all ground handlers should be taking on temporary staff this summer.. but if flights dont increase much this summer with the "credit crunch" then they might not..
i originally started on a 3 month contract over summer, most of them give you the option to either work 2 months (july / august) if ur going to uni, or if ur not then they will let you stay for september as students heading off to uni usually keeps the flight numbers high.
training for ground handling will usually be 1 or 2 weeks and will include classroom sessions about security, triple A, manual handling, dangerous goods and a few other things, to be honest... thats the most boring part but its important.. since ur summer staff dont expect to be trained up... u'll be doing all the basic stuff
make sure you have a contacts from school/college, former employees that you can get a reference from so that u can get security clearance, as u will be on a temporary pass and will need to be escorted everywhere u go..
, so the faster u can get the references the better (will still take 2-3 weeks though..)
its a great job though, but expect to go home sore for a couple of weeks
