scope:

FOREWORD

1. This document was prepared jointly by EUROCAE Working Group 75 "Traffic Collision Avoidance System (TCAS)" and RTCA SC-147 "Traffic Alert & Collision Avoidance System (TCAS)", and was approved by the Council of EUROCAE on 10 April 2013.

2. EUROCAE is an international non-profit making organisation in Europe. Membership is open to manufacturers and users of equipment for aeronautics, trade associations, national civil aviation administrations, and, under certain conditions, non-European organisations. Its work programme is principally directed to the preparation of performance specifications and guidance documents for civil aviation equipment, for adoption and use at European and world-wide levels.

3. The findings of EUROCAE are resolved after discussion amongst Members of EUROCAE and in collaboration with RTCA Inc, Washington D.C., and/or the Society of Automotive Engineers (SAE), Warrendale PA, U.S.A., through their appropriate committees.

4. EUROCAE performance specifications and other documents are recommendations only. EUROCAE is not an official body of the European Governments. Its recommendations are valid as statements of official policy only when adopted by a particular government or conference of governments.

5. Change 2 to ED-143/DO-185B provides for the following five (5) changes:

1. Improve the efficiency of the TCAS surveillance function so as to reduce utilization of the 1030 and 1090 MHz channel without reducing the effectiveness of the equipment's collision avoidance function.

2. Allow TCAS to implement a narrow band Mode S receive function compatible with the RTCA/DO-260B ADS-B receiver requirements without negatively impacting the TCAS receiver function.

3. Update the flight test requirements to add Atlanta as an alternate location for high density Mode S flight testing and to modify the combined air and ground density requirement accordingly.

4. Decrease the TCAS RA broadcast interval from 8 seconds to 1 second to be compatible with the intended use of this data by ground controllers.

5. Clarify the intent of interference limiting by adding text to the requirements and adding a new test.