Marine One’s crew made repeated but unsuccessful attempts to notify Reagan National Airport that President Donald Trump’s helicopter was preparing to depart on Aug. 4 before it flew near a commercial passenger jet, according to a preliminary federal report released Thursday.

The National Transportation Safety Board’s preliminary report said the crew’s first call to Reagan National’s helicopter-control frequency before departing from the Ellipse was not received. A second transmission was “broken and completely unreadable.”

After failing to reach the tower, the Marine One crew tried to relay the required three-minute notification through the helicopter facility at Joint Base Anacostia-Bolling, but that effort was unsuccessful as well, according to the report.

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The missed warning meant Reagan National controllers did not receive notice that would have required them to stop departures before the presidential helicopter lifted off.

Instead, Envoy Air Flight 3742, an Embraer E-170 bound for Pensacola, Florida, was cleared to take off from Runway 1 as Trump departed the White House aboard Marine One for a planned trip to Los Angeles.

The passenger jet was beginning its initial climb as Marine One departed the Ellipse, about 2 miles north of the airport, the NTSB said.

The FAA’s preliminary estimate found the aircraft came within about 0.82 nautical miles of one another laterally and roughly 700 feet vertically. No one was injured, neither aircraft was damaged, and both flights continued without further incident.

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FILE – A passenger jet flies past the FAA control tower at Washington’s Ronald Reagan National Airport, Thursday, March 24, 2011. The incident comes a year after a fatal plane crash involving a passenger jet and an Army Black Hawk helicopter near the airport.

The Envoy flight crew said the jet’s traffic-collision system announced, “Traffic, Traffic,” as the aircraft climbed and accelerated after takeoff. The pilots did not visually spot Marine One, but said the helicopter appeared to the right and below their aircraft on the cockpit display.

The system did not issue a resolution advisory, a more urgent instruction telling pilots to climb or descend to avoid another aircraft, according to the NTSB report.

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FILE – One of the US Marine Corps’ VH-3D Sea King helicopters known as Marine One when carrying the President of the United States is pictured. Officials said Marine One was able to contact the tower at DCA after climbing high enough to establish reliable communications. (Mark Kerrison/In Pictures via Getty Images)

Marine One was eventually able to contact the tower after climbing high enough to establish reliable communications. Controllers then issued a traffic advisory, and the helicopter crew immediately reported having the Envoy jet in sight, the report said.

The newly released report also shows the communications concern had been raised just days earlier.

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On July 30, Marine Helicopter Squadron One, known as HMX-1, met with Reagan National tower staff to discuss operations in the area. During that meeting, HMX-1 told controllers that communications had been “spotty,” the NTSB said.

Controllers had also raised concerns that HMX-1 crews had not always provided the required three-minute warning before takeoff. The two sides agreed that helicopter crews would use backup methods to reach the tower, including relaying the notification through another aircraft, if direct radio communication failed.

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FILE – U.S. President Donald Trump boards Marine One, in Charlottesville, Virginia, U.S., April 10, 2026. No injuries were reported in relation to the incident. (Evelyn Hockstein/Reuters)

That is what Marine One’s crew attempted on Aug. 4, but the message still did not get through.

FAA technicians later determined there was not adequate line-of-sight coverage between the radio transmitter-receiver site and the Ellipse, where Marine One was temporarily operating during construction at the White House. 

The FAA subsequently moved the radios used for the airport’s helicopter-control frequency from a nearby residential neighborhood to the top of Reagan National’s control tower, according to the report.

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The agency later conducted radio checks with two HMX-1 aircraft operating near the Ellipse and reported no deficiencies after the equipment was moved.

The FAA and NTSB began reviewing the incident earlier this month and previously characterized the event as a “momentary loss of separation.”

“Based on our preliminary safety review, there was momentary loss of separation, after which the aircraft continued to move away from one another,” the FAA previously told Fox News Digital. “The air traffic controller was in contact with both the commercial pilot and Marine One pilot during the loss of separation.”

While the aircraft were estimated to be less than 1.5 nautical miles apart horizontally, the NTSB said the preliminary estimate of 700 feet of vertical separation met the applicable FAA standard. In the relevant Class B airspace, the standard requires either 1.5 nautical miles of lateral separation or 500 feet of vertical separation.

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The NTSB said it is continuing to review surveillance data to calculate and confirm the closest point between the two aircraft.

The White House previously said Trump was never in danger.

“Marine One flights are piloted by some of the best aviators in the world, and at no point was the president in harm’s way,” White House spokesman Kush Desai told Fox News Digital.

The NTSB told Fox News Digital its preliminary report “is intended to present the factual information developed to date” and does not contain “analysis, conclusions, or findings related to probable cause.”

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“The investigation remains ongoing, and we are not providing additional comment beyond the information contained in the preliminary report,” the agency said, adding that any safety recommendations would be publicly announced, and further findings would be released through its public docket and final report process.

Fox News Digital’s Robert McGreevy contributed to this report.