I'm not suggesting that it is a bad scheme, or that people shouldn't apply. What I am suggesting is that anyone applying should be able to look at the finances rationally and understand what they are applying for.
Before you start working for BA you are likely to be over £100k down:
£84k for the scheme
£5k additional costs to the school (which aren't re-imbursed)
Living expenses
Plus accrued interest on the debt
You start on £23k plus allowances - lets say £32k. Based on normal UK taxation that would give you net pay of about £34k pa / £2k per month.
Many of the posters here seem to think that the repayment of the bond is income. It isn't - it is repayment of a debt that you have accrued on behalf of the company.
Out of that £2k per month you would have to pay interest on your loan - someothing in the region of £600 to £700 per month is probable. That leaves you with £1,400 per month to live off - which is equivalent to a salary of about £22k pa. That's not a lot of money for the quality of people they say they are looking for.
So then the key question becomes, for how long is your base salary £23k, at what rate does it increase, and what is it likely to increase to? None of those questions are answered in the recruitment literature and they don't seem to be available in the public domain. That in turn means that BA are asking for candidates of exceptional quality but aren't supplying them with the data which any rational person would need in order to make an informed decision about the FPP scheme.
I have no doubt that plenty of qualified candidates will apply regardless, but the lack of information seems odd to me.