Principles of Flight Section

Question 1

What does the term “critical engine” mean?

Answer 1

The engine whose failure would result in the most adverse effects on the aircraft’s handling and performance.

Question 2

Effects of density altitude on the Vmc Demonstration

Answer 2

As altitude increases, the airplane’s performance and the air density both decrease. This causes a stall to occur first instead of a yawing or rolling with a loss in directional control.

Higher density altitude will allow for a lowering of Vmc though.

Question 3

Effects of airplane weight and center of gravity on control

Answer 3

More aft - less stable

Question 4

Effects of bank angle on Vmc

Answer 4

Lowers Vmc - Negative Relationship

You want the largest bank angle but most efficient is 2-3

Question 5

Relationship of Vmc to Stall speed

Answer 5

Stall speed remains the same, however VMC changes with altitude.

Question 6

Reasons for loss of direction control:

Answer 6

Uncoordination

Question 7

Indications of loss of directional control

Answer 7

Yaw and Roll in unguided direction due to:

Asymmetric Lift
Asymmetric Thrust
Asymmetric Drag

Question 8

Importance of maintaining the proper pitch and bank attitude nad proper coordination of controls.

Answer 8

Zero Side Slip Important: Streamline into relative wind thus reducing drag from fuselage when performance is important.

Question 9

Loss of directional control recovery procedures

Answer 9

Pitch Down
Throttle reduced for directional control
If needed

Question 10

Engine failure during takeoff including planning, decisions, and single engine operations.

Answer 10

Calculate:

Takeoff
Clear 50ft. 
Abort Height/Continue Height (600 basic for UND)
Single Engine Service Ceiling
Single Engine Climb Rate
Range & Endurance
Landing Distance
Landing 50ft.

Question 11

When an engine fails you lose:

___% Power
___% Performance

Answer 11

50% Power

80% Performance

Question 12

Explain:

C
A
T
O
M
M
F
F
L
S
B
P

Answer 12

Critical Engine
Must be engine that’s inoperative to determine Vmc speed
Increases Vmc

Aft-CG 
CG moved as far aft as it can possibly go. 
Shortens rudder arm
Less rudder authority. 
Increase Vmc

Trim
Trimmed for takeoff
Potentially increase Vmc if not trimmed

Out of Ground Effect
Can’t use ground effect
Increases Vmc
Less P factor in ground effect

Most Adverse Weight
More lift with more weight so adverse weight. Lightest weight possible.
Closest to zero fuel weight.

Max Power
Increases Vmc

Flaps Wing
Takeoff position
No flaps, higher Vmc

Flaps Cowling
Takeoff position
Largely negligible

Landing gear
Retracted for certification
Increases Vmc
Keel effect when down would pull the plane to a more stable position

Sea Level Pressure
Certified at Seal Level
Air most dense so all 180 hp will act on that engine
More power to fight against

Bank
Increase Vmc
Max of 5° bank for certification
If in straight and level your Vmc increases by about 20 knots due to not enough rudder force

Propellers
For certification are windmilling propeller (increases drag which helps pull airplane to dead engine)

Question 13

Determining loss of directional control:

OODA

Answer 13

Determining loss of directional control:

Observe
Orient Yourself
Decide (what are your options)
Act