scope:

FOREWORD

The availability of the automatic dependent surveillance - contract (ADS-C) in oceanic airspace allows the application of improved separation procedures which enables aircraft to fly closer to their optimum flight level.

The Separation and Airspace Safety Panel (SASP) developed the ADS-C climb and descend procedure (CDP) that is detailed in the PANS-ATM in response to the demand by airlines to facilitate the assignment of optimal altitudes.

This circular provides guidelines and supporting material for the implementation of the ADS-C CDP intended for use with aircraft equipped with ADS-C, direct controller-pilot communication (using either voice or controller-pilot data link communication) and an air traffic service provider equipped with a ground-based automation system capable of calculating the distance between aircraft by using their near-simultaneous ADS-C position reports.