Summary
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 | |
|---|---|
| |
| 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 edit
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 edit
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 edit
Data from Russian Aviation Museum[2]
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