Lift is defined as?

Lift is defined as?

• A. Drag
• B. Downward force
• C. Thrust
• D. Upward force to keep the UAS in flight

Answer: (D)

Lift is the upward force that keeps the UAS in flight. It comes mainly from the rotor blades pushing air downward; as air is accelerated downward, the aircraft experiences an upward reaction that lifts it. The amount of lift depends on rotor speed, blade pitch, air density, and rotor design. In hover, the total lift from all rotors balances the weight; to ascend, lift must increase; to descend, lift must decrease. Drag is the resistance to motion through the air, weight is the downward gravitational force, and thrust is the propulsive force along the rotor axis. While thrust can contribute to lifting in vertical flight, lift specifically refers to the vertical support that counteracts weight to sustain flight.

Lift is the upward force that keeps the UAS in flight. It comes mainly from the rotor blades pushing air downward; as air is accelerated downward, the aircraft experiences an upward reaction that lifts it. The amount of lift depends on rotor speed, blade pitch, air density, and rotor design. In hover, the total lift from all rotors balances the weight; to ascend, lift must increase; to descend, lift must decrease. Drag is the resistance to motion through the air, weight is the downward gravitational force, and thrust is the propulsive force along the rotor axis. While thrust can contribute to lifting in vertical flight, lift specifically refers to the vertical support that counteracts weight to sustain flight.