NVG dilemma
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NVG dilemma
I've heard many opinions and a few bits of data about the bahavior of helmet mounted NVG's in a crash scenario.
My question is, how are yours setup and what are the implications for injury to the user?
The goggles I use are designed to detach from their mounting with forward deceleration of about 13G. I'm concerned about the cord we have around our necks which suspend the goggles when they are not in use; obviously we don't want to drop an expensive piece of equipment on the ground but we don't want them bouncing back into our face causing permanent and possibly career endangering injuries. Obviously the use of a visor is negated with the fitting of NVG's so how can we better protect ourselves from such an occurrence? Has anybody had a relevant crash with NVG's fitted that they would like to share?
Another concern of mine is the weight of the goggles and battery pack. Obviously any additional weight is likely to increase the chance of neck injury in a crash so is it safe to use balance weights on the battery pack?
Is it safe to secure battery packs with velcro, or will this turn the pack into another piece of shrapnel to take you out?
Your thoughts/practices please...
Thanks in advance
Munga
My question is, how are yours setup and what are the implications for injury to the user?
The goggles I use are designed to detach from their mounting with forward deceleration of about 13G. I'm concerned about the cord we have around our necks which suspend the goggles when they are not in use; obviously we don't want to drop an expensive piece of equipment on the ground but we don't want them bouncing back into our face causing permanent and possibly career endangering injuries. Obviously the use of a visor is negated with the fitting of NVG's so how can we better protect ourselves from such an occurrence? Has anybody had a relevant crash with NVG's fitted that they would like to share?
Another concern of mine is the weight of the goggles and battery pack. Obviously any additional weight is likely to increase the chance of neck injury in a crash so is it safe to use balance weights on the battery pack?
Is it safe to secure battery packs with velcro, or will this turn the pack into another piece of shrapnel to take you out?
Your thoughts/practices please...
Thanks in advance
Munga
We flipped our goggles up when not using them...the cord just prevents them from being dropped inadvertently. The battery pack velcro'd to the back of the helmet with a small bag of lead shot to "balance" the weight of the goggles and the battery pack stay in place nicely even if does add some weight.
The advantage of using NVG's for night flight over-rides any other concern in my view. Perhaps one's chances of "crashing" at night is so reduced by use of NVG's it makes concerns about helmet weight and such pretty minor by comparison.
The advantage of using NVG's for night flight over-rides any other concern in my view. Perhaps one's chances of "crashing" at night is so reduced by use of NVG's it makes concerns about helmet weight and such pretty minor by comparison.
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Lost in translation
Hi SASless, thanks for your reply.
I'd not argue against the use of NVG's. I think the thread is a valid discussion as a critical emergency is no less likely at night as it is during the day.
We flip our goggles up in flight too but we wear the cord around our necks regardless. The goggles breaking away is great but it defeats the purpose if they're going to bounce back and smash you in the face; at least in my opinion. Do others use a similar cord, no cord, or something different?
Just because goggles are safe does that not mean we can make them safer?
I'd not argue against the use of NVG's. I think the thread is a valid discussion as a critical emergency is no less likely at night as it is during the day.
We flip our goggles up in flight too but we wear the cord around our necks regardless. The goggles breaking away is great but it defeats the purpose if they're going to bounce back and smash you in the face; at least in my opinion. Do others use a similar cord, no cord, or something different?
Just because goggles are safe does that not mean we can make them safer?
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If they detach at 13G, I would think the goggles would be the least of your worries. When the RAF first got NVG we had a set of eye protection clear goggles to prevent them pivoting down into your eyes. I never wore an anti-drop lanyard. If you need them off in a hurry, you can rip them away and throw them. If they get dropped accidently, go and get another set!!
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Fair enough
Yeah, i've had a look at what kind of crash 13g is and you're probably right; I can't justifiably comment on the survivability of such an impact.
Thank you for your reply. The clear goggles is an interesting little piece of NVG history I think.
Thank you for your reply. The clear goggles is an interesting little piece of NVG history I think.
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Hi M3
The 13G was set to be a compromise so that they didn't drop off with any old "knock" - but was less than the 20G crashworthy requirment for modern helicopter crashworthy seats as fitted to most modern mil helicopters or civ ac built to such modern standards.
