Since I did not get an answer over in "General Aviation", I try this section:
I have a question on slots, not the scheduled/planned slots, but the ACTUAL slots on a given day.
What I have in mind is the following situation: it is bad weather in LHR, and therefore ATC has to limit the number of arrivals to a number lower than planned. Often this results in planes sitting on the ground at their departure airport because they would not be able to land in LHR 90 mins later.
Now, an abstract example: if there is one landing slot at LHR, and there are two British Airways planes, say one in CDG and the other one in AMS, both requesting to leave to LHR (and assuming both are ready to go and all other things being equal): can BA operations influence the ATC decision, for instance, say they would prefer the plane from FRA to make it rather than the one from AMS for operational reasons (rotation of the plane for the rest of the day, more transit pax, whatever other reason)? Or does BA have no say in that and is purely dependent upon ATC discretion?