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Possible AD for certain NAVWORX ADS-B Units

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?
 
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?
 
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.
 
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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.
 
question

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?
 
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.
 
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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.

:(
 
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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.
 
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?
 
Reported SIL

The SIL reported by my ADS600-EXP on my latest report dated 10/05/16 was SIL = 3
 
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?

As part of the data packet of the ADSB transmission, they know it's a NavWorx unit. If I recall correctly, the compliance report listed the Navworx model number.

Now whether or not they act on the data, is another issue........
 
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?

It's an honor system... there's nothing in the transmitted data that identifies the manufacturer.

PS. they "know" on compliance report cause "you told them what unit you have" (they ask for it when you ask for compliance report)
 
Well..... what I heard was a bit different, not that it matters much. I heard that last January the FAA stopped sending traffic info (TIS B) to aircraft broadcasting SIL=0 in the ADS-B data string (indicates EAB/light sport, I think). NavWorx changed the software to broadcast TIS=3, in order to get traffic info displayed on their customers ADS600-B and ADS600-EXP units. SIL 3 is for certified units, not experimental - I think..... The FAA has a beef with this because even though the internal GPS accuracy meets the TSO accuracy requirements, it's not a certified TSO'd GPS. I could be wrong about this, but that's the way I understand it from what I've read/researched. I do have a dog in this fight because I just received my new ADS600-EXP 3 days ago, and would like to use it.......forever...

Anyway, it sort of reminds me of what happened many years ago when PMA(parts manufacturing approval)was first introduced, but the PMA'd parts didn't have to meet any of the original design parameters other than basic shape, size and weight. Customers of major aircraft components, such as engines, expected the original manufacturer to warranty and support their product when it included PMA'd replacement parts that were installed that didn't meet the designed performance requirements of the original engine (Lycoming, GE, etc). Eventually the PMA system became a little more stringent and PMA'd parts became more like the original design (but not quite).

What this has to do with the NavWorx situation has to do with the way the FAA handles things. If NavWorx knowingly changed their software to broadcast a SIL=3 code with an uncertified unit in order to 'steal' the TIS-B info, well, bad on them. If the FAA changed the protocol on what was originally accepted by the FAA air traffic system without informing the previously approved venders of ADS-B systems and offering them a recourse, then bad on them - and I believe that is what happened here. Why? I don't know, but what if the thousands of certified 'light' aircraft were allowed to use uncertified parts that met the original TSO - via an extension or growth of a part 23 rewrite to meet the 2020 ADS-B mandate? Do you think any pressure could be exerted on FAA in the name of protectionism by certain groups, like, say, GAMA? I don't trust anyone in Washington and neither should you. What they are doing could ruin a small American company, and in the name of what? Safety?? Absolutely not! That has been proven, and they (FAA) proved, or shall I say, approved it. Write to them. It's on the NavWorx website - EASY link to make a comment. Experimental aviation needs to stand up to these kinds of threats.
 
I wonder if a compromise solution that Navworx could change the software to broadcast SIL=1, which would make everyone happy and give Navworx and the FAA 4 years to come to agreement/solution on getting the SIL=3, while the user can still get traffic?
 
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SIL 3 is for certified units, not experimental - I think..... The FAA has a beef with this because even though the internal GPS accuracy meets the TSO accuracy requirements, it's not a certified TSO'd GPS. I could be wrong about this, but that's the way I understand it from what I've read/researched.

If the FAA changed the protocol on what was originally accepted by the FAA air traffic system without informing the previously approved venders of ADS-B systems and offering them a recourse, then bad on them - and I believe that is what happened here.

First and foremost, this AD is for TSO'd units. SIL has nothing to do with certified/not certified. It's all about the demonstrated reliability of the GPS to not transmit a wrong position. There are at least two non-TSO'd vendors sending SIL=3. In this particular case, the unit WAS TSO'd and the FAA still claims it's not SIL=3 capable. You can TSO a SIL=0, SIL=1, SIL=2, or SIL=3 device.

