Thus far, HSBC have been very accommodating to all cadets I have spoken to. The details of who to get in touch with are on the CTC forums, with accounts from people who have been through the process as well as some advice. Basically, your financial situation is reviewed when repayments are due, and then typically a 6 month deferal is arranged. Thereafter, you have to negociate further deferals in the same manner as required. Bottom line is communicate with them about the situation. They have a fairly good understanding of what's going on, but get the proceedings underway in plenty of time.