I've played around a bit with aircraft movement data and created the following views. I did a bit of a read across over this thread, and it appears that I get the active/parked(since/where) mostly right. Wondering if you find this useful and if you have any ideas how to improve it:
Active Fleet: Aircraft that have operated a flight in the last 30 days.
Stored Fleet: Aircraft that have not operated a flight in the last 30 days, assumes that the last flight destination is where the aircraft is parked.
Leased Fleet: Non-BA aircraft that have operated a BA flight in the last 30 days.
Historic Fleet: Ex BA aircraft