On Apr 24, 12:19*pm, wrote:

, but do any
travel from east to west and if so, what would be the advantage? Thanks.

Ooh! A chance to self-reference myself! Probably illegal in many
states, but here it is:

http://www.fas.org/spp/military/prog.../at_950411.htm

http://www.fas.org/spp/military/prog.../at_950415.htm