STRUCTURES MMTB Flashcards

1
Q

The basic questions of
configuration, arrangement,
size and weight, and
performance are answered

A

Conceptual Design

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2
Q

Begins when the major changes are over

A

Preliminary Design

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3
Q

Begins in which the actual
pieces to be fabricated are designed.

A

Detail Design

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4
Q

Mathematical modeling of the outside
skin of the aircraft with sufficient
accuracy to ensure proper fit between its
different parts designed by different designers.

A

Lofting

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5
Q

Structural Weight is between 30 to 35%
of the total weight

A

PRELIMINARY WEIGHT ESTIMATE

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6
Q

Total Weight of the aircraft as it begins the mission for which it was designed.

A

Design Take-off Gross Weight

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7
Q

π‘ŠπΆπ‘Ÿπ‘’π‘€ + π‘Šπ‘π‘Žπ‘¦π‘™π‘œπ‘Žπ‘‘ + π‘Šπ‘“π‘’π‘’π‘™ + π‘Šπ‘’π‘šπ‘π‘‘

A

π‘Š0/ total weight

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8
Q

Part of the fuel supply that is available for
performing the mission

A

Mission Fuel

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9
Q

Fuel which cannot be pumped out of the
tanks

A

Trapped Fuel

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10
Q

The firing of gun and missiles, and is often
left out of the sizing analysis

A

Weapon Drop

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11
Q

Rate of fuel consumption divided by the
thrust

A

Specific Fuel Consumption

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12
Q

A measure of the design’s overall aerodynamic efficiency

A

Lift-to-Drag Ratio

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13
Q

Curvature characteristics of most airfoil

A

Camber

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14
Q

Line equidistant from the upper and lower surfaces

A

Mean Camber Line

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15
Q

Maximum thickness of the airfoil divided by its chord

A

Airfoil Thickness Ratio

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16
Q

𝑑/c

A

Thickness Ratio

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17
Q

Point about which the pitching moment
remains constant for any angle of attack

A

Aerodynamic Center

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18
Q

Ratio between the dynamic and the
viscous forces in a liquid

A

Reynold’s Number

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19
Q

οƒ˜Lift coefficient at which the airfoil has the
best 𝐿⁄𝐷

οƒ˜Point in the airfoil drag polar that is tangent to a line from origin and closest
to the vertical axis

A

DESIGN LIFT COEFFICIENT

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20
Q

οƒ˜Stall from the trailing edge

οƒ˜Turbulent boundary layer increases with
angle of attack

A

Fat Airfoils (𝒕⁄𝒄 > πŸπŸ’%)

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21
Q

οƒ˜Flow Separates near the nose at a very small angle of attack but reattaches itself so that little effect is felt.

οƒ˜At higher angle of attacks the flow fails to
attach, which almost immediately stalls
the entire airfoil

A

Moderate Thick Airfoils (6-14%)

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22
Q

οƒ˜The flow separates from the nose at a
small angle and reattaches almost
immediately

A

Very Thin Airfoils (𝒕⁄𝒄 < πŸ”%)

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23
Q

Cause the wing to stall first at the root.

A

Twisting/Washout

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24
Q

οƒ˜Drag increases with increasing thickness
due to separation

A

AIRFOIL THICKNESS RATIO

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25
Q

For a wing of fairly high aspect ratio and
moderate sweep, a larger nose radius
provides higher stall angle and greater
maximum lift coefficient

A

AIRFOIL THICKNESS RATIO

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26
Q

Wing structural weight varies approximately inversely with the square
root of the thickness ratio

A

AIRFOIL THICKNESS RATIO

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27
Q

οƒ˜Angle of concern in supersonic flight

οƒ˜It is common to sweep the leading edge behind the Mach cone to reduce drag.

A

Leading Edge Sweep

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28
Q

Sweep most related to subsonic flight.

