Aviation & Aeronautics
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Breguet Range Equation

Maximum range of a jet aircraft from speed, efficiency, L/D and fuel fraction.

Formula

R=VcLDln⁡WiWfR = \dfrac{V}{c}\dfrac{L}{D}\ln\dfrac{W_i}{W_f}

Variables

RRange
VCruise speed
cSpecific fuel consumption
L/DLift-to-drag
W_i,W_fInitial/final weight

Example

A higher lift-to-drag ratio and a lighter engine both directly stretch an aircraft’s range.

Did You Know?

The Breguet range equation shows why airliners cruise high and light — and why efficient engines extend range so much.

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