A further option for Manchester Airport to Newcastle is to use Northern from Manchester to Oxenholme Lake District, then pay for a separate ticket from Oxenholme Lake District to Carlisle, then resume your journey by Northern from Carlisle to Newcastle. Obviously this costs more than £0 because of the need to buy the separate ticket, but it can have a very competitive journey time. A further option could be to make a change of train at Salford Crescent (or walk from Manchester Piccadilly to Manchester Victoria) and Leeds, with another separate ticket from York to Newcastle. However this adds further changes of train into the mix so of course may be less convenient and is sometimes slower. It all depends if there's a Northern service from Manchester Airport towards Oxenholme Lake District when you're ready to set off. As others have said perfectly permitted to go via Settle or via Whitehaven if you would like to and have enough time!