Night Vision Goggles (NVG discussions merged)
 

Any drivers out there with commercial NVG experience, preferably with emergency services?

I could do with some feedback....many thanks



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TC

I've got over 400Hrs mil exp. Gis a job........

Try Devon and Cornwall Police Air Support. (01392 452 392), they've been "trialling" them for about 5 years. Also McAlpines instruct foreign students on them at Oxford.

PP, don't be greedy, you already have a job!

Bored over......Could really do with a change of scenery!

Civ heli company at calgary airport uses them to fly in Rockies .Cant remember the name of them but i'm sure someone will!

Night Vision Goggles certified in UK police helicopter
 

Ananova News report

Does a pilot or observer need any sort of certification for themselves to use NVG or do you just strap em on and away you go!

Vfr, you definately can't just strap them on and go, You need to do a course. It's like flying around looking through two empty toilet roll tubes looking through frosted green glass. Also despite what people think, they're not used for flying in bad weather. You use them purely so you can see where you're going, so that you can avoid bumping into the limpy bits.

MG,
I did really ask that with a little grin on my face, but was'nt sure anyway, thanks for the answer, by the way I hope you saw my small apology from the thread regarding the LLc.
My Regards

Yes I did thanks. Not that I felt that one was needed. It was more a dig a the 1500' rule than anything else, although it was nice to know the reasoning behind it.

Most of us know, at least in general terms how the night goggles work. I'd be interested to learn a little more detail if anyone who's used them could spare a moment to explain. A Mil pilot?
The force paid £100,000 to have the cockpit certified to use the goggles. What mods have to be made to the cockpit?

The article also says that the force helicopter unit is also the only one in UK with pilots qualified to navigate by instruments alone. Is that correct?

I'm fixed wing but have touched the perifery of NVGs. Modifications are necessary to cockpit lighting - normal cockpit lighting would blind the pilot, because the NVG is effectively an image intensifier, which amplifies the available light. And it's not just a case of turning the brightness down. All in all it is an expensive mod.

The 2 or 3 public service helio units I have come into contact with (police and ambulance) have been day/night VFR ops only, although the VFR limits have been modified to much lower levels (by special authorisation?)

I have about 200 hrs NVG, so here goes:

All the cockpit lights have to be modified to 'NVG-compatible' which effectively makes all the lights blue/green (with one or two exceptions like the warning lights!). This is because the traditional red/orange instrument lighting appears extremely bright to the NVG. This causes two effects - flaring, which is like a halo around the light source which blocks out chunks of the field of view, and 'backing-off', which happens when the goggles try to compensate for the bright light by 'turning down the sensitivity'(sort of) which makes the rest of the picture go very dim. This is also caused by street lights, security lighting, car headlamps, red obstruction lights, camera flashes, the moon etc etc. The effect is worsened if it is very dark outside. While they are generally invaluable pieces of kit, they are likely to be of little use if operating in urban areas.

NVG cannot be used in complete darkness as they are image intensifiers, not IR scopes. There has to be some ambient light for them to work. Even faint starlight is enough. In an area with no cultural lighting, no moon and thick cloud to block out the starlight, they can be almost unworkable.

To expand the bad weather point, they can actually lead you further into danger than flying without them. They will hide the fact that it is getting misty, or that you are in thin cloud until the point where the picture suddenly goes blank and you are quite definitely IMC, which is not nice if it's winter and you have no icing clearance!

Overall, they should enhance the Police's capability, but I would caution against treating them as the new 'wonder weapon' of night ops. The Police should also brace themselves for a spate of compensation claims for back and neck injuries as a result of wearing them.

(It a lot more complicated than that (lots of boffin techno-wizardry) but I tried to keep it simple)

Hope that helps

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PCD

The Strathclyde Police EC135, G-SPAU, leased by Bond and flown by its pilots, is a SPIFR aircraft. The pilots also have current IR's as well.
Draw your own conclusions

Sorry if I'm being slow Marco - but can you give me a little help about what conclusions I might draw? http://www.pprune.org/ubb/NonCGI/confused.gif

That contrary to the initial press release that the Devon & Cornwall aircraft is the only police helicopter in the UK able to navigate by sole reference to instruments.

