Possible AD for certain NAVWORX ADS-B Units

[Scott Hersha]

Anybody know why traffic info isn't sent to equipment broadcasting SIL=0? Didn't that work at first? I thought SIL =0 meant the equipment wasn't 'certified', but what I think I also read was that this uncertified equipment met the position accuracy requirements of the TSO, AND was accepted by the FAA a year ago. If NavWorx changed the transceivers to send the info on the data string to SIL=3, then my question is why did the FAA change their protocol from what was previously accepted, why did they do that? In a non-certified airplane, why does it matter as long as the accuracy still meets the TSO?

[RFSchaller]

I don't have the NAVWORX unit, but it seems to me there are at least two issues:

1. ADs do not apply to aircraft that are not type-certified e.g. ELSA or EAB.
2. If your installation passes the FAA performance test as reported on the summary you can request, why would you replace it?

[MartySantic]

Originally Posted by BobTurner

This is meaningless. The SIL is not calculated by the FAA ground stations; it is programmed into the box by the manufacturer, and then sent out. As I understand the A/D - and I can easily be wrong - the FAA is saying that NavWorks was not authorized to put in SIL=3 into certain boxes using certain components.

Meaningless?? Thought he mentioned his NEW ADS600-EXP unit had a new model number, not covered by the proposed AD?? As such, would be VERY interested in the SIL transmitted. Yes, I very much understand the definition of SIL.

[Radomir]

Originally Posted by BobTurner

This is meaningless. The SIL is not calculated by the FAA ground stations; it is programmed into the box by the manufacturer, and then sent out. As I understand the A/D - and I can easily be wrong - the FAA is saying that NavWorks was not authorized to put in SIL=3 into certain boxes using certain components.

You are 100% correct That's the root of the whole issue.. you can't just randomly program the box to send any SIL you want without showing that it meets the requirements for that SIL.. Doesn't have to be certified, but has to show results of testing to meet the TSO.

Per that FAA letter, there's a clear disagreement between them whether test data provided by Navworx was sufficient to prove that equipment meets the requirements. And the FAA won't let Navworx just program any SIL they pick.... hence the AD...

PS. Doesn't matter that the plane is experimental.. requirements for ADS-B are equal for all. Experimentals are not allowed to transmit "made up" signal.

[Jordan1976]

The FAA "turned off" traffic for SIL=0 devices in Jan 2016 for a few reasons. You can read their justification here:

http://www.faa.gov/nextgen/programs/adsb/media/TIS-B_service_change_summary_final_508_5-13-15-webV2.pdf

Note that they left traffic on for SIL=1 or higher devices, while 2020 compliance requires a SIL=3, so they do not require a full complaint solution, just one with some pedigree.

[Paul 5r4]

I read the above post on the FAA's reason for their changing ADSB parameters. My question is this... why did it not affect any of the other manufactures of ADSB units? Why aren't they having problems like navworx?

[Brantel]

Originally Posted by Paul 5r4

I read the above post on the FAA's reason for their changing ADSB parameters. My question is this... why did it not affect any of the other manufactures of ADSB units? Why aren't they having problems like navworx?

It did... Garmin was also effected by this change in that they correctly output SIL-0 when using an uncertified (or approved equal) position source. When the FAA flipped the switch to not allow clients outputting SIL-0 to receive the traffic uplink, Garmin based panels (using an uncertified (or approved equal) position source) lost uplinked traffic data as well. Garmin refused to lie to the system by incorrectly outputting something higher than SIL-0. Other well known manufacturers also got hammered by this change as well but also followed the rules.

My understanding is that the manufacturers firmware is what decides what SIL level is going to be output. Looks to me like Navworx decided to break the rules by outputting a higher SIL level than 0 without a properly certified (or approved equal) position source. Essentially what appears to be lying to the system and therefore the FAA takes issue with that.

I doubt they are the only ones out there that have tried or are trying to get away with this. There are some other dirt cheap models that most likely are doing the same thing and will eventually get busted by the FAA.

[GalinHdz]

Originally Posted by RFSchaller

I don't have the NAVWORX unit, but it seems to me there are at least two issues:

1. ADs do not apply to aircraft that are not type-certified e.g. ELSA or EAB.
2. If your installation passes the FAA performance test as reported on the summary you can request, why would you replace it?

You are right, aircraft AD's do not apply to ELAS or EAB. But this is not an aircraft AD, it is an equipment AD. It applies to the equipment indicated not the aircraft. That is why the proposed AD states:

"This AD applies to the following NavWorx, Inc., Automatic Dependent Surveillance-Broadcast (ADS-B) Universal Access Transceiver units (unit) installed on aircraft certificated in any category:

(1) Model ADS600-B part number (P/N) 200-0012;

(2) Model ADS600-B P/N 200-0013; and

(3) Model ADS600-EXP P/N 200-8013."

We experimental guys don't get a pass on this one if it becomes an AD.

[Jordan1976]

Another reason you don't get to ignore the AD is that ADS-B is a performance based rule.

FAR 91.225 says:

(b) After January 1, 2020, and unless otherwise authorized by ATC, no person may operate an aircraft below 18,000 feet MSL and in airspace described in paragraph (d) of this section unless the aircraft has equipment installed that--

(1) Meets the requirements in--

(ii) TSO-C154c, Universal Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B) Equipment Operating on the Frequency of 978 MHz;

If the AD goes through, the FAA is telling you that box doesn't meet the performance requirements of the TSO (even if it never had a TSO). You are now fully aware of this fact. You then fly into an ADS-B required airspace. The FAA then says that you, as a pilot, knowingly violated a FAR and takes enforcement action against your airmens certificate.

[Peterk]

All this said...how does the FAA know that you removed the box? Can they discover your manufacturer by recognizing the equipment that is receiving streaming data?

Or is it like flying a non-sport compliant aircraft without a medical...good till you get caught?