Asiana Crash Investigation
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Several companies already make crashworthy, energy absorbing, seats. Here are Martin Baker's: Products
Very popular with the helicopter community, for obvious reasons.
Very popular with the helicopter community, for obvious reasons.
Crumple Zone Seats. As some have pointed out here - a seat that survives while the occupant does not is not really useful. However, it should be possible to design seats that absorb some of the deceleration so that the peak load on the occupant does not exceed a survivable level. So a peak/instantaneous 25G seat with a 10G peak for the occupant perhaps.
While it is obviously good to have seats (and luggage racks and other furniture) that stay in place and don't break loose and fly about the cabin - it doesn't help much to have an undamaged "50g" seat, filled with jelly-that-used-to-be-passenger(-or-crew).
A 100-foot (30-meter) fall is going to cause injuries - unless you have a shock absorber such as the air bags or nets that stunt people use. Or engineered metal shapes that can absorb the force without folding, spindling, and mutilating the occupant (or occupants of nearby seats).
There may or may not be a weight penalty - but that is what engineers are for. To find the optimax for protection vs. weight.
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This brings us to seat pitch the brace position leaning forward onto your thighs hands over head is a good posture but totally infeasible in most aircraft where the beancounters put seats far too close for a brace position to be feasible - a half brace position may well be the worst of both worlds in a vertical deceleration.
... and if the Daily Mail just happened to find out about it?
Only wondering aloud, of course.
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The fact that the fuselage remained intact after the mistreatment of the crash landing is a testament to how modern aircraft design has advanced.
Why in aviation, where although accidents are a lot more rare, are we still using just a single strap?
But the answer to your question is much more simple: Because except for the window seats, there is no hard point to attach a third (or fourth) strap to!
If it would not be mandatory, a lot of people would probably not even wear their seat belt... Like many do in cruise and find themselves under the ceiling in heavy turbulence.
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Remembering that BA have quite a lot of rear facing seats on board their longhaul aircraft, don't see many people complaining about sitting in them (especially me, uppder deck window seat is easily the nicest on board a BA 747-400)
givemewings
Charging extra for checked luggage (as well as hassle from lost or pilfered luggage) begs people to carry-on everything they can.
Not a solution, just reality.
I agree, cabin luggage needs to be looked at. The amount of unnecessary cr@p that people bring on these days is astounding. Had a woman the other day bring on a hold-sized suitcase and then get tetchy when told it was too big.
Not a solution, just reality.
Last edited by visibility3miles; 2nd Aug 2013 at 18:45.
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Personally, we carry loads of [luggage]
and it goes in the hold. Three weeks will not go in a carry-on, never mind the shopping on the way home 
So our carry-ons are minimal, and passports and money-clips/cards are on our person. We will leave the cheap Androids and replaceable iPad and Kindles. My wife and I value each other far more than a bit of electrical stuff. Younger people, or immensely important executives of global companies, or complete idiots, might have a different view.
clipstone1 my wife sits in the rear-facing 63A, I'm in front-facing 63B. Should I be worrying?
So our carry-ons are minimal, and passports and money-clips/cards are on our person. We will leave the cheap Androids and replaceable iPad and Kindles. My wife and I value each other far more than a bit of electrical stuff. Younger people, or immensely important executives of global companies, or complete idiots, might have a different view.
clipstone1 my wife sits in the rear-facing 63A, I'm in front-facing 63B. Should I be worrying?
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@Visibility3Miles
During the liquid bomb panic when only a ziploc bag of essentials was allowed it was amazing how fast turn arounds were. A 76 loaded from start to finish inside 15 minutes. Now there will always be people that want their carry on with them. But there are also many who (trusting souls) are happy to check all their stuff.
I wonder if any of the beancounters have done a cost benefit analysis against delayed turnarounds with 30-40 minutes to load SLF compared to slick 20 minute turnarounds (and a correct weight and balance). I would not be surprised if the charges for checked bags don't come close to paying for the inefficiency that carry-ons cause. But the cost is in a different budget so the beancounter still gets his bonus.
Charging extra for checked luggage (as well as hassle from lost or pilfered luggage) begs people to carry-on everything they can.
I wonder if any of the beancounters have done a cost benefit analysis against delayed turnarounds with 30-40 minutes to load SLF compared to slick 20 minute turnarounds (and a correct weight and balance). I would not be surprised if the charges for checked bags don't come close to paying for the inefficiency that carry-ons cause. But the cost is in a different budget so the beancounter still gets his bonus.
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In contrast, overengineering gives a perception of greater structural strength, but it's an inexact science. No-one built airliners tougher on paper than us Brits (probably in response to the Comet 1 fiasco), but nevertheless the forces in a thunderstorm were capable of tearing a BAC 1-11 to pieces. Similarly, the B737 is very hardy in some aspects (I'm thinking Aloha's 737 "convertible"), but if you tap one too hard in the wrong place, the fuselage will fail roughly in the vicinity of the same two frames every time.
i've flown rear facing in a vc10 and thought it was a total non-issue. The accelerations are, after all, pretty mild.
