A coalition of aviation stakeholders continued to step up its opposition to Ligado Networks' plans for a high-speed 5G nationwide cellular network through bands that have been used for aviation communications, sending another filing to the Federal Communications Commission (FCC) citing a “real threat of harmful interference.” The filing follows a petition the 10 organizations submitted last month urging the FCC to reconsider its approval to enable Ligado to move forward with its cellular network.

Ligado had responded to that petition, saying the FCC approval followed an “extraordinary 17-year-old proceeding. Presented with a compelling and unique opportunity to maximize mid-band spectrum that raised questions about impact on a small percentage of GPS devices, the commission carefully and methodically worked through the complex technical issues presented in the record.”

The company, formerly known as LightSquared, added that its effort has garnered support from the administration, Congress, and industry, and said the aviation stakeholder’s arguments “do nothing to cast doubt on this conclusion. Rather, [the] petitioners rehash arguments that the [FCC] order thoroughly considered and rejected. Petitioners’ arguments are wrong on the merits.”

In the subsequent filing, the stakeholders, however, disputed Ligado’s contentions, saying the company seeks to downplay the expertise of the aviation stakeholders and adding that the aviation community offers ample reason to halt the FCC approval.

“The oppositions filed by Ligado and its hired allies repeatedly resort to mischaracterization of the petition, the order, the FAA’s own analysis that the order is fundamentally based upon, and the record,” the groups said. “More troubling, the oppositions further illustrate the inadequacy of the order’s conditions to address the harmful interference that Ligado’s planned deployments will cause GPS receivers and [satcom] terminals.”

“We continue to emphasize that all parties in the nation’s aviation system, including general aviation, rely heavily on GPS—more so than just a decade ago—and we must challenge even the slightest compromise to the safety of GPS communications,” said Heidi Williams, NBAA director for air traffic services and infrastructure, of the effort to halt the Ligado plans. “It is unfortunate that with its latest filing, Ligado has chosen to simply overlook the legitimate concerns about the company’s plans, instead of drawing from our coalition’s expertise to ensure the continued safety and integrity of operations in the nation’s airspace.”