July 9, 2019
The FAA recently clarified its policies related to ADS-B equipped aircraft after Jan. 1, 2020.
Circumstances outside of an operator’s control may result in a temporary degradation of ADS-B performance and apparent violation of §91.227, and the agency provided a number of scenarios in which an operator may experience service availability disruptions, but not be considered in violation.
“The FAA’s published policy is a common-sense approach to compliance in instances of GPS performance degradation,” said Heidi Williams, NBAA’s director of air traffic services and infrastructure. “The FAA requires operators to conduct due diligence to ensure compliance, however the agency acknowledges there may occasionally be circumstances beyond an operator’s control which technically make a flight noncompliant with the requirements of 91.227.”
Operators are expected to use the FAA’s ADS-B Service Availability Prediction Tool (SAPT), a prediction tool that anticipates the ability of an aircraft to meet the requirements of §91.227 during a particular flight. In general, most business aircraft operators should use the FAA’s SAPT not more than 24 hours prior to the planned departure. If an operator confirms ADS-B service availability using SAPT within 24 hours of the planned departure but later learns before departure through a NOTAM or other means that service might not be available, the operator is responsible for determining another route or means to ensure service.
However, if an operator confirms through SAPT and NOTAMs that service should be available and then service is unexpectedly not available, the operator will not be considered noncompliant. Operators will not be held responsible for changes to intended route after clearance if that changed route is in airspace with a service disruption.
Operators are also not strictly prohibited from launching into airspace where there is a potential for a planned GPS interference event if due diligence in checking SAPT and there is no prediction of a GPS outage or degradation expected. In many planned GPS interference events, GPS outages are not operationally experienced which lead the FAA to take a common sense approach when planned GPS Interference events are scheduled.
Finally, operators may begin flights in the unlikely event of a SAPT outage, which will be announced by the FAA through issuance of a NOTAM.
The FAA recognizes these certain events, as outlined in the policy notice, are outside the operator’s control and will not consider these events to constitute noncompliance with §91.227. NBAA will be doing additional education and outreach on the SAPT tool.