As we reported in the January 2017 Aviation Consumer, the model ADS600-B ADS-B In/Out transceiver from NavWorx was hit with an AD (airworthiness directive) and an unapproved parts notification that forced owners to have their systems removed, and shops and distributors to shelve the products in their inventory. Affecting nearly 600 systems in the field, it was the first ADS-B product hit with an AD.
If you own one of these ADS600-B/EXP-series systems (part numbers 200-0012, 200-0013 and 200-8013), NavWorx has a solution with the second-gen ADS600-B 2.0 product. But as we go to press, the new 2.0 transceiver isn’t approved for installation in certified aircraft.
New GPS Required
The good news is that existing ADS600-B systems might not forever remain proverbial paperweights. To recap, the FAA AD (link to it at tinyurl.com/ydgbopxm) for these first-gen systems centers around the transceiver’s internal WAAS GPS receiver, which the agency determined wasn’t certified per the governing TSO C-154c specification. Moreover, it declared that NavWorx made an unapproved software revision to some units (altering the system integrity level, or SIL) that could communicate unreliable position data to other aircraft and to ADS-B radar.
With pressure from AOPA and consumers to further explain its claims, the FAA said in the AD that it is concerned with the transceiver’s SiRF IV GPS receiver’s integrity—rather than its accuracy—because it doesn’t have fault detection and exclusion capability. According to the AD, this is significant in the event of “signal-in-space error or satellite signal failure.” Incorrectly reporting its own position by 0.2 nautical miles or more can result in incorrect ATC separation instructions and traffic advisories. Incidentally, 0.2 nautical miles is the minimum integrity containment radius around the aircraft’s reported position that’s required in FAR 91.227 ADS-B position reporting criteria.
Worth mentioning is that there have been no reported cases of a collision or safety incident resulting from an incorrect ADS-B transmission from ADS600-B-equipped aircraft. And, flight tests have been made with the system resulting in satisfactory ADS-B performance monitor reports from the FAA.
Real-world technical matters aside, the FAA refused to process all of the $500 rebate reservations submitted by ADS600-B customers and issued a strong warning saying in part that “you may be subject to civil or criminal penalties for any knowing and willful misrepresentation in the reservation request, or in any other matter or representation related to the reservation,” in an email correspondence sent to some customers. The agency did go on to say it would extend the rebate reservation for those who plan to buy a qualifying system. The replacement system can be other brands (there are plenty of other options), the current NavWorx ADS600-B 2.0 or even older systems that have been upgraded to 2.0 status. By the time you read this, the Sept. 17, 2017, deadline for submitting a new rebate reservation will have passed.
The NavWorx upgrade won’t come without a cost, which will depend on the serial number of the ADS600-B/EX product. NavWorx told us that basically any system sold prior to 2016 will cost $500 to upgrade to an ADS600-B 2.0 version and the upgrade for ones that were sold during 2016 are priced at $399. The transceiver will need to go back to NavWorx and a replacement WAAS receiver will be installed.
Dallas Avionics is the primary NavWorx sales distributor and has a procedure in place for sending systems in for upgrade. NavWorx CEO Bill Moffitt told us new ADS600-B 2.0 systems aren’t yet approved for installation in certified aircraft because the FAA hasn’t issued a TSO or approved the STC manual. Moffitt said the company has applied for a global AMOC (alternate method of compliance) for the AD and the ADS600-B 2.0 uses the same proven WAAS GPS module that has been flying in over 1000 experimental aircraft.
Contact the company at www.navworx.com and 888-628-9679.