There was a check XML application in with one of the Microsoft CFS-3 SDK's not sure which one but will have a look in side main folder i remember it as being described in one of the Kits
connect to the internet (so it can access the Microsoft site) and run it
it checks all of the XML Files campaign, arcraft, Buildings, facilities the whole games i would start there you may need to have GMax 1.2 to allow it to install and the Microsoft avsdk15 (aircraft & Vehicle development kit) for the "XDPCheck" tool

Or

Campaign_generator_version_1-1 by Rainer Lübke from sim-outhouse this will check all aircraft & Vehicles but you need Microsoft Excel (spreadsheet) "office & Student" to run it

But just thought try running the standard Microsoft Campaign & look to see if areas on the map are gray (no fly zone) if any are you need to move (such as)
      
<SectorProperties>
         <LandClass>
         <Open>A1~AW17</Open>
            <Open Subtype="Road">N56~O56</Open>
            <Open Subtype="River">K36~R36</Open>
            <Open Subtype="Hedgerow">N33~Z20</Open>
            <Water>A5~BD52</Water>
            <Forest>A12~AX26</Forest>
            <Forest Subtype="River">AC43~ZB45</Forest>
            <Mixed Subtype="Road">E15~AA23</Mixed>
            <Mixed Subtype="River">E43~AT32</Mixed>
            <Mixed Subtype="Hedgerow">V21~Y21</Mixed>
            <Mountain>S48~AR36</Mountain>
            <City Subtype="Road">H16~AB50</City>
            <Town>F46~AR32</Town>
            <Town Subtype="Road">AB15~AB17</Town>
            <Coastal>A4~AX27</Coastal>
            <Swamp>H35~N31</Swamp>
            <Swamp Subtype="Hedgerow">I33~L32</Swamp>
            <Unknown>A1~AK43</Unknown>
         </LandClass>
      </SectorProperties>
   </Grid>


The letters such as "A1" in the "<Unkown>" this is squire from the campaign map section & is a no fly zone to another section i.e. <Forest>A1,A12~AX26</Forest>

hope this helpped
NRev