Avidyne Homepage
Forum Home Forum Home > Avidyne General > SkyTrax Series ADS-B Receivers & Transceivers
  New Posts New Posts RSS Feed - My Ideal ADS-B Solution
  FAQ FAQ  Forum Search   Register Register  Login Login

My Ideal ADS-B Solution

 Post Reply Post Reply
Author
Message
DavidBunin View Drop Down
Senior Member
Senior Member
Avatar

Joined: 20 May 2015
Location: Rockwall, TX
Status: Offline
Points: 720
Post Options Post Options   Thanks (0) Thanks(0)   Quote DavidBunin Quote  Post ReplyReply Direct Link To This Post Topic: My Ideal ADS-B Solution
    Posted: 07 Mar 2018 at 7:52am
My airplane today has an IFD-540 and NavWorx/SkyTrax UAT (mine is a transmitter/receiver but using the IFD as the GPS input) and the airplane still has the original Cessna Mode A/C transponder.

At some future date I imagine I will replace the original transponder with something newer.  Here is my ideal ADS-B solution:

RF Outputs: Mode A & C (1090MHz), UAT (978MHz) I want UAT as my ADS-B Out compliance channel because it allows the use of an anonymous code (meaning I can squawk 1200).  I don't fly internationally and I don't go above FL180.  I don't want a Mode S transponder of any kind and I don't need or want the 1090ES output.

RF Inputs: Mode A & C (1030MHz), 1090ES (1090MHz), UAT (978MHz) In other words, an ATCRBS compliant transponder with a "dual-band" ADS-B In receiver.

Data: I want full interface with the IFD540.  The IFD should be capable of acting as the transponder control panel and the IFD screen should display every available bit of ADS-B In data.

With the exception of the data interface, the proposed Sandia STX360 seems to fit the bill.  But I don't know where they are in the development process and I don't know if they have reached out to Avidyne for a cooperative data interface.

David Bunin
Back to Top
n7ifr View Drop Down
Senior Member
Senior Member
Avatar

Joined: 05 Aug 2013
Location: Phoenix, Az
Status: Offline
Points: 339
Post Options Post Options   Thanks (0) Thanks(0)   Quote n7ifr Quote  Post ReplyReply Direct Link To This Post Posted: 11 Mar 2018 at 10:39am
David - I share your search.  I would be perfectly happy to have only 978 Out for compliance, and Dual IN integrated with TAS to display both on our 540's.

At this point, I would gladly exchange the AXP340 for a 978 OUT unit...  If the TAS "A" promises ever surface, won't that at least give the 540 a way to display Dual ADSB IN & TAS IN?  

Tom W.
Back to Top
DavidBunin View Drop Down
Senior Member
Senior Member
Avatar

Joined: 20 May 2015
Location: Rockwall, TX
Status: Offline
Points: 720
Post Options Post Options   Thanks (0) Thanks(0)   Quote DavidBunin Quote  Post ReplyReply Direct Link To This Post Posted: 13 Mar 2018 at 3:48pm
Honestly, I am not that familiar with the TAS A products.
Back to Top
HenryM View Drop Down
Senior Member
Senior Member


Joined: 13 Oct 2017
Location: Texas
Status: Offline
Points: 111
Post Options Post Options   Thanks (0) Thanks(0)   Quote HenryM Quote  Post ReplyReply Direct Link To This Post Posted: 13 Mar 2018 at 4:39pm
I’m curious why you would want to exchange the AXP340 for a UAT (978MHz) ADS-B Out device? My AXP340 seems to work well.

I would prefer a dual band ADS-B In unit over the SkyTax 100 that I have, but that is independent of the AXP340.
Back to Top
Melohn View Drop Down
Newbie
Newbie
Avatar

Joined: 11 Dec 2013
Location: PHNL
Status: Offline
Points: 26
Post Options Post Options   Thanks (0) Thanks(0)   Quote Melohn Quote  Post ReplyReply Direct Link To This Post Posted: 13 Mar 2018 at 10:08pm
The only reason I can see to want UAT Out over 1090ES Out is for its “anonymous” mode. It seems highly unlikely this will be useful for anyone flying in B, C, or D airspace, where you will still be identifiable via FlightAware ATC recordings.
Back to Top
DavidBunin View Drop Down
Senior Member
Senior Member
Avatar

