prunehead
Don't forget that the MIL uses both upper and lower sidbands, which is easily switchable if you have Collins HF equipment on board. Some of the better MIL equipment actually used 4 independant sidebands, but then again, we weren't restricted to the normal 150w PEP that I think is a requirement for aeronautical mobile (ie. airplane). From memory, we used a very conservative 10kW per sideband (all four of them).
Fly_boy - general rule for HF - short distance between stns, use lower frequency; long distances, use higher frequencies. Pays to listen out on a few freqs first to see what is being used. Also if you are fitted with FSS (freq synthensised system) which allows selection in .1k steps, you can easily work the international frequencies - SP6, INO3, SEA3, PAC9, etc. although I don't recommend calling UJANG PADANG on 8MHz to cancel SAR somewhere in the middle of nowhere.
HF is akin to Morse code - another lost art, along with the Q and Z codes.