title: Acme Sierra
text: # Acme Sierra
  
  The Acme Aircraft Co S-1 Sierra was an experimental aircraft of unusual configuration built in the US in 1948 to investigate the advantages of a pusher propeller configuration. Apart from this engine installation, the aircraft was unusual in having an X-shaped tail incorporating ruddervators on the upper fins. The wing was mounted midway up the fuselage and was unswept. During the 1960s, the US aerospace manufacturer Northrop used the aircraft as a technology demonstrator for boundary layer control concepts.
  
  ## Specifications (S-1 Sierra)
  
  Data from
  
  General characteristics
  
  * Crew: 1
  * Length: 59 ft 1 in (18 m)
  * Wingspan: 20 ft 2 in (6.15 m)
  * Empty weight: 590 lb (268 kg)
  * Powerplant: 1 × Continental C-85 4-cyl. air-cooled horizontally-opposed piston engine, 85 hp (63 kW)
  
  Performance
  
  * Maximum speed: 200 mph (320 km/h, 170 kn)
  