A

Quarter-Chord Line Sweep

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29
Q

Aerodynamic Center for SUBSONIC

A

0.25c

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30
Q

Aerodynamic Center for SUPERSONIC

A

0.4c

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31
Q

Has tips farther apart making them less affected by the tip vortex and the tip vortex strength is reduced

A

High aspect ratio wings

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32
Q

Wing weight increasing with___

A

increasing aspect ratio

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33
Q

will stall at a
higher angle of attack than higher aspect ratio wings

A

Lower aspect ratio wings

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34
Q

If the Aspect ratio is High, the Induced Drag is _______

A

Low

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35
Q

If the Aspect ratio is High, the Lift-Curve Slope is _______

A

High

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36
Q

If the Aspect ratio is High, the Pitch Attitude is _______

A

Low

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37
Q

If the Aspect ratio is High, the Ride in Turbulence is _______

A

Poor

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38
Q

If the Aspect ratio is High, the Wing Weight is _______

A

High

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39
Q

If the Aspect ratio is High, the Wing Span is _______

A

Large

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40
Q

If the Aspect ratio is Low, the Induced Drag is _______

A

High

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41
Q

If the Aspect ratio is Low, the Lift-Curve Slope is _______

A

Low

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42
Q

If the Aspect ratio is High, the Pitch Attitude is _______

A

High

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43
Q

If the Aspect ratio is Low, the Ride in Turbulence is _______

A

Good

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44
Q

If the Aspect ratio is Low, the Wing Weight is _______

A

Low

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45
Q

If the Aspect ratio is Low, the Wing Span is _______

A

Small

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46
Q

Primarily used to reduce the adverse
effects of transonic and supersonic flow

A

WING SWEEP

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47
Q

are wings with one wing
swept aft and the other swept forward.

A

Oblique wings

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48
Q

tend to have lower wave
drag

A

Oblique wings

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49
Q

improves stability

A

Wing sweep

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50
Q

increases the effectiveness of vertical tails at the wing tips

A

Wing sweep

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51
Q

Better ride through turbulence characteristics

A

Wing sweep

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52
Q

Increases Critical Mach Number

A

Wing sweep

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53
Q

Highly undesirable tendency, upon
reaching an AOA near stall, to suddenly
and uncontrollably increase AOA

A

Pitch up

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54
Q

Solution to constant sweep problems

A

Variable Sweep

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55
Q

Complex and attendant balance problems

A

Variable Sweep

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56
Q

If there is an increased wing sweep forward, the Lift-Curve Slope is ___

A

Low

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57
Q

If there is an increased wing sweep forward, the Pitch Attitude in Low
Speed, Level Flight is ___

A

High

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58
Q

If there is an increased wing sweep forward, the Ride through Turbulence is ___

A

Good

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59
Q

If there is an increased wing sweep forward, the Asymmetric Stall is ___

A

Best

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60
Q

If there is an increased wing sweep forward, the Lateral Control at Stall is ___

A

Best

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61
Q

If there is an increased wing sweep forward, the Compressibility Drag is ___

A

Low

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62
Q

If there is an increased wing sweep forward, the Wing Weight is ___

A

Highest

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63
Q

If there is an increased wing sweep on none, the Lift-Curve Slope is ___

A

High

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64
Q

If there is an increased wing sweep (none), the Pitch Attitude in Low
Speed, Level Flight is ___

A

Low

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65
Q

If there is an increased wing sweep (none), the Ride through Turbulence is ___

A

Poor

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66
Q

If there is an increased wing sweep (none), the Asymmetric Stall is ___

A

Good

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67
Q

If there is an increased wing sweep (none), the Lateral Control at Stall is ___

A

Good

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68
Q

If there is an increased wing sweep (none), the Compressibility Drag is ___

A

High

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69
Q

If there is an increased wing sweep (none), the Wing Weight is ___

A

Low

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70
Q

If there is an increased wing sweep aft, the Lift-Curve Slope is ___

A

Low

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71
Q

If there is an increased wing sweep aft, the Pitch Attitude in Low
Speed, Level Flight is ___

A

High

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72
Q

If there is an increased wing sweep aft, the Ride through Turbulence is ___

A

Good

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73
Q

If there is an increased wing sweep aft, the Asymmetric Stall is ___

A

Poor

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74
Q

If there is an increased wing sweep aft, the Lateral Control at Stall is ___

A

Poor

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75
Q

If there is an increased wing sweep aft, the Compressibility Drag is ___

A

Low

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76
Q

If there is an increased wing sweep aft, the Wing Weight is ___

A

High

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77
Q

Ratio between the tip chord and the centerline tip chord

A

Taper Ratio

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78
Q

Affects the distribution of lift along the span of the wing

A

Taper Ratio

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79
Q

More taper

A

lesser the weight

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80
Q

Less taper means

A

more fuel volume

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81
Q

If there is High Taper Ratio, the Wing Weight is ____

A

High

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82
Q

If there is High Taper Ratio, the Tip stall is ____

A

Good

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83
Q

If there is High Taper Ratio, the Wing Fuel Volume is ____

A

Poor

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84
Q

Used to prevent tip stall and to revise the
lift distribution to approximate an ellipse

