Exercise 10 - Flight for Range and Endurance

Question 1

Flight for Maximum Range Definition

Answer 1

Maximum distance per unit of fuel consumed

Question 2

Flight for Maximum Endurance Definition

Answer 2

Maximum time per unit of fuel consumed

Question 3

Induced Drag

Answer 3

• Drag that is a by-product of lift
• Decreases as speed increases

Question 4

Parasite Drag

Answer 4

• Caused by the shape of the aircraft
• Increases as speed increases

Question 5

Lift to Drag Ratio

Answer 5

• Ratio between the lift produced by an airfoil and the induced drag
• Varies with angle of attack

Question 6

Flight for Max Range

Answer 6

• Occurs at maximum lift to drag ratio
• Useful for trying to minimize fuel expenses

Question 7

Range Theory - Factors Affecting Range

Answer 7

• Fuel Available
• Wind
• Angle of Attack
• Weight
• Airspeed
• Centre of Gravity
• Altitude

Question 8

Range Theory - Fuel Available

Answer 8

• range determined by fuel available and whether we lean appropriately
• POH provides cruise performance data

Question 9

Range Theory - Wind

Answer 9

• Tailwind increases range
• Headwind decreases range
• To maximize range, fly slightly faster in headwinds and slightly slower in tailwinds

Question 10

Range Theory - Power and Drag Curves

Answer 10

• Plot of various aircraft performance parameters
• Useful for visualizing what happens when we change speed or other details

Question 11

Range Theory - Drag Curve

Answer 11

• Induced Drag decreases with speed
• Parasite drag increases with speed
• Total drag is sum of both

Question 12

Range Theory - Power Curve

Answer 12

• Power increases slightly with speed
• Thrust and Power aren’t really the same thing

Question 13

Range Theory - Max Lift to Drag Ratio

Answer 13

• Occurs where tangent line intersect drag curve
• Tells us the speed for maximum range

Question 14

Range Theory - Weight

Answer 14

• Heavier aircraft will fly at higher angle of attack
• Must increase power to fly faster
• increased power = increased fuel burn = decreased range

Question 15

Range Theory - Airspeed

Answer 15

• max L/D ratio occurs at a specific AOA, and a corresponding airspeed
• maximum range is a certain airspeed
• doesn’t change with altitude
• does change with weight

Question 16

Range Theory - Forward C of G

Answer 16

Aircraft has higher apparent weight

Question 17

Range Theory - Aft C of G

Answer 17

Aircraft has lower apparent weight

Question 18

Range Theory - Altitude

Answer 18

• Does not affect aerodynamic aspects of range
• significant impact on engine efficiency
• Benefits of high altitude can be wiped out easily
• Altitude selection needs to consider many factors

Question 19

Flight for Max Endurance

Answer 19

• Occurs at the minimum power setting to maintain level flight
• Corresponds to minimum drag
• Useful for waiting for a runway to become available

Question 20

Endurance Theory - Min Drag / Min Power

Answer 20

• Occurs where total drag is at lowest value
• Minimum Power = Lowest fuel consumption
• Going Slower takes more power since induced drag increases faster than parasite drag decreases

Question 21

Endurance Theory - Factors Affecting Endurance

Answer 21

• Fuel Available
• Weight
• C of G
• Altitude
• Turbulence
• Flaps

Question 22

Endurance Theory - Fuel Available

Answer 22

• More Fuel = More Time
• Must be correctly leaned

Question 23

Endurance Theory - Weight

Answer 23

• Higher Weight = More drag
• More power required to overcome
• Reduced endurance

Question 24

Endurance Theory - C of G

Answer 24

• The more forward it is, the higher the apparent weight
• Reduced Endurance

Question 25

Endurance Theory - Altitude

Answer 25

• Lower = Hotter, don’t climb

Question 26

Endurance Theory - Turbulence

Answer 26

• Requires power increase
• Reduces endurance