The EC 135 at Strathclyde is SPIFR and certified in the UK by the CAA.

Good summary there Plastic.

Pertinent points to raise would probably be the operational aspects too:

Goggles are by no means a replacement for day vision because they provide a monochrome image (hazy shades of green! isn't that a song title?), markedly reduce your depth perception, and I think most importantly remove a good chunk of your peripheral vision.

With the most common types of goggles around in the military, you only get about 40 degrees of vision (the area in front of your face) rather than the nearly 180 that normal day vision gives you. It means that you have to use other strategies to give yourself a lookout that covers what needs to be looked at.

As one of my goggle instructors succinctly put it, "You have to move your head around like one of those noddy dogs that you find in the backs of cars."

Light enters the front of the tube in the form of photons. The number of photons depends on the ambient light levels. The photons strike an input screen in the tube and are converted into electrical energy.
This screen is phot-sensitive and multiplies the number of electrons. These electrons are projected onto a phosphor coated screen which converts the electrons back into light in the form of an image.

As previously stated they do not work in complete darkness. On an overcast, no moon night in the desert, you're lucky if you can see the ground from 50'. However in populated countries such as the UK, the cloud reflects the light from built up areas so visibility is usually very good.

Once you've flown with them, you never want to fly in the dark again.

Goggles do need some amount of ambient light to work...and they current models are limited to a 40 degree field of view (though research is being done with 110 degree panoramic NVGs). However, current models are capable of 20/25 visual acuity as opposed to best case 20/200 with unaided night vision.

Cockpit light compatibility is another issue...non-NVG compatible lighting inside the cockpit will gain down goggles so much as to make them unusable. The most predominant compatible lighting is blue/green however I have recently heard of white NVG compatible lighting -- an EMS operation in Asheville, NC recently had their bird outfitted for about $12,000 USD.

And as for weather, NVGs can definitely get you into bad situations -- especially in a "pervasive" precip environment like drizzle, rain, & snow. However, in other areas like mountains, desert, etc. you can see low lying fog or rain shafts and maneuver around them. I've used NVGs to direct a USMC KC-130 aerial refueling tanker that was unaided around a rain shaft to avoid us all going into the clouds. Just my $0.02!

Did I see that the cost of the NVG conversion cost £100,000 to the Cornwall bobbies, if so , why the differance for the American conversion, which has been reported at $12,000.00 , or was the Yankie conversion with a smaller torch?

One of the things that makes these items so expensive, is the twister.

The lense system would produce an upside-down image, so the tubes incorporate a bundle of fibre-optic threads twisted through 180 deg.

Why a simple lense can't be used, i have no idea.

Having flown a lot of hours with them in th RN I held out against them as a ploice pilot. Over urban areas they would be useless, and in our area there was little else. I can see their usefulness to D & C as Dartmoor at night without gogs would be a dangerous place to be.

I'm a Police pilot with the Victoria police Air Wing in Melbourne Australia. I have used NVGs in the Military and now we are seriously considering them here in the Force. We operate IFR Dauphines (2 off) on 24 hour shifts on both EMS and Police ops both Metro and country (The Air Wing covers the whole Victorian state (approx the same size as whole of GB). The terrain varies from fairly flat desert to mountainous terrain.

All I can say is that if I had a choice between flying with NVGs or unaided I'll always pick using the NVGs. Sure they have limits but these can be overcome with training and experience. I'm not advocationg that they should be used to do NOE or multi-ship assualts onto target areas but instead thay would make night navigation sooo much easier and safer.

Our philosophy is that pilots must be IFR rated and current and flying an IFR Helo. Both the pilot and observer in the front seats must be goggled at same time but the GIB won't as he may have to operate the FLIR.

