Senator Maria Cantwell has expressed concerns over a new spectrum auction proposal by Senate Republicans, citing potential risks to aviation safety and national security. The proposal, released on June 5, 2025, mandates the Federal Communications Commission (FCC) to auction at least 100 MHz of spectrum in the upper C-Band within two years. This band is adjacent to frequencies used by aircraft altimeters.
Cantwell highlighted previous issues when the Trump administration auctioned the lower C-Band, which led to significant concerns from the Federal Aviation Administration (FAA) about possible interference with aircraft operations. These concerns were so severe that they nearly resulted in grounding flights across the United States in early 2022.
"At a moment when maintaining safe skies has never been more challenging, this proposal recklessly endangers national security and aviation safety by mandating spectrum auctions in the C-Band before new altimeter standards are even finalized," said Sen. Cantwell. She further criticized the lack of resources allocated for updating vulnerable altimeters on Department of Defense and government aircraft.
Cantwell warned that rushing into these auctions without addressing safety upgrades could lead to serious consequences similar to past issues with 5G C-band implementation but with potentially broader impacts involving military operations.
