Oh sorry I was typing to fast I meant Delta could serve Birmingham they seem different to the others and clearly American and United are focused on LHR, Delta send 763's, 764's and occasionally A332 to Edinburgh I think UA send a 763 occasional but mostly 752's. Delta could be the airline BHX wants it would look good for BHX to be served by the A380, 787, 777 and 767 or A330 or it's long haul routed. Even LHR still gets 752's of UA none of American. I don't know what Manchester gets I know Air Lingus have the A321 LR flying to JFK and Singapore serve Texas with there A350. I think if we do ever get Transatlantic service properly TUI would be the first bet to increase Orlando daily during the Season. Do Tui Serve MCO or do they just serve Melbourne?. For proper US Service all year round I either see Emirates maybe trying something or maybe Delta or perhaps Air Lingus UK.
At the start of the pandemic, American took the decision to retire its entire fleet of B757s and B767s. Their current wide-body and long haul fleet consists purely of the B777 and B787. The "smallest" aircraft they have based at JFK for long haul is the B777-200ER. Even using BHX's best year in recent times - 2016 saw just under 150,000 pax to JFK & EWR combined - a daily 777 would have a load factor of 75%. Obviously depends on yield and having a daily 777 might attract additional passengers, but even then its borderline as to whether or not it would be profitable. Currently American Airlines flies to just 7 destinations in Europe from JFK, the smallest of which is Athens, which in 2019 handled over twice as many passengers as BHX.
United flies the B757 TATL because it fits the smaller markets better. It's more attractive to passengers to have a B757 daily than a B767 five times a week. In total this Summer, United will fly to 30 destinations in Europe from Newark, a large number of which are new routes.
You state American and United are focused on Heathrow - so is Delta, if not more so. 86% of Delta's seats from the US to the UK this summer go to Heathrow, with the remaining 14% going to Edinburgh. Once you factor in Virgin, its LHR 83%, MAN 12% and EDI 5%.
United serves 3 routes from EDI vs Delta's 2, and even taking into account Virgin's flights out of EDI, United still offers over 25% more seats than Delta/Virgin and over 50% than just Delta alone.
Pre pandemic, Delta flew their B757s to a variety of European destinations. They were generally used in smaller markets or for launching new routes, which is likely why they aren't being used for that purpose now as Delta consolidates its European network post Covid. In total this Summer, Delta will fly to 21 destinations in Europe from JFK.
As has been mentioned, TUI is largely a holiday charter airline, and so New York doesn't really fit that model. I'd rather see them add new Caribbean destinations such as Antigua or St Lucia, or if its expansion in the USA, then maybe Las Vegas.
For decades, the B757 was the workhorse of TATL flights outside of the major European Hubs (LHR, CDG, FRA, etc). The A321LR and XLR are the 21st Century equivalent and have already entered service with Aer Lingus, TAP Portugal, JetBlue and SAS on TATL routes. American and United airlines are due to start receiving their XLRs from 2024 and will no doubt use them to increase frequencies on TATL routes, return to pre-Covid destinations they have yet to, and to launch new routes.
who knows whether Aer Lingus UK will keep going if AA were to return to MAN.
Aer Lingus UK also serves Orlando and Barbados from MAN and are largely filling the void left by Thomas Cook rather than American Airlines.