Aviation Industry Says Ligado Concerns Are Far From Settled

Ligado's plans to protect certified aviation GPS receivers from interference still leave helicopter navigation in potential interference danger, said aviation and aerospace representatives. In a meeting with FCC officials, they said results of a Radio Technical Commission for Aeronautics review of Ligado-conducted studies about possible interference to those GPS receivers were inconclusive and incomplete. They urged looking at the yet-to-be-released Department of Transportation Adjacent Band Compatibility assessment of the possible impact of Ligado handsets on precision and other noncertified GPS handsets. They said they share Iridium concerns (see 1703280064) that Ligado's ancillary terrestrial component handsets could bring out-of-band interference to satellite communications and said Inmarsat's system could be similarly affected. The aviation interests said the cost of retrofitting aircraft with new satcom receivers would be immense, and who would pay for such a retrofit isn't an issue Ligado raised. A filing posted Wednesday in docket 11-109 recapped the meeting. Participants included the Aerospace Industries Association, Airlines for America, Aviation Spectrum Resources and Helicopter Association International and representatives from the Wireless, International and Public Safety and Homeland Security bureaus and Office of Engineering and Technology. Ligado didn't comment.