I believe it depends who you are going with. If it your boss I would say that a suit is not nessesary but it looks good. If its someone that is on your level in the company I would say some nice pants (not jeans) and a matching polo shirt would do. You could always wear the jacket from the suit if it matches, and when you are in the plane take it of.
Also one has to take the class he is traveling and his trip to/from the airport. My parents travel sometimes (not long haul) but my dad always wears his suit but without the shirt( pants, regular tee/polo, and a sweater)
But if you really look at it even if you do wear the suit, during the flight you can relax(take tie ,off unbutton the collar and if using a blanket unhook the pants)
But I don't think it would be nice to come walking in with jeans and a nike sweater.
I have flown JFK
in a suit and it wasn't to bad. Its not like u can stretch in eco, and in J you can lay down on the bed.
SRY bout spelling im way to tired 4 this
[Edited 2005-02-15 03:36:46]