A

TWIST

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85
Q

Actual change in airfoil angle of incidence, usually measured with respect
to the root airfoil

A

Geometric Twist

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86
Q

Twist angle changes in proportion to the distance from the root airfoil

A

Linear Twist

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87
Q

Angle between zero-lift angle of an airfoil
and the zero-lift angle of the root airfoil

A

Aerodynamic Twist

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88
Q

If identical airfoil is used root to tip, aerodynamic twist is_____ as the
geometric twist

A

the same

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89
Q

If there is a Large Twist Angle the Induced Drag is,

A

High

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90
Q

If there is a Small Twist Angle the Induced Drag is

A

Small

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91
Q

If there is a Large Twist Angle the Tip Stall is,

A

Good

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92
Q

If there is a Small Twist Angle the Tip Stall is

A

Poor

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93
Q

If there is a Large Twist Angle the Wing Weight is,

A

Mildly Lower

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94
Q

If there is a Small Twist Angle the Wing Weight is,

A

Mildly Higher

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95
Q

The pitch angle of the wing with respect
to the fuselage

A

WING INCIDENCE

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96
Q

Minimizes drag at some operating conditions, usually cruise

A

WING INCIDENCE

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97
Q

If the WING INCIDENCE IS LARGE, the Cruise Drag is ___

A

High

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98
Q

If the WING INCIDENCE IS SMALL, the Cruise Drag is ___

A

Small

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99
Q

If the WING INCIDENCE IS LARGE, the Cockpit
Visibility is ___

A

Good

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100
Q

If the WING INCIDENCE IS SMALL, the Cockpit
Visibility is ___

A

Watch out

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101
Q

If the WING INCIDENCE IS LARGE, the Landing
Attitude is ___

A

Watch out

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102
Q

If the WING INCIDENCE IS SMALL, the Landing
Attitude is ___

A

No problem

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103
Q

Angle of the wing with respect to the horizontal when seen from the front

A

DIHEDRAL

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104
Q

Tends to roll an aircraft whenever it is banked

A

DIHEDRAL

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105
Q

_____of sweep provides about 1Β° of effective dihedral

A

10Β°

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106
Q

Produced by excessive dihedral effect

A

Dutch Roll

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107
Q

Repeated side-to-side motion involving yaw and roll

A

Dutch Roll

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108
Q

To counter the tendency of Dutch Roll, the vertical
area must be _____

A

increased

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109
Q

If there is a POSITIVE DIHEDRAL, the Spiral Stability is ____

A

Increased

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110
Q

If there is a POSITIVE DIHEDRAL, the Dutch Roll Stability is ____

A

Decreased

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111
Q

If there is a POSITIVE DIHEDRAL, the Ground Clearance is ____

A

Increased

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112
Q

If there is a NEGATIVE DIHEDRAL, the Spiral Stability is ____

A

Decreased

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113
Q

If there is a NEGATIVE DIHEDRAL, the Dutch Roll Stability is ____

A

Increased

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114
Q

If there is a NEGATIVE DIHEDRAL, the Ground Clearance is ____

A

Decreased

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114
Q

Allows placing of the fuselage closer to
the ground

A

High Wing

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115
Q

Provides sufficient ground clearance without excessive landing gear length

A

High Wing

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116
Q

Wingtips less likely to strike the ground

A

High Wing

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117
Q

usually presents less
weight but struts adds to drag

A

strutted wing

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118
Q

For a ______ aircraft, a high wing provides ground clearance for the large flap necessary for high CL

A

STOL

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119
Q

Prevents floating which makes it hard to
land on desired spot

A

High Wing

120
Q

Intended to operate at unimproved fields

A

High Wing

121
Q

External blisters and stiffening is needed
which adds weight and drag

A

High Wing

122
Q

Better visibility towards the ground

A

High Wing

123
Q

Restricted visibility towards the rear

A

High Wing

124
Q

Obscures pilot vision in a turn

A

High Wing

125
Q

Blocks upward visibility in a climb

A

High Wing

126
Q

Least interference drag

A

Mid Wing

127
Q

to a degree, has the ground clearance
advantage of the high wing

A

Mid Wing

128
Q

Superior aerobatic maneuverability due
to absence of actual or effective dihedral
which will act in the wrong direction in
inverted flight

A

Mid Wing

129
Q

Needs fuselage stiffening; means more weight

A

Mid Wing

130
Q

Carry-through structure will limit space for a passenger or cargo aircraft

A

Mid Wing

131
Q

Landing gear can be attached to the wing

A

Mid Wing

132
Q

Allows for a shorter landing gear strut which means less weight; however there still must be enough ground clearance

