I feel like such a rookie asking this....
I just downloaded the SimWings Airport pack off of the STEX, a modular airport set by Ace, and a set of runway/taxiway lots - popped into SC4 to fiddle with my new airports and found, to my considerable suprise, that all the new lots (except for the runways and taxiways) do not appear in the menu.
Here's a quick rundown of the stuff I added to my plugins:
SimWings Airport v2.2 *Thalassicus' updated airports still show up, but nothing else*
RMIP Small airport edition 1 *these lots appear in my menu*
RMIP Small airport edition 2
RMIP Runways (concrete and asphalt) *these appear in my menu*
ACE Modular Airport Basepack
Any thoughts would be helpful.
I am about to install the airport packs myself.
I recall in the readmed research that the RMIP Vol1 has a dependency on the SimWings pack and the SimWings pack also has some additional dependencies.
I'll let you know how I am doing on this.