This European standard provides instructions on the methods to be used when designing, selecting, manufacturing, installing, repairing or modifying the aircraft electrical and optical interconnection networks, now called Electrical Wiring Interconnection System (EWIS), and Optical Fibre Interconnection Systems (OFIS), subjects to the limitations defined in Clause 4 of this standard. The general content of this standard is described in page 2. A detailed content of this standard is given in Annex A. This standard lists all the relevant European standards related to EWIS and OFIS in Annex B.