PPRuNe Forums - View Single Post - Vulcans - rear crew disabling pilots ejector seats in flight
Old 8th Jan 2011, 18:57
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Fareastdriver
 
Join Date: Oct 2006
Location: UK
Posts: 4,673
Old Duffer. There was a thread om V bomber rear crew escape some time ago and by luck I still have my post in my computer. I will post it again to explain.


When the V bombers were first designed rear crew escape by ejector seats was not even considered. The Victor was conceived with a jettisonable cockpit, the Vulcan with a seat for the one pilot, the Sperrin with one seat between the two pilots and the Valiant, the last of the design phases, a seat for each pilot.

The designs for the V bombers were the first time that the British aircraft industry had to design military aircraft for prolonged operation above 30,000 ft and the Comet disasters proved how much they knew about it. When the V force cockpits were stressed to 8.5 lbs/in pressure differential that was almost a step into the unknown. It follows that any alteration like cutting extra exit holes for the rear crew was structurally impossible. The only way you could do it was to have a small hole with enough room for ONE seat to exit. This was done with a Valiant as a one off in the early sixties. This proved it was possible to eject from the cabin of a Valiant though I believe the primary research was to study the effects of rear facing ejection.

To have any chance at all you would have to sequence the ejection. You could not eject simultaneously as the seats would all meet at a point above the cockpit. All those who fly with a rocket seat attached to their backsides would think that is easy. Not with a Mark 3A Ejector seat that was necessary to clear the tail of a V bomber. That had a three cartridge, eight foot telescopic gun that ensured the occupant left the end at 80 ft/sec. With a seat like that you have to be fully prepared to eject. Should you not be fully prepared you would be crippled, if unprepared, fatally crippled.

Three scenarios were considered.

Inclined ejector guns for the outer crew members. This would involve them accelerating from Zero to 80ft/sec eight feet vertically and three feet laterally. The sideways forces would be more than sufficient to break their necks.

Tilted Ejector seats. This would require the seat to flop from the vertical to about 25 degrees to aim at the hole in the roof. Put you hand against a convenient object, tilt you seat to twenty-five degrees laterally and consider whether you are in a suitable body configuration to be punched out through the ceiling at 80 ft/sec. No, I thought not.

Shuffle Ejection. The centre occupant would eject and then one of the others would move his seat to the centre position, eject and so on. What do you do with the first ejecteeís gun which is still going to be in the way? What happens if the primary ejectee is killed or wounded? Itís a combat aircraft, remember.

I never knew of a rear crew member who complained about it in a serious way. The history of multiple abandonment of V aircraft suggest that in the time available in most cases only one or two would have survived, ejection seats or not.

It never worried me. As a co-pilot I was required to eject first so as to tell the Board of Inquiry what went wrong.
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