Actuary* speaking.
If the "average life expectancy for a longhaul pilot retiring at 65" was 18 months, that means for every such pilot who lived for more than 10 years about 8 would have to die within one year of retirement to make the figures work - I find this unlikely.
On the subject of Final Salary pension schemes, those who attribute much of the problem to Gordon Brown are (IMHO) spot on. However, closing schemes to new entrants often makes a lot of sense. Final Salary schemes only work in an environment where staff can reasonably expect to remain in the scheme for at least 10 years - preferably well over 20 (this is the amount of time it takes to build up a reasonable fund value, capable of providing a worthwhile, 'frozen' pension)). There are very few occupations left where this is the case, although (as a complete outsider) I could well imagine that BA flight crew could be one of them.
* an actuary is someone that always wanted to be an accountant, but lacked the personality for it ...