Gnome Omega

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Gnome Omega RAFM.jpg
Gnome 7 Omega on display at the Royal Air Force Museum London
Type Rotary aero engine
Manufacturer Société des Moteurs Gnome
First run 1908
Major applications Blériot XI
Bristol Boxkite
Number built 4,000 until 1914[1]
Unit cost £520 in 1909[1]

The Gnome 7 Omega (commonly called the Gnome 50 hp) is a French seven-cylinder, air-cooled aero engine produced by Gnome et Rhône.[2] It was shown at the Paris Aero Salon held in December 1908 and was first flown in 1909. It was the world's first[1] aviation rotary engine produced in quantity. Its introduction revolutionized the aviation industry[3] and it was used by many early aircraft. It produced 50 horsepower (37 kW) from its capacity of 8 litres (488 cubic inches).[4] A Gnome Omega engine powers the 1912 Blackburn Monoplane, owned and operated by the Shuttleworth Collection, the oldest known airworthy British-designed aeroplane worldwide.[5] A two-row version of the same engine was also produced, known as the Gnome 14 Omega-Omega or Gnome 100 hp. The prototype Omega engine still exists, and is on display at the United States' National Air and Space Museum.[2]

sectional views of the Gnome Omega


Gnome 7 Omega
Single-row 7-cyl. original version; 50 hp (37 kW).
Gnome 14 Omega-Omega
Two-row, 14-cylinder version using Omega cylinders; 100 hp (75 kW).


Gnome 7 Omega[edit]

Gnome Omega-powered airworthy Blackburn Monoplane of the Shuttleworth Collection
Gnome 14 Omega-Omega, as shown in a 1913 Gnome catalog.

Gnome 14 Omega-Omega[edit]

Engines on display[edit]

Specifications (7 Omega)[edit]

Brown staining of the Shuttleworth example caused by burnt castor oil

Data from Lumsden.[4]

General characteristics

  • Type: 7-cylinder, single-row, rotary engine
  • Bore: 110 mm (4.3 in)
  • Stroke: 120 mm (4.7 in)
  • Displacement: 8 L (488.5 cu in)
  • Length: 79 cm (31 in)
  • Diameter: 84 cm (33 in)
  • Dry weight: 75 kg (165 lb)


  • Valvetrain: pressure-driven inlet valves were located on the pistons[1]
  • Oil system: Total loss, castor oil
  • Cooling system: Air-cooled
  • Reduction gear: Direct drive, right-hand tractor, left-hand pusher


  • Power output: 37 kW (50 hp) at 1,200 rpm

See also[edit]

Comparable engines

Related lists



  • Hurley, Nick (2018). "Gnome 7 Omega". New England Air Museum. Archived from the original on Aug 17, 2018. Retrieved Aug 17, 2018.
  • Lumsden, Alec (2003). British Piston Engines and their Aircraft. Marlborough, Wiltshire, UK: Airlife Publishing. ISBN 1853102946.

Further reading[edit]

  • Moteurs d'Aviation Gnome (PDF) (in French). 49, Rue Lafitte, Paris: Société Des Moteurs Gnome. 1910. Retrieved 19 June 2018.

External links[edit]