Single Engine Operations

Question 1

4 Categories of V Speeds:

Answer 1

Control – (Vso, Vs, Vmc (important for single engine) )
Performance – (Vx, Vy,Vxse, Vyse)
Limitations – (Vo, Va, Vle Vlo Vne Vfe Vno)
Manufacturer Specs (Vr, Vsse,)

Question 2

Which engine is the critical engine in a conventional airplane?

Which engine is the critical engine in our airplane?

Answer 2

Conventional : Left Engine

Counter-Rotating: Technically both are critical and both aren’t.

Question 3

Define Vmc

Answer 3

The minimum speed at which directional control can be maintained under a very specific set of circumstances outlined in 14 CFR part 23.

Question 4

What criteria does the aircraft have to meet for Vmc

Answer 4

Must Be able to:
o stop the turn that results when the critical engine is suddenly made inoperative within 20°

o using maximum rudder deflection and a maximum of 5° bank, and (2) thereafter, maintain straight flight with not more than a 5° bank.

*No requirement to be capable of climbing at this airspeed.

Question 5

V-speeds are determined at

Answer 5

Sea Level Pressure

Question 6

Vmc is based on a ________ scenario

Answer 6

Worst Case Scenario

Question 7

What is the acronym for Vmc certification?

CATOMMFFLSBP

Answer 7

Critical Engine
Aft-CG
Trim
Out of Ground Effect
Most Adverse Weight
Max Power
Flaps Wing
Flaps Cowling
Landing Gear
Sea Level
Bank
Propeller

Question 8

What is the difference between Vmca and Vmc?

Answer 8

Vmca is the actual Vmc

Vmc is the published Vmc by the manufacturer

Question 9

Explain in Depth what all of the elements of

CATOMMFFLSBP do to make it a worst case possible scenario.

Answer 9

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

Question 10

As altitude increases
Vmc ___________
Stall Speed ___________

Answer 10

Vmc decreases with altitude

Stall Speed stays relatively the same with altitude

Question 11

You want the Stall / Roll & Yaw to happen first

Answer 11

Roll & Yaw

Question 12

You want the Stall / Roll & Yaw to happen first

Answer 12

Roll & Yaw

Question 13

Per the POH will a Stall or Roll & Yaw motion occur first?
When might that not be the case?

Answer 13

Stall first

*except when you’re at max power and engine is relatively new and you’re in thicker air

Question 14

What is Vmcg?

Answer 14

Vmcg : Minimum controllable speed on the ground using only aerodynamic forces, no brakes. Rudder alone, and must be able to do without 150lbs of force.

Question 15

How can you determine loss of control?

OODA loop

Answer 15

Observe
Orient Yourself
Decide (what are your options)
Act

Question 16

What steps do you take when an engine fails to be certain and act appropriately?

Answer 16

Identify Engine Dead:
Rudder (dead foot dead engine)

Verify:
Use throttle
Move back and forth and if no change then engine is not operating
(Non-memory troubleshoot before securing)

Confirm:
EGT: if there’s no exhaust coming out then temperature drops

Question 17

Reasons for loss of directional control

Answer 17

♣ Asymmetric Lift
♣ Asymmetric Thrust
♣ Asymmetric Drag
* Not enough moment on the controls

Question 18

Define Critical Engine

Answer 18

Engine whose failure most adversely affects the performance or handling characteristics of the airplane

Question 19

Factors of a critical engine (PAST)

Answer 19

P-Factor
o Descending propeller blade on the right produces more thrust.
o A positive angle of attack is required for level flight
o More power (thrust) is required for level flight
o Critical engine has shorter arm in conventional styling
o

Accelerated Slipstream
o Equal and opposite so slipstream is accelerated more
o Center of lift (pressure) moves toward descending blade / inboard
o

Spiraling slipstream
o A spinning propeller imparts a rotational force to the airflow.
o Left Engine
o Slipstream tends to impact the vertical stabilizer.
o Helps counteracts the tendency to roll and yaw.
o Faster moving air lower pressure
o Slower moving air higher pressure
o Tail becomes more effective
o

Torque

• Propeller pulling to the right causes tendency to the left
• Loss of critical engine : increase left turning tendencies on critical
• Opposite engine: left turning tendency aids in the combating of yaw

Question 20

What is zero thrust?

Answer 20

– just using engine power instead of oncoming wind to turn propeller

Question 21

How do you initiate recovering from below Vmc engine loss?

Answer 21

Decrease power
Decrease angle
Increase airspeed above 80