N49
Don't know if it's the answer but Europe has only just gone to 65 from 60 a few years ago. The French took some time to move and many Pilots had to retire at 60 because of this (as for example in the UK flights overflew France)
I might be wrong but the 55 rule at BA may have gone up a few years?.
I think the answer to your question is at BA Pilots can afford to retire at 55 (being a heavily Unionised Company rules are also rules so they have no choice but to retire). Most other Airlines in the UK with perhaps the exception of Britannia (Thomson) and Monarch who have fairly good pension schemes, Pilots will soldier on until 60, and a few will go to 65 depending on how many ex wifes they have.
Many BA pilots who retire at 55 go onto other Airlines be it in the UK or Middle / Far East. I have known quiet a few and they are top notch guys / pilots