WASHINGTON (Reuters) -A senior U.S. House lawmaker on Monday urged the Federal Communications Commission (FCC) to delay the auction of portions of a key spectrum band, warning it could impact a nearby aviation frequency band. House Committee on Transportation and Infrastructure Chair Peter DeFazio urged a delay in the auction of C-Band spectrum that starts Tuesday over concerns it could jeopardize aviation safety. He cited a six-month review of 5G network emissions with safety-critical radio altimeter performance by the Radio Technical Commission for Aeronautics (RTCA) that found serious risks of harmful interference on all types of aircraft. DeFazio called on the FCC to work with the Federal Aviation Administration and aviation industry experts “to ensure that the safety of the hundreds of millions of Americans who fly each year is not endangered by the FCC’s rushed plan.” FCC spokesman Will Wiquist said the commission has “no plans to delay the auction.” The FCC concluded in its order that its rules “would protect radio altimeters used by aircraft. And we continue to have no reason to believe that 5G operations in the C-Band will cause harmful interference to radio altimeters.” The C-band is a block of spectrum used to deliver video and radio programming to 120 million U.S. households. The FCC added that the “altimeters operate with more than 200 megahertz of separation from the C-band spectrum to be auctioned, more protection than is afforded in some other countries.” Last month, Airlines for America, representing major airlines including American Airlines, Delta Air Lines and United Airlines, the Aerospace Industry Association, General Aviation Manufacturers Association, major aviation unions and others, raised concerns about the C-Band auction. They said in a Nov. 17 letter to Congress the RTCA review suggests “this risk is widespread and has the potential for broad impacts to aviation operations in the United States, including the possibility of catastrophic failures leading to multiple fatalities, in the absence of appropriate mitigations.”