What are the flashlights on aircraft lifejackets?

You know, the one in the safety briefing where they tell you "this is your lifejacket, pull the tabs to inflate it, you have a whistle and a light.." -- what's the light? What kind of power source? I'm guessing it's the dreaded L-word (LITHIUM, which seems to be attracting a lot of undue attention aboard aircraft, when the irony is that they probably already have a lot of it!).

Curious (and bored) flashaholics want to know. More importantly, want to know if they will work in an emergency or whether we are better off with our EDCs for signalling and illumination in the event of SHTF.

The lights could also be Zinc-Air which require the removal of a tab to activate. The batteries have an extremely long shelf life. The tab could also be water soluable so if you are in the water the light activates automagically.

Re: What are the flashlights on aircraft lifejacke

I am not sure about the mechanism, but these lights do indeed light up when they come in contact with water. I've only tried them in salt (ocean) water, though, and assume they would work similarly in fresh water too.

Re: What are the flashlights on aircraft lifejacke

These are not truly "flashlights" in the traditional sense. They are "lights", whose primary purpose is to enable search and rescue personnel to see you while you are floating in the water. Most are water activated. . . I believe the ones used when I was in the Coast Guard were SALT water activated, but memory may be failing, or they may have come up with a plain old "water" activated version. BTW, with no light or signalling device, you may be surprised to find out that a person in the water under ideal search conditions has about a 1% chance of being spotted. Multiple searches may bring that percentage up to around 3%. Most persons rescued under such conditions stated that the rescue aircraft flew over several times, or that they saw the rescue boat or ship but were not sighted themselves. The light improves these odds immensely.

Most of the one's I've seen were manufactured by "ACR" and worked as strobes, they contained mercury batteries about as big as a AA and loaded from the bottom inside a very waterproof housing. These would have been found on vests worn by carrier deck crews during night ops, I couldn't say what they look like on commercial aircraft cause, fortunately, I've never had to use one. My shipmates on direct support missions commented that "You go over the side at night without a light and you're fish food". That is if the fall to the water doesn't knock you unconcious or you get blended by the "screws"; checking the integrity of your light is the first thing done before leaving the compartment and heading on deck.

Good points, they make sense. Even with a searchlight the crews are not going to be able to cover a large enough area whereas if they have a small point source that stands out, they can scan the area and it is much easier to recognize.

I always thought it was user-activated but they never mentioned how - because it's automatic.

Think I'll carry my C2 when I fly /ubbthreads/images/graemlins/smile.gif How much light is needed? As much as possible? I figure that a constant-on light would be useful (that's on the lifejacket), as well as one high power light to reach out and ping someone when you can identify a craft searching for you.

The lights on life jackets is more so you can find each other and group together. Typically use a low voltage, low output bulb, but have about 10+ hours of life on new batts. They're generally too small and too dim to be considered practical for signalling a plane moving at 350MPH at 35K altitudes. Even if you have dedicated SAR planes, I'd suspect they'd be moving along about 200MPH at 500'. The small little light would look like a reflection on the water if it is seen at all.

The other problem that I've found from personal experience is that it may take DAYS to be found. As an example, the kid next door went out with a bunch of others on a boat and had an engine failure. Mind that they were still in a boat - not just floating all alone with a life jacket. It still took the Coast Guard 3 days to locate them. The small flashlights they had, "AA" types mostly, didn't cut it for attracting attention and they melted down the batteries by the second day trying to signal planes and other boats.

The problem is longevity of your light. A SF sounds great until you realize - you usually get 60min and then it's a fishing weight. Even the famous 40 hours from an Infinity starts to sound a little short. Personally I'd pick a strobe for its repetitive flashes which would tend to attract attention. The fact that it is automatic is a plus. The flashing also tends to conserve battery power so they tend to keep running for a decent amount of time. I'd also carry a typical 2x123 or similar for closer in signalling.

Yeah, that's what I figured I'd use my EDC for, close range signalling. What kind of strobe would you recommend? Brands, names, etc. I think I need another light.

I would think a search plane would be low and slow
not at 350 mph and 35,000 feet

A buddy of mine is the head cheese for the U.S. Customs go fast boat unit in my town, they run the big souped up Magnum and Midnight express god they are fast, he took me out one day and let me drive it, like a fighter jet on water! Anyways I digress, one of the cool benefits to having a buddy like this is he also has given me some cool stuff that has been confiscated and old gear from his team, tactical vests, bullet proof vests, ammo etc... One of the cool things I got that was confiscated was a Mustang survival suit, the light on that is a Firefly plus 1916 from ACR electronics. It has a strobe on one end and a little incandesent flashlight on the other and runs on two AA batteries.

Re: What are the flashlights on aircraft lifejacke

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Blackbeagle said:
The lights on life jackets is more so you can find each other and group together. Typically use a low voltage, low output bulb, but have about 10+ hours of life on new batts. They're generally too small and too dim to be considered practical for signalling a plane moving at 350MPH at 35K altitudes. Even if you have dedicated SAR planes, I'd suspect they'd be moving along about 200MPH at 500'. The small little light would look like a reflection on the water if it is seen at all.