A

Mid Wing

133
Q

Given enough ground clearance, aft fuselage upsweep can be reduced,
reducing drag

A

Mid Wing

134
Q

Ground clearance problems may be alleviated by a dihedral

A

Mid Wing

135
Q

Placing the propeller above the wing
increases interference effects and cruise fuel consumption

A

Low Wing

136
Q

Affects take-off and landing field length,
cruise performance, ride through turbulence and weight

A

WING SIZE AND WING LOADING

137
Q

Wings can be kept small using ___

A

flaps

138
Q

For flight at high altitudes and at low speeds, a ______ is required

A

larger wing

139
Q

In High Wing aircraft the Interference Drag is _____

A

Poor

140
Q

In High Wing aircraft the Dihedral Effect is _____

A

Negative

141
Q

In High Wing aircraft the Passenger Visibility is _____

A

Good

142
Q

In High Wing aircraft the Fuselage Mounted is _____

A

Long/Heavy

143
Q

In High Wing aircraft the Wing Mounted is _____

A

Possibly Draggy

144
Q

In High Wing aircraft the Loading & Unloading is _____

A

Easy

145
Q

In Mid Wing aircraft the Interference Drag is _____

A

Good

146
Q

In Mid Wing aircraft the Dihedral Effect is _____

A

Neutral

147
Q

In Mid Wing aircraft the Passenger Visibility
is _____

A

Good

148
Q

In Mid Wing aircraft the Fuselage Mounted is _____

A

Long/Heavy

149
Q

In Mid Wing aircraft the Wing Mounted is _____

A

Possibly Draggy

150
Q

In Mid Wing aircraft the Loading & Unloading is _____

A

Easy

151
Q

In Low Wing aircraft the Interference Drag is _____

A

Poor

152
Q
A
153
Q
A
154
Q
A
155
Q

In Low Wing aircraft the Dihedral Effect is _____

A

Positive

155
Q

In Low Wing aircraft the Passenger Visibility
is _____

A

Poor for some

155
Q

In Low Wing aircraft the Fuselage Mounted is _____

A

Long/Heavy

156
Q

In Low Wing aircraft the Wing Mounted is _____

A

Short/Light

156
Q

In Low Wing aircraft the Loading & Unloading is _____

A

Need Stairs

157
Q
A
157
Q
A
158
Q
A
158
Q
A
159
Q

If the Wing Loading is High, the Field Length is ____

A

Long

159
Q

If the Wing Loading is High, the Stall Speed is ____

A

High

159
Q

If the Wing Loading is High, the Max. Lift-to-Drag Ratio is ____

A

High

159
Q

If the Wing Loading is Low, the Stall Speed is ____

A

Low

159
Q

If the Wing Loading is High, the Ride quality in
Turbulence is ____

A

Good

159
Q

If the Wing Loading is High, the Weight is ____

A

Low

160
Q

If the Wing Loading is Low, the Field Length is ____

A

Short

161
Q

If the Wing Loading is Low, the Max. Lift-to-Drag Ratio is ____

A

Low

162
Q

If the Wing Loading is Low, the Ride quality in
Turbulence is ____

A

Bad

163
Q

If the Wing Loading is Low, the Weight is ____

A

High

164
Q

A ____ tip is more effective than a rounded tip in alleviating tip vortex
effects

A

Sharp

165
Q

The ____ tip is the most widely used low-drag wingtip

A

Hoerner

166
Q

Tip curved upwards/downwards increase effective span without increasing actual span

A

WING TIPS

167
Q

A ______ tip addresses the condition that vortices tend to be located at the
trailing edge of the wing tip; increases torsional load

A

swept wing

168
Q

It is used for supersonic aircraft; part with little lift is cut-off; reduced torsional load

A

Cut-off forward swept

169
Q

Low structural Weight

A

BIPLANE WINGS

170
Q

Relatively short wing span

A

BIPLANE WINGS

171
Q

Half induced drag compared to monoplane producing same lift

A

BIPLANE WINGS

172
Q

The vertical distance between the two wings

A

Gap

173
Q

The ratio between the shorter to the longer wing

A

Span Ratio

174
Q

The longitudinal offset of the two wings relative to each other

A

Stagger

175
Q

When upper wing is closer to the nose

A

Positive Stagger

176
Q

When lower wing is closer to the nose

A

Negative Stagger

177
Q

Relative incidence between the two wings

A

Decalage

178
Q

When upper wing has a larger incidence

A

Positive Decalage

179
Q

Rear section of the airfoil is hinged so that it can be rotated downward

A

Plain Flap

180
Q

With a _____ flap, CLmax can be almost doubled

A

simple plain flap

181
Q

Creates more lift simply by mechanically increasing the effective camber of the airfoil

