Aircraft — Propulsion units and components — Methods of numbering and describing direction of rotation

Specifies the methods of numbering aircraft engines, engine cylinders and combustion chambers, on drawings, for example, and the methods of describing the direction of rotation of main shafts and rotors and or propellers. The numbering of engines is given for horizontal thrust engines, vertical thrust engines and take-off booster engines. The numbering of cylinders in piston engines is given for in-line piston engines and radial piston engines. Furthermore the numbering of components in turbine engines and in rotorcraft engines is given.