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Ejects Entire Cabin Before Crash ?

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Ejects Entire Cabin Before Crash ?

Old 21st Jul 2020, 07:32
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Question Ejects Entire Cabin Before Crash ?

Is this possible ?
"Engineers have designed passenger planes with a detachable cabin, claiming it could save the life of everyone on-board if the aircraft gets into trouble."

Found an article regarding that in AEROPEEP

Last edited by ddanu9015; 22nd Jul 2020 at 03:22.
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Old 21st Jul 2020, 07:52
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So the cabin can crash somewhere else?
The weight of a detachable cabin would be prohibitive, before you get to any of the dozen other issues.

Last edited by Jump Complete; 21st Jul 2020 at 08:49.
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Old 21st Jul 2020, 08:17
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Thanks for the PM with the article. Is it not possible to post it here? Still not convinced. The weight would be make a it non starter, the strength issues another thing, and, especially with the reliability of modern aircraft, how many crashes result from an intact, in flight aircraft, (other than flying into mountains etc, which this won’t help with.) Most accidents are in the take off or landing phase. Sorry, but I think this is ‘blue skies’ thinking like the circular runways idea a few years ago.
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Old 21st Jul 2020, 08:27
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I am not eligible to post links here yet. To be eligible to post links here I must publish 10 posts. You can post the link here if you are eligible and happy to share the article with others.

However I am agree with you and your points. This is not possible it seems.

Last edited by ddanu9015; 21st Jul 2020 at 08:41.
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Old 21st Jul 2020, 08:29
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This idea got discussed/dismissed on PPRuNe a couple of years ago
The detachable cabin (includes parachute)
based on this article:
https://www.independent.co.uk/travel...-a6814311.html

Last edited by Euclideanplane; 21st Jul 2020 at 08:49.
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Old 21st Jul 2020, 08:34
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One potential problem is weight. The second one is design complexity. The third one - actually building an aircraft like that (on what budget, given that airframers are already quite hard-up?) and certifying it. Finally, getting airlines to buy in large numbers something that is essentially a cat in the sack. And what's the selling point of this wonder jet, given that most accidents cannot be prevented by its design? So, the idea sounds about as plausible as the circular runways.
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Old 21st Jul 2020, 09:11
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It will create much more problems than it solves. Useless for any CFIT, landing or take off problems, mid air etc. Only might help on structural failure during normal flight, which is not the killer problem we currently have in commercial aviation. And even then you come down uncontrolled.

You might come to the conclusion that more lives can be saved if the automatic ejects only the row 0 instead and takes over if too much stupidity is detected.(SCNR)
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Old 21st Jul 2020, 09:26
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The only precedent would be the Egress Capsule from the F111, which worked well, but of course had the required relatively small size and low weight.
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Old 21st Jul 2020, 09:51
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Wasn't there a crash of an F111 where the escape system failed and a subsequent mod to fit Martin Baker seats?
Or maybe my memory is faded.
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Old 21st Jul 2020, 10:19
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The Cirrus have it. On a small very light airplane.
BTW: Where would you drop the rest of the plane to, wings, engines and such?
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Old 21st Jul 2020, 10:38
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The Cirrus parachute recovers the entire plane, not just the passenger compartment.

This hardly a new idea, I remember seeing such a proposal in Flight International back in the 70s.
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Old 21st Jul 2020, 11:22
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As mentioned, this has been previously discussed and dismissed. Speaking as a person who certifies the design compliance of airplanes, I can say that this idea, as applied to the passenger compartment of a civil airplane, is so far away from practical, that no serious designer will entertain it. The effects of added weight, duplicated structure, immense systems complexity, and failure modes would result in a pane with little useful load. Then one must consider all the circumstances of intended and unintended "ejection". Once those issues are managed, and after years of testing and development, FAR Part 25 for certification would need a massive rewrite to provide a certification basis for the novel feature. 'Not going to get any further than humorous discussion.....
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Old 21st Jul 2020, 11:24
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But what is the scenario in which you have the time/opportunity to use it? The major killers are CFIT and low level loss of control- both which give virtually no time to do anything like this.

So, for the couple of times in history they would be used, the cost, potential accidents IT would cause, and loss of payload would render an already marginally profitable industry that much more unviable.

Not going to happen in our lifetime.
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Old 21st Jul 2020, 11:33
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Oops!
And I guess that would need a ‘guarded’ switch!

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Old 21st Jul 2020, 12:17
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What seems to be coming is automated landing. Just press a red button and the aircraft decides where to land and does everything by itself.

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Old 21st Jul 2020, 12:39
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Flying is all energy management, crashing is too.

You give an aluminium tube and the fleshy bodies within a whole lot of energy to move it somewhere. At the end of that journey you have to slowly degrade that energy and place the tube into a safe configuration on the ground (also known as landing). Recovery from a crash follows the same principle, if you release the energy too quickly then everyone dies. Even if the cabin ejects you still have the same problem as the energy is proportional to the mass of the thing you are moving, so a large recovery parachute or other system is required. As Pilot DAR states the cost of duplicating systems in a secondary recovery system is prohibitive, much better to make the systems in the main aircraft more redundant and safer.
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Old 21st Jul 2020, 13:42
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This is a stupid idea for the same reason giving all your passengers a parachute is a stupid idea.
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Old 21st Jul 2020, 13:52
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I remember this from Popular Science Magazine back in the early 1950's when things like ditchings were not such a rarity. It was right there with ideas like "Atoms for Peace" using something like 29 nuclear explosions from 1 to 20 megaton to blast a sea level canal across Nicaragua. I believe the ejection module predated the FB-111 being incorporated in the B-70 and its proposed escort fighter the XF-108 Rapier.
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Old 21st Jul 2020, 14:20
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Here we go again ...

PPRuNe: The detachable cabin (includes parachute)
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Old 21st Jul 2020, 15:26
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Originally Posted by NWA SLF View Post
I believe the ejection module predated the FB-111 being incorporated in the B-70 and its proposed escort fighter the XF-108 Rapier.
...and the B-58 Hustler, with individual crew seat pods. and a single flip-up cockpit roof.

But those were all supersonic aircraft, where extra protection was needed, assuming an ejection at up to Mach 2 (shockwaves).

Seems to me that in a small aircraft (and even larger ones), it becomes six of one, and half a dozen of the other, whether one ejects the cabin - or jettisons the rest of the airframe.

Build a unitary (but not doubled) cabin, and bolt on wings, engine and tail cone. Pull the lever or push the button - and the bolt-on parts fall off at the firewall, wing roots, and rear cabin bulkhead. Not unlike the 1950s schemes for "flying automobiles."

https://en.wikipedia.org/wiki/Aerocar

In any event, almost certainly requires FBW (fly-by-wifi), to eliminate mechanical control runs and connections that have to be severed.

But outside of a little simpler engineering and some weight savings, that doesn't eliminate most of the other problems. "Flying automobiles" never got anywhere either.
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