MULTI-ENGINE AIRPLANES 1 Flashcards
Absolute Ceiling:
The density altitude -no further climb is possible with both engines at maximum power.
Asymmetric Thrust:
Uneven thrust created by the ascending and descending propeller blades.
Thrust produced by the engines of a multi-engine airplane is uneven.
Critical Engine
The engine with the most adverse effect on controllability and climb performance
Drift Down
The unavoidable descent due to the loss of an engine when above the single-engine absolute ceiling of an airplane
Propeller Synchronization
Adjusting the propeller controls to operate the propellers in unison
eliminating the uncomfortable noise associated with two propellers operating at slightly different rates.
Service Ceiling:
The maximum density altitude: 100 FPM rate of climb with both engines operating.
maximum gross weight
clean configuration.
Windmilling
The rotation of an aircraft propeller created by air flowing around it when the engine is not operating.
Zero-Sideslip:
following an engine failure in a multi-engine
the pilot maintains an attitude that minimizes drag, alleviating the sideslip of the airplane.
The single-engine absolute ceiling
Max density altitude with the critical engine feathered and the other engine at maximum power.
The single-engine service ceiling
service ceiling climb airspeed produces a 50 FPM rate of climb.
critical engine is inoperative with its propeller feathered.
VMC:
The minimum control speed with the critical engine inoperative
VMC Color
Red line, as determined under a very specific set of circumstances.
VYSE
The best rate-of-climb (or minimum rate-of-sink) speed with OEI.
VYSE Colow
blue line, as determined at maximum weight and sea-level altitude.
Difference between VYSE and VMC
VYSE is a performance speed. VMC addresses directional control.
VXSE
The best angle-of-climb speed with OEI.
VSSE
The intentional one engine inoperative (OEI) airspeed.
How the Manufacturer Determines VMC
Standard Day Conditions at Sea Level
Most Unfavorable Weight (Light)
Most Unfavorable CG Location (Aft)
Critical Engine Windmilling (Propeller Controls in the Takeoff Position)
Flaps, Gear, and Trim in the Takeoff Position with the Airplane out of
Ground Effect
Up to 5° (Not More) of Bank Towards the Operating Engine
Maximum Available Takeoff Power Initially on Each Engine (Engine Failure Should Happen Suddenly)
VMC Standard Day Conditions at Sea Level. WHY?
still air and standard atmospheric conditions at sea level.
establish a standard of measurement.
VMC Determination Most Unfavorable Weight (Light)
A heavier airplane has a lower VMC due to the horizontal component of lift and inertia.
increase in weight = more lift to maintain altitude.
More Lift= More horizontal component of lift
More Horizontal Component of Lift = require less rudder to counter act yawing.
Heavier airplane will have a higher resistance to yawing.
Most Unfavorable CG Location (Aft)
VMC Determination
The aft-most CG limit is the most unfavorable
Aft CG = rudder’s moment arm is shortened, producing less leverage for the rudder. = less effective to prevent yawing force
VMC Determination Critical Engine Windmilling (Propeller Controls in the Takeoff Position)
A windmilling propeller creates more drag than a stationary propeller.
unfeathered position creates more drag than a feathered propeller.
Therefore, VMC is highest when the critical engine’s propeller is windmilling at the low pitch, high RPM blade angle.
Flaps, Gear, and Trim in the Takeoff Position with the Airplane out of Ground Effect
Drag increases VMC
Ground effect decreases drag and increases VMC.
Up to 5° (Not More) of Bank Towards the Operating Engine
VMC is highly dependent on bank angle. In a bank, the horizontal component of lift helps the rudder counteract the operative engine’s thrust.
When banking towards the operating engine, VMC decreases by approximately 3 knots for every degree of bank less than 5°.
Banking away from the operating engine increases VMC.
Maximum Available Takeoff Power Initially on Each Engine (Engine Failure Should Happen Suddenly)
A higher power imbalance results in more asymmetrical thrust.
VMC increases as power is increased on the operating engine.
Directional Control
engine failure and the engines are not mounted on the longitudinal axis,
there are unbalanced forces and turning moments about the CG.
When Engine fails, what happens to the control of the plane?
Pitch Down
Roll Toward the Inoperative Engine
Yaw
Engine out: Why Pitch Down and how to correct?:
The loss of induced airflow over the horizontal stabilizer results in less negative lift produced by the tail.
Additional back-pressure is required to maintain level flight.
Roll Toward the Inoperative Engine
The loss of the accelerated slipstream air over the wing of the inoperative engine results in a reduction of lift on that wing.
This requires additional aileron pressure into the operative engine.
Yaw when engine is inoperative
Asymmetrical thrust requires rudder pressure toward the operating engine.
How does the Climb Performance is affected when we lose one engine?
The loss of one engine results in a 50% loss of power, but an approximate 80% loss of climb performance
When banking towards the operating engine, how much VMC decreases
VMC decreases by approximately 3 knots for every degree of bank less than 5°.