The FAA gave everyone (the public, the vendors) at least 9 months warning of the upcoming change, and engaged the vendors for almost a year before that. They did not change the protocol, they changed how the ground stations reacted to it, and they left the ability for SIL 1,2, and 3 to wake up the ground stations, not just SIL 3. Many vendors did object to the change, but it wasn't like the FAA didn't engage everyone beforehand, and didn't discuss multiple options. There was a specific safety issue with SIL=0 (certified planes couldn't see you AT ALL because of a quirk in the TSO), and that was a primary basis for the change, and the issue the FAA was looking to solve.
 
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I was told by an avionics guru that there are only 3 companies that make the TSO'd GPS chips and they have raised their prices exorbitantly which led Bill to looking for an alternative. Seems like the big players in the avionics universe weren't too keen on Bill's affordable solution.

Seems the aviation business is learning from big Pharma - Pay the Gov't to eliminate your competition for you.

Larry
 
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.

A key difference here is that Garmin and most others are selling TSO'ed units and all parts must be TSO'ed. In essence, they must prove to the FAA that ALL TSO specs are met and receive the FAA stamp of approval.

Last year, the FAA gave makers of experimental units the ability to utilize non-TSO'ed parts inside of a packaged non-TSO product as long as they met the performance specifications outlined in the TSO. Unless Navworx used parts that didn't allow their units to meet the performance spec for SIL=3, they didn't do anything wrong by using non-TSO parts and outputting a SIL=3. You can't compare Navworx to Garmin, as they are selling different products. Unfortunately the FAA didn't publicly state if or how they would police the industry on "meeting the performance spec."

My guess is that the FAA is quietly pulling back on some of the freedom it issued last year in a quiet way. This is likely due to political pressure from the larger players in the certified arena.

Larry
 
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FAA BS

It's absolutely amazing to me that right in the middle of the FAA's push... AKA $500 rebates... to get everyone on board with ADSB they pull something like this and I don't care if they gave everyone 9 months warning. It really looks like they didn't have things all figured out or as some stated, it's the big companies applying some political pressure to make life hard on smaller companies. Navworx puts out a fantastic product for a very reasonable price. Along with minimal install time, it's just a great unit.

After flying with my navworx ADSB a few months I can say it increases safety 1000%. Weather is one thing but with most of my flights local... weather is never much of an issue. Traffic on the other hand, well I never knew there was so much around me and so close too. The FAA changing the rules is a huge step back for lots of people. It took months of research/reading/asking questions/saving money to get ADSB.... and now the threat of having to take it out looms. Unbelievable!

Sorry, needed to vent a little. :-(
 
I wonder if a compromise solution that Navworx could change the software to broadcast SIL=1, which would make everyone happy and give Navworx and the FAA 4 years to come to agreement/solution on getting the SIL=3, while the user can still get traffic?

Except that breaks the rules and is unfair for the rest of the manufacturers that have followed them...
 
Except that breaks the rules and is unfair for the rest of the manufacturers that have followed them...

This is what Dynon is doing with their uncertified GPS source antenna on the Skyview system, I think. My understanding is that when the new certified GPS source is added, then the SIL changes to 3. So not sure if unfair or not. Isnt SIL=1 for uncertified GPS sources?
 
This AD is for a TSO'd unit. From the AD:

If you go further in that paragraph, you find:

NavWorx produces ADS-B units under Technical Standard Order (TSO) C-154c. NavWorx has implemented a design change by revising its software for ADS-B units, Model ADS600-B part number (P/N) 200-0012 and 200-0013 and Model ADS600-EXP P/N 200-8013.

Clearly the proposed AD will affect both the B and the EXP.

What I don't understand here is the FAA's statement that a TSO'ed GPS chip is required. I was under the impression that a year ago, the FAA gave manufacturers the right to use non-TSO'ed components that met the performance requirements of the TSO. They failed to mention that this would require a SIL=0, thereby rendering the product useless in 2020. I have a feeling this a new revelation to unwind what they initially offered.

