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..anyone want to hazard the difference in arrival times with say a 20 knot x wind component, cruising at 160 knots for the entire course - It is very surprising.
Surprising indeed, as the difference is really minimal!
For your original problem: Distance=400NM, TAS=160KT, Crosswind of 20KT the groundspeeds (rounded to full knots) will be 161 and 159 for constant heading and constant track, resulting in a time difference of 1 minute and 53 seconds (for a still-air flying time of exactly 2h 30m). Interestingly, allowing yourself to drift will actually shorten your trip time by a few seconds compared to the no-wind case!
To better visualise the effect, you can use the extreme example of an TAS of 100kt into a 100kt crosswind! Trying to follow your magenta line will result in an infinite trip time (limited only by your fuel supply) wheres drifting with the wind will take you to your destination even fasten than in still air...
(BTW: Thanks for this interesting topic, it refreshes some grey memory cells from the CPL course, where the subject was called "effective true airspeed"
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