[Babul]

you are creating the airportcheckpoint in the command for both airports, LS and SF.. that looks good
what doesnt look good, is that in the EnterCheckpoint you are...
case 1: destroying airportcheckpoint[playerid],
and in
case 2: destroying airportcheckpoint
...without the [playerid]. i bet its the [playerid], either missing, or too much, idk which airport CP gets succesfully destroyed....
airportcheckpoint = CreateDynamicCP[playeird](blablabla); shoudl work i guess hehe