Le Rhône 9C
| Industry | Aircraft engine manufacturing |
|---|---|
| Founded | 1912 |
| Products | Le Rhône 9C rotary aircraft engine |
The Le Rhône 9C is a French-manufactured nine-cylinder rotary aircraft engine developed by Société des Moteurs Le Rhône / Gnome et Rhône. Commonly referred to as the Le Rhône 80 hp for its rated output, this engine powered numerous military airplanes throughout the First World War. Production licenses were granted for manufacturing in the United Kingdom, the United States, and Sweden.
Design and development
Debuting in 1912, the 9C delivered 80 horsepower and was the inaugural nine-cylinder variant in the Le Rhône rotary lineup. It retained copper intake pipes and a single push-pull rod mechanism actuating two overhead valves, similar to preceding seven-cylinder versions. Unlike the subsequent 110 horsepower 9J model, its induction pipes and push rods were positioned at the front of the engine.
Prior to WWI, aircraft equipped with the Rhône 9C established multiple endurance records, including a significant journey from Paris to Gdańsk with only one refueling stop. The engine also powered aviator Georges Legagneux when he set a new world altitude record in 1913 while flying a Nieuport.
The 9C was adopted early for military aviation, initially installed in the 1912 Voisin Type 1. Throughout WWI, it was employed in various single-seat fighters such as the Nieuport 11 “Bebe” and the Sopwith Pup. As the conflict progressed, most newly manufactured 9Cs were allocated to training aircraft.
Captured examples of the 9C were fitted into German Fokker Eindekkers, substituting for Oberursel engines—these being licensed versions of the Gnome Lambda. The Le Rhône-powered Eindekkers demonstrated enhanced climbing ability and ceiling performance.
Surviving engines and reproductions
Operational Le Rhône 9C engines continue to exist across Europe and North America, powering both original and replica WWI-era aircraft within aviation museums and historical reenactment groups. Notably, the Shuttleworth Collection’s airworthy Sopwith Pup and the Owl's Head Transportation Museum’s reproduction Pup—constructed during the 1960s originally at Old Rhinebeck Aerodrome—both utilize the 80 hp Le Rhône 9C rotary powerplant, regularly flown during summer seasons.
These functioning engines play a vital role in heritage aviation by ensuring authenticity in restored planes, thereby supporting museum visitor engagement and educational outreach. Additionally, a working example of the Le Rhône 9C is displayed at Buenos Aires’ Museo Nacional de Aeronautica, reflecting global appreciation for this classic engine.
Engines on display
- A Le Rhône 9C is installed on the Sopwith Pup exhibited at the Royal Air Force Museum London. After a short flight period following restoration in the 1970s, this aircraft is now permanently grounded.
- Public exhibitions of Le Rhône 9C engines are also available at both the Aerospace Museum of California and The Hangar Flight Museum, contributing to heritage tourism and historical education efforts.