A group of 11 aviation organizations, including NBAA, HAI, and AOPA, have expressed concern about potential GPS navigation signal interference from a proposed broadband cellular communications network operating within frequency bands currently used by GPS. A prior attempt to implement a high-speed nationwide cellular network by Ligado Networks, formerly known as LightSquared, revealed signals from its cellular towers significantly disrupted aircraft navigation systems.
Thus, the U.S. Federal Communications Commission denied LightSquared's plans in February 2012, following strong opposition from the aviation industry, including NBAA and the industry-wide Coalition to Save Our GPS.
Ligado now claims it has limited GPS signal disruptions to within a 500-foot diameter around transmission towers, which the company claims should mitigate interference concerns. However, the aviation groups said, this has not been validated through evaluation of various operational scenarios by the FCC and FAA, nor have significant safety concerns yet been addressed.
“We fully recognize the value that robust connectivity systems offer during aviation operations,” the coalition said a letter to FAA Acting Administrator Dan Elwell. “However, we cannot ignore the risk potential that the Ligado Networks proposal presents to aviation operations.”