The flexi system by CTC should make you think very hard about becoming an airline pilot. Sadly, it is another nail in long term prospects of good terms and conditions. It means that an airline will employ you for 6 months, or whenever their high peak season is, and give you an unpaid period of leave until the next peak season. Unless you can rotate with another airline whose high peak is exactly the opposite, in which case will probably require you to travel to another continent, subject to employment laws, you will be on a very poor annual salary - don't burn your bridges with Tescos when you leave the shelf-stacking job, since you'll need to go back there for the winter.