Technical data
Type Stal-11
Function Passenger
Year 1936
Crew 1
Engines 1*860hp M-100A
Length 12.5m
Wingspan 15.0m
Wing area 31.0m2
Empty weight 1830kg
Loaded weight 2700kg
Wing Load (kg/m2) 87
Power load (kg/hp) 3.1
Maximum Speed at 0m 430km/h
Cruise Speed 370km/h
Landing Speed 80km/h
Ceiling 8000m
Fuel 380kg
Seats 4
Cargo ?kg

Stal-11 (R-9) by A.I.Putilov

32k b/w "History of aircraft construction in the USSR", Vol.1 p.562

Passenger/mail delivery aircraft, capable to perform reconnaissance missions in wartime. Low wing monoplane with retractable landing gear of very uncommon design. Both wing and fuselage had monocoque construction with stainless steel frame and 0.8 to 2.5mm thick plywood skin.Wing spars - light and elegant 3-D frames, with numerous weight saving holes. Plywood strips (~40mm wide) were attached to the frame via point-wielded short 'nails'. Then the skin was glued on those strips.

Military designation - R-9, same as TsKB-27/R-9 by S.A.Kocherigin.

Material use in Stal-11
Stainless steel40%
Other steels 20%
Plywood 30%
Other materials10%

Surface quality was very good, entire construction was very light and rigid. Wing airfoil was developed at TsAGI by F.G.Glass. Flaps could be deployed at angles up to 60°.

Aircraft was ready on Fall 1936. Extensive trials were carried out, in both civil and military configurations. Approximately 300 landings were performed.

No production followed. Looks like project was cancelled with arrest of leading designers.

  • "History of aircraft construction in the USSR", Vol.1 p.562-563;
  • None found;

  • Created February 19, 1999 Back to
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