An incident this week saw Marine One, the helicopter carrying President Donald Trump, come within a mile of a passenger jet in Washington, D.C. airspace.
The incident occurred at 2:30 p.m. on Tuesday, according to The New York Times.
"Before taking off, the crew of Marine One ... made three attempts to warn controllers in the National Airport tower that they were three minutes away from taking off," said The Times, which reviewed audio recordings posted to ATC.com. These warnings, however, "appeared not to have been heard by the controller, and the helicopter advanced. That put it in the flight path of an Envoy Air passenger jet."
Experts have been alarmed for years about the growing congestion and logistical pressures of D.C. airspace.
Last year, a military helicopter collided with an American Eagle flight over the Potomac River — the first fatal crash of a passenger jet in the United States in 16 years.