A new version of EN 4604-009 was published by the European Committee for Standardization. EN 4604-009:2014 applies to “Aerospace series – Cable, electrical, for signal transmission – Part 009: Cable, coaxial, light weight, 50 ohms, 180 °C, type KW (light WN) – Product standard.” The new version is available for purchase on the CEN website.
“This European Standard specifies the required characteristics of a light weight coaxial cable, 50 Ω, type KW for use in aircraft electrical systems at operating temperature between 55 °C and 180 °C and specially for high frequency up to 6 GHz. Nevertheless, if needed, 65 °C is also acceptable as shown by rapid change of temperature test.”
*Description from CEN website