In the hype of the install now to get functionality promises I was one of the early ones to get in line for the Navworx system which is one of the cheapest on the market offering ADSB in/out. It took a while to get it with the navworx backlog, but since I've had it I've been happy.

It seems that there were issues early on with the integrity the units output to the big network in order to get data sent back and wake up the towers. From the way I understand it, the CEO of navwork Bill Moffit had worked out a deal with the FAA to keep the data coming and they were happy with the agreement. Now it sounds like the FAA is trying to impose some bullshit AD on the units because of the previous agreement which would mean my unit would become an expensive paperweight.

If this does go through it's going to be extremely frustrating. Here is the standard bureaucratic bullshit that we always see when a gov't entity is in charge of the show. I feel sorry for the guys at navworx having to deal with the bullshit instead of being able to focus on the product. As the document reads, it sounds like it applies to all certified and experimental units. Anyone else out there who equipped early and will now possibly get fucked over from ole uncle sam?

Letter from Navworx on the situation: http://www.navworx.com/documents/AD%20Statement.pdf

The rules are briefly summarized (but not defined) by AC 20-165. In order to broadcast a non-zero SIL, you need to be using a GNSS source "compliant" with any version of TSO-C129,TSO-C145, TSO-C146, or TSO-C196, that provides an output horizontal protection level (HPL) or horizontal integrity level (HIL).

Few (as in almost no) receivers do this for lack of sufficient cadence or predictive reporting.

It is sad that the FAA would continue to pretend that this kind of requirement for VFR bug smashers is even useful, relevant, or contributes to any functional objective they had in mind for the NAS overhaul. In other words, while relevant for IFR and aircraft travelling relatively fast, the requirements offer nothing when used with slower, VFR aircraft.

Navworx decided to set the SIL report message portion to 3, apparently. Their notice does not delve into how they assert their system meets the above requirements. It may well be that they feel they have meet those requirements. It may be that the FAA differs on that point. This is unsurprising given the lack of conciseness the FAA chooses to communicate, particularly on technical matters. They may not even be in agreement with themselves in this or other matters.

Here is the FAA Docket on the proposed AD:

https://www.regulations.gov/document?D= ... -9226-0001

I am an interested party since I have a NavWorx kit on order w/ deposit and an approved rebate based on one of the AD covered units.

I know the AOPA is scratching their heads on this as well but here is what I understand.

The -0112 and -0113 units received approval for the appropriate TSO's. Those models are now obsolete and replaced by the -0012 and -0013 models which are listed on the proposed AD.

Step one. If I understand the Fedspeak and technical jargon correctly, NavWorx changed the GPS contained in the new versions and for some reason(s) the new GPS is not considered certified by the FAA.

"The design of the units includes an internal uncertified GPS source. ADS-B units with an uncertified GPS source are required to broadcast a SIL of 0."

Step two, as of 1 January 2016 all certified units must communicate with the NextGen system via SIL >0 and SDA >0 . NavWorx has set the current units to SDA 3 (don't know about SIL) in order to communicate w/ TIS-B now and after Dec. 21, 2019.

Step three: Only certified units per the Jan 1, 2016 rule are permitted to communicate via SDA 3. Evidently because the FAA does not consider the GPS in the current NavWorx units to be certified they are not communicating on the proper frequency.

Which is (are) the reason(s) for the AD.

I don't understand why this issue got this far down the road. If the GPS had an issue, I am assuming the FAA notified the mfg. of it. I would think the mfg. would not change a key component and not run it past the FAA.

Very frustrating.

TD

On another note with ADSB this has been very frustrating just having it. Once every 2 months since I've had it installed Mr William Adams with the FAA has contacted me stating my unit is failing and he is getting failure reports. I then have to fly above 3500' for 30 min and surprisingly it passes. The issues is the FAA doesn't understand how their own system works. When I brought this up to Mr. Adams his response was "I'm just a regulator and I can't tell you how that system works."

Here's the issue, I fly very frequently 700' and below for 5-10 minute flights. Their reports are generated for each flight and is based on a percent of failures. At those low altitudes and short flights a few failures are a higher percentage and it triggers a failure in their system. Which then starts the whole process over again.

But, it has all been worth it for the traffic and weather thus far. Standing by to stand by and see who gets the shaft on this deal

Timberwolf wrote:On another note with ADSB this has been very frustrating just having it. Once every 2 months since I've had it installed Mr William Adams with the FAA has contacted me stating my unit is failing and he is getting failure reports. I then have to fly above 3500' for 30 min and surprisingly it passes. The issues is the FAA doesn't understand how their own system works. When I brought this up to Mr. Adams his response was "I'm just a regulator and I can't tell you how that system works."

Here's the issue, I fly very frequently 700' and below for 5-10 minute flights. Their reports are generated for each flight and is based on a percent of failures. At those low altitudes and short flights a few failures are a higher percentage and it triggers a failure in their system. Which then starts the whole process over again.

But, it has all been worth it for the traffic and weather thus far. Standing by to stand by and see who gets the shaft on this deal

Maybe what you have to do is voluntarily go above 3500' AGL for 30 minutes more often.

It is a shame that those charged with enforcing the system's requirements don't understand how the system works.

Seriously, it's easy to see why there would be "failures" logged by the system, if you're flying under 1000' AGL most of the time. Unless you have an ADS-B tower very nearby at those low altitudes, terrain will often block the signal from your airplane to the ADS-B tower and vice versa--you're undoubtedly not picking up weather or ADS-B traffic either.

Cary

.

Pilots are usually of a few types - most with some semblance of tolerance for each other.

Of course there will be an ATP smoker systems manager that tends to look down on the
Regional pilots who ocassionaly look down and back at the part 135 society taxi drivers
who may look down on the part 135 Fishing and Hunter hauler crowd which are glad they
are not smelly Fish Pilots in the set net business - but then when offered a "higher" job often
say, "You ain't gonna stuff me in a starched shirt - choke me up with a tie and tell me that
I am not allowed to tie on any damned external loads.

BUT - Business is Business and survival can make for some ugly dog fights.
Navworx is not the first - there was some other outfit shut down for sneaking in unqualified foreign parts.
Even an excellent outfit I have known for some time (since inception) was put through a temporary North West FSDO wringer over two items our of hundreds. Looked like an obvious competitive move to me.
Could be wrong - Been a while since I reviewed ALL the details. Just know my acquaintance
Is still in business and doing fine. He is a much better design engineer and FAA pacifier than he is a pilot.
But that is a whole couple of different stories.

Gotta be care full out there - Quite often there is a big difference between initial price and eventual cost.

Chris C