A

Plain Flap

182
Q

Increases the drag and pitching moment

A

Plain Flap

183
Q

Only the bottom surface of the airfoil is hinged

A

Split Flap

184
Q

Causes a slightly higher CLmax than that for
a plain flap

A

Split Flap

185
Q

Performs the same function as a plain
flap, mechanically increasing the effective
camber

A

Split Flap

186
Q

Produces more drag and less change in the pitching moment compared to a plain
flap

A

Split Flap

187
Q

A small, highly cambered airfoil located
slightly forward of the leading edge of the
main airfoil

A

Leading Edge Slat

188
Q

Essentially a flap at the leading edge, but
with a gap between the flap and the
leading edge

A

Leading Edge Slat

189
Q

CLmax is increased with no significant
increase in drag

A

Leading Edge Slat

190
Q

The slot allows the higher-pressure air on
the bottom surface of the airfoil to flow
through the gap, modifying and
stabilizing the boundary layer over the
top surface of the airfoil

A

Single-Slotted Flap

191
Q

Higher CLmax compared to a single-slotted
flap

A

Double-Slotted Flap

192
Q

This benefit is achieved at the cost of increased mechanical complexity

A

Double-Slotted Flap

193
Q

Mechanically sucks away a portion of the
boundary layer through small holes or
slots in the top surface of the airfoiI
which delays flow separation

A

Boundary Layer Suction

194
Q

Translates or tracks to the trailing edge of
the airfoil to increase the exposed wing
area and further increase lift

A

Fowler Flap

195
Q

A leading-edge slat which is thinner, and
which lies flush with the bottom surface
of the airfoil when not deployed

A

Krueger Flap

196
Q

The ______ exists mainly for trim, stability and control

A

empennage

197
Q

οƒ˜Lightweight

οƒ˜Horizontal tail is in the wake of the wing

οƒ˜Does not allow for aft-mounted engine

οƒ˜Low horizontal tails are best for stall
recovery

A

Conventional

198
Q

Heavier due to strengthening of the
vertical tail to support the horizontal tail

A

T-Tail

199
Q

Allows for a smaller vertical tail due to
end plate effect

A

T-Tail

200
Q

Horizontal tail is clear of wing wake and propwash

A

T-Tail

201
Q

Allows for an aft-mounted engine

A

T-Tail

202
Q

Most prone to Deep Stall, Where the wing blankets the Elevator causing a stall

A

T-Tail

203
Q

Compromise between conventional and
T-tail

A

Cruciform

204
Q

οƒ˜Less weight penalty compared to T-tail

οƒ˜Undisturbed flow in lower part of rudder
at high angles of attack

οƒ˜No endplate effect

A

Cruciform

205
Q

Undisturbed flow in vertical tails at high
angles of attack

A

H-Tail

206
Q

May enhance engine out control in
multiengine aircraft with the rudders
positioned in the propwash

A

H-Tail

207
Q

Endplate effect on the horizontal tail;
reduced size possible

A

H-Tail

208
Q

οƒ˜ Heavier than conventional

οƒ˜ Hides hot exhaust from heat seeking
missiles

A

H-Tail

209
Q

Allows for smaller/shorter vertical tail

A

H-Tail

210
Q

οƒ˜May allow for a reduced wetted area

οƒ˜Reduced interference drag

A

V-Tail (Butterfly)

211
Q

οƒ˜Control/Actuation complexity

οƒ˜Adverse roll-yaw coupling

οƒ˜Surfaces are out of the wing wake

A

V-Tail (Butterfly)

212
Q

οƒ˜Proverse Roll-Yaw Coupling

οƒ˜Reduced spiraling tendencies

οƒ˜Ground clearance problems

A

Inverted V-Tail

213
Q

οƒ˜Avoids complexity of ruddervators

οƒ˜V surfaces provide pitch control only

οƒ˜Rudder in third surface

A

Y-Tail

214
Q

Avoids blanketing of the rudders due to
wing and forward fuselage at high angles
of attack

