1) I can build the second fighter type. 2) While it remains in the airbase, this new type's icon is that of the attack helicopter. 3) When I select the new type's icon, the bottom left panel is completely blank for orders. 4) When I select the new type's icon, the bottom right panel is completely blank for the number of aircraft in the airbase. 5) When I scramble all units out of the airbase, all units of the second fighter type do go out. 6) When I set a rally point before building the second fighter type, units of this type do go out to patrol the rally point.
Am I missing something? Should other xml files be edited, as well?
The unit that I have in mind uses existing BH3s and TGAs, and replaces the mis-labelled "Harrier Jet" in the unitrules.xml file: