Loathesome as I find Jet2, I have to say that this is a non-issue. Many European airlines offer unpaid leave every winter to their pilots and this does not mean the company is about to go under. As easyJet have demonstrated yesterday by posting their worst ever winter losses but promising their best ever profits for the whole year, companies make all their money in the Summer. Most training occurs over the winter and with less flights being flown generally there are always too many line pilots. Unpaid leave is just a beancounter's way of fleecing pilots - reduced salary for 2 months off but 900hours flying in the other 10!