A

Twin Tails

215
Q

οƒ˜Reduces height; area is distributed between the two vertical tails

οƒ˜Usually heavier than a single centerline

mounted vertical tail

A

Twin Tails

216
Q

οƒ˜Allows for a pusher propeller
configuration

οƒ˜are typically heavier than a
conventional fuselage construction

οƒ˜May be connected or not; high-, mid-, or
low-mounted horizontal tail, which can
have a V configuration

A

Boom-Mounted Tails

217
Q

οƒ˜ Doubles as a propeller shroud
οƒ˜ Conceptually appealing, however proven
inadequate in application

A

Ring Tail

218
Q

οƒ˜Negligible contribution to lift

οƒ˜Used to control angle of attack of wing

οƒ˜Used to balance pitching moments due to
flaps

A

Control Canard

219
Q

οƒ˜ Contributes to lift; higher aspect ratio for
reduced induced drag; greater camber for
increased lift

οƒ˜ Pushes wing aft; bigger pitching moments
due to flaps

οƒ˜ Canard is closer to CG; less effective pitch
control; surface must be increased;
resulting in more trim drag

οƒ˜ Pitch up tendencies are avoided

A

Lifting Canard

220
Q

οƒ˜ 50% theoretical reduction in induced drag
because lift is distributed between the
two wings

οƒ˜ Aft wing experiences downwash and
turbulence caused by the forward wing

οƒ˜ Wings must be separated as far as
possible

A

Tandem Wing

221
Q

οƒ˜Theoretically offers minimum trim drag

οƒ˜Additional weight; more interference
drag; complexity

A

Three Surface

222
Q

οƒ˜ Incorporated into a faired extension of
the wing or fuselage

οƒ˜ Used to prevent pitch up but can also
serve as a primary pitch control surface

A

Back Porch/Aft-Strake

223
Q

οƒ˜Offers the lowest weight and drag

οƒ˜Reduced wing efficiency

οƒ˜Most difficult configuration to stabilize

A

Tailless

224
Q

οƒ˜Drag of the proposed installation
οƒ˜Accessibility and Maintainability
οƒ˜The vertical and/or lateral location of the
thrust line(s) are critically important in
this respect
οƒ˜Weight and balance consequences of the
proposed installation
οƒ˜Inlet requirements and resulting effect on
β€˜installedβ€˜ power and efficiency
οƒ˜Acceptable FOD characteristics
οƒ˜Geometric clearance when static on the
ramp:
o No nacelle or propeller tip may
touch the ground with deflated
landing gear struts and tires
οƒ˜Geometric clearance during take-off
rotation:
o No scraping of nacelles or of
propeller tips is allowed with
deflated landing gear struts and
tires
οƒ˜Geometric clearance during a low speed
approach with a 5 degrees bank angle
οƒ˜No gun exhaust gases may enter the inlet
a jet engine

A

ENGINE DISPOSITION CONSIDERATIONS

225
Q

a) Wing-Mounted
b) Fuselage-Mounted
c) Empennage-Mounted
d)Any Combination of the Above

A

WING MOUNTING

226
Q

The vector sum of the rotational speed
and the aircraft’s forward speed

A

Tip Speed

227
Q

PROPELLER DIAMETER
𝑑 = 22 4^√𝐻p

A

Two Blade

228
Q

PROPELLER DIAMETER
𝑑 = 18 4^√𝐻P

A

Three Blade

229
Q

PROPELLER DIAMETER
𝑑 = 20 4^√𝐻P

A

Three Blade (Agricultural)

230
Q

οƒ˜The propeller or inlet plane is forward of
the CG

οƒ˜There is a more effective flow of cooling
air for the engine

A

Tractor

231
Q

οƒ˜Tend to be destabilizing with respect to
static longitudinal and directional stability

A

Tractor

232
Q

οƒ˜The propeller is working in an
undisturbed free stream

A

Tractor

233
Q

οƒ˜The propeller slipstream disturbs the
quality of the airflow over the fuselage
and wing root

A

Tractor

234
Q

οƒ˜The propeller or the inlet plane is located
behind the CG

οƒ˜Tend to be stabilizing

οƒ˜May save empennage area

A

Pusher

235
Q

οƒ˜Allows a shorter fuselage, hence smaller
wetted surface area

οƒ˜Higher-quality (clean) airflow prevails
over the wing and fuselage

οƒ˜Engine noise in the cabin area is reduced

A

Pusher

236
Q

οƒ˜The pilot’s front field of view is improved

οƒ˜Propeller is more likely to be damaged by
flying debris at landing

οƒ˜Engine cooling problems are more severe

A

Pusher

237
Q

PROPELLER CLEARANCES
Tricycle

A

7 inches

238
Q

PROPELLER CLEARANCES
Conventional

A

9 inches

239
Q

PROPELLER CLEARANCES
Over Water

A

18 inches

240
Q

Employed by many sailplanes for its
simplicity

A

Single Main

241
Q

οƒ˜ Flat attitude take-off and landing
οƒ˜ Aircraft must have high lift at low AOA
(high AR with large camber and/or flaps)

