This standard establishes uniform requirements for Packaging for the Common Functional Modules (CFM) within an Integrated Modular Avionic (IMA) system. It comprises the module physical properties and the Module Physical Interface (MPI) definitions together with guidelines for IMA rack and the operational environment. The characteristics addressed by the Packaging Standard are: Interchangeability: çø For a given cooling method all modules conforming to the packaging standard will function correctly when inserted into any rack slot conforming to the standard for the cooling method. çø All modules conforming to the Module Physical Interface (MPI) definitions for connector, IED and cooling interface will function correctly when inserted into any rack slot conforming to the same MPI definition. Maintainability: çø All modules are easily removable at first line. çø No special tools required at first line. çø No manual adjustment is necessary when installing modules. No tool is required for installation or removal of the modules. çø Mechanical keying is provided that prevents insertion of a module into a rack slot that may cause an unsafe condition. The Module Physical Interface definition, contained within this standard, does not include the properties of the signalling used in the optical interface (e. g. wavelength). These are covered in EN 4660-003.