By David Shepardson WASHINGTON (Reuters) -The head of the U.S. Federal Aviation Administration (FAA) who is leaving halfway through his five-year term said on Thursday that he was not pressured by the White House to resign. FAA Administrator Steve Dickson, a pilot and former Delta Air Lines executive who was tapped for the job by President Donald Trump in 2019, told a small group of reporters he had decided to leave effective March 31 because of family reasons. Asked if Transportation Secretary Pete Buttigieg or the White House had pressured him to step down, Dickson said no, “in fact, they as…