As for cockpit mods. Well if you have paid 100,000 pounds then you've been had!!!! We got an approx quote of 20,000 pounds to do a Dauphin cockpit which is larger than the EC135 and even if you double that price its still way less than the 100,000 suggested. And that was from an UK firm (Oxley Avionics. You can do it for even less if you use the system that Rocky Mountain Helicopters (with the help of Red Wing Aviation) in the States did for their Mama One EMS chopper. You need to shop around!!!

Anyway I have a powerpoint presentation that we put together here on CD if anyone would like a copy please email me and I'll send it (but not too many otherwise the postage will kill me)....

[This message has been edited by NASUS (edited 12 June 2001).]

[This message has been edited by NASUS (edited 12 June 2001).]

For what its worth, I've been doing all kinds of research into NVGs for civilians for my graduate research project. The prices I've come across for NVG compatible cockpit mods for the 2 EMS operations currently certified here in the US were approx $12,000 USD for the MAMA One BO-105 and approx $23,000 USD for the Mercy Air Ambulance AStar in Redding, CA. Big difference between the two are block lighting for the MAMA and integrated lighting for the Mercy birds. Each have their own advantages and disadvantages.

As for goggle costs...the current quote I received for ITT F4949 (AN/AVS-9) NVGs were about $9,000 per set. Add another $1,000 for a helmet, goggle mount, and battery pack.

My rough cost analysis for a 3 helicopter, 10 goggle set operation was approx $175,000 USD.

As for NVGs in urban areas...one of the most surpising outcomes of my research survey is that many (about 75%) of Law Enforcement members that have responded are using NVGs right now (public use aircraft -- don't have same FAA requirements as EMS). Most are urban ops and most have stated that they wouldn't fly without them anymore. One respondent stated "If our goggles are out of service, our helicopters are out of service". Interesting.

Nasus, NOE and multiship ops is what NVG flying is all abou!!

Although I usually find myself agreeing with Arkroyal, particularly with his contributions to the Chinook thread, I have to differ re his comments about using NVG in urban/ extensively culturally-illuminated areas. Although my current area of ops is primarily jungle, we also have urban tasking and the occasional maritime/ offshore energy installation job. I cheerfully use (and teach the people here to use) NVG in all areas - the only time I move them up out of line of sight is during the final stage of a low-level approach to an oil rig (the other pilot on the 'dark' side of the aircraft keeps his down and monitors the situation ready to take over if I lose references) . Under all other circumstances, the picture obtained by combined use of NVG (which are only Gen2+, by the way) and peripheral unaided vision is far more useful than that available with the Mk1 eyeball alone. I wouldn't go so far as to say 'no NVG, no fly', but I'd rather have them than not.

Over the jungle, we use a combination of focused (sp?)white lights, diffuse IR (Brightstar) and NVG to provide the optimum picture for hovering over the canopy to winch out troops or casualties. Most of the LPs, although OK by day, are in our opinion too small to risk landing by night. We get a better picture by using the treetops as our hover references. Not a tactical application, simply best use of resources to get a proper peacetime job done.

Can those of you who fly police/ems ops and utilise NVG on certain ocassions, tell me whether you fly with them permanently fitted to the helmet, or take them off in between use. If they are kept on, when does neck/head/strain kick in?

many thanks, in advance

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Thermal runaway.

To Mightygem. Sure from a military perspective multi-ship formation at NOE heights is what it is all about (but the hazards are greater) BUT not from a civil use perspective which is what Police and EMS/SAR is all about. Sure there might be the odd occasion where a fast rope insertion might be required for our special police ops but again would only be one acft and rare.

Therefore if Gen 3+ ANVIS is used in the emergency services perspective to get from A to B at night below LSALT over hilly country it is quite, quite safe and probably safer than having to punch into IMC and then trying to find a suitable letdown (which is never at the location you want to go)or pick-up icing. Like everything in aviation it has limitations but ones that can be overcome to make it a damn good aid to night flying.

Nasus, yes military of course.

