Jonathan E. Caldwell

Jonathan Edward Caldwell (March 24, 1883 – November 8, 1955) was a Canadian-American self-taught aeronautical engineer born in Hensall, Ontario. He designed innovative but unsuccessful aircraft, including the 1923 Cyclogyro with rotating Ferris wheel-like frames and the 1934 Disk-Rotor Plane for vertical takeoff, funded via Gray Goose Airways amid legal troubles with shareholders. After abandoning prototypes in Maryland in the late 1930s, they were rediscovered in 1949 by the U.S. Air Force's Project Sign during the UFO wave post-Kenneth Arnold sightings. Investigated as potential flying saucer explanations, the wreckage was deemed unrelated to sightings. Caldwell, tracked to California, dismissed it as a 1939 project. His failed inventions are often misidentified in UFO lore as alien craft evidence, though USAF confirmed them terrestrial.