You'll only get a definitive answer by asking someone at your own workplace, but FWIW
1. As far as I know for ID90's you have to go through your
own airline's staff travel department/office/admin. I'm not sure there's any other way of obtaining them - anyone else know for certain?
2. Most of the major scheduled outfits have some form of reciprocal staff travel arrangement with the other major carriers....
PS.. lexxity beat me to