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Blackbeagle is right. . . the lights aren't used to actually "signal" the aircraft. Nonetheless, even a small light improves the chance that an aircraft would see you at night, if conditions are suitable. During the day, the light is not particularly useful. When everyone bands together, the effect is magnified. . . not only are the lights "combined" to a certain extent, the overall search target is bigger, dramatically improving the chances of visual detection.

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markdi said I would think a search plane would be low and slow not at 350 mph and 35,000 feet

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A C-130 conducting a search for a "PIW" (Person in the Water) would typically fly 200-500 feet above the surface, and would probably fly no faster than 150 knots, and certainly no faster than 170 knots. A helicopter conducting the search would usually fly at 250 feet or lower, and about 100 knots. If both are flying together in the same area, the C-130 would generally fly at 500 feet, with the helo about 250 feet.

I used to do this for a living. . . I was shocked when I learned how difficult it is to see a person in the water!

Re: What are the flashlights on aircraft lifejacke

I do search and rescue with our local Canadian Coast Guard Aux. unit. We spend a lot of time searching for PIW and spend a lot of time evaluating different equipment that might bring your *** home when things get ugly...

Personal opinions only follow...
I like the Firefly 2 line from ACR. A version of these is replacing what the Military used to call the 4F which was also made by ACR but took a funky mercury, then lithium batteries.
The Firefly 2 line (P/Ns3995.X) has a couple different versions. Maunally turned on, water activated, and one with both strobe and constant on.

The Firefly Plus someone mentioned is more aimed at the recreational rather than industrial/commercial market.
There is also a line of thought that says that you don't want to be using your emergency equipment as a flashlight so if you do go over you've not already depleted your batteries.

Tomorrow we are running search patterns with a SEE-Rescue streamers. These things are awesome from the air but we are going to see how much more effective the are when you are searching from in a low boat...

The comments above made about lights on live jackets are pretty much spot on. The lights are not really bright enough for long distance spotting of individuals.

Nothing is more effective than a bright flashlight being directed at the searcher, but strobes don't require any effort other thatn turning them on.

Equipped.com has some valid comments of the effectiveness of some of the various tools we see and use
Jenks

Re: What are the flashlights on aircraft lifejacke

Dye capsules can make a huge spot in the water which can be seen better during the daytime. It would be slick, with the recent bioengineering of glowing stuff, to use a bacteria or something that consumes something in saltwater and turns it into light. The spot could grow larger and larger the longer you were in the ocean. Then they could come back after your rescue, and spray it with something harmless that the bacteria was designed to be highly sensitive to.

There are those transmitters that are mounted on military aircraft pilot seats, that satellites pick up, to locate ejected pilots. It is a *very* sensitive system. I had some of my Marines working on the repair, and they were doing the final test. The radios were attached to a load box, and the system was located inside the shop, which is basically a fancy connex box (big metal shipping container you see stacked on ships, guess about 8' by 8' by 20').
Anyhow, I come back from lunch (which was at 6pm), and some airforce guy with some kids was walking around with a box attached to the center of a 2 x 4 with two telescoping antennas on the end, and they were walking around watching the meter. Every so often, they'd get excited, swing around and they'd be walking in the direction of the shop. Then it occured to me.... Turns out, the Air Force search and rescue teams had been flying around, with folks on foot, and ... Thing was, the signal was much weaker than normal, and would spike every so often (guys walking out their "shop" and opening door). The daycrew had forgotten to put a new RF gasket on the box that was damaged and removed. There was a slight gap about 1/8" wide that the signal was getting out of. The signal was really weak when the shop door was closed, but the sattelite was still picking it up. Anyhow...

Re: What are the flashlights on aircraft lifejacke

SDU/5 Military Strobes. Uses 2 Lithiums in a sealed sleeve. You can find them on ebay for about $25.00. There is even a replacement cap available that allows the use of 2 123 Lithiums.

Re: What are the flashlights on aircraft lifejacke

Besides having a strobe/flashlight etc., what about the advantages of also having one of the newer PLB's that transmit on both the Search and Rescue frequency and also on the International distress frequency that can be picked up by the COSPAS-SARSAT satellite? I would think that one of these units would be great for any situations where you might need help and be unable to communicate with anyone. Any thoughts?

Re: What are the flashlights on aircraft lifejacke

The main problem with the PLB and EPIRB's is they are expensive, Figure about $600 for the 406 Mhz units without a GPS engine built in, and about $900 for units with the GPS built in. The main players seems to be ACR and McMurdo/Pains-Wessex. The GPS engine on the McMurdo/Pains Wessex didn't do so well in testing, and in fact there is an unofficial recall out. If you have a GPS equipped McMurdo/Pains Wessex they will send you a prepaid return shipping container and replace the unit. In theory they are contacting owners (they got the registrant information from NOAA, so they know where these things are.)


