FAA says it's investigating possible safety violation involving helicopter transporting Trump

The Federal Aviation Administration said Tuesday it is looking into a potential air-traffic safety violation involving a military helicopter that was transporting President Donald Trump. 

"The FAA is investigating a safety incident involving Marine One, but it didn’t appear to be a dangerous close call and the aircraft weren’t apparently converging," the FAA said.

Federal regulations require that aircraft in that airspace be separated by 1.5 miles horizontally and 500 feet vertically. Trump's Marine One helicopter took off from the White House on Tuesday afternoon, but air traffic controllers hadn't put a hold on commercial flights arriving and departing Ronald Reagan Washington National ​Airport. Controllers expect that Marine One give them at least three minutes' warning before they take off, which may not have happened on Tuesday. 

Following a fatal collision last year between a U.S. Army Black Hawk helicopter and an American Airlines regional passenger jet, the FAA set restrictions on helicopter and airplane traffic around the airport, the Wall Street Journal reported.