WASHINGTON—The aviation industry told the White House on Tuesday it will take “significant time” to ensure it is safe for major U.S. wireless companies to use C-Band spectrum for 5G communications. In a letter sent to the White House, Boeing Co, Airbus SE, U.S. airlines, pilots, and others said they need the Biden administration and Federal Communications Commission (FCC) “to help aviation and telecommunication industries reach acceptable mitigations.” Last week, AT&T Inc and Verizon Communications agreed to delay by a month the commercial launch of C-band wireless service from Dec. 5 until early January. The Federal Aviation Administration issued a bulletin last week alerting manufacturers, operators, and pilots that action may be needed to address potential interference with sensitive aircraft electronics caused by the 5G deployment. The FAA said operators “should be prepared for the possibility that interference from 5G transmitters and other technology could cause certain safety equipment to …