If there isn't a position for you in the winter you will receive a letter telling you that once your contract has ended you are being layed off full stop. You then have to wait for a new contract to come through the post with a new start date and you re-join. LGW has the highest turnover of staff and a very busy winter programme so fingers crossed you should be OK - unlike some of us at other bases who get laid off year after year after year after year...........