Larry
 
The location of the GPS antenna on the aircraft can vary from plane to plane, perhaps 10 feet or more. So what difference does it make if the GPS position is accurate to within 10 inches or 10 feet? If a GPS receiver provides a position that is accurate to within 10 cm, but the antenna is located 10 feet off center, the ADS-B location of the aircraft will be 10 feet off. Is that dangerous? ATC usually provides 3 miles or more of separation between aircraft. The accuracy of even the cheapest GPS is a very small fraction of 3 miles. The argument has been made that very accurate GPS is needed for airport taxi operations. Really? What controller would issue taxi instructions that would allow aircraft to miss each other by a few inches?
Shouldn't the mission of the FAA be to improve safety, not to hinder it? It reminds me of a country to our south where the police are ones committing the crimes.
Regulations, that deprive pilots of traffic information and force manufactures to increase prices, do not contribute to safety. They are immoral.
 
Funny that you mention that.. there are transceiver settings related to antenna position (offset from centerline of aircraft) to account for exactly the issue you're mentioning. :) So they already got that covered...
 
As posted above, your ADSB-out is supposed to broadcast wingspan, length, and GPS antenna position when you're on the ground. And in the FAA's vision of the future, no controller will issue ground instructions - a computer will.
Make no mistake, ADSB is all about saving the FAA money, and keeping GA out of the way of the airlines. Traffic and wx are just the 'carrot' to make the 'stick' ($$) seem more palatable.
 
This is what Dynon is doing with their uncertified GPS source antenna on the Skyview system, I think. My understanding is that when the new certified GPS source is added, then the SIL changes to 3. So not sure if unfair or not. Isnt SIL=1 for uncertified GPS sources?

You can earn a TSO for SIL-anything. You can properly test/demonstrate to SIL-anything.

You can't just transmit SIL > 0 without demonstrating or earning the TSO to SIL-1 thru 3 which is what the FAA seems to be complaining about.

As far as I know neither Garmin or Dynon do this.....(output SIL > 0 without following the rules)
 
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I was under the impression that a year ago, the FAA gave manufacturers the right to use non-TSO'ed components that met the performance requirements of the TSO. They failed to mention that this would require a SIL=0, thereby rendering the product useless in 2020. I have a feeling this a new revelation to unwind what they initially offered.

I keep seeing this as an 'impression' but does anyone actually have a source document that says this? It's not private information...it would be in some FAA document/AC/Order somewhere.
 
So, looking at TSO C154c and AC 20-165, the difference between SIL 3 and SIL 0 precision is as outlined in the table from the AC:

AC 20-165

Figure 7. Probability of Exceeding the NIC Containment Radius.

SIL Value
Probability of exceeding the NIC containment radius
3 ≤ 1x10-7 Per Hour or Sample
2 ≤ 1x10-5 Per Hour or Sample
1 ≤ 1x10-3 Per Hour or Sample
0 > 1x10-3 Per Hour or Sample or Unknown


And, it would appear that the manufacturer, by changing the transmitted SIL value from "0" to "3" in the software change, is implying that its non-approved GPS position source has demonstrated that level of precision.

So it would seem that the basic question is whether or not the position source actually has demonstrated that performance requirement as required by the TSO.
 
Has anyone heard anything out of Navworx or FAA lately on status of AD? Any sign of possible resolution or compromise for the 600 EXP units?
 
Has anyone heard anything out of Navworx or FAA lately on status of AD? Any sign of possible resolution or compromise for the 600 EXP units?

Per the Navworx web site:

Currently we are waiting on the resolution of the AD on or about December 20th. Based on the final AD, the AD may be rescinded, or the AD may be modified to allow for just previously approved GPS sources.


I wouldn't expect to hear any updates from Bill until the first of the year.
 
600 EXP units

I too have the exp model. I sent Bill a message on Nov 2nd asking about the exp model since it wasn't mentioned in their letter on their website and received this reply:

"We're working that now in case the EXP stays on the AD , but it shouldn't as it meets the FAA policy and performance requirements for experimental aircraft." Bill Moffitt

I didn't really understand the response because the exp met the performance requirements when it was first placed on the AD list by the FAA!
 
"We're working that now in case the EXP stays on the AD , but it shouldn't as it meets the FAA policy and performance requirements for experimental aircraft." Bill Moffitt

I too do not understand the response. Are the policies and performance requirements different for experimental aircraft vs. certified?

