From Helene Cooper, Leslie Kean, and Ralph Blumenthal's 12-17-17 New York Times article entitled "2 Navy Airmen and an Object That 'Accelerated Like Nothing I've Even Seen'":
following recounts an incident in 2004 that advocates of research into
U.F.O.s have said is the kind of event worthy of more investigation, and
that was studied by aPentagon program that investigated U.F.O.s.
Experts caution that earthly explanations often exist for such
incidents, and that not knowing the explanation does not mean that the
event has interstellar origins.
David Fravor and Lt. Cmdr. Jim Slaight were on a routine training
mission 100 miles out into the Pacific when the radio in each of their
F/A-18F Super Hornets crackled: An operations officer aboard the U.S.S.
Princeton, a Navy cruiser, wanted to know if they were carrying weapons.
CATM-9s,” Commander Fravor replied, referring to dummy missiles that
could not be fired. He had not been expecting any hostile exchanges off
the coast of San Diego that November afternoon in 2004.
Fravor, in a recent interview with The New York Times, recalled what
happened next. Some of it is captured in a video made public by
officials with a Pentagon program that investigated U.F.O.s.
we’ve got a real-world vector for you,” the radio operator said,
according to Commander Fravor. For two weeks, the operator said, the
Princeton had been tracking mysterious aircraft. The objects appeared
suddenly at 80,000 feet, and then hurtled toward the sea, eventually
stopping at 20,000 feet and hovering. Then they either dropped out of
radar range or shot straight back up.
The radio operator instructed Commander Fravor and Commander Slaight, who has given a similar account, to investigate.
two fighter planes headed toward the objects. The Princeton alerted
them as they closed in, but when they arrived at “merge plot” with the
object — naval aviation parlance for being so close that the Princeton
could not tell which were the objects and which were the fighter jets —
neither Commander Fravor nor Commander Slaight could see anything at
first. There was nothing on their radars, either.
Commander Fravor looked down to the sea. It was calm that day, but the
waves were breaking over something that was just below the surface.
Whatever it was, it was big enough to cause the sea to churn....