Performance Flashcards

Question

Fill in the blank: The typical maintenance cost is ______ per flight hour.

Answer 1

$1500-2000

Answer 2

$243.6 million ## Footnote This penalty is associated with damages to airline customers and other financial impacts.

Answer 3

$1.77 billion ## Footnote This amount reflects the financial impact on airline customers due to the incident.

Answer 4

$500 million ## Footnote This fund was created to support beneficiaries of crash victims.

Answer 5

2,800 employees ## Footnote This layoff was a direct consequence of the financial strain on the company.

Answer 6

$19 billion ## Footnote This loss is significant and reflects the broader impacts on Boeing's financial health.

Answer 7

First annual loss in more than a decade ## Footnote This indicates a major shift in Boeing's financial stability.

Answer 8

* Lift * Drag * Thrust * Weight ## Footnote These forces are crucial for understanding aircraft performance.

Answer 9

L = 1/2 𝜌V² ∙ S ∙ Cₗ ## Footnote Here, 𝜌 is air density, V is velocity, S is wing reference area, and Cₗ is the lift coefficient.

Answer 10

Lift coefficient ## Footnote This is a non-dimensional parameter that depends on airfoil cross-section and wing planform shape.

Answer 11

Cₗ has strong dependence on AOA (Angle Of Attack) ## Footnote This relationship is critical for understanding lift performance.

Answer 12

Lift force is generated when P₁ < P₂ ## Footnote This condition indicates that pressure under the airfoil is less than pressure above it.

Answer 13

D = q ∙ S ∙ Cᵈ ## Footnote Here, q is dynamic pressure, S is wing reference area, and Cᵈ is the drag coefficient.

Answer 14

Cᵈ = Cᵈ₀ + k ∙ Cₗ² ## Footnote This equation relates drag coefficient to lift coefficient and accounts for induced drag.

Answer 15

AR = b²/S ## Footnote Here, b is the wingspan and S is the wing reference area.

Answer 16

Induced drag factor decreases ## Footnote A larger aspect ratio leads to more efficient lift generation.

Answer 17

Cₘ = 0 for steady state ## Footnote This indicates that the aircraft is trimmed and stable during flight.

Answer 18

Linear up to the stall region ## Footnote This behavior is critical for understanding lift performance before stall occurs.

Answer 19

Increases lift ## Footnote Camber affects the airfoil's performance and lift characteristics.

Answer 20

Loss of lift due to high angle of attack ## Footnote This condition can lead to a significant decrease in aircraft control.

Answer 21

Depends on AOA and deflection angle ## Footnote Changes in AOA and elevator deflection will influence the pitching moment.

Answer 22

P₂ + U₂² = P₁ + U₁² ## Footnote This is a form of the Bernoulli equation applicable outside the boundary layers.

Answer 23

T must counteract drag ## Footnote This relationship is crucial for maintaining steady flight conditions.

Answer 24

V² = 2W/(ρS kCᵈ₀) ## Footnote This equation helps determine the most economical speed for cruising.

Answer 25

V for min T or D: V = 2∙Wρ∙S∙kCD0

Answer 26

Tmin = 12∙ρ∙S∙CD0∙(2∙Wρ∙S∙kCD0) + 2∙k∙W²ρ∙S

Answer 27

Low fuel consumption, economical speed to cruise at

Answer 28

dP/dV = 32∙ρ∙V²∙S∙CD0 − 2∙K∙W²ρ∙V²∙S = 0

Answer 29

V² = 2∙Wρ∙S∙K3CD0

Answer 30

When available maximum thrust becomes less than minimum drag required for cruise flight

Answer 31

D = 12∙ρ∙V²∙S·(CD0 + k∙CL²)

Answer 32

T = W∙γ + 12∙ρ∙V²∙S·CD0 + 2kW²ρ∙S∙V²

Answer 33

Requirements on Vclimb or other structural/operational requirements

Answer 34

γmax = ρ/ρsmeng ∙ Tmax - 2∙W∙k∙CD0/W

Answer 35

dCτ/dβ < 0

Answer 36

Yaw into the wind

Answer 37

Leads to a restoring roll moment

Answer 38

Lateral stability

Answer 39

Directional stability

Answer 40

Function of sideslip angle, aileron deflection, rudder deflection, angle of attack, Mach number, Reynolds number

Answer 41

Lift increases

Answer 42

Lift decreases

Answer 43

Mτ = ClqSb

Answer 44

dCN/dβ > 0

Answer 45

γ = (T - D)/W

Answer 46

It determines the maximum thrust available

Answer 47

Thrust minus drag

Answer 48

Initial response in the roll axis. ## Footnote Introducing a positive dihedral angle leads to restoring roll moment.

Answer 49

𝑑𝐶𝜏𝑑𝛽 < 0

Answer 50

Initial response in the yaw axis. ## Footnote This refers to how an aircraft responds to yaw disturbances.

Answer 51

𝑑𝐶𝑁𝑑𝛽 > 0

Answer 52

The tendency to converge on initial equilibrium point following a small disturbance from said equilibrium point.

Answer 53

A system in equilibrium when the sum of all forces and moments acting on it are identically zero.

Answer 54

* Stable * Unstable * Neutrally stable

Answer 55

A measure of how the pitching moment changes with angle of attack.

Answer 56

It decreases.

Answer 57

It increases.

Answer 58

The point where the pitching moment does not depend on the angle of attack.

Answer 59

C/4 from the leading edge.

Answer 60

A measure of how stiff the 'spring' is about the pitch axis.

Answer 61

The aircraft is stable.

Answer 62

𝑑𝑀𝑑𝛼 < 0

Answer 63

𝑑𝑀𝑑𝛼 > 0

Answer 64

The sum of moments is equal to zero.

Answer 65

The aircraft can be trimmed but unstable.

Answer 66

The aircraft can be trimmed and stable.

Answer 67

The center of gravity affects the aircraft's ability to return to equilibrium after a disturbance.

Answer 68

𝑀𝐶𝐺=𝑀0𝑤 − 𝐿𝑤cos𝛼(𝑋𝐴𝐶-𝑋𝐶𝐺) + 𝑀𝑜𝑇 - 𝐿𝑇cosα(𝑋𝑇-𝑋𝐶𝐺)

Answer 69

The tail helps to modify the pitching moment to achieve stability.

Answer 70

Usually negative.

Answer 71

Usually positive.

Answer 72

Angle between xB-axis and the tail center line.

Answer 73

* hCG = XCGC * hAC = XACC

Answer 74

LT = XT - XCG

Answer 75

CMCG = CM0w + (hCG - hAC) CLw + LTCLTSTSw

Answer 76

CLT = CLαT(α + iT)

Answer 77

CLw = CL0w + CLαw ∙ α

Answer 78

It tells how effective the tail is.

Answer 79

The specific CG position that gives Neutral stability.

Answer 80

S.M. = hCG - hN

Answer 81

The aircraft is unstable, indicating CG is behind NP.

Answer 82

It degrades the pitch trim authority of the elevator.

Answer 83

* Moving CG forward increases stability * Moving CG back decreases stability

Answer 84

CM0 > 0 indicates positive pitch stiffness.

Answer 85

dCM/dα < 0

Answer 86

It measures the tail's effectiveness.

Answer 87

It indicates poor tendency to resist gusts and upsets.

Answer 88

CM0 + (hCG - hN) CLwα < 0

Answer 89

A positive static margin indicates stability.

Answer 90

T cos α - W ∙ sin γ - D = 0

Answer 91

sin γ ≈ γ and cos γ = 1

Answer 92

They illustrate limits on aircraft motion.

Answer 93

α ≤ αmax and CL ≤ CLmax

Answer 94

L ≤ nmax

Answer 95

To develop general steady flight equations.

Answer 96

The aircraft tends to return to the equilibrium point.

Answer 97

Large static margin.

Answer 98

It increases drag in trim flight.

Answer 99

Changing the heading of the aircraft.

Answer 100

* Rolling moment - Γ * Yaw moment - N

Answer 101

It aids in changing the heading of the aircraft.

Answer 102

Thrust is required to maintain level flight during a turn.

Answer 103

𝐶Γ = Γ12𝜌𝑉2𝑠𝑏 ## Footnote 𝐶Γ𝛽 ∙ 𝛽 + 𝐶Γ𝛿𝑎 ∙ 𝛿𝑎 + 𝐶Γ𝛿𝑟 ∙ 𝛿𝑟

Answer 104

𝐶𝑁 = 𝐶𝑁𝛽 ∙ 𝛽 + 𝐶𝑁𝛿𝑎 ∙ 𝛿𝑎 + 𝐶𝑁𝛿𝑟 ∙ 𝛿𝑟 ## Footnote Yaw moment is defined as 𝑁 𝐶𝑁 = 𝑁12𝜌𝑉2𝑠𝑏

Answer 105

Zero ## Footnote This simplifies the determination of required deflections for given flight conditions.

Answer 106

* Side slipping: deflecting rudder to deflect thrust vector * Banking: deflecting ailerons to lift vector

Answer 107

L𝑠𝑖𝑛𝜇 = 𝐶𝑒𝑛𝑡𝑟𝑖𝑝𝑒𝑡𝑎𝑙 𝑓𝑜𝑟𝑐𝑒

Answer 108

* Lift * Thrust * Weight * Drag

Answer 109

𝑇 − 𝐷 = 0

Answer 110

𝐿𝑊 = 1𝑐𝑜𝑠𝜇 = n < 𝑛𝑚𝑎𝑥 ## Footnote n is the load factor.

Answer 111

V vs 𝜇 (or n) ## Footnote It defines the structural limits for the aircraft.

Answer 112

𝜔 = 𝑇𝑢𝑟𝑛 𝑅𝑎𝑡𝑒 = ሶ𝜎

Answer 113

r = 𝑉2𝑡𝑎𝑛𝜇/𝑔

Answer 114

𝑇 = 𝐷 = 12 𝜌𝑉2S(𝐶𝐷0 +K𝐶𝐿2)

Answer 115

* Stall Constraint: 𝑉 ≥ 𝑉𝑠𝑡𝑎𝑙𝑙 * Structural Load constraint: n < 𝑛𝑚𝑎𝑥 * Thrust constraint: 𝑇 ≤ 𝑇𝑚𝑎𝑥

Answer 116

To calculate the radius of the turn and determine at what altitude this radius can be achieved.

Performance Flashcards

(146 cards)