FAA notes compliance exceptions for ADS-B airspace

The policy statement, published in the Federal Register July 3, does not offer blanket absolution for failing to comply with ADS-B equipage and performance requirements. It spells out a clear framework for forgiveness, making it clear that operators who are notified of “consistent and repeated” noncompliance should not expect a free ride.

To be considered not responsible for a degradation of GPS performance that violates the ADS-B rule, the aircraft operator must have “exercised appropriate due diligence prior to conducting an operation.”

Operators who encounter GPS interference—a focus of AOPA advocacy efforts to mitigate the flight-safety risk—would not be held responsible for a GPS performance failure resulting in noncompliance.

The FAA added that an aircraft operator should proceed with a proposed flight if a planned GPS-interference event would be the only expected impediment to complying, noting that “requiring operators to avoid the affected area would cause significant disruption to air traffic in that vicinity. Furthermore, there is no guarantee that these operators would experience actual interference and a degradation in GPS performance in the area.” If signal degradation did occur, the aircraft’s broadcast data would notify air traffic control, which would control the aircraft using a “backup strategy.”

Additional guidance is published in the July 18 edition of the Notices to Airmen Publication.

AOPA has vigorously advocated for relief from the widespread and increasing planned GPS-interference events that are a necessary part of military training but often affect vast areas of navigable airspace. While the FAA and the military investigate solutions to the loss-of-navigation-signal hazard for general aviation, AOPA has advised GA pilots that as a stopgap measure when an in-flight loss of GPS reception degrades flight safety, the pilot in command should notify ATC to “Stop buzzer,” a phrase used to immediately halt a GPS interference activity. A pilot invoking “Stop buzzer” should first ascertain that it is the GPS signal, not on-board equipment, that has faltered, even though this takes time and taxes pilot workload.

The FAA also addressed the case of transport-category operators who are required to use the FAA-developed Service Availability Prediction Tool (SAPT) to verify compliance before flight, and affirmed that if an operator confirmed availability of ADS-B in preflight with SAPT, a deterioration of ADS-B performance would not result in enforcement action.

SAPT is “a preflight availability prediction tool, developed by the FAA, that predicts the ability of an aircraft to meet the requirements of § 91.227(c)(1)(i) and (iii) along a given route of flight.” The prediction is based on the functioning of the aircraft’s position source and is “primarily intended for pilots, dispatchers, and commercial operators to verify their predicted surveillance availability before flight and ensure compliance with the ADS-B Out rule,” the document said. The SAPT information is primarily for commercial operators who have equipped with ADS-B but have not yet upgraded their position source.

Because some transport-category aircraft with older equipment won’t have receivers capable of meeting the rule requirements in all technical scenarios until closer to the year 2020, the FAA granted a limited exemption requested by Airlines for America from some performance requirements “to provide additional time for suitable receivers to be made available.”

General aviation ADS-B compliant installations are up-to-date and include Wide Area Augmentation System (WAAS) technology. General aviation operators are not required to conduct preflight service predictions for ADS-B, Duke said.