ME & SE Aerodynamics And Maneuvers Flashcards
(34 cards)
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