| Technical data | |
|---|---|
| Type | Stal-11 |
| Function | Passenger Reconnaissater |
| 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
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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 steel | 40% |
| Other steels | 20% |
| Plywood | 30% |
| Other materials | 10% |
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.
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