On Thu, 21 Jun 2007 16:01:50 -0700, "Bob Gardner"
wrote in :

Do I have to include celestial nav in the next editions of my books? Would
very many current pilots recognize a bubble sextant if it bit them in the
butt?

I know you're just joking, but my point was, that while the
electronically controlled UAV would be out of commission in the event
of an EMP or CME, it would be possible, if not practicable, for the
human piloted aircraft to continue on course by dead reckoning at
least.