A cross-section of aviation organizations is appealing to the U.S. Federal Communications Commission (FCC) to reconsider its approval for Ligado Networks to move forward with a high-speed broadband cellular network, saying the proposed use of frequency bands near those used by GPS and satellite communications networks puts “air safety and aviation operations at risk.”

In a May 22 petition to the FCC, 10 organizations said the FCC order of approval on April 20 failed to address numerous concerns, including Ligado’s ability to act as a “good neighbor” without interfering with other frequencies.

“The order ignores the large body of evidence the aviation community provided showing that FAA-certified GPS devices would be regularly used in close proximity to Ligado base stations,” the petitioners said and further objected to the lack of public review of the draft order before the FCC decision.

In addition, the organizations further questioned the FCC’s decision to leave it up to Ligado and Inmarsat to resolve the need for measures to protect satcom from interference, including the development of terms for a retrofit for aircraft equipped with Inmarsat satcom. “The order’s encouragement of Ligado and Iridium to keep talking hardly passes for sound spectrum management and a similarly-flawed response to demonstrated interference concerns,” they stated. “The order’s inadequate treatment of the satcom issues amounts to the Commission adopting no protective measures whatsoever.”

Potential for interference from Ligado will endanger life and property, they said, adding, “The Commission should resolve this matter promptly, before Ligado is permitted to deploy and operate its terrestrial network under the flawed operational and technical parameters adopted by the order.”

NBAA noted that the approval comes as Ligado —formerly known as LightSquared—previously failed twice to win approval for deployment of the low-power 5G network. Ligado has stated it has limited GPS signal transmissions to nearby transmission towers, but NBAA fears this is not enough.

“Given our National Airspace System’s extensive use of GPS, including ADS-B-enabled air traffic control services and GPS-supported terrain warning systems, any question of even the slightest risk of interference should have been enough to pause this approval process,” said NBAA COO Steve Brown. “We believe the FCC should promptly reconsider its order and the methods by which it was granted.”