Issued in June 2009. This document supersedes the "Minimum Performance Specification for Airborne VHF Communication Equipment operating in the frequency range 117.975- 137.000 MHz (Receiver-Transmitter)", ED-23B, March 1995. This document contains a minimum operational performance specification for airborne VHF communications equipment (receiver and transmitter) intended to be used for airground communication. It is designed to ensure that equipment certified to it will be compatible with the relevant ICAO Standards and Recommended Practices as described in ICAO Annex 10 Sections 4.5, 4.7 and Appendix D. It is also intended to cover equipment suitable for use in an 8.33 kHz channel separation environment. NOTE: In the following text the channel spacing for 8.33 kHz channel assignments is defined as 25 kHz divided by 3 which is 8.3333.... kHz. This minimum operational performance specification defines the minimum performance expected of an aircraft VHF receiver-transmitter equipment; the performance of a specific equipment may be enhanced or superior to this specification depending on the intended application and configuration.