Kenneth Arnold Flying Saucer Formation

On June 24, 1947, civilian pilot Kenneth Arnold was flying a CallAir A-2 near Mount Rainier, Washington when he observed nine bright objects flying in a tight echelon formation. Arnold clocked their speed at approximately 1,700 mph by timing their transit between Mount Rainier and Mount Adams — roughly three times the top speed of any jet aircraft then in service. He described the objects as crescent or boomerang-shaped, moving in a linked chain like 'the tail of a Chinese kite.' The FBI's Seattle field office opened a formal investigation at Army Air Force request, documenting Arnold's background as an experienced pilot and respected businessman. FBI file 62-83894 notes the Army Air Materiel Command at Wright Field expressed 'great interest' in the report and dispatched investigators. No conventional explanation was found. Arnold's report triggered over 850 similar sighting reports to the FBI and military within weeks, directly precipitating the formation of Project Sign in 1948.