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Warning to anyone doing Demo Mode on IFD units

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programmer@pcmforles View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote programmer@pcmforles Quote  Post ReplyReply Direct Link To This Post Topic: Warning to anyone doing Demo Mode on IFD units
    Posted: 28 Jan 2020 at 3:22pm

Need to put out a quick warning to all, especially anyone using the DEMO command to run their IFD in Demo mode for practice or customer demonstrations.

MAKE SURE YOU TURN OFF YOUR TRANSPONDER BEFORE RUNNING THE DEMO MODE.

I just finished up a Demo outside for a new customer and setup a departure and approach and let the demo fly it. Unfortunately it put out an ADS-B signature of the airplane flying and reporting altitude of that GPS position. I noticed it due to flight aware giving me an alert that the airplane was flying. With the controllers now watching ADS-B on their scopes this is a potential big issue.

I called the Tower and asked them if they had a ghost ADS-B signal for that tail number and they did. I explained what happened and they asked me to make sure not to EVER do that again. I just wanted to pass the word along to everyone else so this doesn't happen to them and create issues. I think I may have messed up a few approaches into Reno today. I imagine if I hadn't realized and called them right away I would probably be getting an FAA call or letter.

Pass this along to anyone else you may know that isn't on the forums but may do demo mode IFD work.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote PA23 Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2020 at 6:05pm
WOW, that makes for an interesting story!  You probably set off some traffic alerts too with people scratching their heads as to where the airplane was.

Besides the fact I wouldn't want to be standing anywhere near the transponder antenna (you are shielding inside the plane) while it's transmitting so it should be off anyway.  One thing to note is many of the new 1090ES transponders cannot be turned off without pulling the breaker.  I'd guess the possibility would be to not transmit GPS position data to the transponder and the transponder would have stayed in ground mode, which still transmits BTW.

I wouldn't be surprised if you still get a letter from the FAA asking for an explanation, I wouldn't expect any type of enforcement action because you weren't airborne and it wasn't intentional.  The other question is, I don't know how smart the system is, if a ground receiver is picking up your signal that is nowhere near where you say you are will the system reject the location as invalid?  It would be interesting to pull the performance report.

-Jeff
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programmer@pcmforles View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote programmer@pcmforles Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2020 at 6:57pm
I've actually already had a visit with the FAA as our office is here on the field.   I feel they may see this capability as a potential threat (not what I did accidentally, but the potential for misuse).   We have a few great guys are our FSDO and I'm working with them to get them as much info as possible.
That is a great thought about the ADS-B receive antenna rejecting the info if it was data saying the airplane is no where near where it is.   I hope the system is that smart.   But, I imagine it is more of just a pass thru :(
Yes, if it were a Lynx unit they are difficult to turn off.    I didn't think about it as I didn't think it would turn it on to Alt reporting out of ground mode, but apparently the demo put out ground speed as well and the AXP340 uses that discrete from the IFD to switch from ground to airborne.  I was reporting altitude during this "flight" so all the data looked fully legit.   It wasn't like it was showing field level altitude or 0 feet during the flight, it was showing legit altitudes.



Edited by programmer@pcmforles - 28 Jan 2020 at 6:58pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Gring Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2020 at 8:30pm
cool, so if you wanted to commit some illicit crime, you could set up your demo mode to creat an alibi. Cool!
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programmer@pcmforles View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote programmer@pcmforles Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2020 at 9:18pm
:)   never though of that angle.....
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PA23 Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2020 at 9:32pm
The sad part is, I think everything worked exactly as it was intended.  Many of the glass displays require a GPS position to display properly and while in a demo mode they would still need some sort of GPS position to display properly.

I think what you have is simply an unintended consequence of something working as expected.  I hope we aren't going to be required to install squat switches next to avoid this issue.
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programmer@pcmforles View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote programmer@pcmforles Quote  Post ReplyReply Direct Link To This Post Posted: 28 Jan 2020 at 10:31pm
Agreed, I think everything did what it was supposed to do as the Demo mode shows everything over onto the Aspen.   I really do hope it is isn't going to be something that requires action of some sort, although a squat switch would not keep someone devious from doing this either as that ins't a difficult thing, but it would keep from inadvertent activation.   Maybe they can pop into the newest software update to not to activate the simulated squat ground switch when in Demo Mode. 
I just think that it was not contemplated that this could occur this way.   I should have though to turn the transponder off, but I'm sure if it wasn't me someone else would have had the same thing happen.   
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mfb Quote  Post ReplyReply Direct Link To This Post Posted: 29 Jan 2020 at 9:37am
What this really shows is how easy it is to spoof the ADS-B system. A bad guy with a little money, imagination, and engineering smarts could swarm a major airport with a thousand fake targets. That would effectively shut down the airspace.

Pretty scary.

Mike
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programmer@pcmforles View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote programmer@pcmforles Quote  Post ReplyReply Direct Link To This Post Posted: 29 Jan 2020 at 10:49am
And I think that is the fear of my local FSDO.   Thus the reason they wanted me to get them as much information as possible as to how this occurred.    Hopefully there are safeguards in there that would prevent someone putting false traffic out there, especially a swarm.   I do think there are definitely authentications in the system since if you are not putting out a clean ADS-B out traffic solution you cannot receive the TIS-B in products on certified unit, so if you have a configuration issue it will block your ability to receive traffic.   So, hopefully this traffic solution algorithm would prevent such a thing.
Unfortunately it seems like I managed to put out a valid traffic solution signature while on the ground and hopefully the data from this can be used to prevent any future occurrences.   
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Post Options Post Options   Thanks (0) Thanks(0)   Quote AviSteve Quote  Post ReplyReply Direct Link To This Post Posted: 04 Feb 2020 at 12:21pm
Steve Lindsley
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PA23 Quote  Post ReplyReply Direct Link To This Post Posted: 04 Feb 2020 at 2:20pm
I did reach out to a friend of mine at the FAA that is involved with the ADS-B stuff and pointed him to this thread.  He commented "Redundant radar coverage and wide area multilateration should've helped the system dismiss the target as illegitimate." 

Of course he didn't know the full details so he doesn't know if the system worked the way it was supposed to, your aircraft may only have shown up in a tiny area.
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