The 406 Mhz units are big improvement over the 121.5Mhz units. A lot more powerful (5 watts versus typically 50mw), and the much better frequency stability (makes for a more accurate doppler based fix), and they transmit the ID of the beacon at the bare minimum. A couple of passes with a COSPAS/SARSAT bird is good for about +/-20km with the 121.5's, and about +/-6km with the 406's. The real breakthrough comes with the GPS equipped units. They transmit position with the beacon ID, so the alarm and the position can be picked up by one of the geosynchronous birds along with the position to raise the alarm. The result is the time from raising the alarm to having a good position (often +/- 30 meters) is unlikely to exceed about 20 minutes, whereas without the position, if you are unlucky, it can take several hours to get a usable fix. At this point the PLB's only weigh about half a pound, and are easily carried on your belt or around your neck. Suffices to say that knowing where to look +/- 30 meters makes finding the person in the water a whole lot easier.

The other advantage the 406Mhz units have is they are registered. When the alarm goes off, they know who you are from the Beacon ID, and what to look for. In fact the first thing they will do is call the contact phone numbers and make sure it isn't a false alarm, and get whatever details they can.

The 121.5 Mhz units are just a beacon, no information is transmitted on the beacon.

EPIRB's are PLB's with bigger batteries, some are self deploying (if they get under more than about 8 feet of water, they will automatically release from the mounting, and all of them will powerup if they end up in the water. They are effectively buoys with a PLB inside, many have small strobe's on board as well. They are also priced like EPIRB's, although the self deploying units tend to be a bit dearer.

Re: What are the flashlights on aircraft lifejacke

The reason I mentioned the PLB's is that a friend almost always has one of these with him whenever he goes out into the boonies and there's no form of communication at all. His works on both frequencies (I guess they all do) and he's hardnose about having it with him all the time. This is his insurance whether he hikes, flies or sails so it's worth the cost. For him it's a tax write-off.

[ QUOTE ]
KevinL said:
What kind of strobe would you recommend? Brands, names, etc. I think I need another light.

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I would go with the ACR MS2000M.

Re: What are the flashlights on aircraft lifejacke

There could be many ways that can be implemented.

I would think of a multi-dimentional system with a combination of things (mentioned above).
1) Flashing Signal
2) Satellite Signal + Distress Signal
3) (In case of Lost Humans in Sea) There are various Imaging Techineques (that currently satellite uses). Instead of searching using Human Eye, why not have an "Electronic Eye" that is similar to those satellites Except for that it is mounted on some Low Level Flying Search & Rescue Aircrafts. The Data Collected while "Scanning" / "Combing" can directly be sent to some sort of supercomputer that will detect "Human Motion" in Real time. This (Possible 'human suspects') will be given back to the "Sacnner" (mounted on low level Aircraft) to search / zoom specific spot and detect things in real time. .. If those "Scanners" (that are mounted on Satellite) have a resolution of 1 CM... then same will have atleast 1 MM Scale of resolution ??? Isnt it enough ???


Ok, Going Little off Line & High Tech: How about "In-Human" Implants of some sort of "Chip" that can be scanned by Satellites directly up above?.... I understand that it will evoke a lot of reaction about personal privacy & Freedom. But if you are paying it against the cost of life ??? will still any body be interested?

Also, Acording to some recent researches, Human Body itself emmits Electro-Magnetic Waves Ratiation (though very week), Each Individual has a specific E.M.W.R. "Signature", US Military is currently working on a "Classified" Project to locate individuals based on this E.M.W.R. (this was what I read on a .mil site some time ago). I do not know the truth (if this is correct or not). But if it is, any ways, and if there have been R & D to successfully detect those E.M.W.R Signatures, Our Privacy is already lost /ubbthreads/images/graemlins/wink.gif ... Scary stuff... isnt it?

On another site, they mentioned "Human Body generates Enough of Heat, that can be converted in to electricity, enough to drive something" "Which in turn can be used to power 'such' devices" where 'such' is being refered to chips installed at birth .... lol.... ""Human Body generates Enough of Heat, that can be converted in to electricity" sounded to me like, the author is inspired by movie "The Matrix" /ubbthreads/images/graemlins/smile.gif any ways...

Thats all i have to share for now.

Thanks & Regards,
ViReN

Re: What are the flashlights on aircraft lifejacke

Oh by the way the E.M.W.R Signatures are also sometimes refered by "common" (so called) people as "Vibes" there are "Matching Vibes" Non matching ones etc etc... One can feel them but cannot see them ... (does this mean that human body also has got some sort of E.M.W.R Signature Reseptors?) .... i do not know if all the information that i have read is true or not... its on internet... If at all this information is true, E.M.W.R Signatures can successfuly be read for good purposes. and should do good for search & Rescue... !!!

ViReN