
Article 1 
This Regulation lays down common airspace usage requirements and operating procedures for airborne collision avoidance to be fulfilled by:

((a)) operators of aircraft referred to under Article 4(1)(b) and (c) of Regulation (EC) No 216/2008 undertaking flights into, within or out of the  United Kingdom; and
((b)) operators of aircraft referred to under Article 4(1)(d) of Regulation (EC) No 216/2008 undertaking flights within the airspace  of the United Kingdom.
Article 2 
For the purposes of this Regulation the following definitions shall apply:

((1)) ‘airborne collision avoidance system (ACAS)’ means an aircraft system based on secondary surveillance radar (SSR) transponder signals which operates independently of ground-based equipment to provide advice to the pilot on potential conflicting aircraft that are equipped with SSR transponders;
((2)) ‘airborne collision avoidance system II (ACAS II)’ means an airborne collision avoidance system which provides vertical resolution advisories in addition to traffic advisories;
((3)) ‘resolution advisory (RA) indication’ means an indication given to the flight crew recommending a manoeuvre intended to provide separation from all threats or a manoeuvre restriction intended to maintain existing separation;
((4)) ‘traffic advisory (TA) indication’ means an indication given to the flight crew that the proximity of another aircraft is a potential threat.
Article 3 

1. The aeroplanes referred to in Section I of the Annex to this Regulation shall be equipped with and operated in accordance with the rules and procedures as specified in the Annex.
2. The Civil Aviation Authority  shall ensure that operation of aeroplanes referred to in Article 1(2)(a) of Regulation (EC) No 216/2008 comply with the rules and procedures specified in the Annex in accordance with the conditions set out in that Article.
Article 4 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Article 5 

1. This Regulation shall enter into force on the 20th day following its publication in the Official Journal of the European Union.
2. Article 3 shall apply as of 1 March 2012.
3. By way of derogation from paragraph 2, in the case of aircraft with an individual certificate of airworthiness issued before 1 March 2012, Article 3 shall apply as of 1 December 2015.
...
ANNEX (1) 

((a)) aeroplanes with a maximum certificated take-off mass exceeding 5 700 kg;
((b)) aeroplanes authorised to carry more than 19 passengers.
 (2) Aircraft not referred to in point 1 which are equipped on a voluntary basis with ACAS II shall have collision avoidance logic version 7.1.
 (3) Point 1 shall not apply to unmanned aircraft systems.

Operators shall establish ACAS II operational procedures and training programmes so that the flight crew is appropriately trained in the avoidance of collisions and becomes competent in the use of ACAS II equipment.
