They used a roof-mounted, air-cooled, condenser of thin copper tubes in which the exhaust steam was condensed.
In 1918 most aircraft were biplanes with wooden frames, canvas skins, wire rigging and air-cooled engines.
It is of typical biplane layout, with the upper wing supported by cabane struts from the forward fuselage, and these also house the air-cooled radiator.
A significant disadvantage for air-cooled engines is that the rear cylinder runs hotter than the front cylinder.
Its air-cooled fuel cell systems use low-power fans to provide cooling and the oxidant supply for operation.
It was the first air-cooled inline engine, a design that proved extremely popular for light aircraft.
As far as petrol engines are concerned, perhaps the most interesting development of the year is an air-cooled engine operating with sleeve valves instead of poppet valves.
Perhaps the most striking engine advance of the year has been that of an air-cooled engine operating by means of a sleeve valve.
