Forces of Flight

Question 1

Relationship between W, L in a climb?

Answer 1

W>L

Excess thrust must exist for the climb

Question 2

Relationship between T,D in a descent?

Answer 2

T

Question 3

What are the 2 things the pilot can control to change lift?

Answer 3

AOA and Velocity

Question 4

Lift equation?

Answer 4

L = CAS^2 x AOA

Question 5

How does lowering the flaps affect the C_L vs Alpha curve?

Answer 5

Lowering the flaps increases the camber of the 38s symmetric wing, increasing the amount of lift at a given AOA, raising the C_L curve

Question 6

What is the definition of an aerodynamic stall?

Answer 6

When the wing is not longer able to produce lift at a given AOA. On the C-L vs Alpha graph, this occurs at the peak of the curve.

Question 7

How do you identify C_L Max on a T_R graph?

Answer 7

It is the left most point

Question 8

How does weight affect the level-flight stall speed?

Answer 8

Weight increases stall airspeed

Question 9

How does flap setting affect the level-flight stall speed?

Answer 9

Lowering the flap decreases stall airspeed

Question 10

How does bank angle affect the level-flight stall speed?

Answer 10

Increases stall speed

Question 11

How is parasite drag affected by an increase in CAS?

Answer 11

Parasite drag increases with an increase in CAS

Question 12

How is parasite drag affected by configuration?

Answer 12

Extending the gear or speed break increase the parasite drag, raising its drag line on the Drag vs CAS graph

Question 13

How is induced drag affected by an increase in CAS?

Answer 13

Induced drag decreases with an increase in CAS

Question 14

How is induced drag affected by an increase in AOA?

Answer 14

Induced drag increases with an increase in AOA

Question 15

How is induced drag affected by an increase in weght?

Answer 15

Induced drag increases with an increase in wegiht

Question 16

How is induced drag affected by an increase in bank angle?

Answer 16

Induced drag is increased with an increased bank angle

Question 17

Briefly describe how total drag changes with airspeed?

Answer 17

Your airspeed (CAS) is initially low. At these low airspeeds, induced drag (drag created by the production of lift) is the dominant drag force. As speed increases, induced drag affects decrease until Lift/Drag Max. As airspeed increases past this point, parasitic drag becomes the dominant drag force and increases as CAS increases

Question 18

What is L/D Max in the 38?

Answer 18

230 KCAS + 1 KCAS per 100 lbs of fuel

Question 19

How does an increase in weight affect the total drag vs. CAS (level flight) graph?

Answer 19

An increase in weight raises the curve and moves it to the right

Question 20

How does an increase in bank angle affect the total drag vs. CAS (level flight) graph?

Answer 20

An increase in bank angle raises the curve and moves it to the right

Question 21

How does lowering your gear (changing configuration) affect the total drag vs. CAS (level flight) graph?

Answer 21

Changing your configuration (dropping the gear) raises the curve and moves it to the left. It decreases L/D Max (L/D Max occurs at a lower airspeed)

Question 22

Define thrust available:

Answer 22

Thrust available is the amount of thrust the engines can produce based of multiple parameters including:

• A given throttle setting
• Velocity
• Density

Question 23

Define thrust required:

Answer 23

The amount of thrust needed to maintain level unaccelerated flight

Question 24

How is thrust available affected by an increase in RPM?

Answer 24

An increase in RPM increases the thrust available

Question 25

How is thrust available affected by an increase in ambient temperature?

Answer 25

Thrust available decreases

Question 26

How is thrust available affected by an increase in pressure altitude?

Answer 26

Thrust available decreases

Question 27

On a thrust vs. CAS graph, where is the region of normal command?

Answer 27

It occurs after L/D Max

Question 28

On a thrust vs. CAS graph, where is the region of reverse command?

Answer 28

It occurs before L/D Max

Question 29

Where is the stall airspeed located on this graph?

Answer 29

The left most point

Question 30

What is the lock point and where is it on this graph?

Answer 30

Minimum continous level-flight airspeed, ID by the yellow dot on the far left of the graph. This is at 200 knots