GPS for ELT??

Discussion in 'Avionics and Upgrades' started by pmanton, Feb 25, 2017.

  1. pmanton

    pmanton Cleared for Takeoff PoA Supporter

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    I believe they make a GPS to marry with an iPad. How about one to marry with an ELT?
    I have an iFly GPS, however it's interfaced with my fuel flow.
    Any ideas?

    Paul
    Salome, AZ
     
  2. citizen5000

    citizen5000 Ejection Handle Pulled

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  3. Stewartb

    Stewartb Final Approach

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    I know nothing about the iFly thingy but if it doesn't have RS232 data out you'd be smart to pick up a used Garmin handheld like a 296 to connect to your 406. Actually the Area 500 would be a better choice since it doesn't require an external antenna. New they're only about $500. Used? No idea. Enabling the ELT with GPS is optional. The 406 is light years better than a 121.5 even if you don't enable it. If you believe enabling is a life saving feature? Pay to play.
     
  4. pmanton

    pmanton Cleared for Takeoff PoA Supporter

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    I just installed an ACK 406 ELT and am looking for an easy way to provide it a GPS signal. I'm using the RS232 from my iFly GPS for the fuel monitor. If I could split the RS 232 and send it 2 ways I'd be home free.
     
  5. airdale

    airdale Pattern Altitude

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    FWIW the reports I have heard say that ELT location where the ELT is not-GPS augmented is very, very good. i.e., GPS coordinates are not critical. Non-GPS locations are doppler solutions, so take a few LEO satellite passes to establish. If there is GPS info, the geosynchronous bird gets GPS coordinates immediately in the 406 signal. So it's theoretically tens of minutes slower without GPS, which will have little effect on getting the cavalry on the way as AFRCC will be trying to contact the beacon owner prior to kicking things off.

    You could call AFRCC and ask: 800-851-3051 Unless they are very busy, I have found them to be very helpful with the occasional question. There is a duty officer 24x7 who will pick up the phone.

    Personally I would not worry about trying to mickey-mouse a GPS connection. That said, the NEMA 0183 is a broadcast type protocol (RS-232 is an electrical spec.) so there should be no protocol problem sending it two places simultaneously. A little hunting around with the boat guys should provide some ideas on any electrical issues.
     
  6. JohnAJohnson

    JohnAJohnson Cleared for Takeoff

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    Airdale is right, with one caveat. Both the Fuel Monitor and ELT must accept the same protocol. In other words, if the Fuel Monitor requires 9600,8,n,1, and the ELT requires 115k,7,n,2, you are probably out of luck, otherwise, parallel away.
     
  7. pmanton

    pmanton Cleared for Takeoff PoA Supporter

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    Thanking Airdale I'll not worry about providing GPS to the ELT.:)
     
  8. Stewartb

    Stewartb Final Approach

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    406 ELT location accuracy takes time. Not long, but about 30-45 minutes to get a good location solution. The problem is that planes burn and sink. If the ELT signal stops after a few minutes there is no location solution.

    I know a few Alaska RCC pilots. They use gps enabling in their own planes and recommend it to other pilots. You have the tools to broadcast your location instantly. You really ought to use them.
     
  9. airdale

    airdale Pattern Altitude

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    I have no problem with this argument. Essentially, we are talking about making a probability calculation where nobody really knows the probabilities. What is the probability of "burn and sink?" I have no idea. The first probability is whether the ELT survives the crash in functional condition. That one is quite a bit below 1.0. Then is the wreck situation such that the antenna has survived and can see the sky? I remember one where a Seneca ended up upside down in a swamp. ELT worked fine, but the underwater antenna signal was only detectable within about 1/8 mile. Little chance that the SARSAT system would see one like that. SO then if all those gates are passed, what % of airplanes sink or burn? Are composite airplanes like the Cirrus at significantly higher risk of a consuming fire that would take the ELT?

    My backup is to carry a PLB. Lots of probability numbers apply there, too, most importantly will I be too damaged to trigger the thing?
     
