FSX flightplanner

Hi all,

I'm tying to get some of my big questions on FSX answered and one is do I need the FSX SDK to make ai flightplans work? I've spent ages working on ai flightplans and they've all compiled perfectly (I'm using ai fligtplanner) but the planes never appear at all at the airport. It worked for me in fs2004 and there must be something I'm doing wrong. Anybody know what I can do? Thank guys.