As previously implied, we use the simple 
method to determine the
drag of the aircraft. The total drag of the aircraft can be roughly
approximated with this equation (that discards the fact that 
has
an effect on 
, the Oswald Efficiency Factor):
Where:
is calculated with the equivalent skin friction method, which states:
Typically, for this type of aircraft, equals 0.0035, which gives
us a of 0.014.
This works only for subsonic flight, and therefore we need to add some extra term to deal with the wave drag. As a quick approximation, this method will do:
But in this case an even quicker method is needed, since we do not
know enough about the size of the aircraft to calculate 
. Look at
some other aircraft to estimate how much the parasite drag will raise
at M1.4, a common value seems to be that it doubles the subsonic drag.
The doubled value of 
is also the value used when calculating the
required wingloading for the dash mission segment. To roughly estimate
the value of 
in eq3.1 above, we use this formula:
