A monoplane called the S-2 Kite was developed in 1931. Designed by Omer Woodson, it was a probe into the inexpensive, ultralight aircraft market.

It had an uncovered, girder-like fuselage, and thick, cantilever wing. One was built, NX489M c/n 1002.

Simplex failed to get anywhere with the project, but the idea went with Woodson and company test pilot Myhres when they left in 1930 to form Cycloplane Co.

Sioux Aircraft Corporation built aircraft under the name Sioux Kite.

S-2 Kite
Engine: Szekely SR-3, 40hp
Seats: 1

The 1928 Simplex K-2-C Red Arrow (ATC 44) was designed by Omer Woodson with origins in the Woodson M-6. Of wooden construction it was Side-by-side canopied cockpit and semi-cantilever wing. The first few were powered by 75hp Kinner engines and priced at $4,495.

The 1928 Simplex K-2-S Red Arrow (ATC 43) was the same as the K-2-C, but with side-by-side open cockpit and priced at $4,115.

About 10 K-2s were built. Piloted by Dick Myhres, one, NC6504, won the 1928 California Class-A Race (Los Angeles-San Francisco) in a field of 16 aircraft in 3hr10min averaging 126mph.

Sioux Aircraft Corporation built aircraft under the name Sioux Red Arrow.

K-2-C Red Arrow
Engine: 90hp Kinner K-5
Wingspan: 34’4″
Length: 22’3″
Useful load: 570 lb
Max speed: 120 mph
Cruise: 108 mph
Stall: 37 mph
Range: 550 mi
Seats: 2

K-2-S Red Arrow
Engine: 90hp Kinner K-5
Wingspan: 34’4″
Length: 22’3″
Seats: 2

The first design of the Simplex firm was a racing monoplane with a 320 hp Hispano-Suiza engine for the Coupe-Deutsch race of 1922. The design was due to Carmier, and the plane was to be flown by a well-known fighter pilot, Georges Madon. It was a cantilever monoplane with a tractor engine and full-span controllers. The short fuselage ended in a vertical fin with a rudder. The pilot sat rather far back behind the leading edge of the wing ; in addition, a barrel radiator excluded any view forward. So it was not surprising that even a very experienced pilot like Madon could meet with an accident during a test flight prior to the race. He escaped with severe injuries, and the general impression created was rather unfortunate. Since Fétu had previously met with a grave accident with the Arnoux biplane, the fate of this interesting development was sealed. Arnoux himself seems to have been discouraged from further pursuing his line of investigation.

The 1928 Simmons SP-1 Sport Monoplane built by Herbert H Simmons was registered N7477 c/n 61. A two-place, open cockpit monoplane, the registration was cancelled on 22 July 1930.

Engine: Super LeRhône static
Wingspan: 36’6″
Length: 21’9″
Seats: 2