For those who haven't read it yet:
https://assets.publishing.service.go...by_Leaders.pdf
24. While preserving regulatory autonomy, the Parties will put in place provisions to promote regulatory approaches that are transparent, efficient, promote avoidance of unnecessary barriers to trade in goods and are compatible to the extent possible. Disciplines on technical barriers to trade (TBT) and sanitary and phytosanitary measures (SPS) should build on and go beyond the respective WTO agreements. Specifically, the TBT disciplines should set out common principles in the fields of standardisation, technical regulations, conformity assessment, accreditation, market surveillance, metrology and labelling. The Parties should treat one another as single entities as regards SPS measures, including for certification purposes, and recognise regionalisation on the basis of appropriate epidemiological information provided by the exporting party. The Parties will also explore the possibility of cooperation of United Kingdom authorities with Union agencies such as the European Medicines Agency (EMA), the European Chemicals Agency (ECHA), and the European Aviation Safety Agency (EASA).
25. In this context, the United Kingdom will consider aligning with Union rules in relevant areas.
X. TRANSPORT
A. Aviation
60. The Parties should ensure passenger and cargo air connectivity through a Comprehensive Air Transport Agreement (CATA). The CATA should cover market access and investment, aviation safety and security, air traffic management, and provisions to ensure open and fair competition, including appropriate and relevant consumer protection requirements and social standards.
61. The Parties should make further arrangements to enable cooperation with a view to high standards of aviation safety and security, including through close cooperation between EASA and the United Kingdom's Civil Aviation Authority (CAA).
The way I understand it is that the UK would be leaving EASA but keep its national regulations aligned to allow future close cooperation. Regarding to licensing and certification, it will be interesting to see what is going to happen by 29th March 2019;
if mutual recognition is ended, are we going to see a straight "guillotine" or perhaps some sort of grace period to allow effectively obtaining both EASA and UK national licences, certification etc?