The FAA has endorsed use of the Iridium satellite data service for air traffic control (ATC) communications in oceanic airspace, providing airlines and business jet operators with what is considered a low-cost solution for Future Air Navigation System (FANS) datalink messaging.
The FAA will no longer restrict FANS-over-Iridium (FOI) capability, following the recommendations of a Performance-based Operations Aviation Rulemaking Committee (PARC). After gathering data from a year-long series of field trials involving Cargolux Boeing 747-400 freighters, Continental Micronesia 737s and Delta 737/757s equipped with Iridium datalink transceivers, the PARC concluded that Iridium meets speed, reliability and service requirements for ATC communications. FAA has adopted an International Civil Aviation Organization (ICAO) Global Operational Datalink Document as guidance.
Iridium voice and data communications have been available for aeronautical operational control (AOC) communications between an aircraft and its airline, but could not previously be used for ATC communications, also known as air traffic services (ATS). The options for ATS in oceanic airspace have been Inmarsat satellite communications and high-frequency (HF) radio via service providers Arinc and SITA. The FANS 1/A system, which supports controller-pilot datalink communications and automatic dependent surveillance-contract (ADS-C) position reports downlinked by aircraft, uses primarily Inmarsat.
Iridium installations are lower cost and lighter weight than Inmarsat broadband systems, and draw less power. Iridium’s 66 low-earth-orbit satellites provide coverage of polar regions used by airlines for long-haul flights; Inmarsat’s constellation does not. Aircraft outfitted with FANS 1/A systems are also exempt from Europe’s Link 2000+ mandate, which is based on a different, VDL Mode 2 datalink.
For the PARC field trials, the International Communications Group (ICG) of Newport News, Virginia, provided Cargolux and Delta with its NxtLink ICS-220A device, combining a data modem and two voice/data transceivers. Continental Micronesia aircraft were fitted with Iridium equipment from Avionica of Miami.
“If you look at the price of an Iridium installation, it’s about half that of an HF radio installation and about less than a quarter that of an Inmarsat Aero H+ system,” said Armin Jabs, ICG’s chief operations officer. “It has all of the advantages of cost, coverage, services. I guess conservatively, the [retrofit] market could be as much as 10,000 aircraft.” He said airframers have initiatives under way to offer Iridium systems as a forward-fit option by around 2013 for both wide- and narrowbody aircraft.