Something flew over the west coast in late October, that much we know. But the mystery plane disappeared before anyone could figure out what it was and has defied all attempts at identification since. Was it a classified U.S. government aircraft, a flying saucer, or something else?

The War Zone reports that in the afternoon of October 25, air traffic controllers started querying commercial airline pilots flying between Portland and Seattle, asking if they could help identify a mystery object. The object in question didn’t have a traffic collision avoidance system (TCAS) transponder turned on, was not responding to radio communication, and, most intriguingly, could not be picked up on radar.

Getty Images

Numerous pilots reported they saw the aircraft, but none came close enough to identify it. Ultimately, Oregon Air National Guard F-15 fighters from Portland International Airport were sent up to investigate, but saw nothing. The War Zone article also cites two Reddit users familiar with the incident and who seem to corroborate much of what the air traffic controller audio has to say.

The aircraft was near Crater Lake, Oregon when air traffic controllers started asking nearby pilots about it. The aircraft was described as a white object flying north between 35,000 and 40,000 feet. At one point in the air traffic controller audio clip, one pilot says the mystery bird is 12 to 15 miles away, and distances from other aircraft ranged from four to 20 miles. Another pilot, observing the aircraft, estimates an airspeed of 370 knots, or 425 miles an hour on the ground, also noting he is not getting a TCAS transponder signal.

What was it?

One of the Reddit users quoted by the article thinks it was an aircraft running drugs to Canada. While anything’s possible, the “aircraft” was not keeping a low profile in the way you would expect a smuggler to. The mystery aircraft was flying a conspicuous flight path, traveling during broad daylight, and passing multiple passenger aircraft. It seems more plausible smugglers would probably fly low enough to avoid possible identification by other pilots. More importantly, the U.S./Canadian border is 1,538 miles long on the ground. It would be much easier to cross the border in a four-wheel drive truck than an aircraft.

Another possibility is a classified government aircraft, perhaps some highly classified new design. This theory, too, has problems. In you want to keep a plane a secret, then flying at dusk in one of the densest air corridors in the continental United States doesn’t make sense. There lies the problem with many possible explanations: If the pilots of the aircraft didn’t want anyone to know their business, why did they fly in such a conspicuous manner?

One more theory: Boeing is partially based in Washington State and is working on an entry into the Navy’s new MQ-25 Stingray drone competition. The drone probably includes at least some stealthy design characteristics that would make it difficult for civilian air traffic control radars to track, and an unorthodox design may make it hard for other pilots to visually identify. The drone operator may have been unable to hear air traffic controller queries of his aircraft. But there are plenty of places to test new drones, particularly over the Nevada desert, and flying an unknown aircraft in a dense aviation zone is potentially hazardous.

Or maybe there was nothing there after all. Could it be possible that all of the pilots who reported the aircraft were actually seeing nothing? After all, radar saw nothing. Told by air traffic control (someone in a position of authority) that there was an aircraft in the area, could pilots have “seen” something that was not there?

Yet even the hallucination explanation has a problem. If these pilots so easily experienced what amounted to a mass hallucination, why is this phenomenon not more common, and why are these pilots flying? One pilot, United Flight 612, is asked by air traffic if he sees the mystery aircraft at his 3 o’clock position and quickly pipes up, “Yeah we got him, he’s about four miles away.” It is apparent from the tone of his voice he had been watching the object, which he later describes as a “white speck” “about four or five thousand feet above us,” for some time.

No single explanation seems to fit this incident. The War Zone has filed Freedom of Information Act requests for more information. Whatever happened over the West Coast on the evening of October 25 remains a mystery. Read more and listen to the audio at The War Zone.

This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io