Nominee Anthony Tata offered a partial apology for past comments attacking Democrats and Trump critics as traitors.
The F-16s being shipped to Ukraine lack critical components like an engine and radar, the Air Force said, meaning they cannot be used operationally.
Authorities said they are investigating the crash of an experimental MX Aircraft MXS near Hampton, Virginia.
The commander's comments come amid concerns from Congress that the Pentagon is considering reducing the number of U.S. troops on the continent.
