Sikorsky S-9
The Sikorsky S-9 Kruglyj (Rounded One) was a Russian single engine prototype aircraft completed in the spring of 1913 by the Russian Baltic Railroad Car Works while Igor Sikorsky was the chief engineer of the aircraft manufacturing division.
S-9 | |
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Sikorsky S-9 circa 1913 | |
Role | Experimental Monoplane |
National origin | Russian Empire |
Manufacturer | Russian Baltic Railroad Car Works |
Designer | Igor Sikorsky |
First flight | 1913 |
Number built | 1 |
Design and development
The S-9 was a three-seat mid-wing monoplane with constant-chord wire-braced wings originally powered by a Gnome air-cooled rotary engine rated at 100 hp (75 kW). It was the first monocoque monoplane built in Russia and the cylindrical tapered fuselage was constructed of plywood 5 mm thick in the forward section and 3mm thick aft. Construction was completed in the spring of 1913.[1][2]
Operational history
Upon completion the S-9 was found to be substantially heavier than anticipated and the engine only delivered 80% of its rated horsepower. Initial flight tests revealed very poor performance. The engine was replaced by a 100 hp (75 kW) Gnome Monosoupape and further flights showed only a nominal increase in speed. The machine was eventually scrapped.[1]
Specifications
Data from Russian Aviation Museum[2]
![](../I/Sikorsky_S-9_aircraft_circa_1913_close_up.jpg.webp)
General characteristics
- Crew: One
- Capacity: Two passenger
- Upper wingspan: 39 ft 4 in (12 m)
- Wing area: 320 sq ft (30 m2)
- Empty weight: 1,521 lb (690 kg)
- Gross weight: 2,183 lb (990 kg)
- Powerplant: 1 × Gnome Monosoupape 7-cylinder air-cooled rotary piston engine, 100 hp (75 kW)
- Propellers: 2-bladed
Performance
- Maximum speed: 56 mph (90 km/h, 49 kn)
- Wing loading: 6.8 lb/sq ft (33 kg/m2) max load