  10. bkspero

    bkspero Pre-takeoff checklist

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    Issues with the ELT being compromised by the crash are pretty well mitigated by triggering the gps linked 406 ELT using the panel switch on the way down prior to impact. That way it broadcasts a pretty good position to the satellite prior to possibly being compromised by a crash. If it survives the crash and continues to transmit, then it will update the position to the crash site.

    A PLB can also be activated prior to a crash, but it needs time to get its gps lock prior before it can transmit a position.
     
  11. Stewartb

    Stewartb Final Approach

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    There was a well reported accident in northern Alaska a couple of years ago where a C-182 crashed with three guys on board. The plane instantly flipped in a swamp and all three got out with scrapes and bruises. The 406 ELT antenna was submerged but the RCC was able to pinpoint the position before dispatching a couple of off-duty Troopers in their own planes to check the crash site where they found and picked up the survivors. The ELT signal in that accident airplane worked fine. The president of Artex is on record saying that 406 ELTs will work fine in most cases without any antenna connected. That seems to be supported.

    My 10 year-old Artex ME406 does not support GPS enabling. No matter, I use Spidertracks when I fly and frankly I believe that's a better solution than any ELT. But, my new plane does have an ACK E-406 and it is GPS enabled. This plane will carry a Spider, too. This locater equipment is so good and so affordable there's no good reason not to use it.
     
  12. airdale

    airdale Pattern Altitude

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    You make my point for me. It's all probabilities. Probably the most common scenario where the ELT is destroyed is CFIT, which is exactly the situation where you will not know that you are "on the way down" before you hit the cumulogranite. Also, how many of us who know we "are on the way down" will be 100% busy working on a best landing option and not remember a little red switch that we haven't thought about in years and which is not on our emergency checklist? I would not bet big money on myself to remember the switch though I should probably update my checklists. YMMV

    Hopefully all of these work out like @Stewartb's anecdote. But they won't, of course.
     
  13. Stewartb

    Stewartb Final Approach

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    Here's the story to support my "anecdote". :)
    https://www.adn.com/aviation/articl...cessna-four-survivors-near-kaltag/2014/06/02/

    If you want the ultimate in safety get a Spidertracks unit and enable the takeoff and landing notifications to somebody who cares about you. If your plane stops, they're notified immediately. With a touch of a button on the app they can see a satellite map view of your exact location. My wife is a big fan.I have a sat phone and an Inreach and both are great tools but for airplanes? Spidertracks is the best.
     
  14. bnt83

    bnt83 Final Approach PoA Supporter

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    If you have say, ADS-B with mode S squawking position at all times, does the search & rescue team use that recorded position information? I mean if we can look it up on flightaware do they get the data from ATC for rescue ops?
     
  15. airdale

    airdale Pattern Altitude

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    Oh, I wasn't questioning your info. Call it a "story" or an "anecdote" it still is not statistically significant on its own. IOW, the plural of "anecdote" is not "data."

    But to your point, the satellite based systems certainly have an advantage, though at a subscription cost. I have flown with a SPOT and it was pretty neat. Actually, when ADS-B is really in wide use it will be a tremendous asset for SAR. Basically no "S" any more. Then it will only be at altitudes when a ground station is not visible where the satellite based systems will keep their advantage.

    Yes. AFRCC routinely gets radar data from ATC, which now includes ADS-B info. It's just part of the drill when an airplane goes missing. They also get cell phone data, which can often be used to associate a phone with a particular tower. That's actually a pretty good reason to leave cell phones on when flying, though the FCC says it is a no-no.

    The weak point in ADS-B is that the airplane must be in sight of a ground station. AFIK there is no plan to listen to ADS-B reports from a geosynchronous bird, though that would probably be technically possible. It depends on data rates and collision probabilities and I have no idea what those numbers look like. Overall, pretty neat stuff though.
     
  16. James331

    James331 Touchdown! Greaser!

