CPL Aerodynamics · Practice

The cruise altitude for maximum jet range at constant Mach is influenced by the 'tropopause'. At and above the tropopause, further altitude increase provides:

• A.constant SAR regardless of altitude in the stratosphere
• B.no further improvement in SAR from temperature
• C.improved range because jet SFC improves in the colder tropopause temperatures
• D.reduced range because the tropopause acts as a density discontinuity that increases wave drag