At approximately 5:10 PM Alaska time on November 17, 1986, Japan Airlines Flight 1628 — a Boeing 747-200F cargo jet ferrying French Beaujolais wine from Paris to Tokyo via Reykjavík and Anchorage — was cruising at 35,000 feet over the east-central Alaska town of Fort Yukon. Captain Kenju Terauchi, a seventeen-year pilot and former fighter pilot, noticed lights well below and ahead of his aircraft that kept pace with his heading for several minutes.
The lights resolved into two square-shaped craft, each roughly the size of a DC-8, glowing with rows of amber nozzles or thrusters along their surfaces. They flew ahead of the 747 for several minutes at matching speed, then suddenly rose and positioned themselves on either side of the aircraft only a few hundred feet away, bathing the cockpit in a yellow-orange glow so strong that Terauchi could feel heat through the windows. The two objects then departed, and Terauchi reported a third, far larger craft appearing behind the 747 — 'a gigantic ball' or walnut-shaped mothership that he estimated to be twice the size of a supercarrier.
The large object followed the aircraft for over thirty minutes. Ground radar at the FAA's Anchorage Air Route Traffic Control Center showed an intermittent primary return behind the 747's transponder trace. The Elmendorf Regional Operations Control Center briefly saw the same returns on military radar. Controllers vectored the 747 through several maneuvers, and the object matched each one. It finally peeled off as the 747 approached the Alaska Range.
Terauchi's report, initially considered routine, became an international story after Japan Airlines and the FAA acknowledged it. FAA division chief John Callahan preserved the case files and radar tapes against policy shredding and decades later testified publicly to Congress. The FAA's official conclusion was that the radar returns were 'possibly spurious,' but Callahan and other analysts consider it one of the most credible and best-documented civilian commercial UFO encounters in aviation history.