Editor's note: The above video has audio from February released by the Federal Aviation Administration of pilots reporting an anomalous sighting over southeastern Arizona. 

A new series about the government's investigations of UFOs is coming to the History Channel. Among the first-hand accounts of UFO sightings in the series, Navy pilots reported encountering unidentified objects reaching 30,000 feet at "hypersonic" speeds during training flights. 

WATCH: Navy pilots speak out about UFO sightings

In 2014 and 2015, then-Navy pilots Lt. Ryan Graves and Lt. Danny Accoin were training to deploy to the Persian Gulf. The pilots said in an interview with the New York Times they recorded objects with no distinct wings or engines moving around them.

The pilots told the Times the objects were accelerating to hypersonic speed and making sudden stops and instantaneous turns, maneuvers a human pilot would be incapable of performing. 

The sightings were reported to a Pentagon program known as the Advanced Aerospace Threat Identification Program, which tracks UFOs, according to the Times.

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A Navy spokesperson told the Times some of the sightings could have been commercial drones, but in some of the cases, there was not enough data to speculate what the objects were. 

But before you go leaping to conclusions about little green men, military officials are not saying that unidentified flying objects are necessarily extraterrestrial objects. 

According to a Navy Times op-ed, the Advanced Aerospace Threat Identification Program is less about identifying potential alien spacecraft than it is about correcting pilots' misinterpretations of their observations—or "Taking the 'U' out of 'UFO.'"

Graves and Accoin, along with other fighter pilots and U.S. intelligence officials, will appear in the History Channel's six-part series premiering Friday, "Unidentified: Inside America's U.F.O Investigation."

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