UFO files detail strange, silent triangular craft: "Absolute acoustic silence"

Washington — Federal agents in the western U.S. this year encountered a large, triangular aircraft that zoomed through the sky from a standstill while making no noise or giving off any exhaust, according to new documents released by the Pentagon.

The agents' recollections were included in the Defense Department's latest release of files related to UFOs, or UAP, unidentified anomalous phenomena. Friday's disclosure was the seventh under an executive order that President Trump signed earlier this year mandating the release of sensitive UAP files. The latest batch included 28 PDF files.

The triangular craft is detailed in two documents: a memo from the Pentagon's All-domain Anomaly Resolution Office describing investigators' debrief with the agents, and a signed statement the agents gave to the FBI. 

The encounter occurred in June near an unspecified "national security site" in the western U.S.

The agents told investigators that they were alerted to the object by a third agent stationed nearby. They quickly repositioned themselves to get a better look, and spotted the craft above a ridgeline a few miles to the west, against the glow of the sky after sunset.

"We initiated a visual survey of the western horizon and almost immediately observed a substantial, nonreflective, dark black triangular object most resembling a delta wing drone," they said in their FBI statement. "We estimated the object's wingspan at approximately nine to fifteen feet, its depth at six to nine feet, and its thickness at one to two feet."

The FBI document included illustrations showing the scene and a representation of the craft.

The AARO report notes that the "unidentified craft was executing a slow, controlled, perfectly vertical ascent directly over the ridge line. The craft climbed approximately two to three hundred feet while maintaining a completely static orientation without tilting, swaying, or wobbling. The non-reflective, matte black exterior presented a continuous, featureless profile."

Investigators wrote that the "ascent occurred in absolute acoustic silence."

The agents told the FBI that when viewed through an infrared scope, the object "appeared hotter than ambient temperature with a completely consistent thermal signature across the entire airframe and no visible exhaust gases."

When the craft was 200 to 300 feet above the ridgeline, it "instantaneously" stopped moving and began hovering, staying perfectly still for about 20 seconds, the AARO debrief said.

The craft then sped off, reaching a velocity "compared to that [of] a military fighter jet." The agents lost sight of it within a few seconds. 

"Absolute acoustic silence persisted throughout the high-velocity phase," the memo said. "No impact signature, smoke, dust, or physical disturbance was observed. A ground survey of the canyon drainage conducted the following morning located no wreckage, ground scarring, or vegetation damage."

The incident is similar to other encounters reported by federal agents in the western U.S., detailed in previous releases of UAP files.

In 2023, federal law enforcement agents at an undisclosed location reported seeing orange orbs that released smaller red orbs over a two-day period, according to files released in May. A later batch included the agents' own accounts, with one describing red lights that "accelerated instantly" and another comparing the orbs to "grapes being expelled from a basketball." 

Another instance, detailed in August, involved an agent who recorded infrared video of two "black-hot" objects moving together at the same slow speed.

Regarding the June incident, the Pentagon noted that AARO said it "warrant[s] further investigation due to the close alignment of the phenomena's reported morphological features and kinematic profiles with those of other reported incidents in the western United States region."