Aviation & Aeronautics
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Thrust Required (level flight)

In steady level flight, thrust must equal drag, which is weight divided by L/D.

Formula

T=WL/DT = \dfrac{W}{L/D}

Variables

TThrust
WWeight
L/DLift-to-drag ratio

Example

In level flight an aircraft with L/D = 15 and weight 15 000 N needs only 1000 N of thrust.

Did You Know?

In steady level flight, thrust exactly equals drag and lift exactly equals weight.

thrustdragperformance