A

Bicycle

242
Q

οƒ˜ Used by aircraft with narrow fuselage and
wide wing span
οƒ˜CG should be aft of the midpoint of the 2
wheels

A

Bicycle

243
Q

οƒ˜ More propeller ground clearance
οƒ˜ Less drag and weight
οƒ˜ Easier lift production due to attitude,
hence initial AOA

A

Conventional/Tail Dragger

244
Q

οƒ˜ Inherently unstable (ground looping)
οƒ˜ Limited ground visibility from cockpit
οƒ˜ Inconvenient floor attitude

A

Conventional/Tail Dragger

245
Q

οƒ˜Stable on the ground; can be landed with
a large β€œcrab angle” (nose not aligned
with runway)

οƒ˜Improved forward ground visibility

A

Tricycle

246
Q

Flat cabin floor for passenger and cargo
loading

A

Tricycle

247
Q

οƒ˜Flat take-off and landing attitude
οƒ˜Permits a very low cargo floor

A

Quadricycle

248
Q

οƒ˜For extra heavy aircraft (200-400 kips)
οƒ˜Redundancy for safety

A

Multi-Boogey

249
Q

Maximum load anticipated in service

A

Limit or Applied Load

250
Q

Maximum load, which a part of structure
is capable of supporting

A

Design or Ultimate Load

251
Q

𝐷𝑒𝑠𝑖𝑔𝑛 πΏπ‘œπ‘Žπ‘‘ = πΏπ‘–π‘šπ‘–π‘‘ πΏπ‘œπ‘Žπ‘‘ Γ— 𝐹. 𝑆.

A

Design or Ultimate Load

252
Q

οƒ˜Factor which the limit load must be
multiplied to establish the ultimate load

οƒ˜Normally 1.5 unless otherwise specified

A

Factor of Safety

253
Q

Load factor corresponding to limit loads

A

Limit Load Factor

254
Q

Load Factor corresponding to ultimate
load

A

Ultimate Load Factor

255
Q

Ratio of the specified load to the total
weight of the aircraft

A

Load Factor

256
Q

οƒ˜Greatest air loads on an aircraft usually
come from the generation of lift during
high maneuvers

οƒ˜Aircraft load factor expresses
maneuvering of an aircraft as a multiple
of the standard acceleration due to
gravity g(32.174 ft/sec2)

A

Maneuver Loads

257
Q

οƒ˜At lower speeds, the highest load factor
an aircraft may experience is limited by
the maximum lift available

οƒ˜At Higher Speeds the maximum load
factor is limited to some arbitrary value
based upon the expected us of the
aircraft

A

Maneuver Loads

258
Q

-The loads experienced when the aircraft
encounters a strong gust can exceed
maneuver loads in some cases

-When an aircraft experiences a gust, the
effect is an increase (or decrease) in
angle of attack

A

Gust Loads

259
Q

Maneuvering Load Factors
For Normal Category

A

2.5 < 𝑛 < 3.8

260
Q

Maneuvering Load Factors
For Utility Category

A

2.5 < 𝑛 < 4.4

261
Q

Maneuvering Load Factors
For Acrobatic Category

A

2.5 < 𝑛 < 6.0

262
Q

Negative limit Maneuvering Load Factor
Should not be less than
-0.4n

A

Normal and Utility

263
Q

Negative limit Maneuvering Load Factor
Should not be less than
-0.5n

A

Acrobatic

264
Q

οƒ˜Obtained in a pullout at the highest
possible angle of attack on the wing

οƒ˜The lift and drag forces are perpendicular
and parallel respectively to the relative
wind

A

Positive High Angle of Attack

265
Q

Occurs in intentional flight maneuver in
which the air loads on the wing are down
or when the airplane strike suddenly
downwards while in level flight

A

Negative High angle of Attack

266
Q

The wing has the smallest positive angle
at which the lift corresponding to the
limit-load factor may be developed

