ME & SE Aerodynamics And Maneuvers Flashcards
Vmc (Minimum controllable airspeed)
Is the calibrated airspeed at which, when the critical engine is suddenly rendered inoperative, it is possible to maintain control of the airplane with that engine still inoperative, and thereafter maintain straight and level flight at the same airspeed with an angle of bank of not more than 5 degrees.
Vmc speed
56kts
What factors determine Vmc?
Windmilling prop, unfavorable weight, rearward CG, out of ground effect, gear position, power setting, flap position, trim setting
Which prop configuration causes the most drag?
Windmilling prop
How much angle of bank is needed during Vmc?
2-3° but not more 5°
What makes an airplane turn?
Horizontal component of lift
How many redlines are there and what speeds do the represent?
2 redlines
- Vmc: 56kts
- Vne: 202kts
What is the blue line on the ASI?
Vyse: 88 (best single-engine rate of climb speed)
Rudder effectiveness is directly proportional to
The airspeed because an increase in airspeed causes an increase in airflow over the control surfaces
Vmc decreases as altitude
Increases because the good engine produces less power
Factors determine Vmc
C: Critical engine inoperative and windmilling
R: Rearward CG
M: Most unfavorable weight
A: Airborne and out of ground effect
L: Landing gear retracted
O: Operating engine full power
F: Flaps takeoff configuration
T: Trim set for takeoff
Three types of dead engine prop position
Windmilling
Stopped
Feathered
In a conventional airplane, which engine is critical?
The left engine
With respect to CG placement, as the CG moves forward the distance from the rudder becomes greater. Therefore,
The rudder will become more effective and will require less deflection for a given airspeed (law of the lever)
With relation to Vmc, forward CG =
Lower Vmc
With relation to Vmc, rearward CG =
Higher Vmc
Does a heavier airplane have a higher or lower horizontal component of lift?
Higher, therefore the heavier airplane will have more turning force towards the operating engine.
Why does a heavier airplane have a higher resistance to yawing and rolling towards the inoperative engine?
The power of the operating engine will be less effective in displacing the heavier aircraft
What are the three periods of time the FAA used different weight when calculating Vmc for certification?
Before 1996: Max gross
1996-2018: Unfavorable weight
2018-Present: Max takeoff weight
Landing gear provide three distinct changes in aerodynamics that will affect Vmc. What are they?
Change of CG
Addition of drag behind the CG cause by the main gear
The keel effect that is generated by extending the gear
Flap Takeoff Configuration: 5°-15°
The airplane will experience a significant increase in lift with a small drag penalty
Flap Takeoff Configuration: 15°-25°
At middle flap setting, the airplane will have an equal increase in lift and drag
Flap Takeoff Configuration: 25°-40°
At high flap settings, the airplane will sustain a higher penalty than the amount of lift developed.
Vmc with decrease by how many knots per degree of bank?
3 kts per degree of bank
During engine failure you should
Pitch
Power
Drag
Identify
Verify
Troubleshoot
Feather
During Pitch, you should
Pitch and maintain directional control
- Vyse (Blue line)
During Power, you should
Indicated in the POH
Usually mixtures rich
Propeller controls full forward
Throttles full forward
During Drag, you should
Gear up
Flaps up
During identify, you should
Dead foot = Dead engine
If the left engine fails the airplane will yaw to the left, causing the use of right rudder pressure
During verify, you should
Pull the throttle back on the suspected failed engine
If it is correct, no change will be noticed
During troubleshoot, you should
Should only be done if you have sufficient time and altitude
Follow the procedures outlined in the POH
During feathering, you should
Depends on whether it is an actual engine failure or a simulated engine failure
Actual:
Feather immediately in a low altitude or IMC situation
Feather before the lock pins engage at low RPM, preventing feathering
Simulated:
Normally you do not actually feather. Instructor will position in zero thrust position
When actually feathering, make sure you are at sufficient altitude in the event of failed restart
How to restart engine
With un-feathering accumulators, move propellor back to cruise
Without un-feathering accumulators, started must be engaged
Once engine restarts, keep the power to a minimum until the temperatures are within the normal operating range
How do you monitor the operative engine
Monitor the temperature gauges to make sure to avoid overheating
Open the cowl flaps and full rich mixture
Turn off any unnecessary electrical equipment. Loss of power means loss of alternator
Understand your systems interrelate to recognize any other potential problem
