Arup S-4 Explained

The Arup S-4 (Model 104) is the last in a series of round-wing aircraft from C.L. Snyder.^[1]

Design and development

The S-4 was engineered by Raoul Hoffman. The test pilot was Glenn Doolittle, a cousin of Jimmy Doolittle.^[2]

The S-4 used a low aspect ratio, semi-circular planform wing with a conventional landing gear and a small rudder with attached elevator on the rear of the fuselage. The aircraft was entered through a door mounted on the bottom of the aircraft.^[3]

Operational history

The S-4 prototype flew extensively in promotional demonstrations. The S-4 was emblazoned with Sears Roebuck and Company logos. The aircraft was scrapped for war materials in World War II.^[4]

Variants

• Hoffman Flying Wing a design based on the Arup S-4 aircraft.^[5]
• Milt Hatfield Little Bird - similar design.^[6]

Aircraft on display

A replica is on display in the atrium of South Bend Airport^[7]

Notes and References

1. Book: Avrocar: Canada's flying saucer : the story of Avro Canada's secret projects.
2. Web site: Round aircraft designs . 7 September 2011 . dead . https://web.archive.org/web/20120402075442/http://celticowboy.com/Round%20Aircraft%20Designs.htm . 2 April 2012 .
3. Popular Aviation. August 1935. 92.
4. Web site: Low AR-planes. 7 September 2011.
5. Experimenter. December 1957.
6. Sport Aviation. March 1987. Milt's Little Bird. 43. Bernard L Rice.
7. Web site: KSBN airport. 7 September 2011. https://web.archive.org/web/20120322143921/http://jetphotos.net/viewphoto.php?id=349450&nseq=6. 22 March 2012. dead.