Is this all taking place at the same airport. ???It could be, do you have enough parking space. ??? Another thing make sure you have the correct version AFCAD.
FS2002 only: There is a bug in the FS2002 AI terrain avoidance mechanism that prevent aircraft from landing at certain airports (e.g. Maui), or certain approaches to some airports. There is often not much that can be done about this, but it sometimes helps to open an alternate approach to avoid the ‘buggy’ terrain area by changing the wind direction, or making a whole different runway the active runway using AFCAD. Shifting the airport fix (see the Airports.txt file section) 5 or 10 miles away from the airport, and away from mountains, may also help. The terrain avoidance has been improved for FS2004.

FS2002 only: There is also a bug in the FS2002 AI descent planning. If they materialise at a medium distance on approach, such as 40 miles from the airport, they usually materialise at an adequate altitude for the descent profile, but then the aircraft will ‘rocket’ back up to their cruising altitude. They eventually re-establish a normal descent profile, but they are far too high to land given the limited distance to the airport. This can be fixed by reducing the cruise altitude in the flight plan, unfortunately this may require an unrealistically low altitude, such as 20000 feet for a 747. Opening a different runway (approach) may also help.

Another reason aircraft may not land is if the runway is too short for the type of aircraft.