A Delta Air Lines flight narrowly avoided a collision with a U.S. military jet shortly after takeoff from Washington National Airport on Friday.

A congressional hearing has reinforced the idea that the January collision between an American Airlines passenger jet and an Army helicopter that killed all 67 people aboard both aircraft could have been prevented.

Aviation safety has come under renewed scrutiny following a series of incidents. Pilots and experts insist flying is still very safe, but there are key moments during any flight when the risk is enhanced.