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-   -   Possible AD for certain NAVWORX ADS-B Units (https://vansairforce.net/community/showthread.php?t=142967)

rzbill 10-22-2016 05:10 AM

Quote:

Originally Posted by maus92 (Post 1120699)
Its internal GPS hardware does not and can not meet the specs of the TSO C-154c..

What are you basing that statement on? Technical knowledge of the equipment or the FAA statements that are being challenged by Navworks?

If it is technical knowledge, please share.

EDIT **** Just checked mine and it is a 200-0112 which is OK per the proposed AD. I guess that justifies the extra bucks that I was internally whining about after the prices dropped significantly.

Radomir 10-22-2016 10:55 AM

From navworx statement:

"FAA certified our products 3 years ago. At that time our testing demonstrated that the products? GPS module met 91.227(c) integrity. Nevertheless, the FAA required that we output at an integrity level lower than our testing demonstrated. " (bold mine)


So how many customers bought this unit thinking they are 2020 compliant? Was it advertised so? Was it disclosed to buyers that they are buying a non-compliant unit? (if you're not emitting SIL=3 you're not compliant).... and most importantly, YES a unit can be certified with SIL=0... it'd be completely useless for 2020 compliance, but it would be certified :) And, NO you cannot certify with SIL=0, then switch to SIL=3 via software update as "minor modification" down the road. That doesn't fly with the FAA (and it did not in this case).

az_gila 10-22-2016 11:34 AM

Demonstrate vs Calculate
 
Quote:

Originally Posted by Radomir (Post 1120907)
From navworx statement:

"FAA certified our products 3 years ago. At that time our testing demonstrated that the products’ GPS module met 91.227(c) integrity. Nevertheless, the FAA required that we output at an integrity level lower than our testing demonstrated. " (bold mine)


.....

Definition..

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.

IIRC from the Dynon discussion when they introduced the GPS2020 the SIL is a number that is calculated, rather than "demonstrated" and also, if my memory is still OK, Dynon said there were only a few people around that had the skills to do this calculation.

I wonder if this is actually what caused the problem.

MartySantic 10-22-2016 02:06 PM

Sure would be nice if Bill at Navworx or Neil (AllThumbs) would respond here on VAF and let the RV community know what is REALLY happening.

maus92 10-22-2016 05:45 PM

Quote:

Originally Posted by rzbill (Post 1120827)
What are you basing that statement on? Technical knowledge of the equipment or the FAA statements that are being challenged by Navworks?

If it is technical knowledge, please share.

EDIT **** Just checked mine and it is a 200-0112 which is OK per the proposed AD. I guess that justifies the extra bucks that I was internally whining about after the prices dropped significantly.

I'll share anyway: I based my statement on my ability to read the public notice of the proposed AD and certain legal training. I have no direct knowledge of the technical work performed by the manufacturer to show its "equipment maintains an equivalent level of safety" as described in TSO-C154c and related standards documents described within the order. Nor do I know why the FAA now considers the original deviation work performed by the manufacturer to be invalid in light of a software revision, other than what is mentioned in the NPRM. However, based on earlier discussions on this board, and guidance from Garmin, the ability to produce and demonstrate equipment that meets the MPS of TSO-C154c is a complex undertaking.

NM Doug 10-22-2016 08:07 PM

Quote:

Originally Posted by MartySantic (Post 1120935)
Sure would be nice if Bill at Navworx or Neil (AllThumbs) would respond here on VAF and let the RV community know what is REALLY happening.

It may be that having lawyers involved (as was mentioned earlier in the thread) will really slow down (put on hold?) Navworx-customer communication on the issue. I'm in the proposed AD's EXP boat, having recently installed the unit with several hours' help from an A&P, so I'm anxious to hear what the remedy will be...but am also "on standby" as flightlogic aptly puts it.

roadrunner20 10-22-2016 08:33 PM

FWIW, I was an early adopter and have been flying with my unit since last Oct.
I am very satisfied with all it's operations.

ADS600-EXP
SN:150643
PN:200-8013-01-01

My compliance report in Nov/2015 reported SIL=3.

Let's see what happens. I'm sure Bill will make it right. From what I understand, the TSO compliance was not an easy task.

Paul 5r4 10-22-2016 09:33 PM

Navworx
 
I tried several times yesterday to reach navworx by phone. It was no surprise that it went straight to their voicemail each time. As per the Navworx statement regarding the AD, I'd like to contact the FAA supporting my unit and Navworx. I really don't know what to say though. What have others said? I am a VERY satisfied navworx customer and my unit seems to function flawlessly. I don't really understand the SIL thing but what I've read it's the possible error in the horizontal plane. I'm wondering what that means. Are they talking a few feet or several hundred or is it strictly the number of times of a potential error per hour?

BobTurner 10-22-2016 09:53 PM

Quote:

Originally Posted by Paul 5r4 (Post 1120999)
I tried several times yesterday to reach navworx by phone. It was no surprise that it went straight to their voicemail each time. As per the Navworx statement regarding the AD, I'd like to contact the FAA supporting my unit and Navworx. I really don't know what to say though. What have others said? I am a VERY satisfied navworx customer and my unit seems to function flawlessly. I don't really understand the SIL thing but what I've read it's the possible error in the horizontal plane. I'm wondering what that means. Are they talking a few feet or several hundred or is it strictly the number of times of a potential error per hour?

They're talking a few feet. What happened is the FAA spec guys were allowed to run wild. One new application of ADSB-out is to automate ground control. That's why wingspan is included in the data. To make sure large aircraft on adjacent taxiways don't clip wings, you need very good accuracy.

BigJohn 10-23-2016 06:44 AM

Quote:

Originally Posted by MartySantic (Post 1120935)
Sure would be nice if Bill at Navworx or Neil (AllThumbs) would respond here on VAF and let the RV community know what is REALLY happening.

Hi Marty. For once my procrastination in ordering the Navworx box paid off! This situation didnt come about overnight, and although Im sure there is a lot of scambling going on right now it won't get solved overnight. (Keep in mind there are lawyers involved.) Just hope that whatever the resolution to the situation turns out to be Navworx can suvive it and stay in business.


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