ADS-B TSO'd GPS Sources

[lolachampcar]

I thought I posted this last night but do not see it. Please forgive me if this is a duplicate.

TSO'd GPS position is not required for ADS-B until 2020. Until then, the Dynon puck will work just fine and the ADS-B ES message will tag the position quality as undetermined.

Does anyone know what the current TSO'd GPS sources are and their costs? I've found the Freeflight 1201 at just under $3000 which means we get to pay $2800 for the TSO and 3 samples per second fewer position updates.

 

[lolachampcar]

NexNav mini is manufactured and marketed by Accord Technology LLC located at Phoenix, Arizona, USA

No idea on price or even if it can be purchased.

 

[dynonsupport]

To be precise, there are only a few specific formats that are supported by the transponder for direct connection today, and those are only supported by a couple of specific devices. I suspect that may change over the years as more valid devices come to market. Here's a sneak peak excerpt from the latest installation guide, which covers compatibility and what it allows the transponder to report about its position:

GPS DATA (a setting in the transponder setup menu) : Determines the source of GPS position updates for ADS-B Out:
Use of any of the DIRECT GPS-to-transponder position reporting methods below require that the GPS that is connected to the transponder be TSO’d when used in the US. Additionally, only specific models are supported via these connections. Other counties may have different regulatory requirements for GPS position indicators that are connected directly to the SV-XPNDR-26X’s direct serial input.

o DIRECT (AVIATION): Generic GPS outputting Aviation format data, connected directly to SV-XPNDR-26X pin 3, transmitting at 9600 baud. As this data format does not contain all of the information that ADS-B position inputs require, Dynon does not recommend using this connection for any purposes. Using this setting causes the transponder to transmit the following ADS-B performance parameters:
SIL: 0 (Unknown integrity)
NACp: 0 (Unknown position accuracy)
NIC: 0 (Unknown containment)
NACv: 1 (10m/s accuracy)

o DIRECT (FREEFLIGHT): Freeflight 1201 or 1204 GPS, connected directly to SV-XPNDR-26X pin 3, transmitting at 19200 baud. Using this setting causes the transponder to transmit the following ADS-B performance parameters:
SIL: 2 (Level C integrity)
NACp: Sent from GPS to transponder. Refer to GPS documentation.
NIC: Sent from GPS to transponder. Refer to GPS documentation.
NACv: 1 (10m/s accuracy)

o DIRECT (GARMIN ADS-B): Garmin GNS 400W/500 (WAAS) or Garmin GTN series, both with appropriate software updates as designated by Garmin, connected directly to SV-XPNDR-26X pin 3, transmitting at 9600 baud. Note that this option only works with transponder software 2.02 or above. See the Transponder Software Updates section below for more information about transponder software. Using this setting causes the transponder to transmit the following ADS-B performance parameters:
SIL: 2 (Level C integrity)
NACp: Sent from GPS to transponder. Refer to GPS documentation.
NIC: Sent from GPS to transponder. Refer to GPS documentation.
NACv: 1 (10m/s accuracy)

o SKYVIEW: SkyView reports its GPS position to the transponder via its nominal SkyView<>SV-XPNDR-26X serial connection. Using this setting causes the transponder to transmit the following ADS-B performance parameters:
SIL: 0 (Unknown integrity)
NACp: 8, 9 or 10. Dynamic, as reported by GPS.
NIC: 8 (Containment radius <0.1 NM)
NACv: 1 (10m/s accuracy)

 

[lolachampcar]

Thanks Dynon. I suspect if/when someone comes up with a $1K GPS puck the transponder guys will add the format.

 

[jeffa]

In regard to the Freeflight 1201 specifically (which does not have a cockpit display), will Skyview have the ability to display a caution or warning message if the quality/integrity of the GPS source fails or falls below an allowable level?

As it stands with my 1201 installation, I don't even have the ability to see if it is tracking satellites.  Thankfully, I can tells it's operating and drawing current because of my VP-X page. 

 

[lolachampcar]

And can skyview take the 1201 feed as a TSO'd nav source for IFR flight?

 

[jeffa]

And can skyview take the 1201 feed as a TSO'd nav source for IFR flight?

No, according to Freeflight, the 1201 outputs a proprietary message that only the Chelton EFIS system reads.  As of 2 months ago, when I originally installed the 1201, Dynon tech support told me that they had no current plans to allow the 1201 to be used as a Nav source. 

So, it's strictly a source for the ADS-B for now.  It gives some merit to the Garmin GNS and GTN series (allowing both a Nav and ADS-B source), but they were out of my price range.

 

[dynonsupport]

Even if we could read the Freeflight devices as a position source, this does not magically make SkyView legal for IFR. TSO'd IFR GPS units carry TSO's for the whole system, not just the GPS sensor. The way databases are processed, what is shown on the screen, the algorithms for calculating the flight plan are all TSO'd.

Because of this, we've made no effort to be able to read a standalone TSO'd GPS sensor into the SkyView screen.

 

[jeffa]

Just posing this question one more time, not sure if Dynon support saw this:

In regard to the Freeflight 1201 specifically (which does not have a cockpit display), will Skyview have the ability to display a caution or warning message if the quality/integrity of the GPS source fails or falls below an allowable level?

 

[dynonsupport]

We will not have a way to display integrity information from a standalone receiver such as a Freeflight 1201. As far as I know, this is not a requirement of the ADS-B out TSO.

You can see, via the transponder status page in the setup menu, if the transponder is receiving a valid position.