The reason Ryanair and easyJet haven't tried it is that it adds substantial costs to the business. I suspect easyJet is now at the limit of what they can do as a loco without their cost base markedly rising. If your B73H does six legs per day you have six loads of passengers to sell to, one or two legs long haul with passengers asleep does not drive the same revenue. Norwegian can sell £300 less than BA to LA on selected days in summer is fine if you want to fly from your local at LGW direct to LAX, and it will do well if the start up calamity with the B787 doesn't go on and on. Laker used to serve this same market with DC10s up to 1981, LGW-JFK, MIA, LAX once they had the Series 30, via Bangor on the Series 10. If they do well enough, I have little doubt BA might shuffle another B777 to Gatters and try and spoil things, for everyone I might add.