For CHQ (supposedly running a class late this Summer/early Fall for attrition): least JFK, then LGA, CMH, and SDF is the most senior

S5: EWR and LGA, most senior is IND or ORD

YX(170): CMH/PIT (least), middle PHL, most senior is DCA/ORD/IND

Renewed talks of a Miami base again, if so; it will probably be super senior... I work for CHQ, so it's the cert I know most about.