Problem
You are on a great circle track departing from 25°30.0'N, 077°00.0'W and your initial course is 061.7°T.
The position of the vertex is 37°20.0'N, 025°45.0'W. There is a floating pub at the vertex. If you leave at
0800, April 3 and travel at 20 knots, when will you be seated with a drink in hand?
How to Solve:
First establish what you need to know and what you do already know from the information provided.
Second, solve for what you don't know. In this case, we do not yet know DLo, so we will solve by subtracting λv from λ1.
Lastly, now that you only have one unsolved variable, solve for your Dv and ETA using the appropriate equations
(see right).
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Solving
sin Dv = (cos L1)(sin DLov)

sin Dv = (cos 25.5)(sin 51.25)





Time = 134.225 hrs = 5 days 14 hours 14 minutes






2214, 8 Apr with a beer in hand




