On Nav
computer calculate TAS: In AIRSPEED window put temperature (+4ºC) next to
FL55, go to CAS 120 kts on inner scale and read TAS
on outer scale: 131 kts.
Put centre dot on TAS
(131 kts), rotate to put wind direction (190ºT) under
HEADING index and mark wind velocity 30 kts below
centre dot on centre line (at 101 kts).
Track (course) is 045ºM,
variation 15ºE = 060ºT.
Rotate to put track
(060ºT) under HEADING index and note drift 9º Port, rotate to put track (060ºT)
under drift (9ºP) and note that drift has changed to 10º Port so put 060º under
10ºP.
Heading (under HEADING
index) is 070ºT, variation 15º E = 055ºT and groundspeed is under the wind
mark, 147 kts.