TC, they are not that easy to put on when your busy flying. I've worn them for over an hour without any neck problems, as long as you have a counterweight for the back of the helmet.

TC

If multi-crew (eg working with observer or crewman), goggling-up is straightforward with the non-handler passing the NVG from the box to the pilot. With practice, Nightbird/Nightop can be fitted using only the left hand in seconds. Longest I've done at low level is 8h 30m out of a 10 hr sortie - slept well the next morning. No major discomfort, though.

I agree with Mightygem and T&B that wearing goggles is OK. A weight bag is essential and a GOOD fitting helmet.....and this is an issue in it's own. Normally in police and EMS work wouldn't have to wear them for more than 2 hours in one hit as by then we have to refuel and stretch our legs.

REGA, the Swiss rescue agency, initially train their helo pilots on NVG by getting them to ride bicycles on a pitch black airfield!

A very cheap and ingenious way to introduce them to the necessary head movements required to gain adequate visual information.

Good morning PPruners,
Re the wearing of NVG's is there any effect on eyes caused by the continued use of these, is it similar to watching a VDU or is it like natural vision only tinted green?

Actually yes there is an interesting little effect called pink eye. Basically, after about half an hour or so on the goggles, your eyes adjust to only looking at the green part of the light spectrum. Going back to conditions where everything is lit by white light, everything has a kind of pink tint to it. The effect doesn't last long and depends how long you were using the goggles for.
My longest period was just over 4 1/2 hours and it took about 1/2 hour for my vision to return to normal. MightyGem used to teach this stuff so he could probably offer a more in depth explanation.

Not much to add to that really. Forty, you obviously know me. Any clues??

My few pennies worth...like anything else, the more you fly with goggles the more you become comfortable with them (and the bigger your neck muscles become!). I've had a set mounted on my helmet (not necessarily always in the down position though) for over 7 hours on an attempt to rescue a Japanese fisherman in the north atlantic a few years back. My whole body hurt after that nasty mission. In any event, our normal NVG training sorties are in the 3-5 hour range and the goggles are always on (except for the odd "leak" check). The goggles have a loop of cord that allows you to dismount them and let them hang down from your neck. They can be easily re-mounted with 1 hand with minimum practice. We don't do that much on tactical sorties but will do it if transitioning to instruments or required to fly over downtown (Las Vegas) at altitude. I still wear them for every landing if I have them (which is always if planning on being out after dark).

NVG and the RAF
 

I have just read that the RAF Helicopters were unable to assist the SAS whilst on some night incursion work in Afghanistan, reason given was that the RAF heli's don't have the ability to fly in the dark. Now please forgive me for being a little simple minded, but if you have NVG and associated birds, what else is needed to fly in the dark, or has some vital piece of info been missed out here?. . <img src="confused.gif" border="0">

Don't believe anything you hear, anything you read, and only half of what you see!

It'll sound like I'm bitchin' - and I probably am ....... but the RAF operate similar ( but not exactly the same)rules to Civilian professional pilots for duty hour time. Now it has always struck me as strange that the RAF use these rules (being a military outfit used to flexible and unplanned ops) .... but they do quote 'duty hours' and I have seen it up close and personal in situations I can't go into in this forum.

So the reason for not night flying might be that they flew during the day and have busted their crew duty time ...... who knows? It might be cos their NVG were U/S?

Please consider this in the category of 'Cat thrown in with Pigeons' - I am convinced I will receive that kind of reaction ...... hey we're here for some fun aren't we?

NVGs still need some light to magnify. Not enough light to magnify seems to be the probable reason. As for the crew duty time theory - nonsense.. .AP <img src="eek.gif" border="0">

I would cetainly favour the theory of lack of starlight making the use of NVGs unuseable.

As to Duty Periods, it is true that the RAF have duty times that work in a similar way to civil operators, but they are usually only applied during peace/training sorties. Operations such as Afghanistan would work on different limitations no doubt worked out by those "in theatre". If crews are required to night fly, they will be given the adequate rest prior to being needed.