Editing Aircraft engine (section)

====Rotary engine====
[[File:Le Rhone 9C.jpg|thumb|right|Le Rhone 9C rotary aircraft engine]]
{{main|Rotary engine}}

Rotary engines have the cylinders in a circle around the crankcase, as in a radial engine, (see above), but the crankshaft is fixed to the airframe and the propeller is fixed to the engine case, so that the crankcase and cylinders rotate. The advantage of this arrangement is that a satisfactory flow of cooling air is maintained even at low airspeeds, retaining the weight advantage and simplicity of a conventional air-cooled engine without one of their major drawbacks.
The first practical rotary engine was the [[Gnome Omega]] designed by the Seguin brothers and first flown in 1909. Its relative reliability and good power to weight ratio changed aviation dramatically.<ref>{{cite book|title=Aviation|last=Gibbs-Smith|first= C.H.|publisher=NMSO|location=London|year=2003|isbn= 1-9007-4752-9 |page=175}}</ref>