Ornithopter
Caldwell then turned to an even more bizarre aircraft design, an ornithopter. The wings were equipped with flexible fabric valves which were supposed to open on the upstroke and close on the downstroke, allowing it to generate lift with no forward motion and thus provide VTOL service, like the cyclogyro.
Caldwell, now living in Denver filed a patent on his new design in December 1927, which was finally granted as US1730758 in October 1929. In early 1928 he started another company in Nevada to raise funds to develop it, 'Gray Goose Airways', inc., issuing 10,000 shares of stock at ten cents per share, retaining a 51 percent interest. The funds were used to develop a human-powered prototype.
By 1931 there was still no working prototype, and Caldwell moved to Orangeburg, New York, and later to Madison, New Jersey. A January 14, 1932 newsreel film shows the ornithopter being readied for a test. This was apparently attempted without success, by the otherwise unknown Emile Harrier. Additional funds were then raised by another stock issue in order to build a full-sized prototype at Teterboro Airport. He also apparently restarted his cyclogyro work, and an article appeared in one of the Popular Mechanics-like magazines showing the design equipped with a V-8 engine mounted in an odd twin-fuselage with the pilot and passengers below.
Before the ornithopter prototype could be completed, the New Jersey Assistant Attorney General charged Caldwell with fraud in September. In his notes, the Attorney, Robert Grossman, noted that "no one connected with the company possessed sufficient knowledge of aeronautics to build a practical ship." Caldwell eventually reached an agreement that allowed him to continue construction of the ornithopter prototype until December, as long as no more shares of stock were sold in that time. Grossman also noted that Caldwell had begun work on yet another entirely new design, using a disk wing.
In December there was still no prototype, and Caldwell moved the company to New York. The New York Attorney General started questioning the business almost immediately.
Read more about this topic: Jonathan Edward Caldwell