There are actually loads of permutations....here are some random thoughts in no particular order...
- AL flies 330/350 wide bodies on lhr route at peak times only releasing slots for BA longhaul
- AL feeds into LHR and services UK regions for BA just as it has for Little Red. BA then turns a profit on regional due to the significantly low cost base which AL has
- AL takes over Lgw routes utilising it's lower cost base and again makes loads of profit
- Some BA or AL flagged aircraft fly lhr/dub then onto US utilising CBP facilities
- big cull of back office staff/middle management at AL as no longer needed once integrated into BA which in turn generates huge underlying profitability
BA could fly their wide bodies to LHR at peak times and make better use of their slots but the simple fact when they are beginning flights to Greek islands it shows they have way to many slots currently.
Vueling is part of the group so if LGW is such a problem they could take it over.
It will never happen and I am not even sure FR would support such a move.
Not sure they would like Aer Lingus and Vueling under the same management.