Story ID: 
ADS-B Gets Green Light from the FAA
By: Chad Trautvetter
Caption: Following successful ADS-B deployment at key sites in the U.S., the FAA  gave the go-ahead for the system’s national rollout, with coast-to-coast  U.S.
Word Count: 144
Following successful ADS-B deployment at key sites in the U.S., the FAA  gave the go-ahead for the system’s national rollout, with coast-to-coast  U.S. coverage forecast in 2013. The agency’s announcement also stated  that wide-area multilateration (Wam) “will serve as a backup to ADS-B in  the event of a GPS outage in high-value ­airspace.” Puzzlingly,  however, the FAA has an expert panel currently examining GPS backups,  with its recommendations still to be made, while the ­agency’s final ADS-B rule  in May downplayed Wam as a backup candidate. Possibly, this is a  pre-emptive FAA strike, following continuing concerns of the Government  Accountability Office in September that the Department of Defense cannot  be certain the GPS constellation will always provide adequate civil  coverage before 2018. The expert panel’s recommended solutions might  also not be widely available commercially to counter any early GPS  outages.