Denver International Airport CEO Phillip Washington has withdrawn his nomination to lead the Federal Aviation Administration (FAA) after facing criticism from Senate Republicans. President Joe Biden nominated Washington last year, but the Senate Commerce Committee recently delayed a vote on the nomination due to some lawmakers' outstanding questions. Republican leader Senator Ted Cruz was among those who opposed Washington's appointment, claiming that he needed a waiver from rules requiring civilian leadership to head the FAA because he had retired from the US Army in 2000. However, the Department of Transportation had already issued a letter stating that Washington was fully qualified and did not require a waiver. The FAA has faced several safety incidents recently, including a pilot messaging database outage that halted airport flights for two hours and a series of near collisions involved in six serious runway incursions since January. The withdrawal of Washington's nomination is a setback for the government amid a closely divided Senate.