The FAA issued a technical amendment to the automatic dependent surveillance-broadcast (ADS-B) Out performance requirements to support air traffic control (ATC) service, correcting a final rule published on May 28, 2010. In that rule, the FAA amended its regulations by adding equipage requirements and performance standards for ADS-B Out avionics on aircraft operating in Class A, B, and C airspace, as well as other specified classes of airspace within the U.S. National Airspace System (NAS).

In the final rule, the FAA established FAR 91.225, which provides the ADS-B equipment requirements necessary to operate in certain classes of airspace effective Jan. 1, 2020. In reviewing those paragraphs, the FAA noted that the regulatory text implies that the equipment must meet all the requirements of the referenced TSOs. As the ADS-B Out rule is a performance-based rule, it was not the FAA's intent to arguably limit operators to only install equipment marked with a TSO in accordance with 14 CFR Part 21, subpart O. The FAA's intent was to permit equipment that meets the performance requirements set forth in the referenced TSOs.

In this week's NPRM, the FAA proposed in FAR 91.225(a)(1) and (c)(1) that the equipment installed "meets the performance requirements in TSO-C-166a" (72 FR 56947, 56971)." The inadvertent removal of the word "performance" in the paragraphs implementing these provisions in the final rule was in error and resulted in confusion as to whether the regulation permits other than equipment marked with a TSO, provided that equipment meets the specified performance requirements. Therefore, the technical amendment states that aircraft must feature equipment that meet the necessary performance requirements but not the actual type certification requirements of the TSO.