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-   -   Accident statistics - head/neck injuries (https://www.pprune.org/rotorheads/354943-accident-statistics-head-neck-injuries.html)

Freewheel 17th Dec 2008 04:14

Accident statistics - head/neck injuries
 
I've been pondering workplace safety and am interested in whether anybody can point me towards statistics for the cause of death for pilots in accidents - pilots only at this point. I'm looking to put together an outlay/outcome analysis for the company.

There is clear evidence that wearing fire resistant clothing and a helmet reduces the danger from an accident. I'm looking for what's next.

I have the impression that spinal / basal skull fractures are the next most significant group, but no more than that. Does anybody know of anything available?

SASless 17th Dec 2008 06:00

Helmets and Nomex work for some crashes....but anti-gravity suits would be better yet.

http://www.kpho.com/2007/0727/13772039.jpg

JimL 17th Dec 2008 06:38

The best way to acquaint yourself with this subject is to google "helicopter head injuries" and then search down the list for the relevant papers (leave individual reports to one side; they may be interesting but summaries are more important).

Three to start with (not necessarily the best):

Flight Safety

Analysis of Injuries among Pilots Killed in Fatal Helicopter Accidents

Pilots killed in Fatal Helicopter Accidents

Jim

Madbob 17th Dec 2008 10:12

Helicopter Accident Survival Stats
 
Freewheel

You might like to look at the BoI / accident report of the mid-air collision in January 2007 at RAF Ternhill involving two Squirrels.

The QFI in ZJ263 was sadly killed but the "stude" survived with serious head injuries and there is no doubt that wearing a helmet saved his life....The other crew of two also survived, albeit with less severe/minor injuries

Ministry of Defence | About Defence | Corporate Publications | Boards of Inquiry

Many moons ago I knew an RAF Medical Officer (Wg Cdr David Anton) who must have retired some time ago but he was an aviation pathologist and an expert in accident investigation where aircrew injuries were being assessed. Apart from identifying cause of death:( in fatal accidents he had the happier task in others of seeing first hand how improvements in crash-worthiness, fire mitigation, aircrew clothing/helments etc. actually worked.:)

I haven't a clue where his is now but I am sure he is very well known in av med circles. Martin Baker may be another source worth contacting, apart from making ejection seats they also design and manufacture crash-worthy seats for both FW and RW ac. (Thankfully I have never had recourse to use either apart from a one-off "ejection" up the gantry rig then at North Luffenham before the joys :bored: of being let loose with a JP at Linton!)

MB

mickjoebill 17th Dec 2008 11:37

Time to get collared?
 
I would be very interested to hear if wearing neck collars would reduce injuries in heli accidents and have considered wearing one myself after F1 introduced the HANS system, where a rigid support is worn over the shoulders to which the helmet is strapped.
HANS wouldn't work in a heli as I think it would restrict head movement too much.

But, priced at under $30 the basic foam wrap around collar types aren't expensive and the racing car driver collars come covered in fire resistant materials.
Neck Collars


Pros and cons of wearing one?

Mickjoebill

HELOFAN 17th Dec 2008 11:50

Maybe some military stats would be handy too.
Not sure who would provide any info though.

Was reading some stories about Mil guys and early NVG's.
They were really heavy & pilots were suffering broken necks after hard landings due to the excess weight.

Also know of a Apache pilot that is off due to fractured vertibrates due to wearing lots of lovely body armor,being hunched over & lots of vibrations.
Turns out this isnt uncommon.

Though they are mil pilots, they are not 2 way rifle range related incidents.

HF

JimEli 17th Dec 2008 16:25

a neck collar is virtually worthless.

R44-pilot 17th Dec 2008 16:29

"a neck collar is virtually worthless."

Gotta agree, thats horizontal impact, should think most spinal injurys are due to the vertical impact.

Might work ok with planes...... :bored:

Freewheel 17th Dec 2008 22:23

Thanks everybody so far.

I'm taking a multi-pronged approach so an aeromedical guy is rustling up some academic sources for me. I've contacted my local accident authority also.

I managed to google around a brazilian sites for lawyers and sites giving statistics relating to fatal/serious/minor injury classifications, but none I found gave me the injury types. There's also information here, but nothing as specific as I'm hoping for.

