Brainscape's Knowledge GenomeTM

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


See full index

AT 106 > 106 Through Exam 2 > Flashcards

106 Through Exam 2 Flashcards

1
Q

Define flight controls

A

a moveable airfoil that can be manipulated by the pilot

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

Normal category

A

non acrobatic operations
+3.8 - -1.52 G

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

Utility

A

limited acrobatic
+4.4 - -1.76

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

Acrobatic

A

unrestricted
+6 - -3G

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

Why do positive Gs make you feel heavier

A

centrifugal force acts in the same direction as weight

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

When is the stability of the aircraft?

A

the time between manipulation of the flight controls

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

Static stability

A

will the aircraft return if displaced

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

dynamic stability

A

how the aircraft will return if displaced

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

What does dihedral do

A

contributes to stability in the roll axis
helps restore wings level

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

Yaw stability is around what axis

A

vertical

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

what contributes to yaw stability

A

vertical stabilizer
swept back wings

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

How do swept back wings help with yaw stability

A

back wing has less frontal area: less lift, less drag
front wing has more frontal area: more lift, more drag

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

pitch stability is about the ____ axis

A

lateral

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

Flap which hinges down

A

Split flap

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

hinge of trailing edge leaves gap between wing and flap

A

slotted

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

extends out and down
inside wing when retracted

A

Fowler
only wing to increase surface area when deployed

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

winglets and sharklets do what

A

reduce induced drag

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

straight taper characteristics

A

CP moves more with AoA
max Cl greater
Cd lower

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

why is thickness taper combined with planform taper

A

Decreased Cp movement from thickness taper offsets increased cp from planform taper

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

mean aerodynamic chord

A

way of measuring chord length on non rectangular wings

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

high wing pros

A

better lift/drag ratio
better lateral stability
shorter landing distance

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

Low wing pros

A

easier to build
better roll maneuverability (less lateral stability)
shorter take off distance

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

Tee Tail advantages

A

allows for flow of air over rudder at high AoA
horizontal stabilizer is out of the way of engines
keeps horizontal stabilizer and rudder out of main wing downwash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Vee Tail advantages

A

decreases interference drag
decreases pressure and skin friction by combining “ruddervator”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why do fighters have two tails?

A

stabilization in event of damage and reduce the height needed for full flight control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What do flying wires do

A

transmit lift back to fuselage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what do landing wires do

A

transmit downward impact of landing, or negative G loads, on wings back to fuselage

28
Q

what do interplanetary struts do

A

transmit lift loads and landing loads between top and bottom wings

29
Q

what do cabane struts do

A

support top section of wing above fuselage and transmit lift loads of wing roots to fuselage

30
Q

what is the Center Section

A

airfoil shaped section above fuselage to which upper wings attach

31
Q

when does interplanetary interference become a problem

A

when gap is less than one chord length apart

32
Q

What is decalage (fixed wing)

A

Angle of difference between upper and lower wings of biplane
When one of the wings set to a higher angle of incidence than the other

33
Q

What did the NASA AD-1 demonstrate and who was the designer

A

an aircraft wing can be pivoted obliquely from zero to sixty degrees in flight
Burt Rutan

34
Q

Ruddervator (V tail) advantages

A

lighter
less wetted surface
reduced drag
increased stealth
canted surfaces reflect radar away from surface and engine mounting reduces infrared signature
improve safety and cabin noise reduction

35
Q

Ruddervator disadvantages

A

more complex control system
have to be structurally more robust
control forces required for operation are higher

36
Q

What is the tandem wing aircraft

A

both wings left up, no horizontal stabilizer pulling down

37
Q

Tandem wing disadvantages

A

very difficult pitch stability
very limited CoG

38
Q

What type of aircraft did the wright brother’s make? (in respect to wings)

A

biplane canard

39
Q

What’s the difference between a tandem and canard

A

tandem: two full wings
Canard: main wings and smaller wings that can only carry 25% of weight

40
Q

Canard characteristics

A

both wings provide lift (more efficient)
canard stalls before main
not as stable as conventional aircraft

41
Q

Conventional tail characteristics

A

best pitch stability
Drag from horizontal stabilizer
interference drag (tail surfaces to fuselage)
Pressure drag from horizontal and vertical stabilizer

42
Q

Flying wing characteristics

A

no horizontal tail - drastically reduced drag
sharp swept back wings for yaw stability

43
Q

What are split rudders

A

split control at wingtips for rudders

44
Q

What are elevons

A

ailerons moved inboard and combined with elevators

45
Q

As air approaches the speed of sound…

A

it becomes compressible

46
Q

What is the mach number

A

the speed of the aircraft in relation to speed of sound

47
Q

Define Subsonic

A

any region below transonic

48
Q

define transonic

A

first evidence of localized sonic or supersonic airflows and begins at critical mach number
ends when all flows around aircraft are supersonic

49
Q

Define sonic

A

speed of sound

50
Q

define supersonic

A

any speed faster than speed of sound

51
Q

define hypersonic

A

any speed above Mach 5
where plasma begins to affect the airflow

52
Q

How does drag react in transonic flight

A

drag rises quickly at Mcrit then drops off when fully supersonic

53
Q

Normal shockwave characteristics

A

perpendicular to direction flow
air slows from supersonic to subsonic
pressure, temperature, density increase BEHIND shock
air flow direction does not change
tremendous drag

54
Q

Oblique shock wave

A

generated by nose and leading edges
shock inclined to flow direction
supersonic speed to lower supersonic speed
airflow changes directions ACROSS shock
pressure, temperature, density increase THROUGH shock
creates some drag

55
Q

Supersonic lift

A

Caused purely by AoA
shock produced at leading edge
shock going down is stronger than shock going up
(pressure jump down is larger than pressure jump up)
causes greater pressure under the airfoil

56
Q

describe the supercritical wing

A

long flat upper camber with downward turn near trailing edge

keeps airspeeds constant across wing

lowest pressure concentrated around highest camber
smaller pressure differentials spread out over bigger area of wing which keeps lift produced the same

57
Q

supersonic aircraft have a _____ overall cross-sectional area and ____ aspect ratio

A

larger, smaller

this creates smooth transitions from wings to fuselage cross-section

58
Q

What is the Whitcomb area rule

A

essentially a series of tests looking at different factors in order to get reduced drag between Mach ,75 and 1.2

59
Q

Why is wing sweep beneficial when supersonic

A

keeps wing tips out of the shock waves
(if the shock wave contacts the wing tips, airflow over the tips and ailerons can be disrupted)

60
Q

For a helicopter in hover, the forces

A

are all acting vertically

61
Q

What does the collective stick do (left of pilot)

A

increases (or decreases) AoA of all main rotor blades together in order to increase lift

62
Q

What does the cyclic stick do (in front of pilot)

A

changes blade pitch at only one part of rotating cycle
tips rotor disk forward and moves helicopter forward

63
Q

Why do helicopter rotors run at a constant rpm

A

increasing rotor speed to get more lift takes too long (changing pitch is instantaneous)

rotor blades need centrifugal force to hold them straight out or lift forces will fold up and break the blades

64
Q

In North America, the main rotor spins ____ as viewed from top

A

counter clockwise

65
Q

Moving the foot pedals____

A

changes the pitch of the tail rotor

66
Q

If tail rotor quits, the helicopter____

A

spins around in a circle in the opposite direction of main rotor

67
Q

what is translating tendency

A

in a hover, the sideways thrust of the tail rotor tries to drag the helicopter sideways - if uncorrected, drifts to right

AT 106 (3 decks)

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