"Matt Whiting" wrote in message
...
It is easy to show that mathematically, a 90 degree crosswind results in
no tailwind component. Without a correction, it results in no headwind
component as well.

I'd like you to show that since it is easy.

Including crab, a 90 degree crosswind creates a groundspeed of cos(T) * true
airspeed, where T is the crab angle. cos(T) is always less than or equal to
1, so your groundspeed is always less than or equal to your true airspeed,
and so there is no POSITIVE tailwind component (if my inclusion of the word
"POSITIVE" here makes a difference to your previous post, then you're just
being intentionally obtuse, as my meaning was perfectly clear: a 90 degree
crosswind never increases your groundspeed, no matter how strong).

And a crosswind is relative to your track, not your heading.

A crosswind is relative to whatever you define it to me relative to. If you
don't care about where you are going (as is sometimes the case), a 90 degree
crosswind doesn't affect your speed in the direction of your heading at all
(though it does, obviously, affect your speed along your ground track).

OK, now show us the math! :-)

Done.

Pete