I hadn't thought of M-B. Will get in touch.

The HANS device was partially the inspiration behind the project. I had seen it around for years in motorsport and also didn't think it allowed enough movement until I was given a passenger ride in a touring car recently and was allowed to try the driver's spare. I thought it was a little restrictive for some types of operation but had much potential. I've found a paper on the known circumstances of use for various HANS devices and the G numbers are shocking.

What I've found so far is that lower spinal injuries (lumbar) tend to be from vertical compression loads such as rotary accidents and centre around where the spine has bent and the vertebrae have come into contact. Keeping the torso in place and supported during an accident event is most helpful there (ie sitting properly in a well designed seat and having your harness done up). Upper spinal injuries, (cervical) which tend to be more debilitating, tend to come from the unrestrained movement of the head and neck, the movement of which is relatively similar in vertical and horizontal accidents due to the anchoring of the movement in the torso. This is what I'm interested in, as well as those injuries that occur through the head striking an object and forming an axis, creating a severe bending moment on the spine or a Basilar Skull Fracture. I don't think a collar is of much value due to the compression of the material. Better than nothing, perhaps, but nowhere near as good as it needs to be.

What I'm really looking for is enough information to determine whether this injury type is common enough to get a return for further research.

SASless 17th Dec 2008 23:21


sitting properly in a well designed seat and having your harness done up)
Well Sir.....that rules out helicopters then!

Name me one helicopter that has a "well designed seat"....just one!

Freewheel 18th Dec 2008 00:35

SAS,

According to the certification requirements, the Guimbal Cabri G2 has a seat designed well enough to pass the tests. Never having sat in one, I can't vouch for it's comfort. There is still footage of the tests around somewhere.


Stroking seats are a substantial improvement in many respects, but allow the torso closer to the controls and any pedestal where fitted.Whether this may bring an increase in facial/skull injuries I'm not sure, but if so, they could certainly be reduced by restraining head movement.

The EC120 seats are reasonably comfortable, but I've never spent more than around 3 hours of a day in one. Others may have more information.

The AS350 can be bought new or retrofitted with seats similar (or identical?) to the EC120 seats, but I've never sat in one which had them. I believe most of the Eurocopter range has similar seating.

Nick - the S92? Are the seats designed for crush or are the wheels expected to accomodate this movement?

The MD900 has supposedly crashworthy seats, can anybody confirm?

I suppose I need to know whether anybody has had experience of these or any other seat in preventing/reducing/exacerbating/doing absolutely nothing for a back/neck or head injury in an accident.


PM if you prefer, all responses remain confidential. The information if used will be adjusted to remove as much identifying material as possible.

garsr1 18th Dec 2008 01:45

We used to have a A109E and have been operating the A109S. It has the new crash worthy seats I will look up the specs. and repost the benefits over the old seats. The most obvious difference between the Power and the Grand seat is that the Grand seat sits higher and you have room for compression. Also the head rest can not be removed and is attaced to the seat back and allowed a little for and aft movment. All of the passenger seats also have the new crash worthy seats.

John Eacott 18th Dec 2008 02:35

Re neck restraints, BMW Motorrad have developed and currently markets a neck brace for motorcyclists. Review here, maybe this is the sort of system that could be developed for use with helmets in high risk areas?

http://www.bmw-motorrad.com/dbimages...615_medium.jpg

garsr1 18th Dec 2008 03:28

This subject will also bring up another question. How well will we be able to move our heads to check for obsticals or traffic. I have never wore a hans device so I dont know how restictive it is. I know a that there can be thousands of risk vs. need camparison for something like this.:ugh:

Benjamin James 18th Dec 2008 05:16

Motorcross riders use them, so surely it can adapted to helicopter use.




I'd happily where a heli specific device if it could save me on the rare occasion the crash suits such a device, but I get the feeling I'm in the minority.

John Eacott 18th Dec 2008 05:31


Originally Posted by Freewheel
What I've found so far is that lower spinal injuries (lumbar) tend to be from vertical compression loads such as rotary accidents and centre around where the spine has bent and the vertebrae have come into contact. Keeping the torso in place and supported during an accident event is most helpful there (ie sitting properly in a well designed seat and having your harness done up).

