Editing Jet aircraft (section)

==Range==
{{main|Range (aircraft)}}
For a long range jet operating in the [[stratosphere]], the speed of sound is constant, hence flying at fixed angle of attack and constant [[Mach number]] causes the aircraft to climb, without changing the value of the local speed of sound. In this case:

<math>V=aM</math>

where <math>M</math> is the cruise Mach number and <math>a</math> the local speed of sound. The range equation can be shown to be:

<math>R=\frac{aM}{c_T}\frac{C_L}{C_D}ln\frac{W_1}{W_2}</math>

which is known as the ''Breguet range equation'' after the French aviation pioneer [[Louis Charles Breguet]].