As a former Air Force Avionics craftsman/technician, i can relate to the two-man concept. I signed off thousands of red"x" inspections on F-16 aircraft for over 12 years. I could not sign-off my own maintenance, even being an expert in such. The only way to do that was to get certified as a master mechanic(CMM) that only one or two of the hundreds of technicians i worked with had. The Air Force actually stopped the program after only a short period.......too much responsibilty for one person...... especially when you're dealing with a jet fighter with only one engine and no margin for error!! That's the way ALL maintenance should be done, even on vehicles.......!!