The maze of aviation companies linked by common designs/engineers Fred Landgraf and Paul M. Lewis seemed to justify the merge of two topics here, although the ties are sometimes difficult to establish.
- Gray Goose Airplane was established by Jonathan E. Caldwell in Denver, CO, in 1928.
- A Gray Goose Airways existed in 1930 at Boeing Field, Seattle, WA, but the connection is not certain.
- In 1931, the Colorado-based company was found in Orangeburg, NY, and Madison, NJ, possibly as subsidiaries.
- Circa 1933, Lewis-American Airways was founded by Paul Lewis in Denver, CO.
- In 1934, that company was located in Washington, DC.
- It was renamed as the Lewis-American Airplane Co. but then became Gray Goose Airways, still in Washington, DC.
- However, another source states that circa 1938, the Lewis-American Airplane Co. became Lewis-American Airways Inc.
- Circa 1938 still, Rotor Planes was created in an unknown location. The ties between this and the previous companies are not clearly established.
- 1939 marked the end of operations for Gray Goose.
Apparently, seven aircraft were produced over that decade (I'm not listing projects here):
- The MD-1 Gray Goose of 1930 [355V (c/n A-1)], a two-seat high-wing monoplane with 165hp Wright J-6 pusher engine, which vibrated itself to pieces when it was first cranked up.
- The Gray Goose of 1931, a redesign of the former by Fred Landgraf, likely rebuilt from same or registration reused.
- The Ornithopter of 1932, a human-powered, flapping-wing aircraft originally designed in 1927 by J. E. Caldwell.
- The Lewis-American Model A of 1935, a two-seat open-cockpit high-wing monoplane with 210hp Lycoming engine, described as a "revolving wing airplane" and designed by P. M. Lewis.
- The Windmill Plane, circa 1936, an ornithopter type apparently started in 1923 (most likely by Caldwell), with four tandem walking beams that opened and closed ten overhead slats and a very large powerplant.
- The Gray Goose Cyclogyro, circa 1937 [4308 (c/n 1)], a single-seat open-cockpit ultralight VTOL monoplane with 7hp Harley-Davidson engine and two 3-bladed airfoil-equipped paddlewheels, designed by Landgraf.
- The Gray Goose Model A of 1938 [N(X)99Y (c/n 1)], a single-seat experimental disk-rotor plane with nine-cylinder air-cooled radial engine.
Why the 1923 and 1927 machines, which seemed like such backward designs, were finally completed in the 1930s, is not known.
What was Caldwell's involvement (if any) in Lewis-American is not known either.