CTC will 'secure' £30,000. This means if you fail the course early on, CTC will pay up to £30,000 of the remaining money owed to the flying school. This means you will be liable for the other £30,000 of debt from the time you sign the papers in the bank.
If you fail later on in the course when CTC deemed you to have had your 60 grands worth, they could ask for the other 30K.
The £60K loan, plus any other loan is, to be paid back, in full, with interest, over a 7 year period after employment.
Your salary upon starting is reduced by £1000 per month to pay back your loan from source.
£12K x 7 years = £84K*
Remember this is not a sponsored course; you are offered preferential financial arrangments with very strong chance of employment!
*edit: I'm sure it's not this figure to the penny but a rough estimate