A

Positive Low Angle of Attack

267
Q

οƒ˜Occurs at the diving-speed limit of the
airplane

οƒ˜Occurs in an intentional maneuver
producing a negative load factor or in a
negative gust condition

A

Negative Low Angle of Attack

268
Q

AIRPLANE CATEGORIES

οƒ˜Limited to airplanes that have a seating
configuration, excluding pilot seats, of
nine or less, a maximum certificated takeoff of 12,500 pounds or less

οƒ˜Intended for non-acrobatic nonscheduled passenger, and non-scheduled
cargo operation

οƒ˜Limited to:
o Any maneuver incident to
normal flying
o Stalls except whip stall
o Lazy eights, chandelles, and
steep turns, in which the angle
of bank is less than 60Β°

A

Normal Category

269
Q

AIRPLANE CATEGORIES

οƒ˜ Limited to airplanes that have a seating
configuration, excluding pilot seats, of
nine or less, a maximum certificated takeoff weight of 12,500 pounds or less

οƒ˜ Intended for Normal operations and
limited acrobatic maneuvers

οƒ˜ Not suited for snap or inverted
maneuvers

οƒ˜ Used in operations covered under the
normal and limited acrobatic operations

οƒ˜ Limited to:
o Spins
o Lazy eights, Chandelles, and
steep turns, in which the angle
of bank is more than 60Β° but
less than 90Β°

A

Utility Category

270
Q

AIRPLANE CATEGORIES

οƒ˜Limited to airplanes that have a seating
configuration, excluding pilot seats, of
nine or less, a maximum certificated take-off weight of 12,500 pounds or less

οƒ˜Have no specific restrictions as to type of
maneuvers permitted unless the
necessity therefore is disclosed by the
required flight test

A

Acrobatic Category

271
Q

AIRPLANE CATEGORIES

οƒ˜limited to propeller-driven, multiengine
airplanes that have a seating
configuration, excluding pilot seats, of 19
or less, and a maximum certificated takeoff weight of 19,000 pounds or less

οƒ˜Cannot be type certificated with other
categories on a single airplane

οƒ˜Limited to:
o Normal flying
o Stalls (except whip stalls)
o Steep turns, in which the angle
of bank is not more than 60Β°

A

Commuter Category

272
Q

LIMITED ACROBATIC MANEUVERS

οƒ˜The degree of back varies from 45 to 75Β°

A

Steep Turn

273
Q

LIMITED ACROBATIC MANEUVERS

οƒ˜If done intentionally and a flight condition
if it occurs, which is a result of a complete
stall after which the airplane, still in
stalled altitude, loses altitude rapidly and
travels downward in a vertical helical or
spiral path

A

Spin

274
Q

LIMITED ACROBATIC MANEUVERS

οƒ˜ Airplane is operating at an angle of attack
of maximum lift

οƒ˜ Loss of flying speed and in many cases
temporary loss of lift and control

A

Stall

275
Q

LIMITED ACROBATIC MANEUVERS

οƒ˜The result of a complete stall in which the
nose of the airplane whips violently and
suddenly downward

οƒ˜In some cases, The airplane slides
backward a short distance before the
nose of the plane drops

οƒ˜Causes severe strains on the engine
mounts and all surfaces

A

Whip Stall

276
Q

LIMITED ACROBATIC MANEUVERS

οƒ˜Combines the dive, turn and the climb

οƒ˜The nose of the airplane describes a
horizontal figure eight lying on its side
upon the horizon

A

Lazy Eight Flight

277
Q

LIMITED ACROBATIC MANEUVERS

οƒ˜Maneuver of the composite type,
combining climb and turn, approach to a
stall and recovery back to normal flight

A

Chandelle

278
Q

WING SPAR LOCATION
15-30% of the chord

A

Front Spar

279
Q

WING SPAR LOCATION
65-75% of the chord

A

Rear Spar

280
Q

WING RIBS SPACING
Light Airplanes

A

36 inches

281
Q

WING RIBS SPACING
Transports

A

24 inches

282
Q

WING RIBS SPACING
Fighters and Trainers

A

Vary Widely

283
Q

EMPENNAGE SPAR LOCATION
Front Spar

A

15-25% of the chord

284
Q

EMPENNAGE SPAR LOCATION
Rear Spar

A

70-75% of the chord

285
Q

EMPENNAGE RIBS SPACING
Light Airplanes

A

15-30 inches

286
Q

EMPENNAGE RIBS SPACING
Transports

A

24 inches

287
Q

EMPENNAGE RIBS SPACING
Fighters and Trainers

A

Vary Widely

288
Q
A