FW,

From personal experience: I have compression fractures of L3 and L4 vertebrae from a vertical impact following a wirestrike. Bell 206L, with the early (poxy) seat base, which was next to useless for a <80kg such as myself. Thrown around and also knocked out (no helmet, last time ever that happened!) but: the director in the left front seat was a 100+kg fellow, and his weight actually broke his seat frame which absorbed most of the impact :ooh: As a result, he had severe bruising, but no major injury, and walked away :)

Early design parameter crashworthy Bell seats, as long as you're on the heavy side they'll work for you :p

Freewheel 18th Dec 2008 22:22

John, who would have thought being a fat b@stard would be a health benefit....


The Leatt Brace is the best thing I've seen so far - prevents cervical movement in 360 degrees very well without restricting normal head movement - however;

Helicopter helmets typically go no lower than required to get the earcup over the ears. Motorsport helmets cover the entire skull, jawline and then some. In a downward or forward accident, the head will naturally tend to travel downward and forwards. The likelihood of the jaw being the item that stops travel of the head is therefore high.

Gentex offer a maxillofacial shield for the HGU-56P helmet, but I doubt it's designed to accept such a load.

I wonder (and I'm shuddering at the cost) if a specific brace compatible helicopter helmet may be required, since we probably won't get the features we look for in aviating, not to mention looking a bit silly wearing motorcross helmets.... (not that it's ever stopped me before).

PurplePitot 18th Dec 2008 22:30

When you've finished that study can you start another one that involves strapping a pair of NVG on to the front and a 600gm weight onto the back of your head - I suspect you'd lose the lot, head and all.... :eek::eek::eek:

Freewheel 18th Dec 2008 23:02

PP,

The selfish bit is that I'm looking to see what can be done for our specific operation, but I'm trying to keep in mind the wider industry. It will definitely have relevance for those who spend a minority of their time inside the shaded area of the H-V diagram....

With NVG's, a tether (HANS type) device will probably suffer more than a brace device I suspect, but only a properly instrumented test will determine that. One thing's for sure, with an extra 1-1.5 kilos on your head, something's better than nothing....

topendtorque 21st Dec 2008 03:50

Interesting
can't comment on the heavy NVG gear, but thoughts of velcro or detonating attach bolts comes to mind. Heh Heh.:E
A bit like the brief we give to shooters, "If'n there's silence just throw that damn thing out the window first, got it?"

Re Neck breaks, I cannot recall one. I would place a preference on mobility and vision perepheral far above a neck brace.

The upper back seems to be the most common in the R22, I assume because of the lower intera blades not always availing themselves of the opportunity of zero forward airspeed. Particularly that trait combined with lap sach harness is bad news. The spine will curve under forward deceleration.

The 47's seemed to have the lower back injuries much more often. i have noticed that the 47 guys get up and walk more often and sooner than the R22 guys. Having bumped a '47 once I was very thankful of the full harness, felt just like a bad fall from a horse.

The Hillers I recall, had a couple of nasty full on, engine xmon the lot straight onto the luckless driver in the centre seat whenever a heavy forward airspeed bump arrived.

The bump I had in a R22, left me to crawl away from it, (three cracked vertabrae upper back) and unable to carry a full jerry can in one hand for 18 months, but i clould carry two inside twelve months.

I agree that light weight people seem to suffer more. a recent case was extraordinary.

The crew member "Left hand seat in an R22" suffered quite badly in the upper back, not quite breaking the spinal chord. It appears, - we think - that on the second contact which was the left hand skid at still about ten knots, which broke the forward port cluster, that at the same time the M/R blade contacted the ground heavily port side, thus throwing the xmon and associated framework forwards and pushing the firewall forward right behind where his back was being firmly pushed by his feet.
(a breaking cluster always means that there is severe stress to be shared around, mostly by the person closest to it to help absorb.)

Sort of a rabbit chop if you like. He didn't even have seat belt bruising. he was a light weight extremely fit, very good ex pro bull rider, young man. The driver stepped out with light bruising. The cabin virtually unmarked ecept for the fire wall bump.

We have long lamented the abscence of full harness in R22's but I maintain that the discipline of teaching zero forward airspeed touchdowns is by far the most important at ab initio stage for any person down in the grey shaded area.
tet


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