I think the comment above was aimed at the eurofighter which has such bad aerodynamics that it would just start to tumble without it's onboard computer. Most of the rest of them would be managable, and in anycase fighterbombers tend to have ejecter seats.
I'm looking forward to landing a helicopter with the engine off, now that'll be an adreniline rush. For all those people thinking it'll just fall out of the sky, your wrong, they fly quite well with no propulsion, if the gearbox was to cease however, it would drop from the sky like a fat kid from the top of a tree.