Quite a high number die from cervical or high thoracic spine injuries. Very few die from "organ displacement" to the exclusion of all else (often there are two or more possible causes of death in aviation fatalities and it comes down to just picking one or listing them all).Spine is the least of your problems-Organ displacement & inner bleed out.
It's actually doable but you wind up with something that looks like a cropduster since that's one reason they are shaped the way you are thanks to Fred Wieck and his colleagues at Texas A&M along with John Swearingen and Stan Mohler (FAA CAMI) and Hugh DeHaven (Cornell Medical College).If you built up the cockpit enough to largely hold shape in a serious nose down crash, the airplane may well become unflyable for weight, and the decels will still be huge and thus tough to make survivable;
The acronym we use to teach folks about occupant protection is: CREEPCockpit has to be sturdy enough to hold shape fairly well - failing here means direct damage to the human;
Seat has to protect against vertical crash pulse - the seat and (perhaps the floor structure) are the only things that can do this and we lose ALL of our vertical velocity over a very short travel;
Harness system has to keep you in place - failure here means secondary collisions and direct damage to the human;
Yes, but then you get into other issues like reduction of usable space, changing load paths so far as the seat occupant is concerned, etc. It's a lot simpler and more practical in many cases to increase the strength and/or number of seat attachment points especially if you're designing 'clean sheet'.There is a lot of moment arm in a high seat that is bolted only from the bottom. Is there a way to secure the seat from higher ?
Ok roger that. I found that pretty strange..since the airliner was still moving but slowly...the mass of the pilot could have played a role too ?Also in that Air France crash, there was some indication that the seat attachment points had been subject to fatigue cracking which reduced their strength. I don't recall if that was mentioned in the final report or not.
Possibly. It would depend on how the shoulder harness are attached on a particular seat. That said, for the most part with aircraft seats, it really doesn't take much to break them loose especially in GA. The failure points (in terms of load) are often well below the human threshold for surviving without any significant injury let alone not suffering fatal injuries.I found that pretty strange..since the airliner was still moving but slowly...the mass of the pilot could have played a role too ?
There have been some done (especially the helicopters and the composite aircraft) with new and sometimes purpose built birds. The Langley crash test series goes back into the 1960s (reports available online) and cover a fairly broad swath. They even did one using a Beech Starship.I was just wondering how much the weariness of the planes has to do with the results..or were these kites new on the tests ?
Thanks, that product would be very handy. Seems it would be fairly easy to design a seat with good crash absorption properties using this aluminum honeycomb. Back of the envelope:
That's how the NASA Langley test series got started in earnest. There are a few NACA/NASA tests that predate that (the earliest I am aware of is a vague reference to a test in the 1930s for which no one seems to be able to find the results).There were a bunch of airframes (I seem to recall Piper, but I could be mistaken) that were damaged in a flood... still solid but could not be made airworthy)... that were donated for crash testing.
One of the complicating factors for seat design is the recoil rate of the foam used for padding. Small things can make a big difference.Of course, that much spring back probably is NOT good for the occupants. Some amount of permanent deformation would reduce the shock load, I think.
It's not easy for a few reasons with the primary one being that many crashes have more than one vertical impulse involved (especially if the aircraft cartwheels or bounces). With energy-dissipating materials designed to work by crushing, one they've "shot their load" (the vaguely sexual term that gets used fairly often in discussions of this in the safety community; we're an odd bunch.....) then the occupant is exposed directly to whatever comes next. "Multi-shot" energy absorption is one of the goals of a lot of the research into seat design. This is one reason why landing gear and the subfloors of aircraft are often used to "isolate the cabin" so to speak from initial impact forces.Seems it would be fairly easy to design a seat with good crash absorption properties using this aluminum honeycomb
One of the problems with non-metal foams is the pyrolysis of their constituent materials into various nasty compounds (hydrogen fluoride, hydrogen cyanide, CO, etc). There are some that have very minimal toxic gas production but they tend to be quite expensive. Rohacell-S is the one that jumps to mind.Frangile polyurethane foams are sometimes used within door panels to help absorb and dissipate the energy in a side crash
...or you simply attach the energy-absorbing material to the bottom of the seat and leave a little clearance from the floor/walls. This negates that issue while still serving its intended purpose.Note that you need some elastic deformation. Even during 10 mph taxi-ing you will see absolute massive accelerations (albeit with very small deflections). I'd guesstimate that you need at least half an inch or so of elastic deformation before you start hitting the crush zone.
What would be the advantage of fitting it to the seat bottom instead of to the bottom? I'd think that, if attached to the bottom it's less likely to "tumble over forwards"?...or you simply attach the energy-absorbing material to the bottom of the seat and leave a little clearance from the floor/walls. This negates that issue while still serving its intended purpose.
You'd be surprised how lax a lot of the vehicle fire safety standards actually are.I would assume that it vents a minimal amount of noxious gasses.
In theory. The problem is that most situations that lead to crashes are not amenable to simply including a ballistic parachute. This is one reason why Cirrus has a safety record that makes the Pinto look like a IIHS five-star crash test case.n this respect, having a BRS system can aliviate that issue.
It can't. But the circumstances that occur in real world crashes, while they tend to not lend themselves to crash testing as easily as the "let's belly in this plane that Piper handed us" scenarios the NASA folks have tested for the most part (not knocking the work done by my colleagues and friends there, just pointing out the limitations), are fairly predictable, reasonably straight-forward and can be designed for. You can shave 30-40% off of fatality rates simply be improved fuel tank design. That honestly is the "easiest" fix in all of these sorts of discussions that is likely to render a significant and noticeable impact (pun intended) upon the number of pilots and passengers killed annually. Once we get past that, we can start to focus on correcting the misguided notions that lead to pilots and builders underestimating the forces involved and the capability of the human body to survive those forces.In the end, I don't think that a system can be designed to provide safety under all circumstances.
Part of it, maybe-- pulling that red handle is real expensive-- but you see a lot of cases where the pilot panics and pulls it too soon instead of flying the airplane. Another contributor is cases where the chute gives the pilot a false sense of security and continues on into a situation where he should have turned around.Regarding the BRS, I was under the impression that part of the poor record for the Cirrus was the reluctance of the pilot to pull the handle until it was too late.