A coalition of 11 general aviation advocacy groups have expressed concern over the potential impact to satellite-based global positioning system (GPS) navigation capabilities 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.
The Federal Communications Commission (FCC) ultimately denied LightSquared’s plans in February 2012, following a strong chorus of opposition from the aviation industry, including the industrywide Coalition to Save Our GPS.
Ligado claims it has since limited GPS signal disruptions to within a 500′ diameter around transmission towers, which the company maintains should mitigate interference concerns.
However, the aviation groups noted those assertions have not been validated through evaluation of various operational scenarios by the FCC and FAA, adding “significant safety concerns still have not been addressed,” in a letter sent to the FAA.
“We fully recognize the value that robust connectivity systems offer during aviation operations,” reads the June 15 letter to FAA Acting Administrator Dan Elwell. “However, we cannot ignore the risk potential that the Ligado Networks proposal presents to aviation operations.”
Heidi Williams, director for air traffic services and infrastructure for the National Business Aviation Association, emphasized the importance of GPS navigation not only for pilots, but to the entirety of FAA’s NextGen air transportation system.
“Despite offering several benefits to operators, such as the potential for enhanced communications and flight tracking, it would be irresponsible to deploy Ligado’s proposed network without clear and indisputable third-party validation that it does not interfere with GPS,” she continued. “The potential for harmful consequences to pilots, passengers and citizens is simply too great.”
Besides officials with NBAA, other advocacy groups signing the letter include the Air Line Pilots Association (ALPA), Airborne Public Safety Association (APSA), Aircraft Owners and Pilots Association (AOPA), Airlines for America (A4A), Association of Air Medical Services (AAMS), Helicopter Association International (HAI), Helicopter Safety Advisory Conference (HSAC), National Agricultural Aviation Association (NAAA), National EMS Pilots Association, and the Professional Helicopter Pilots Association (PHPA).