Would sure like to see someone state the facts so I can formulate a response to the AD that is based on fact and not hearsay & guesses. Does Navworx have the supporting information that indicates the TSO requirements have been met? Or the the FAA concluding it does not because a specific GPS chipset was not used.

The recent midair collisions that have made news in recent weeks could have been avoided with a GPS accurate to hundreds of feet. An accuracy of a few feet would not have provided any more useful information to those that perished.
 
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Agree that the information is limited at best to be able to respond to the AD. I would like to respond that the ADS 600 Exp unit should be dropped from the AD due to the fact that the FAA accepted the performance of that unit some time ago as per Navworx,and can be installed on an experimental ,But haven't done that yet due to lack of info.
 
My Navworx AD Response

I am listing my response here and soliciting ALL to submit a comment on the FAA website.

https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=FAA-2016-9226

The National Transportation Safety Board issued a Safety Alert Nov. 15, 2016, to pilots with suggestions on what they can do to reduce their chances of being involved in a midair collision.

SEE and AVOID ONLY GOES SO FAR.

Two recent mid-air collisions exemplify this point. On July 7, 2015, a Cessna 150 and an F-16 Air Force fighter jet on a training mission collided. An air traffic controller advised the F-16 pilot that the Cessna was a potential traffic conflict. The F-16 pilot was not able to visually acquire the Cessna until it was too late to avoid the collision. The two occupants of the Cessna were KILLED; the F-16 pilot ejected and survived. On Aug. 16, 2015, a North American Rockwell Sabreliner inbound for landing a Cessna 172 that was practicing landings at the same airport collided. The four occupants of the Sabreliner and the sole occupant of the Cessna were KILLED.

The Safety Alert highlights the value of traffic avoidance technologies to pilots as an aid to detecting and avoiding other airplanes in flight.

The proposed AD is clearly CONTRARY to this NTSB recommendation. AND is contrary to the desires of the FAA to equip most if not all with ADS-B out. AND is contrary to the NSTB 2017-2018 MOST WANTED LIST. The first listed HERE is to INCREASE IMPLEMENTATION OF COLLISION AVIODANCE TECHNOOGY.

Many have purchased the Navworx ADS-B transceiver because it was listed by the FAA as a unit approved and eligible for the rebate. The proposed AD mandating removal, months after, makes many VERY unhappy. In addition, the cost to the Navworx owner as listed in the proposed AD is in error. The cost to the owner should not only include a reasonable estimate of the A&P removal cost (4 hours at $80/hour) but should also include the cost of a new ADS-B transceiver and its installation costs.

I fly with the Navworx ADS-B transceiver installed. After flying with this equipment for 9 months, it clearly provides me with a very much desired safety margin. I fly in VFR conditions and my experimental aircraft is NOT IFR equipped. FAA?s concern appears to be with the accuracy of the Navworx reported GPS position. I DO NOT, nor do I believe many others need an accuracy of inches or a foot. This is clearly a case where engineers developed a set of specifications and did not use any engineering judgement whatsoever, nor did they consider the multitude variations where the ADS-B out units could be installed. (Certified vs. Experimental, VFR vs. IFR, etc., Light planes vs. those that utilize Class A airspace.)

The FAA must reconsider the ramifications of the proposed AD and either cancel it or revise it. If I am forced to disable and remove the Navworx equipment, the probability of me being involved in a mid-air collision has increased many-fold.
 
Navworx ADSB...comments to FAA

Here are the comments I posted on the FAA site:

"
1. This Proposed rule will decrease MY Safety!! Without the Navworx ADS600 I will be unable to see other traffic.

2. I rely on my unit to spot VFR traffic and it has already avoided several significant traffic conflicts. Without ADS-B readout in the busy airspace I fly (San Francisco Bay Area) my safety and the safety of my passengers is significantly degraded!!!

3. The estimate of this AD costing only $85 is not based in reality. I have over $8000 of parts and labor invested in my adopting the required ADS-B out requirement and it will cost at least $500 to remove the unit and another $500 to reinstall the Navworx assuming they modify it for free. If I have to buy a new unit that's at least $2500 more. So at a minimum, this Proposed rule will cost me $$1,000 hours and at most $11,500.