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    GPS enable it, to me it's not even a question, plus depending on where and how the plane ends to stopped on the ground that ELT might not have a lot of run time before its destroyed/submerged/etc, so having those few blips encoded with your lat/lon seems critical IMO
     
  17. Stewartb

    Stewartb Final Approach

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    A couple of high profile accidents in Alaska in the past couple of years used forensic radar analysis to determine the accident locations. It takes time. Neither one ended well. Very interesting stuff, though. Alaska doesn't have the communications coverage that you lower 48 guys enjoy.

    Google forensic radar in SAR and you'll see some articles that talk about cell phone and transponder tracking. The data isn't good. 406 ELTs are much better tools for getting found. When an RCC gets an ELT signal they don't just rush to the helicopter to go look. They do a telephone investigation to validate the signal is real. That takes about 45 minutes on average. The more info you can provide to reduce the time they spend trying to validate the signal, the better off you are. Alaska FAA let's us link Spiders, Inreaches, and SPOT tracking on our flight plans. That's the first place they look so it's a good way to help. My Spider account info is listed on my 406 registration, too, since I don't always file a flight plan. Use your head. Employ tools to let others help you when you need it most. And help reduce the time those SAR guys are out in the crap risking their lives and spending public dollars looking for you.
     
  18. GeorgeC

    GeorgeC En-Route PoA Supporter

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    I thought ADS-B receivers were supposed to go on the Iridium Next constellation?
     
  19. Stewartb

    Stewartb Final Approach

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    Did you put a 406 in your 185? I recall you commenting in another thread that you planned to someday.
     
  20. James331

    James331 Touchdown! Greaser!

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    I was going to on annual but between shipping and all it didn't work out timing wise, for sure I'll be doing it in the next 6 months, I have a ACK 121.5 now so the ACK 21.5 to 406 conversion is basically plug and play.
     
  21. Stewartb

    Stewartb Final Approach

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    Maybe. Mounting requirements are very specific. Your current mount probably doesn't comply with the requirements. Definitely not if your mount is on the left side of the baggage area where Cessna put them.
     
  22. James331

    James331 Touchdown! Greaser!

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    We looked at it, the existing ACK 21.5 mount is actually used for the new ACK, diffrent antenna but uses the exact same hole/s as the old 121.5, think it even uses the same panel mounted switch.
     
  23. Stewartb

    Stewartb Final Approach

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    Not what I meant. Current ELT requirements state the mount must be attached to structure, not skin. Using a 100# pull tester the installed ELT can't move more than 1/10th of one inch under 100# of pull in any direction. That isn't easy to accomplish and the vast majority of ELT installations would fail the test.
     
  24. airdale

    airdale Pattern Altitude

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    I hadn't heard that. That would be really neat, assuming the birds transmit as well as receive. Then coverage would be 100% even at low altitudes and in the mountains.

    Edit: From a quick search it looks like it may be a subscription service offered by INMARSAT and Iridium. Seems to be called ADS-C, with the "C" standing for "contract" and the market being the airlines. I'm sure we'll hear more.
     
  25. James331

    James331 Touchdown! Greaser!

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    It's structural on mine, ether way it's where it going ;)
     
  26. Stewartb

    Stewartb Final Approach

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    To rah rah for 406 and enabling only to do a less than required install makes no sense. The install matters. Hopefully your mechanic does it right.
     
  27. NoHeat

    NoHeat En-Route

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    When my old ACK 121.5 ELT was replaced with an ACK 406 MHz model (it's a very straightforward swap), the shop also added a wire from the ELT (in the back of the plane) to my Garmin 430 GPS (on the panel). That way, if the ELT activates, it will announce my exact position.

    I think this is a standard thing to do.

    With ADS-B out requirements coming up, most small planes that don't already have GPS in the panel are going to need it. Installing GPS for that purpose will be an opportunity to improve also the plane's ELT, by adding that wire.
     
