Which term describes the additional lift gained when moving into forward flight due to rotor efficiency?

Which term describes the additional lift gained when moving into forward flight due to rotor efficiency?

• A. Translational Lift
• B. Hover Lift
• C. Dynamic Lift
• D. Induced Lift

Answer: (A)

Translational lift is the extra lift you gain when you move forward because the rotor disc starts to see air already moving in the direction of flight. In a hover, the rotor downwash creates a lot of induced flow, which reduces efficiency. As you begin moving forward, forward air velocity through the rotor adds to the rotor’s own airflow, lowering the induced velocity and effectively increasing the blade’s angle of attack at the same RPM. That combination produces more lift for the same power, and the effect grows with speed during the transition from hover into forward flight. The other terms don’t describe this forward-flight enhancement: hover lift is just the lift needed to stay in place, dynamic lift isn’t the standard rotorcraft term for this situation, and induced lift refers to the lift associated with hover-induced downwash rather than the forward-flight improvement.

Translational lift is the extra lift you gain when you move forward because the rotor disc starts to see air already moving in the direction of flight. In a hover, the rotor downwash creates a lot of induced flow, which reduces efficiency. As you begin moving forward, forward air velocity through the rotor adds to the rotor’s own airflow, lowering the induced velocity and effectively increasing the blade’s angle of attack at the same RPM. That combination produces more lift for the same power, and the effect grows with speed during the transition from hover into forward flight. The other terms don’t describe this forward-flight enhancement: hover lift is just the lift needed to stay in place, dynamic lift isn’t the standard rotorcraft term for this situation, and induced lift refers to the lift associated with hover-induced downwash rather than the forward-flight improvement.