FAA Declares ADS-B Unairworthy
NavWorx Resisting Cooperation with FAA
The FAA has issued an Airworthiness Directive which proposes to terminate the use and installation of ADS-B transceivers manufactured by a specific company. The product at issue was heavily advertised as an “affordable” solution to the FAA’s requirement for installation. This is a significant action in two dimensions—in the FAA’s achieving its full NextGen coverage and as a matter of airworthiness directive processing by a TSOA holder.
First, by pulling the NavWorx unit’s TSOA status, the FAA is announcing its intention to remove one of the low-cost options in its critical NextGen implementation schedule.
ADS-B may be the cornerstone to most of the NextGen operational benefits; so much so that the FAA describes it as:
“ADS-B is transforming all segments of aviation. Real-time precision, shared situational awareness, advanced applications for pilots and controllers alike – these are the hallmarks of ADS-B NextGen surveillance.”
It is such an essential aspect of this transformative ATC technology that the FAA has issued a mandate of 01/01/2020 for equipage of the ADS-Out units as a predicate for flying into airspace. The efficiencies and safety which justify the expenditure of billions of taxpayer dollars on NextGen DEPEND on the installation of these instruments.
The GA aircraft owners, who are the customers for the NavWorx products, are concerned about the cost of purchasing these units. The FAA is so concerned about this segment’s compliance with the mandate that it has issued an exemption policy to reduce the burden on these aircrafts’ owners and established a REBATE offer in which the FAA would reimburse the purchasers with FAA’s budgeted funds.
Given these considerations, the issuance of the AD indicates that the FAA has very strong concerns about this company’s transponder. There are aircraft operating today using the NavWorx units, customers who have purchased this company’s product for near term installation and prospective purchasers who considered the price point as an attractive feature. All three of these categories of GA owners who have heretofore relied on this specific model now must seek other options.
The second significant aspect of this AD proceeding is the company’s baffling response to the airworthiness allegations. Refusal of entry to the inspectors and unwillingness to be proactive with the agency by NavWorx are not conducive to resolution with the FAA. The company seems to have ignored that the federal aviation safety organization holds the sole power to issue or withdraw a TSOA.
The FAA first issued an unapproved part warning as to NavWorx Inc. model ADS600-B remote-mounted universal access transceivers (UATs) and then to the more formal action of issuing Federal Register notice stating:
“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…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 [Source Integrity Level] of 0. The software revision (version 4.0.6) resulted in the units broadcasting a SIL of 3. This design change was not approved by the FAA and rendered the units noncompliant with TSO-C154c. Because the ADS-B unit incorrectly broadcasts a SIL of 3 instead of 0, the unit could communicate unreliable position information to ATC and nearby aircraft, resulting in an aircraft collision.”
Those are very serious allegations which would ordinarily cause the company to which this AD was directed to seek a meeting with the FAA to resolve the technical criticisms expressed. A simple explanation of why the FAA’s stated problems are incorrect would result in the FAA’s withdrawal of the AD.
Instead NavWorx, according to the FAA, “declined on repeated occasions to allow FAA personnel to conduct the required inspections. The suspension is immediate and will remain in effect until NavWorx consents to the inspections and demonstrates compliance with FAA standards.” That posture basically escalated the matter to the formal AD process.
In response NavWorx posted a statement on its website in part which asserts:
“The FAA has never shared with us any instance of our units doing so, there is no support for this claim in the docket, and we are unaware of any unit doing so. In fact, for two and a half years the FAA had no problem with the ability of our units to correctly communicate the position of aircraft with the units.”
The FAA says that the Model ADS600-B part number (P/N) 200-0012 and 200-0013 and Model ADS600-EXP P/N 200-8013 are emitting the wrong signal. That is something which would appear to be easily resolvable in a demonstration of a production unit.
The FAA specifically stated that “during the suspension, NavWorx may not mark or otherwise indicate that its ADS600-B units meet FAA standards.” The company continues to advertise the ADS600-B unit on its website as of 11/28/2016 with the heading that it is TSO “certified.” That action, or inaction, does not appear to demonstrate that the company sees compliance with FAA orders to be a priority.
It is unfortunate that NavWorx has decided the path of greatest resistance in establishing the airworthiness with a product of such great importance to NextGen.
Tune in to learn about the future transmissions.
Press Release – FAA Suspends Approval of Certain NavWorx ADS-B UnitsShare this article: