title: Sikorsky S-18
text: # Sikorsky S-18
  
  The Sikorsky S-18 was a Russian twin engine aircraft designed by Igor Sikorsky and built by the Russian Baltic Railroad Car Works aviation division at Petrograd during World War I.
  
  ## Design and development
  
  The S-18 was a large three bay biplane fighter/interceptor powered by two 150 hp (112 kW) Sunbeam Crusader V-8 water-cooled engines mounted on the lower wing in a pusher configuration. The aircraft featured armor protection for both crew members with the gunner/observer seated in the nose and armed with a single machine gun. The aircraft was very heavy and with the less than reliable Sunbeam engines neither example built was able to leave the ground.
  
  ## Specifications
  
  Data from Russian Aviation Museum
  
  General characteristics
  
  * Crew: Two
  * Length: 31 ft 10 in (9.7 m)
  * Upper wingspan: 54 ft 2 in (16.5 m)
  * Lower wingspan: 50 ft 2 in (15.3 m)
  * Wing area: 620 sq ft (58 $m^2)$
  * Empty weight: 3,274 lb (1,485 kg)
  * Gross weight: 4,630 lb (2,100 kg)
  * Powerplant: 2 × Sunbeam Crusader V-8, side-valve, water-cooled, piston engine, 150 hp (110 kW) each
  
  Performance
  
  * Wing loading: 7.4 lb/sq ft (36.2 $kg/m^2)$ max load
  