Have the UK Government reached an agreement with the EU on commercial UK <-> EU flights in a no deal scenario?
The UK and EU have both offered assurances that flights will continue to fly in the event of a “no deal” scenario.
Although it looks like an agreement to cover the long term has not yet been negotiated.
https://www.gov.uk/government/publications/flights-to-and-from-the-uk-if-theres-no-brexit-deal/flights-to-and-from-the-uk-if-theres-no-brexit-deal (“After March 29th if there is no deal”)
While the EU is implementing legislation to keep planes flying in case of a no-deal brexit, it's not business as usual. According to the FT, the legislation caps the number of flights between the EU and UK at 2018 levels.
Specifically, the FT writes:
The criticism by Alexandre de Juniac, director-general of the International Air Transport Association, was in a letter to Michel Barnier, the EU’s chief Brexit negotiator, responding to Brussels’ plan to cap flight numbers between the UK and EU at 2018 levels.
Edit: a new FT article has suggested that for British airlines to maintain "full flying rights" requires they are majority-owned by EU shareholders. According to the same article, Ryanair and Easyjet do have plans to fulfil these requirements, however, IAG (owner of BA, Iberia, and others) does not meet these requirements (only 25% of ownership is EU-based).
The article also notes that different EU countries prefer different approaches. To quote the article:
French calls for hauliers to enjoy full single market rights for a limited period after Brexit was rejected by other member states.
Germany and the Netherlands were among countries calling for a more disciplined approach to contingency measures for a no-deal Brexit, according to a diplomatic note of the meeting.
In its original proposal, the commission avoided giving airlines a period to adjust. At this week’s meeting it noted “the concerns” of several member states over airlines’ ownership and control, including Spain, France, Cyprus, Hungary and Ireland. But EU officials noted “we should not give an uncompetitive advantage to those which did not plan in advance”.
It's not clear to me if the 7 month grace period has been agreed definitively by the EU or not.