Part of the deal was that all aircrew wearing such NVG were to wear the seperately provided clear visor across their eyes - which was there specifically to minimise eye/upper skull damage in the event of the NVG not detaching and rebounding into the eyes during a lower velocity hard landing (for whatever reason such was caused!!) - particualry if the NVG had been stowed in the up positon and had much greater distance to travel. There are some very (gut wrenching) videos from the 80's of crash test dummies at Farnborough demonstrating these effects and gathering data to prove the case for such visor protection.
However, certainly the history of UK mil use of NVG over the last 25 or so years has eschewed the use of such visor protection - and maybe with statistical hindsight this has proved OK - but be in no doubt - if you have a "gentle" vertical crash when wearing NVG with no break away mechanism - you ain't likely to have much eyesockets left.
Cheers
TS
The 13G was set to be a compromise so that they didn't drop off with any old "knock" - but was less than the 20G crashworthy requirment for modern helicopter crashworthy seats as fitted to most modern mil helicopters or civ ac built to such modern standards.
Part of the deal was that all aircrew wearing such NVG were to wear the seperately provided clear visor across their eyes - which was there specifically to minimise eye/upper skull damage in the event of the NVG not detaching and rebounding into the eyes during a lower velocity hard landing (for whatever reason such was caused!!) - particualry if the NVG had been stowed in the up positon and had much greater distance to travel. There are some very (gut wrenching) videos from the 80's of crash test dummies at Farnborough demonstrating these effects and gathering data to prove the case for such visor protection.
However, certainly the history of UK mil use of NVG over the last 25 or so years has eschewed the use of such visor protection - and maybe with statistical hindsight this has proved OK - but be in no doubt - if you have a "gentle" vertical crash when wearing NVG with no break away mechanism - you ain't likely to have much eyesockets left.
Cheers
TS
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And what if after a 13G crash the NVGs flew out the window and a big brown dog chocked on them.
And of course “What about the insurance!!??”
There are simply too many un-answered safety and legal question that remain.
Munga you had better leave yours at home and be safe.
Cold meat and salad for the lot of you.
Gymble
And of course “What about the insurance!!??”
There are simply too many un-answered safety and legal question that remain.
Munga you had better leave yours at home and be safe.
Cold meat and salad for the lot of you.
Gymble
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Very interesting
Thanks a lot TS, that is just the kind of information that makes posting these threads worthwhile. I'd sure like to get my hands on those videos, I'll have a look around.
Munga
Munga
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Why bother replying?
If you're not going to be constructive then keep your opinion to yourself. You're either a cowboy or an idiot if you don't take flight safety and your personal well-being seriously.
Do the statistics a favour and leave it to the professionals, mate.
Do the statistics a favour and leave it to the professionals, mate.
There are no limits
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Quite a few helmet manufacturers now offer the option of mounting your NVG on the hard visor cover allowing you to use your clear helmet visor to protect your eyes.
I still have my Face Protective Visor that I used once and found it to be totally incompatible with spectacles/eyeglasses. In fact I also have the special specs too, or did I throw them away because they made you look too much like a weirdo?
Probably very fashionable now!
I still have my Face Protective Visor that I used once and found it to be totally incompatible with spectacles/eyeglasses. In fact I also have the special specs too, or did I throw them away because they made you look too much like a weirdo?
Probably very fashionable now!
Hi NVG-pals,
I won't put the questions about safety in case of a crash to far away.
I've collected around 600 hrs NVG-time in the last few years and every (except of one engine problem) scary moment I had in these years were while flying with NVG.
(Wishing to be on the ground the while flying rather than wishing to be airborne while being on the ground)
With lives at stack crews are often willing to take more risks - unfortunately fog and/or low cloud or deteriorating weather seems to close in much faster at night as normally anticipated with day flying experience.
Twice I could get a pick up and end the flight IFR - icing makes this difficult in winter, when NVG are most used due to long dark hours....
