L 56/30 Official Journal of the European Union 27.2.2015 COMMISSION IMPLEMENTING REGULATION (EU) 2015/310 of 26 February 2015 amending Regulation (EC) No 29/2009 laying down requirements on data link services for the single European sky and repealing Implementing Regulation (EU) No 441/2014 (Text with EEA relevance) THE EUROPEAN COMMISSION, Having regard to the Treaty on the Functioning of the European Union, Having regard to Regulation (EC) No 552/2004 of the European Parliament and of the Council of 10 March 2004 on the interoperability of the European Air Traffic Management network (the interoperability Regulation) ('), and in particular Article 3(1) and (5) thereof, Whereas: (1)  Commission Regulation (EC) No 29/2009 (3 lays down requirements for the coordinated introduction of data link services based on air-ground point-to-point data communications. (2)  Air navigation service providers and operators have reported technical issues when implementing Regulation (EC) No 29/2009, particularly disconnections, known as Provider Aborts (PAs’), of existing air-ground data communi- cations enabling the operations of data link services (DLS’) and which are beyond acceptable performance levels. For that reason certain air navigation service providers have already taken mitigation measures, consisting of the restriction of DLS operations to aircraft equipped with specific avionics through so-called ‘white lists’, so as to address potential safety impacts of those PAs in the operations of data link service. (3) At the request of the Commission, the European Aviation Safety Agency (EASA) conducted an investigation (*) to identify the root cause or causes of those technical issues and to recommend measures to address them. The investigation revealed that the random PA occurrences could not be attributed to a single, predictable cause but rather to a combination of factors related to the radio frequency environment and to the current single frequency implementation of the data link infrastructure. It was found that this excessive rate of random PAs causes a degradation in the network performance potentially presenting aviation safety risks by increasing the pilots and controllers’ workload and creating confusion leading to a loss of situational awareness. (4)  EASA concluded in its investigation report that acceptable data link performance levels can only be established by deploying a multi-frequency infrastructure, which is also to be optimised for radio frequency interference prevention. It recommended establishing and implementing a plan of actions to further investigate the identified technical issues and to validate the necessary technical solutions. However, these measures require time and EASA therefore recommended to reconsider the date of application of Regulation (EC) No 29/2009 and the timeframes of that Regulation. EASA also recommended that the implementation of the plan of actions be preferably performed by the deployment manager as referred to in Commission Implementing Regulation (EU) No 409/2013 (9. (5)  In addition, with a view to addressing specifically the aviation safety aspect of DLS operations pursuant to Regulation (EC) No 29/2009, on 23 May 2014 EASA issued Safety Information Bulletin No 2014-14, which recommends that operators revert from data to voice when confronted with a high level of PAs. (6)  In line with the EASA recommendations, the Commission instructed the SESAR Joint Undertaking (‘SJU’) to draft a work plan for further investigation of the identified issues and for carrying out the specific actions () OJL 96, 31.3.2004, p. 26. (%) Commission Regulation (EC) No 29/2009 of 16 January 2009 laying down requirements on data link services for the single European sky (OJ L 13,17.1.2009, p. 3). () European Aviation Safety Agency, Report ‘Technical issues in the implementation of Regulation (EC) No 29/2009, version 1.1, 23.4.2014, document reference 2014 _03_24 E4 D 51431 REP _DLS 1.1 (*) Commission Implementing Regulation (EU) No 409/2013 of 3 May 2013 on the definition of common projects, the establishment of governance and the identification of incentives supporting the implementation of the European Air Traffic Management Master Plan (OJL123,4.5.2013,p. 1).