MULTI-ENGINE AIRPLANES 2 Flashcards
Explain how does sideslip occur?
engine failure = yaws towards the inoperative engine due to asymmetrical thrust.
The rudder must be used to maintain directional control.
With the rudder deflected, the airplane’s nose is misaligned with the relative wind, resulting in a sideslip.
The sideslip increases drag and reduces performance.
What is the solution to sideslip?
zero-sideslip condition
How to Establish a Zero-Sideslip Condition
Bank towards the operative engine by 2° to 3° (“raise the dead”).
Less rudder force because of more horizontal lift
“Split” the ball/brick (slip-skid indicator) towards the operative engine by one-half of a ball width.
What happens if you don’t position the ball?
loss of climb performance.
Four Factors that Make the Left Engine Critical
Asymmetrical Thrust (Yaw) Accelerated Slipstream (Roll and Pitch) Spiraling Slipstream (Yaw) Torque (Roll)
Explain Asymmetrical Thrust (Yaw)
descending propeller blade produce greater thrust than the ascending blade when the airplane is operated under power and at positive angles of attack.
the left engine’s failure will result in the most asymmetrical thrust (adverse yaw) as the right engine will be providing the remaining thrust.
Accelerated Slipstream (Roll and Pitch)
longer moment arm to the center of thrust of the right engine than to the left engine.
the centerline of lift is farther out on the right wing, resulting in a greater rolling tendency with a loss of the left engine.
which engine creates more significant downward pitching moment due to the greater loss of negative lift produced by the tail.
The left engine’s failure also results in
Spiraling Slipstream (Yaw)
A spiraling slipstream of air from the left engine strikes the vertical stabilizer from the left. This helps counteract the yaw caused by a failure of the right engine. The right engine’s slipstream does not hit the vertical stabilizer. If the left engine fails, the right engine’s slipstream will not counteract the yaw toward the inoperative engine.
Torque (Roll)
For every action, there is an equal and opposite reaction.
The airplane will tend to roll towards the inoperative engine regardless of which engine is failed.
On a multi-engine airplane with clockwise rotating propellers, the effect of torque during OEI flight will:
Increase the tendency of the airplane to roll towards the inoperative engine (left engine failed);
Counteract the tendency of the airplane to roll towards the inoperative engine (right engine failed).
Approximate Drag Factors for Light-Twins Full Flaps:
Full Flaps: -275 FPM
Approximate Drag Factors for Light-Twins Windmilling Propeller:
-200 FPM
Approximate Drag Factors for Light-Twins Gear Extended:
-250 FPM
Critical Density Altitude
Lower minimum control speed (VMC) as altitude is increased. stall speed (VS) does not decrease with altitude.
There exists an altitude where each of the following exists:
The density altitude where VMC and VS are equal is called the critical density altitude.
airplane could experience an abrupt change in attitude or enter into a spin.
Climb Requirements for Certification
manufacturer must determine climb performance at various weights and altitudes.
does not need to demonstrate climb performance.
