The 1935 Arup S-4 was a remake of the S-3, with a 70hp LeBlond engine. Small elevators were added atop the fin. Some reports tell of a return to conventional gear, but photos in Aug 1935 Popular Aviation show a nose gear.

US patent #2,062,148 was assigned to Cloyd Snyder in 1937 for a variable wingform aircraft.

Registered N14529, it was first flown on 19 March 1935. Only the one was built.

A smaller single-place replica was built and flown c.1985 in Bristol IN.

Engine: 70hp LeBlond
Wingspan: 22’0″
Length: 18’6″ Useful load (included two parachutes): 550 lb
Max speed: 110 mph
Stall: 28 mph
Ceiling: 9,000′
Aspect ratio 1:1.78
Seats: 2

The 1934 Arup S-3 was a two-place flying wing larger version of S-2 with ailerons moved flush with the wing-tips, and tricycle gear.

Registered N14147, it first flew on 15 July 1934.

It was destroyed by an unsolved arson fire after its test flight.

Engine: 70hp LeBlond 5DE
Wingspan: 22’0″
Length: 17’6″
Useful load: 490 lb
Max speed: 97 mph
Cruise: 90 mph
Stall: 20 mph
Seats: 2

The 1933 Arup S-2, or Snyder A-2, single-place flying wing was designed by Raoul Hoffman and C L Snyder. Developed from Snyder’s flying-wing glider, Arup 1 Dirigiplane, it featured wing-tip “ear” ailerons, and STOL flight characteristics.

Registered BX/R12894 it first flew on 7 September 1933, piloted by Glenn Doolittle. Only the one was built.

Engine: 36hp Continental A-40
Wingspan: 19’0″
Length: 17’2″
Seats: 1