So it would look as if this indeed is the 767 replacement and additionally some growth and then some of the oher L/H fleet replacement.

It is probably correct that 50+ 747-400's isn't that flexible for a fleet and that some routes need more capacity and some less. At the time BA purchansed the 747-400 the options for L/H airframes was much more limited. Also based on the 77W BA's aim seems to be to slightly reduce Y capacity but maintain W, J and F (and in some cases even expand it). The J market in particular has changed beyond all recognition to that of 20-30 years ago. At that time nearly all Premium Travel was corporate paid for wheras now invdividuals paying for J is now 50% of the market and this is likely to continue in the future. As much as we all go on about capacity, with a few exceptions Y as a cabin makes no money at all and barely covers fuel costs........

So the next stage of the fleet will be interesting. It is clearly now the A350 vs 777X. I think you might see the options on the A380 converted but I suspect that BA is taking a cautious approach and wants to see how they perform in real life. This was what happened with the 77W - it was only after a few months when they could assess the peformance of these new birds that they then decided they really liked them and that they were peforming above all expectations. I would expect BA to review the A380 a few months after entry into service in terms of performance - I suspect that they will perform well but of course 469 seats is a lot to fill....

FD