Its also very obviously safer for your body, and could plausibly save weight in seat design.
Its also very obviously safer for your body, and could plausibly save weight in seat design.
One wonders whether, as an increasing percentage of bookings are made on the internet, we're not approaching an age in which passengers are required to inform basic data like height and weight. LoCos might allocate seating on that basis, which might mean I (at 6'4") pay more but get a greater seat pitch than my wife (5'4") who would have to sit in a different "zone".
I do remember sitting facing back on the Vanguard, not on the Trident. During takeoff it helped to have the belt fairly tight but during the flight, no different. Landing, well, if the imagination rambled to a fast decelration scenario, one might want a helmet.
I do remember sitting facing back on the Vanguard, not on the Trident. During takeoff it helped to have the belt fairly tight but during the flight, no different. Landing, well, if the imagination rambled to a fast decelration scenario, one might want a helmet.
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Actually an extra 30 knots would have put them on the runway and not in the rocks. Maybe not by them but by any competent cockpit crew. Hopefully they would have finally looked out the window when they tried to go around and had the airspeed to land. As hopeless as they were as pilots maybe nothing would have helped. They had no instrument scan and didn't look out the window so not much chance of a landing for them.
I'll argue that a sub 140 knot, wings level emergency or botched landing should be survivable without significant number of spinal injuries.
In most of these accidents other than cracking in one or two pieces, the fuselage does not deform. Yet there is significant space below the floor, which is full of crushable stuff in the form of bags and bag containers.
The lower half of the fuselage could be designed to deform and the top "semi circle" comprising of passenger floor and ceiling, would form the safety cell.
The bag containers, when loaded could themselves form part of a system of energy absorption.
The design imperative that the tube should be strong enough to withstand pressure differential should not be affected as those pressure forces are exerting force from the inside, whereas crash energy is being exerted from the outside.
In most of these accidents other than cracking in one or two pieces, the fuselage does not deform. Yet there is significant space below the floor, which is full of crushable stuff in the form of bags and bag containers.
The lower half of the fuselage could be designed to deform and the top "semi circle" comprising of passenger floor and ceiling, would form the safety cell.
The bag containers, when loaded could themselves form part of a system of energy absorption.
The design imperative that the tube should be strong enough to withstand pressure differential should not be affected as those pressure forces are exerting force from the inside, whereas crash energy is being exerted from the outside.
Last edited by mickjoebill; 4th Aug 2013 at 05:03.
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Rear-facing seats are being employed in many of the new business-class seating arrangements as a way to pack more seats into limited space, especially now that flat bed seats are used. The NY Times writes about it in today's paper: http://www.nytimes.com/2013/08/04/bu...ess-class.html
I remember reading Flight a few years ago, (but cannot remember all the details), but the basic gist was that a car seat manufacturer was considering producing seats for airliners. When he started researching the issue, he was told rather stuffily and patronisingly by an aircraft seat manufacturer that there was a lot more to airliner seats than car seats. For example, the goon said, airline seats have to withstand 16g.
"Really" said the seat maker, "that's very interesting: our car seats have to withstand 35g".
Incidentally; 'The bean counters' are often held to be the villains of cost cutting measures, but actually, it is the passengers - who want ever cheaper flights, and who will chose the ticket that is £5 cheaper - who are the ultimate drivers of things such as reduced seat pitch.
Dozy; the Comet 1 failures were a very unfortunate disaster, but calling it a "fiasco" is too harsh - and you might want to rephrase that. Facts about structural science and design that we now take for granted were simply not known back then.
"Really" said the seat maker, "that's very interesting: our car seats have to withstand 35g".
Incidentally; 'The bean counters' are often held to be the villains of cost cutting measures, but actually, it is the passengers - who want ever cheaper flights, and who will chose the ticket that is £5 cheaper - who are the ultimate drivers of things such as reduced seat pitch.
Dozy; the Comet 1 failures were a very unfortunate disaster, but calling it a "fiasco" is too harsh - and you might want to rephrase that. Facts about structural science and design that we now take for granted were simply not known back then.
Last edited by Uplinker; 4th Aug 2013 at 14:20.
Although safety experts say assuming the crash position would have limited jolting to the spine, passengers appear to have received little or no warning of the impact.
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Crash Seats
I flew the last five years of my career with Eastern on the J41, a victim of the French not over 60 rule
The front 2 seats of the J41 have airbags built into the lap straps, they never gave any trouble and the pax showed no reluctance to use them
The front 2 seats of the J41 have airbags built into the lap straps, they never gave any trouble and the pax showed no reluctance to use them