  28. bnt83

    bnt83 Final Approach PoA Supporter

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    Problem is that most factory installed mounts that were done 20+ years ago are too flexible, absorbing impact loads instead of transmitting them to the ELT and it's g switch. Some of those old mounts are fastened directly to the tailcone skin, depending on the airplane, is one of the most flimsy places it could be mounted to. The installation manual for the new 406, even if plug & play, most likely explains this in great detail.
     
  29. James331

    James331 Touchdown! Greaser!

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    Agreed, but not all are still in the same factory positions
     
  30. NoHeat

    NoHeat En-Route

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    If an ELT is intended to be activated by high g's, how often does that fail to happen in an off-field landing or crash?
     
  31. bnt83

    bnt83 Final Approach PoA Supporter

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  32. Stewartb

    Stewartb Final Approach

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    Last edited: Feb 27, 2017
  33. NoHeat

    NoHeat En-Route

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  34. denverpilot

    denverpilot Tied Down

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    Yes. Others covered it. Forensic "radar" they call it. Multiple saves this year from it already and it's only just March.

    I think... think... anyone can put the info about SpiderTrax or the others into your 1800wxbrief.com profile now, but not in front of a computer to check.

    Only thing left even looking or listening to 121.5 is the search aircraft and if they're up, it's a day or more later after the crash and someone reported you overdue and they did ramp checks and all that... nobody's listening anymore.
     
  35. Stewartb

    Stewartb Final Approach

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    From the link I posted in #32. My biggest disappointment in AOPA is that they lobbied against a 406 requirement. Now 406s can be had for about $500 and guys hold on to their 121.5s. Crazy.

     
  36. GeorgeC

    GeorgeC En-Route PoA Supporter

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    How much does the installation cost?
     
  37. airdale

    airdale Pattern Altitude

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    I'm too lazy to chase it down but I believe that there is still a FAR that says we are all to be monitoring 121.5 "when able" or some phrase like that.

    Since the SARSAT stopped listening on 121.5 most of the reports come from airliners at altitude. This is nice in a way but from 35,000' this localizes the signal to the area of, maybe, a single state. It is the bug smashers at lower altitude who provide much better localization. I have had cases where ATC asked me to check 121.5 to see if I have a signal. So there really are still people listening. That's not a reason to stick with the old boxes, though.

    BTW for those who may not know it, the new "406" ELTs, when triggered, also emit a signal on 121.5. The 406 signal is a periodic data burst but the continuous 121.5 signal is intended for reception by conventional VHF radios and DF-ers.
     
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  38. Stewartb

    Stewartb Final Approach

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    And for what it's worth? The Alaska RCC Pave Hawk helicopters do no have 121.5 homing equipment. If the 406 ELT is operating there's no value in the 121.5 component in the majority of SAR operations.

    Funny story. The summer before last I was washing my airplane at the Lake Hood wash rack. A CAP guy with a hand held 121 homing device stopped and asked to check my airplane because there was a 121.5 beacon active in the area, obviously in a parked plane. I told him it wasn't me, that I had a 406. He didn't understand. I told him had it been me I'd have gotten a phone call before he did, and that I have a buzzer that alerts anyone near the airplane that the ELT is transmitting and if that wasn't enough he could check the panel monitor if he wanted to. He had no clue what I was taking about and walked around my airplane with his little gizmo like he was the Prince of the airport. If that's who they send to look for 121.5 beacons? I'm really glad to have a 406!
     
    Last edited: Feb 28, 2017
  39. James331

    James331 Touchdown! Greaser!

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    I'm glad they didn't mandate it, it's called freedom, you're free to make your own choices, personally I'll end up upgrading, however I also currently have a GPS 406 EPIRB that rides in the plane, so the 406 ELT isn't a huge upgrade for my situation.



    So these multi million dollar SAR ships can't even home in on the most common type of beacon.... FAIL.

    And I want my tax dollars back now.
     
  40. Stewartb

    Stewartb Final Approach

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    Your freedom costs everyone else money. That's selfishness. If you want to be free take the darn thing out. Man up, rebel! At least now we know post #16 was a load of crap.