Uncertified ADS-B Units in Experimental Aircraft.

Discussion in 'Instruments / Avionics / Electrical System' started by proppastie, May 30, 2017.

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  1. May 30, 2017 #21

    BBerson

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    It is a way to keep pesky pilots away from busy airports if the units cost too much. Transponders did that decades ago.
    I want the ADS-B to be so cheap that everybody gets it to use for VFR as well. What good is a new collision avoidance system that only a few are equipped for?
    The big airports already have a radar system.
    The rest of us have nothing.
    ADS-B was invented for places with no radar, like Alaska. But it must be cheap. I only need a two mile transmit range to avoid a collision. A $200 transceiver can do it.
    The see and avoid system just isn't good enough.
     
  2. May 30, 2017 #22

    BBerson

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    I would be interested in a $200 uncertified ADS-B handheld that isn't approved for Class C.
    I don't need to go into class C.
     
  3. May 31, 2017 #23

    davidb

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    My point is ADS-B is NOT a very good collision avoidance system. TCAS isn't either unless all aircraft have the equipment. I don't think there is any plans for ADS-B to incorporate resolution advisories. I guess if your system is connected to the intercom to provide aural alerts, it is somewhat effective for situational awareness. But, even if it was free, you'd never get 100 percent participation. Without aural alerts and full participation, it is just a distraction and could lead to a false sense of security.

    Having just flown across the country, I only had two aircraft with yellow arrows. I saw the planes visually before I looked down out of curiosity to see if they showed on the iPad. Neither was a threat because we were at proper VFR/IFR cruising altitudes. In the traffic pattern or other areas of dense traffic, eyes outside and ears on the radio will provide much better awareness and avoidance.
     
  4. May 31, 2017 #24

    BBerson

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    The unit could be built into the headphones to give directional aural alerts. It could also have an indicator in the sunglasses to direct eyes to the targets while looking outside. (light planes, ultralights and drones with ADS-B)
    Mostly for use around the airport.
     
  5. May 31, 2017 #25

    Kyle Boatright

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    I realize midairs are a threat. But statistics show they are a much, much smaller threat than dozens of other things out there. I'm not going to adopt (or not adopt) technology because it does/doesn't give comprehensive traffic alerts. If it helps, great. If not, no big deal. I'll be eyes-out in either case.
     
  6. May 31, 2017 #26

    TFF

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    Mid airs are a pretty small threat. ADSB is about warnings but you have to be 1500 ft or closer before the alarm. No way you could have something like 3 miles as a warning as it would be going off all the time. The one we just got the screen can be scrolled so you can look ahead at traffic patterns. You will never get the hand prop crowd to get one until required so there will always be a problem with the only people that could hit you.
     
  7. May 31, 2017 #27

    BBerson

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    Well, a pilot must squint and scan with constant alertness to make see and avoid work. After hours of not seeing anything I suppose many (maybe most) pilots figure the odds are small and just quit looking and relax and enjoy the flight.
     
  8. May 31, 2017 #28

    gtae07

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    That's probably part of it. But also, quite frankly, the human eye/brain combination sort of sucks at this task. Many times I've had ADS-B traffic alerts on a Skyview and been clued in to where I should look--and still couldn't find the traffic till I was almost on top of it. And given that I'm usually operating underneath or just outside a Class B, sometimes that traffic is much bigger and faster than me and coming up from behind. How many of you really scan much past the 3-9 line when you're not in the pattern?

    A midair is one of those low-probability/high-consequence scenarios. ADS-B is helpful with traffic and other things (weather, primarily). But as pointed out, it's not 100% reliable.
     
  9. May 31, 2017 #29

    tspear

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    Actually the FAA has over the years posted plenty of data which shows that a lack of mid air collisions is not because of see and avoid. It is based on big sky theory, and dedicated routes.
    With GPS enabling more pilots to no longer flying routes, you are setting up the case for a perfect storm in more congested airspace. It used to be that you could count on the general directions most pilots would come to/from airports based on the routes, no you have pilots coming direct from all directions.

    Tim
     
  10. May 31, 2017 #30

    BBerson

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    A thousand drones can fly in formation without collision, we should be able to do it. The problem is FAA doesn't want to cut the ground control link. (And their jobs).
    I guess with private airplane ownership numbers falling every year the risk is less. Accept for drones.
     
  11. Jun 5, 2017 #31

    Authmion

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    Its very expensive. Cheapest I have found for it, and they say its built for Experimentals, was www.uavionix.com. and that was ~1k+

    I know there are some DIY ADS-B IN solutions (I have a Stratux Rasberry pi device for that) But has anyone figured out how to DIY ADS-B out?
     
  12. Jun 5, 2017 #32

    D Hillberg

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    ADS-B is going to reduce the number of civil pt 91 aircraft flown for the simple reason It's an added cost. More folks are going to say the hell with it.
     
  13. Jun 6, 2017 #33

    proppastie

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  14. Jun 6, 2017 #34

    Hot Wings

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    Gathering that data and assembling it into a file for transmission using an Arduino or Raspberry shouldn't be a huge project for someone with a little more experience than I possess. I don't know enough about transponder protocal to know how they need the data formated. I'm guessing most use some proprietary format?

    The data isn't a big problem, its the radio side of the problem that needs to be solved - at least that's how I perceive things.
     
  15. Jun 6, 2017 #35

    Hot Wings

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    Android alshimers..... Dbl post.:emb:
     
  16. Jun 6, 2017 #36

    Hephaestus

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    It's out there standard format. Why you can read the data with a usb TV tuner ;)

    Transmitting easy as a transmitting SDR (2-300)

    But wait there's more.

    Since some drones need them - hold off, the Chinese drone guys will have them down to beer money $ within 3 years. Then it's just approvals & STCs.
     
  17. Jun 6, 2017 #37

    Hot Wings

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  18. Jun 6, 2017 #38

    Hephaestus

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    I think the SDR started bi-directional, but we only heard about them when those TV dongles came out and were found to be way better than just watching tv ;)
     
  19. Jun 6, 2017 #39

    spaschke

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    I have looked at the protocol specs. ADS-B protocol is straight forward, but the extended squitter/ WAAS transponder protocol complicates it, a lot. But if you do what uavionics does, uses existing transponder, it takes out the most complicated part. I didn't spend a lot of time researching it, so I may have some misunderstandings.

    There are a few sdr transmitters, HackRF is the most well known. The transmitter is relatively weak, 2 watts I think. A boost amplifier may be needed.

    I've got to get my airplane flying before I have time to think about something like this.
     

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