This is the £138million question. I hear TUI are quite short on aircraft since leaving DSA and are unlikely to be able to commit to a new base. Jet2 are an outside possibility because they’ve reached a level of maturity where their customer base is incredibly loyal, but it still poses the question of why would they when they happily fly from LBA and EMA already, and both airports are investing heavily in their passenger facilities at the moment.
Jet2 will not be interested in DSA unless it demonstrated it could fill enough flights, which it did not in its entire lifespan. They are quite a pragmatic company, not known for taking too many risks but instead opting for safe bets, which DSA certainly isn't.
Question marks over easyjet, purely because it’s an open market for them in Yorkshire. There is a chance that should an experienced airport operator be at the helm of a DSA 2.0, they could influence easyjet enough to take a risk and go all in. Problem with that is their lacklustre support received when they attempted it twice previously, and they maintain a token presence at LBA I believe as a means of communication as it’s highly plausible they’re a target airline for when LBA has sufficient space to host them. However, with very little presence east of the Pennines they are a best case scenario for high volume growth at the moment. But just look at what happened at Southend as a cautionary tale.
easyJet are an unknown element, but as with Jet2 they need to fill flights and would be unlikely to consider being the first operator at DSA.
Wizz might return, but knowing Wizz they might stay at LBA. Anyone’s guess.
Wizz have reportedly said that they have been able to grow some of their core routes since moving to LBA, so they are unlikely to want to move back to DSA.
Ryanair, who knows. They got an excellent deal before but still couldn’t be convinced to base there. One of their largest bases in the U.K. is at EMA, and they’re growing at LBA. Is there room?
If Ryanair couldn't make it work at DSA, well who could?
KLM, perhaps they could be tempted across from Humberside. However they have operated from Humberside in various guises for 50 years. Is a change likely considering the clamping down on slots at AMS? It didn’t work out well when they tried to set up from LPL and EMA so what makes DSA an attractive proposition for them?
As with Wizz, if their business is steady on Humberside why would they move?
DSA's prime failing is that there simply isn't enough demand to attract and keep major commercial airlines interested an making money. Its an airport nobody really needs, and serves only to feed the egos of a few Labour councillors in South Yorkshire.
Interestingly, TUI has recently signed a deal with Ryanair actually to sell TUI holidays with Ryanair flights. If the fees are priced right, I could definitely see Ryanair operating flights into DSA from their bases in Spain / Portugal / Greece in the same way they do to airports like Teeside, Newquay and Norwich. It’s much lower risk than basing aircraft at DSA, although probably will mean the airport needs continual subsidy.
As above, Ryanair will only fly from there if they can fill flights. They couldn't previously so its highly unlikely they'll try again.