14 CFR 91.225: Automatic Dependent Surveillance-Broadcast Out Equipment and Use

An Automatic Dependent Surveillance-Broadcast system, commonly known as ADS-B, is a system that continuously reports aircraft positional data to Air Traffic Control (ATC) ground stations and to other aircraft (FAA, 2021). This system complements ATC aircraft tracking radar systems and provides direct altitude and positional deconfliction with other aircraft. It’s very useful in areas with no ATC coverage, like on oceanic routes, by providing aircraft situational awareness on other aircraft’s positions flying in the area.

 

The requirement for aircraft to have an ADS-B system installed is mandated by 14 CFR 91.225. After January 1^st, 2020, this law states that no person may operate an aircraft without an ADS-B system under the following conditions (eCFR, 2021):

·      Flying in Class A airspace.

·      Under 18,000 feet MSL in Class B and C airspace areas.

·      Within 30 nautical miles of a Class B airport.

·      Class E airspace within the 48 contiguous states and the District of Columbia at and above 10,000 feet MSL, excluding the airspace at and below 2,500 feet above the surface.

·      Class E airspace at and above 3,000 feet MSL over the Gulf of Mexico from the coastline of the United States out to 12 nautical miles.

 

This law further states that the ADS-B system must be operating in transmit mode at all times unless (eCFR, 2021):

·      Aircraft approved by the Federal Aviation Administration (FAA) performing national defense, homeland security, intelligence, or law enforcement duties.

·      When told by ATC that ADS-B transmission data would jeopardize the safe execution of air traffic control functions. 

(Courtesy of: http://www.ads-b.com)

References:

 

eCFR. (2021). Code of Federal Regulations: 14 CFR 91.225.

https://www.ecfr.gov/current/title-14/chapter-I/subchapter-F/part-91/subpart-C/section-  91.225

 

FAA. (2021). Equip ADS-B.

            https://www.faa.gov/nextgen/equipadsb/