Joined: 20 May 2015
Location: Rockwall, TX
Status: Offline
Points: 720
Post Options Post Options   Thanks (0) Thanks(0)   Quote DavidBunin Quote  Post ReplyReply Direct Link To This Post Posted: 18 Mar 2018 at 11:31am
Originally posted by Melohn Melohn wrote:

The only reason I can see to want UAT Out over 1090ES Out is for its “anonymous” mode. It seems highly unlikely this will be useful for anyone flying in B, C, or D airspace, where you will still be identifiable via FlightAware ATC recordings.


I don't normally receive a discrete squawk code when flying in class D airspace.  I do in class B of course.

I don't encounter class C often enough to recall if they assigned me a code or not.

The other reason for desiring a UAT out device is that they tend to be AT LEAST a thousand dollars cheaper than an equivalent 1090ES product.  I can't explain why, but that is the marketplace.

Back to Top
George P View Drop Down
Newbie
Newbie
Avatar

Joined: 29 Jan 2017
Location: Big Horn, WY
Status: Offline
Points: 35
Post Options Post Options   Thanks (0) Thanks(0)   Quote George P Quote  Post ReplyReply Direct Link To This Post Posted: 18 Mar 2018 at 12:48pm
You don't get a squawk code in D airspace because they normally do not see you.  Yhey have no radar.  Class B and C airspace are by definition radar equipped airspace so you will always get a discreet code while in them.
Back to Top
HenryM View Drop Down
Senior Member
Senior Member


Joined: 13 Oct 2017
Location: Texas
Status: Offline
Points: 111
Post Options Post Options   Thanks (0) Thanks(0)   Quote HenryM Quote  Post ReplyReply Direct Link To This Post Posted: 18 Mar 2018 at 6:07pm
I thought with ADS-B, you transmit a unique code for your airplane, along with the squawk code. Even when squawking 1200, they can know who you are.
Back to Top
BobsV35B View Drop Down
Senior Member
Senior Member
Avatar

Joined: 24 Aug 2011
Location: Downers Grove,
Status: Offline
Points: 121
Post Options Post Options   Thanks (0) Thanks(0)   Quote BobsV35B Quote  Post ReplyReply Direct Link To This Post Posted: 19 Mar 2018 at 10:38am
Hi Henry! Do not cunfuse me with someone who knows what is happning, but I do know that when I am squaking 1200, my track, altitude, and N number show up on Flight Aware!! No secrets any more!!

Old Bob
Old Bob, Ancient Aviator
Back to Top
Melohn View Drop Down
Newbie
Newbie
Avatar

Joined: 11 Dec 2013
Location: PHNL
Status: Offline
Points: 26
Post Options Post Options   Thanks (0) Thanks(0)   Quote Melohn Quote  Post ReplyReply Direct Link To This Post Posted: 19 Mar 2018 at 5:03pm
According to AOPA:

FAR 91.227 specifically allows operators with TSO-C154c-compliant 978UAT ADS-B Out equipment to temporarily transmit a self-assigned (randomized) 24-bit address, and no call sign. This option is not available for aircraft with 1090ES ADS-B Out equipment. Beginning January 1, 2020, the UAT anonymous 24-bit address feature may only be used in ADS-B-mandated airspace when the pilot has not filed a flight plan and is not requesting ATC services. The ADS-B call sign—for general aviation pilots, typically the aircraft’s N number—may be omitted only when using the anonymous 24-bit address.

So, you can enable anonymous mode on a UAT, although you don't have to. It isn't clear how often the message is anonymized, and probably varies by manufacturer. 

If you fly into any airspace where the ATC is being recorded, it is pretty easy to identify and track back an aircraft using anonymous mode, regardless of squawk code. I believe this was added due to concerns that airport operators might try to use the ID to charge aircraft for airport related services.

Back to Top
Gring View Drop Down
Senior Member
Senior Member


Joined: 30 Dec 2011
Location: Kingston, NY
Status: Offline
Points: 487
Post Options Post Options   Thanks (0) Thanks(0)   Quote Gring Quote  Post ReplyReply Direct Link To This Post Posted: 19 Mar 2018 at 7:42pm
I don't like that all of these Flightaware stations are tracking ADS-B equipped airplanes.  Every little flight is captured and available on Flightaware, and I find that intrusive.  Glad I am still flying some airplanes without any transponder at all.  I have no plans to put one in them either.