(got the feeling, that weather briefings where I fly are becoming less accurate than in the past - either the weather is much better than forecasted - or I get a pretty good flying conditions from them, ending up spending hours sitting on the ground somewhere in the nowhere and waiting for the cloudbase to rise from antkneelevel to a flyable condition)
Still, before flying at night without NVG, I prefer to have them.
Thought also about possibilities to reduce the risks implemented.
Flying without the cord is quite an expensive idea - a dropped NVG costs a lot.
I don't put the cord around my neck, I attach it to the cable - but that's also not perfect.
Thinking about attaching velcro to two pieces of cord and velcro to the helmet on each side of the mounting.
That would hold the NVG, when it would be inadvertently disconnected and wants to fall to the ground cause the force would be along the velcro.
In case of a crash with breaking forces I guess it could fly away to the front, because then the cord with attached velcro would pull in another direction, that is 90 degrees.
Still, it won't prevent a vertical acceleration - which you would have in case of an engine failure in hover without proper cushioning of the landing.
Don't like the idea of a clear visor - I like my NVG as close to my eye as possible to see as much as possible through them.
It's time, that we get an overhead display in the visor ;-)
Greetings Flying Bull
I won't put the questions about safety in case of a crash to far away.
I've collected around 600 hrs NVG-time in the last few years and every (except of one engine problem) scary moment I had in these years were while flying with NVG.
(Wishing to be on the ground the while flying rather than wishing to be airborne while being on the ground)
With lives at stack crews are often willing to take more risks - unfortunately fog and/or low cloud or deteriorating weather seems to close in much faster at night as normally anticipated with day flying experience.
Twice I could get a pick up and end the flight IFR - icing makes this difficult in winter, when NVG are most used due to long dark hours....
(got the feeling, that weather briefings where I fly are becoming less accurate than in the past - either the weather is much better than forecasted - or I get a pretty good flying conditions from them, ending up spending hours sitting on the ground somewhere in the nowhere and waiting for the cloudbase to rise from antkneelevel to a flyable condition)
Still, before flying at night without NVG, I prefer to have them.
Thought also about possibilities to reduce the risks implemented.
Flying without the cord is quite an expensive idea - a dropped NVG costs a lot.
I don't put the cord around my neck, I attach it to the cable - but that's also not perfect.
Thinking about attaching velcro to two pieces of cord and velcro to the helmet on each side of the mounting.
That would hold the NVG, when it would be inadvertently disconnected and wants to fall to the ground cause the force would be along the velcro.
In case of a crash with breaking forces I guess it could fly away to the front, because then the cord with attached velcro would pull in another direction, that is 90 degrees.
Still, it won't prevent a vertical acceleration - which you would have in case of an engine failure in hover without proper cushioning of the landing.
Don't like the idea of a clear visor - I like my NVG as close to my eye as possible to see as much as possible through them.
It's time, that we get an overhead display in the visor ;-)
Greetings Flying Bull
In the UK if you are NVGing then you are normally issued with/ have the option of wearing an FPV (face protection visor, clear visor that attaches to the visor mechanism) , however, most people choose not to as they belive that the risk comes from outside the cabin rather than from thier own goggles.
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I'd never fly with the "neck" cord around my neck, matter of fact every tech manual I've seen instructs you not to. Post crash you've now got to worry about neck damage from the weight before they come off the mount followed quickly thereafter by the goggles coming flying back at you courtesy of the cord. What I did do was lightly tape the cord to the top of my helmet. Then when you smuck the goggles on the window/rotor brake/door frame/etc they will fall off the mount then slowly pull through the tape. This gives you lots of time to grab them before they fall and yet still gives me hope that they'll depart my helmet long before the 13g point. Last thing I want is something wrapped around me neck that can snag as I am egressing, especially underwater!
I have flown with low profile oakley style safety glasses under the nvgs, but since I don't normally fly with glasses on, the extra noise entering me ears by the arms breaking the earcup seal turned me off of them.
Tough compromise, not wanting to drop them, yet also not wanting to break your neck during a survivable crash!
I have flown with low profile oakley style safety glasses under the nvgs, but since I don't normally fly with glasses on, the extra noise entering me ears by the arms breaking the earcup seal turned me off of them.
Tough compromise, not wanting to drop them, yet also not wanting to break your neck during a survivable crash!
