Month in the Patent Office

In an aircraft in which the engine is mounted in front of, and in a cowling continuous with, the wings, the cooling air enters through slots C1 in the wings and passes forwardly over the engine cooling surfaces to be discharged through an annular opening D, the size of which can bo adjusted by sliding axially a nose D1, preferably mounted on a tubular member D3 projecting into the airscrew spinner. The nose may be adjusted manually or by a thermal device. The air flow may be assisted by fans C2 driven by the engine or by electric motors and slats C3 may aid the flow round the bends. The cross‐sectional area of the ducts increases progressively ; exhaust is discharged by an annular ring E, air flow being thereby increased and drag on the aircraft reduced. The surfaces cooled may be finned cylinders, a liquid cooling radiator, or an oil or a charge cooler.