4. The proposed rule does not quantify the safety risk of continued operation with the subject hardware. I believe it must be very small, so if the proposed rule must move forward, I would suggest a reasonable period of time to comply with the rule...not "remove the hardware immediately". I would suggest 1 year from AD issue?

5. I suggest that the proposed rule address VFR and IFR use separately. I believe the time to reach compliance for "use only in VFR conditions" should be one year as a minimum and maybe should not even apply to VFR only use!"

Bob Cowan
RV-7a, 400 +hrs
 
800 units effected?????

This AD is supposed to affect only 800 aircraft!!! That's a lot of airplanes! One additional thought to consider is this.... That's 800 units alone... there are untold folks flying with the benefit of just the ADSB IN. So, if each of the 800 affected aircraft is always sending a signal to another 3-5 airplanes in their umbrella of coverage then the much truer number is something like an ADDITIONAL 2400 to 4000 aircraft on top of the 800! I understanding this is speculation. I thought of this after a chat with my hanger neighbor who has just ADSB in. Sometimes he's piggybacked on me so if I'm not ADSB out equipped that's me and another plus an unknown amount more affected. Food for thought.
 
This AD is supposed to affect only 800 aircraft!!! That's a lot of airplanes! One additional thought to consider is this.... That's 800 units alone... there are untold folks flying with the benefit of just the ADSB IN. So, if each of the 800 affected aircraft is always sending a signal to another 3-5 airplanes in their umbrella of coverage then the much truer number is something like an ADDITIONAL 2400 to 4000 aircraft on top of the 800! I understanding this is speculation. I thought of this after a chat with my hanger neighbor who has just ADSB in. Sometimes he's piggybacked on me so if I'm not ADSB out equipped that's me and another plus an unknown amount more affected. Food for thought.

Your point is well founded. PLEASE post as an AD comment on the FAA website!
 
Here are the comments I posted on the FAA site:

"
1. This Proposed rule will decrease MY Safety!! Without the Navworx ADS600 I will be unable to see other traffic.

2. I rely on my unit to spot VFR traffic and it has already avoided several significant traffic conflicts. Without ADS-B readout in the busy airspace I fly (San Francisco Bay Area) my safety and the safety of my passengers is significantly degraded!!!

3. The estimate of this AD costing only $85 is not based in reality. I have over $8000 of parts and labor invested in my adopting the required ADS-B out requirement and it will cost at least $500 to remove the unit and another $500 to reinstall the Navworx assuming they modify it for free. If I have to buy a new unit that's at least $2500 more. So at a minimum, this Proposed rule will cost me $$1,000 hours and at most $11,500.

4. The proposed rule does not quantify the safety risk of continued operation with the subject hardware. I believe it must be very small, so if the proposed rule must move forward, I would suggest a reasonable period of time to comply with the rule...not "remove the hardware immediately". I would suggest 1 year from AD issue?

5. I suggest that the proposed rule address VFR and IFR use separately. I believe the time to reach compliance for "use only in VFR conditions" should be one year as a minimum and maybe should not even apply to VFR only use!"

Bob Cowan
RV-7a, 400 +hrs

Where did you get the idea that the FAA cares about your safety? They do not (after all, ADSB-in is not required). What they care about is reducing their costs (eventually eliminating radar) and protecting the airlines from you. So they will never agree to let VFR aircraft use less than "perfect" equipment.
 
I've been trying to get up to speed on the actual argument of this AD and having a ADS600-EXP P/N xxxx 8013 that's specifically named in the AD, I have a horse in this race. Asking all who have this model installed to go back and take a look at the FAA compliance report data on your original install. Looks like page 5 has the meat on it as to accuracy and SIL and SDA which is all the talk of this AD. First of all the report was 100% compliance as per the FAA. But I was interested in just what the accuracy was /is.

Of all the arguments in this AD my ADSB was reporting well within the requirement of TSO that being .05nm or 304 ft called NACp !! it actually was (better than TSO ) under 98.5 feet 100% of the sample both times. 2455 data points on one test and 1780 points on the other it was 100% under the bracket of < 30meters!!!!! ie 100% compliant!!

