Indexing to create a subset collection:
On the start page popup menu, "Maintain Indexes" menu item, check the menu item "Create Subset Files".
When this menu item is checked, it will become deselected when the function is completed. It works once then we can forget it. Creating the subsets takes several minutes.
This function will be performed the next time the scenery is indexed. A collection of Subset files is created and these can be seen on the Flight Generator Page, Airports Subset dropdown menu.
Subsets can also be created, and combined and subtracted together, on the Browse Airports, map page.
NOTE: With an AIRAC loaded the subset will only include those in the AIRAC. Generally we would build the Subset collection without AIRAC.
Soft Loose and Hard surfaces:
Notice also in this menu there are items for Soft Loose and Hard surfaces. These are the definitions into which those surface values belong. We can specify here which surface types appear in each group.
These Soft Loose and Hard surfaces types are set against aircraft preferences in the Mission page, Surfaces checklist window.
These settings in Ideal Flight are what we use to extract routes between grass strips or gravel or sand and so on.