The vice chair of the National Transportation Safety Board has been abruptly removed from his position, the White House confirmed Tuesday, a rare move that comes as the federal agency charged with investigating aviation disasters juggles more than 1,000 cases. The Trump administration removed ​​Alvin Brown a little more than a year after he was sworn in for a term that was expected to end in 2026. The White House didn’t say why he was removed and Brown has not publicly commented.