The SIL level was shown as reporting 2455 data points and 1780 points respectively ( on the two test) at < 1x10-7 which is at a level of SIL=3 interesting to note none at lower levels. ie 100% compliant!!

The SDA was reported again both test at a level 2 100% of the time ie 100 % compliant!!

By Performance Std set in the TSO it appears to me to meets all Performance Standards of the TSO and that are measured by the FAA .

So whats this all about concerning the 600 EXP model. I have no info on the other models.

I would like to see a plot of others data concerning the questionable parameters but it will take someone smarter that me to plot that out correctly. I will volunteer my data if any takers. Its already public knowledge!! At any rate go back and see what your 600EXP was reporting out at I bet you find it is 100% compliant.
 
I've been trying to get up to speed on the actual argument of this AD and having a ADS600-EXP P/N xxxx 8013 that's specifically named in the AD, I have a horse in this race. Asking all who have this model installed to go back and take a look at the FAA compliance report data on your original install. Looks like page 5 has the meat on it as to accuracy and SIL and SDA which is all the talk of this AD. First of all the report was 100% compliance as per the FAA. But I was interested in just what the accuracy was /is.

Of all the arguments in this AD my ADSB was reporting well within the requirement of TSO that being .05nm or 304 ft called NACp !! it actually was (better than TSO ) under 98.5 feet 100% of the sample both times. 2455 data points on one test and 1780 points on the other it was 100% under the bracket of < 30meters!!!!! ie 100% compliant!!

The SIL level was shown as reporting 2455 data points and 1780 points respectively ( on the two test) at < 1x10-7 which is at a level of SIL=3 interesting to note none at lower levels. ie 100% compliant!!

The SDA was reported again both test at a level 2 100% of the time ie 100 % compliant!!

By Performance Std set in the TSO it appears to me to meets all Performance Standards of the TSO and that are measured by the FAA .

So whats this all about concerning the 600 EXP model. I have no info on the other models.

I would like to see a plot of others data concerning the questionable parameters but it will take someone smarter that me to plot that out correctly. I will volunteer my data if any takers. Its already public knowledge!! At any rate go back and see what your 600EXP was reporting out at I bet you find it is 100% compliant.

The problem is that report only spits out what is being transmitted by the unit in question for many of those reporting variables. SIL and SDA for instance are fixed variables that are determined and output by the device. The report just tells you how many of the received packets had that level of SIL/SDA embedded in them.

That report has no idea what the pedigree of your position source or the SDA of the device actually is....
 
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So how or who would be able to measure those values ie SIL and SDA if it's not a measurable value? Assume the horiz boundry numbers are actually the measured performance they are talking about. Then I'm confused on how an installation can demonstrate " MEETS PERFORMANCE" without being TSO d via a pedigree from the mfg.
 
Manufacturer.... they would have to ensure their equipment meets TSO... it doesn't have to be certified, but proper tests need to be done to ensure it meets TSO.... and manufacturer pencil-whipping it is a no-no in FAA's eyes.
 
Manufacturer.... they would have to ensure their equipment meets TSO... it doesn't have to be certified, but proper tests need to be done to ensure it meets TSO.... and manufacturer pencil-whipping it is a no-no in FAA's eyes.

Actually, I think the whole thing is really pencil-whipped, but with much mathematics, statistics and computer simulations behind the pencil.

Source Integrity Level (SIL) indicates the probability of the reported horizontal position exceeding the containment radius defined by the NIC on a per sample or per hour basis, as defined in TSO-C166b and TSO-C154c.

System Design Assurance (SDA) indicates the probability of an aircraft malfunction causing false or misleading information to be transmitted, as defined in TSO-C166b and TSO-C154c.


I think the above are actually calculations based on some measurements rather than a measured value, after all they are just probabilities. :)
 
FAA Emergency order suspends -012, -013

Just in directly from the FAA

Interesting - doesn't mention the -EXP units - which if I understand correctly contain the same GPS hardware as the -012 and -013 units.
 
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