Gnome Omega
# Gnome Omega

The Gnome 7 Omega (commonly called the Gnome 50 hp) is a French seven-cylinder, air-cooled aero engine produced by Gnome et Rhône. It was shown at the Paris Aero Salon held in December 1908 and was first flown in 1909. It was the world's first aviation rotary engine produced in quantity. Its introduction revolutionized the aviation industry and it was used by many early aircraft. It produced 37 kW (50 hp) from its 8 L (490 cu in) engine capacity. A Gnome Omega engine powers the 1912 Blackburn Monoplane, owned and operated by the Shuttleworth Collection, the oldest known airworthy British-designed aeroplane worldwide. 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.

Like all early Gnome et Rhône engines the Omega featured a single pushrod driven exhaust valve on the cylinder head; the intake valve was located in the piston crown, opening by inertia on the downstroke and feeding the intake charge from the crankcase into the upper part of the cylinder. No throttle was provided, the pilot controlling his speed by switching off the ignition when necessary.

## Variants

### 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).

## Applications

### Gnome 14 Omega-Omega

* Avro 501
* Blériot XIII
* Bleriot XXIII
* Bristol-Gordon England G.E.2
* Coventry Ordnance Works Biplane 10
* Deperdussin 1912 Racing Monoplane
* Nieuport IV.H floatplane
* Short S.41 Tractor Biplane
* Short S.57 Seaplane
* Short S.64 Folder Seaplane
* Short Admiralty Type 74

## Engines on display

* The very first Gnome rotary engine ever built, Gnôme Omega No. 1, is on display at the National Air and Space Museum, Washington, D.C.
* A preserved production Gnome 7 Omega engine is on public display at the Royal Air Force Museum London.
* A restored Omega is on display at the New England Air Museum, Windsor Locks, CT.

## Specifications (7 Omega)

Data from Lumsden.

### General characteristics

* Type: 7-cylinder, single-row, rotary engine
* Bore: 110 mm (4.3 in)
* Stroke: 120 mm (4.7 in)
* Displacement: 8 L (488.2 cu in)
* Length: 79 cm (31 in)
* Diameter: 84 cm (33 in)
* Dry weight: 75 kg (165 lb)

### Components

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

### Performance

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