The Rankin RBM-4 of 1928 was a two-place low wing monoplane powered by a 60hp LeBlond 5D engine. Fist flown by Basil B Smith, they were priced at $2,500.

One appears in a 1936 register as four-place cabin with a 200hp Wright NC9622 (how the NC was acquired is unknown)] c/n 3, owned by brothers Alexander, Arch, and Charles Rankin of Wayne MI. Company promotion also told of a three-place open cockpit with 90hp LeBlond 7D also in progress, with a useful load circa 500 lb and max speed of 110mph, as well as an ambitious plan for a network of national distributors.

Engine: 60hp LeBlond 5D
Wingspan: 37’1″
Length: 25’6″
Useful load: c.350 lb
Speed: 100 mph
Seats: 2

A four-seat light cabin monoplane of Ramor Flugzeugwerke design in early 1930s. Powered by a de Havilland Gipsy 1 engine.

An invention of William Rahn in collaboration with Gus Miller, formerly with the Zeppelin Works in Germany, this 1933 experimental aircraft was only 15 feet long, and carried two 6-foot span rotating wings on each side. Powered with a 240 hp supercharged Wright Whirlwind motor, the wings are disposed about a central axis and change their incidence so as to produce both lift and negative drag.

It was said to fly forwards at up to 100 mph without the aid of a normal propeller.

The two 6′ rotating wings on each side theoretically would cause the plane to rise or descend vertically, or fly laterally without a conventional propeller up to 100mph, but it is unrecorded if this 15′-long creation, registered NX13247, ever accomplished any of these feats.

The 1930 Racek PB-4 was designed by Přikryl and Blecha of Czechoslovakia.