I use 1.45 sq.ft. "eqivalent parasite drag area", CD=1, not to be confused with "flat plate area", CD=1.28, in my equations for my 235. I calculate induced loss separately, since this depends on air density and gross weight. The combo usually comes out to about 1.55-1.65.

Paul,

 

Thanks.  Here is an interesting thought series.

 

What does the prop add when rotating at cruise pitch?

 

How about the gear, if extended at 120 KIAS?

 

What about the coefficient of a C172 with its struts, rivet heads, wheels, etc?

 

What about its prop?

 

The reason for this line is that I believe that a "slick" airplane is more adversely affected by non-seizure engine failure with a rotating cruise prop than an already draggy commercially built spam can.