Unsuccessful in locating the plane, Arnold looped over Mineral and began to head towards Yakima when flash! A bright light hit his eyes. There, in the distance, were nine metallic objects travelling directly across his flight path, North to South. He estimated the aircraft were approximately 20 to 25 miles from him, each one having a diameter of 50 feet and a width of 2.5 feet, with the exception of the leading aircraft, which Arnold described as darker and larger than the rest. He estimated the entire formation of aircraft was 5 miles long based on their flight over a plateau between Mt. Rainier.

Initially Arnold didn’t think much of these aircraft, as the US military was experimenting with a variety of new jet designs. The fact that he couldn’t see a tail on them was certainly interesting, but it was their motion through the air that caught his attention more than anything: they moved so erratically and at such a high speed that Arnold was convinced no human could have survived piloting them. In fact, it was his description of this movement, like a saucer skipping on water, that led to the term “flying saucer”, which was incorrectly interpreted as the classic UFO shape we know today.

Wanting to determine exactly how fast these strange craft were travelling, Arnold timed their travel between two peaks that were a distance of 39.8 miles apart, with a result of 1 minute and 42 seconds. This meant the aircraft would have been flying at a speed of 1400 miles per hour, a speed that wouldn’t be officially reached by a manned aircraft until almost 11 years later by the Lockheed F-104 Starfighter.

Read the official government reports below, as well as excerpts from Arnold’s book The Coming of Saucers. Compare their consistency to each other.