On the range graph there
is a figure on the right hand side of the setting lines which is the true
airspeed in knots (in the case of the full throttle/2300rpm line this is
160kts). To apply the headwind correction, deduct 40 from 160 to give the
groundspeed of 120kt, then multiply the 844nm by the GS/TAS formula (i.e. by
120/160), which gives 633nm.
but the question is a little
unfair....it just asks for the range...so do they mean NAM or ground nm?
2 reasons for going for
ground range
Firstly, they give you a
wind component in the question data, so use it....secondly, the answers offer
'nm' ranges...if they had wanted nautical air mile range, I'm pretty confident
they would have stated NAM in the answers.