Aircraft Zero-lift Drag Coefficient at Landing with Gear Down

The aircraft drag polar is expressed as:

..\Images\IMG00027_shg.gif

For parabolic drag polars:

..\Images\INFO0264_wmf.gif

where:

..\Images\INFO0265_wmf.gif

is the wing aspect ratio.

..\Images\INFO0266_wmf.gif

is the Oswald's efficiency factor.