Edited by Gring - 19 Mar 2018 at 7:43pm
Back to Top
DavidBunin View Drop Down
Senior Member
Senior Member
Avatar

Joined: 20 May 2015
Location: Rockwall, TX
Status: Offline
Points: 720
Post Options Post Options   Thanks (0) Thanks(0)   Quote DavidBunin Quote  Post ReplyReply Direct Link To This Post Posted: 23 Mar 2018 at 9:59am
Originally posted by Melohn Melohn wrote:

According to AOPA:

FAR 91.227 specifically allows operators with TSO-C154c-compliant 978UAT ADS-B Out equipment to temporarily transmit a self-assigned (randomized) 24-bit address, and no call sign.


Correct.  During the design phase of the ADS-B system, AOPA specifically lobbied to protect our personal privacy and ensure that this capability was part of the rule.

Originally posted by Melohn Melohn wrote:

It isn't clear how often the message is anonymized, and probably varies by manufacturer.


For every piece of UAT equipment that I am familiar with, a random number is selected each time the squawk code changes from a discrete value to 1200.  If the squawk is 1200 as start-up, a random number is selected.

The random number does not change during flight unless a discrete code is set in the transponder (i.e. pilot receiving ATC services) in which case it changes to the actual aircraft's 24-bit address, or power is interrupted (UAT picks a new random number upon reapplication of power).

If/when ATC services are terminated and the pilot sets the transponder to 1200, the UAT selects a new random number.
Back to Top
oskrypuch View Drop Down
Senior Member
Senior Member


Joined: 09 Nov 2012
Location: CYFD
Status: Offline
Points: 2269
Post Options Post Options   Thanks (0) Thanks(0)   Quote oskrypuch Quote  Post ReplyReply Direct Link To This Post Posted: 23 Mar 2018 at 12:24pm
Originally posted by DavidBunin DavidBunin wrote:


For every piece of UAT equipment that I am familiar with, a random number is selected ...

I wonder if they designed that, specifically to address the privacy concerns that small aircraft operators have.

* Orest

Back to Top
bobcain View Drop Down
Newbie
Newbie


Joined: 26 Aug 2010
Location: 7K8
Status: Offline
Points: 28
Post Options Post Options   Thanks (0) Thanks(0)   Quote bobcain Quote  Post ReplyReply Direct Link To This Post Posted: 30 Mar 2018 at 10:48am
I hadn't come across this thread until now, but I fully agree with David's thoughts.  Anonymous mode is very important to me - and not because I operate illegally.  I am fortunate that most of my flying is outside areas requiring an "out" signal.

My biggest struggle is to understand the difficulty to provide a UAT with dual band receive.  To my knowledge the GDL88 may be the only certified unit with this capability?  I have visions of sitting at some small rural airport outside of ground station coverage, getting ready to depart, and having no idea someone is inbound with Mode S that maybe isn't talking and I won't see them as traffic.  1090 receive is the only remedy.

I recently purchased an Aspen ATX100 but if FreeFlight come along with dual band receive, I'll be first in line.
Back to Top
BobsV35B View Drop Down
Senior Member
Senior Member
Avatar

Joined: 24 Aug 2011
Location: Downers Grove,
Status: Offline
Points: 121
Post Options Post Options   Thanks (0) Thanks(0)   Quote BobsV35B Quote  Post ReplyReply Direct Link To This Post Posted: 30 Mar 2018 at 3:15pm
May I Beat on this dead horse just a bit?

Mr. BobCain,

There is no requirement for any transponder if we stay out of class B/C and below ten thousand feet in other than mountainous terrain. Odds are that you will have unseen conflicting traffic any time you are out of FAA Controlled airspace, not just at that little out of the way airport.

About ninety percent of the airspace in the USA allows such flight legally. No transponder of ANY sort required. In fact, NO Radio is reqired!

Happy Skies,

Old Bob
Old Bob, Ancient Aviator
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.055 seconds.