL Prep > Principles Of Flight > Flashcards

Principles Of Flight Flashcards

1
Q

Define axis of rotation

A

The line through the rotor head at right angles to the plane of rotation.
The blades actually rotate around this axis

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

You are flying above freezing level in rain & notice ice on rotors. What effect does the ice on the middle of the rotors have on an auto rotation?

A

Higher rate of descent
Less range

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

List factors that may induce ground resonance.

A

Rotor Head
- Unbalanced blades
- Incorrect tracking
- Faulty lead/lag dampers

Fuselage Factors
- Ship operations
- Slope landings
- Uneven oleo/tire pressures

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

Disc loading on a helicopter is found by dividing the what?

A

Weight
By
Disc area

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

What is the point on an aerofoil through which lift acts called?

A

Centre of pressure

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

During forward cruising flight the individual rotor blades when compares to each other are operating how in regards to IAS, AoA & Lift

A

Act at unequal airspeed
Unequal angles of attack
Equal lift moment

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

Describe a recommended technique to avoid blade sailing in an anti-clockwise rotor system

A

Park with wind from the right of the helicopter & keep cyclic central

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

Why does an IGE hover require less power than an OGE hover?

A

Because induced flow & rotor drag are reduced

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

Spanwise lift of a rotor blade may be equalized how?

A

Decreasing the angle of attack towards the tip. Also known as washout.

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

Total rotor thrust always acts ______ the ______

A

In line with
Axis of rotation

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

When translational lift becomes effective on climb out, _______ increase & if collective is neither lowered or raised the rate of climb will initially ______?

A

Angles of attack
Increase

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

You need to land at some remote location. The reported conditions are hot & humid. You look at your performance graph & find it’s just within limits for landing.
What effect does humidity have?

A

You may not be able to land because humidity is not taken into account in most performance graphs.

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

What effect does Tailwind / Headwind on
- Rate of climb / descent
- Angle of climb / descent

A

RoC & RoD no change in either scenario.

AoC & AoD - Shallow with tailwind. Steepen with headwind.

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

Conditions that lead to tail rotor vortex ring state.
(Anti-clockwise main rotor)

A
  • High rate hover turn to the right.
  • Wind from the left.
  • Sideways flight to the left.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Distinguish differences between symmetrical and non-symmetrical blades.

A

Symmetrical
- Chord line & mean camber line the same.
- Not as efficient at lift
- Fixed center of pressure
- Lower stall/critical angle

Non-Symmetrical
- Chord line different to main camber line
- Better production of lift
- Centre of pressure that moves

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

Define shaft axis

A

The line consistent with the rotor shaft (mast). Only when plane of rotation is exactly perpendicular to the shaft axis will the axis of rotation coincide with the shaft axis.

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

You make a climbing turn using max power, what will happen to rate & angle of climb if you increase Angle of Bank at the same ISA.

A

Climb rate decrease
Climb at shallower angle

18
Q

You are hovering over a slope with obky thr front of the disc IGE.
What will helicopter tend to do?

A

Roll right

19
Q

How can vortex ring state develop?

A
  • Some power in use
  • Low airspeed (below translation)
  • Moderate/High RoD (400-800fpm)
20
Q

You are operating out of Denver at 5200” what effect does this have on the areas in the height velocity graph?

A

Both shaded areas increase in size due to high density altitude

21
Q

You are hovering OGE with a 20kt headwind if the wind dissappears, will it affect power required & how?

A

Yes
Increased power required

22
Q

You have tail rotor failure in cruise. On descent at 6-8ft above ground, aircraft begins to yaw to the right.
What should you do?

A

Roll off throttle to align aircraft with direction of travel & conduct running landing.

23
Q

Spanwise imbalance is rectified by doing what?

A

Adjusting the weight at the tip of a blade

24
Q

Describe differences between low inertia and high inertia blades

A

High Inertia
- RRPM fluctuates less
- Once rotating, requires less power
- Flares easier to execute
- Requires strong & heavy rotor head designs

Low Inertia
- More maneuverable
- Quicker to recover loss in RRPM

25
Q

A balde is most efficient when?

A

Lift is greatest for the lowest pitch

26
Q

Compared to Non-Symmetrical aerofoils, the major disadvantage of using symmetrical aerofoils in the main rotor blade is what?

A

A lower lift/drag ratio

27
Q

Rotor blade angle of attack is what?

A

Angle between Relative Airflow (RAF) & Chord Line

28
Q

Angle between place of rotation & Chord line is what?

A

Blade (pitch) angle

29
Q

What effect might a CoG aft of the limit have?

A

Not enough forward cyclic to compensate

30
Q

The stalled, driving & driven regions of a rotor during an autorotation at increasing forward speed will move off-centre to where?
(Anti-clockwise rotor)

A

To the left of the mast

31
Q

On approach with constant IAS an increasing tailwind will cause what?

A

Shallower approach path

32
Q

If a helicopter in an autorotation, has a rotor RPM at the bottom of the normal range/top of the yellow what will occur?

A

There will be an increase in the autorotative range.

33
Q

Define aspect ratio

A

Length of blade (span)
Over
Width of the blade (chord)

34
Q

Angle of attack is what?

A

The angle between the relative airflow & the chord line of the blade

35
Q

Why is the mast on some helicopters titled slightly to one side?

A

To counteract tail rotor drift

36
Q

Flapback occurrs during _____ flight or when _____ into a wind because the ____ blade has a _____ relative airflow

A

Forward
Hovering
Retreating
Slower

37
Q

Delta-3 hinges are fitted to some helicopters as they cause the blade to what?

A

Feather as it flaps

38
Q

What would give the greatest gliding distance in an autorotation?

A

An IAS slightly above the minimum rate of descent speed and low rotor RPM

39
Q

What effect does increased gross weight have on the height velocity graph?

A

All regions increase in size

40
Q

What factors encourage the inset of vortex ring state?

A

Flight conditions requiring high collective settings & increase power

  • High gross weight
  • High altitude
  • High density altitude

CPL Prep (10 decks)

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