Draft:Self-Sustaining Outlet

A Self-Sustaining Outlet is an FAA communications facility that provides VHF air-ground communications between air traffic controllers and pilots in remote, otherwise uncovered areas that are not served by commercial power and telephone facilities. There are over 80 of these facilities in Alaska, often on mountain tops.

The program began in the 1960s; the Self-Sustaining Outlet Replacement Program, which began in 1998 and was completed in July 2021, updated 14 locations with modern facilities.

An SSO facility consists of a "high site", a base station, and a controlling station.



The high site is typically located on a mountaintop and communicates with aircraft via VHF radio. It consists of a 7-foot base diameter cylindrical fiberglass building weighing 1500 pounds, typically painted green. This contains radio equipment and power equipment including batteries. Outside are two 4-panel solar arrays to continuously recharge the batteries. The high site equipment is usually delivered by helicopter.

The high site is linked by line-of-sight UHF radio to a base station, located at the base of the mountain where land-based telecommunications services are available.

The base station is hard-wired (connected via leased cable or 4-wire to the controlling station, carrying audio data and push-to-talk control signals. The controlling station is located near the aircraft facility being serviced, typically an Automated Flight Service Station.