where:

 

image\PERF0532_wmf.gif

is the increment in zero lift drag coefficient of the drag polar due to approach flaps.

 

image\PERF0533_wmf.gif

is the zero-lift drag coefficient of the aircraft drag polar during landing approach.

 

image\PERF0534_wmf.gif

is the zero-lift drag coefficient of the aircraft drag polar with landing flaps and landing gear retracted.

 

image\PERF0535_wmf.gif

is the zero-lift drag coefficient of the aircraft drag polar with take-off flaps and landing gear retracted.