The dilemma of saving the rear crew was demonstrated at Scampton in '58/59?, when a 617 Sqdn Vulcan lost it's nosewheels on take-off (over steering whilst being towed). It was decided that the rear crew would bale out over Waddington
Unfortunately the Nav Radar's parachute failed to open. The aircraft made a perfect landing at Scampton, though there wasn't much left of the nose u/c!