Welcome to SimV kickboy,

As you're using Afcad, I'll assume you are designing for FS2004.

You need to 'exclude' the objects. The 'easiest' way is to use the 'Excbuilder v2.0' utility.

Download  ExcBuilder v2.0 here: http://www.scenery.org/design_utilities_b.htm

Excbuilder v2.0 requires 2 other downloads, if you don't already have them.

The FS2004 BglComp SDK from here: http://www.scenery.org/tutorials_fs2k4_SDK.htm

FSConnect.dll from here: search the Avsim library for fsc300.zip

A couple of tips for using Excbuilder:

-Make sure that the coordinates you enter are from the Northwest corner and Southeast corner of the 'exclusion area'. The best way is to Slew in the 'Top Down' view in the sim. Set the Top Down view options to North Oriented. In 'Slew' mode, press the keyboard Space bar to set the aircraft heading to 360*. Then slew around to collect the coordinates.

-The objects your excluding are probably autogen objects. You need to set the Exclusion Type to 'All Objects' to exclude autogen.

-Depending on the orientation of your airport it might be better to generate several smaller exclusion rectangles if you don't  want to exclude the autogen from the surrounding area.

**********************

A 'better' method is to create new airport terrain using the SBuilder program. It has functions to exclude objects, create new terrain landclass, flatten the area (required for Afcad surfaces to show properly if the area is not flat and level), and to place new scenery objects (hangers, etc.) for your new airport.

If you're interested in Sbuilder, let us know and we'll supply the links so you get the latest version. The learning curve for Sbuilder is higher but it is an excellent program  for any scenery design project in FS2004.

Dave