President Donald Trump is nominating Gen. Kenneth S. Wilsbach to be the Air Force’s 24th Chief of Staff, according to a congressional notice. Wilsbach will succeed Gen. David W. Allvin, who unexpectedly announced Aug. 18 he was retiring two years into what is typically a four-year term. Allvin’s retirement ceremony is currently planned for Oct. 10. Wilsbach must still be confirmed by the Senate, but the tentative plan is for a changeover around Nov. 1.