I asked this during indoc and was told the company wnats you within 2 hour drive of your airport. There's a long list. Some are grandfathered in and others are active. The grandfathered bases are only for crewmembers that already have it as a base but the airline travel as diminished enough to where it's not a base anymore but they still honor it for them (depends on the amount of traffic they get). On the scheudle type. Company can't schedule you anything longer than 8 days unless you waive that, all the way up to 14 day trips. I see a good mix of 6,7, and 8 day trips with anywhere from 5-8 days off in between.