A United Jet flew about 15 feet above the busy New Jersey Turnpike on its approach to the runway.
The chair of the NTSB expressed concern over the possibility of a mid-air collision at the Burbank Airport.
The air traffic controller who was managing numerous aircraft around Reagan National Airport felt a "little overwhelmed" just a few minutes before an American Airlines jet collided midair with an Army helicopter near Washington D.C., an investigator said.
Questions remain as the NTSB investigates the deadly plane crash that killed former NASCAR driver Greg Biffle and his family
The captain of one of the Delta Air Lines regional jets that collided at the intersection of two taxiways at LaGuardia Airport in New York last month told investigators he did not recall hearing instructions to give way to the other plane.
All 67 people on board Flight 5342 and the helicopter were killed when they collided as the jet approached Reagan National.