There are some jobs Navs can still do, but no one respects (or trusts/listens to) a flight safety officer without wings.
I have vivid memories of a "full" brevet Flight Safety Officer at brecky time in the MPA Officers' Mess. The toast had jammed (again) in the toaster (belt fed incinerator) and he was happily poking out the stoppage with his little metal knife; mains power on, of course. Nice bloke, though.