USAF Lieutenant McCarthy and another pilot flying two F-86E jets, 51st Fighter Interceptor Wing, 25th Fighter-Interceptor Squadron, at 30,000 feet, airspeed 500 knots, on 280° heading. Sighted a silvery oval-shaped object south of Changsong-ni and north of Nangnim Mountain, seen to the north, larger than a MiG jet airplane at nine o'clock position below, to the south, at estimated altitude of 8,000-10,000 feet, about 1,200-1,500 mph, and about 20 miles away. Object on south to north straight flight path in a "rolling maneuver," disappeared at about three o'clock position to N.

Google map of this location.