An APD is a once per year (renews in your hire date month) ability to drop up to a 4 day trip (Not long ago DL had almost no trips longer than 4 days in any category). You don't get paid for it if you drop it. Here's the important part: With an APD, you can't pick up anything over the days that you've dropped. So let's say you dropped a 4 day trip on the 4th - the 7th. You want to pick up a trip that departs the evening of the 7th. You can't.

The idea behind the APD was that with the reserve days almost always capped, if something important is going on at home and you really need the days off, you can use an APD to get that. If it falls over a holiday, like Jan 1, then Skeds can decline to drop the trip even if coverage is good enough for an APD.

That said, if you have a medical issue or treatment you need to take care of, a family event such as a graduation or marriage, you can always ask your C.P. for the time off, he has the ability to call skeds and have them drop a trip. If you go that route, don't be surprised if he asks you to white slip something else or pick up another trip in the month especially if your category is short of pilots. I don't know why some C.P.'s ask that, but they often do. Sometimes C.P.'s will cover those sorts of drops with your vacation time, so you kind of get paid (vacation pay) -- if you don't want that to happen, make sure you communicate that to them.

You can check the contract for more details about the APD. It's not as useful as it once was, and it will probably cost you money to use. But basically it's there if something comes up and you don't have any other way of being off work... Cough Cough.

If you have a family emergency, ie: a death, your C.P. will authorize up to 4 paid days off, S-1 passes, to deal with that issue, all you need to do in that case is make a phone call.