title: Hirtenberg HS.9
text: # Hirtenberg HS.9
  
  The Hirtenberg HS.9 was an Austrian two-seat touring or training aircraft of the early 1930s.
  
  ## Design and development
  
  A derivative of the Hopfner HS-5/28 via the Hopfner HS-8/29, the HS.9 was a parasol wing monoplane with a fixed tailskid landing gear and room for two occupants in tandem open cockpits, and first flew as the Hopfner HS-9/32 in 1932, powered by a de Havilland Gipsy I engine. Production versions had Siemens Sh 14 engines with NACA cowlings. A single example of a refined version with an uncowled Siemens engine was flown in 1935 as the Hopfner HS-9/35, shortly before the Hopfner company went bankrupt.
  
  When Hopfner's assets were purchased by Otto Eberhardt Patronenfabrik, production continued of both de Havilland- and Siemens-powered aircraft under the Hirtenberg brand.
  
  ## Variants
  
  * HS-9/32 - Original version by Hopfner
  * HS-9/35 - developed version of HS-9/32
  * HS.9 - Production aircraft with a Siemens Sh 14a piston engine.
     * HS.9A - Production aircraft with a de Havilland Gipsy Major piston engine.
  * HS.16 - military trainer version of HS.9
  
  ## Operators
  
  ### Austria
  
  * Austrian Air Force (1927-1938)
  
  ## Specifications (HS.9A)
  
  Data from British Civil Aircraft since 1919 Volume 3.
  
  General characteristics
  
  * Crew: 2
  * Length: 8.05 m (26 ft 5 in)
  * Wingspan: 10.972 m (36 ft 0 in)
  * Empty weight: 568.8 kg (1,254 lb)
  * Gross weight: 948 kg (2,090 lb)
  * Powerplant: 1 × de Havilland Gipsy Major , 90 kW (120 hp)
  
  Performance
  
  * Maximum speed: 190 km/h (118 mph, 103 kn)
  