Yes, you are correct. You need the EA before you can use an AV or CS. Just like you need a car before you can modify the engine or give it a new paint job.
I have RF Evolution, which includes the ElectriFly Fokker DVII. The aircraft list indicates that this aircraft was in Expansion Pack 3 (2007) and in the Airplane Mega Pack (2011).
BTW - if you can afford it, RF Evolution is worth the upgrade. It includes almost everything from the previous versions, including the Expansion Packs. There are a few things missing, reportedly because of licensing constraints. But, overall, it is great and has new features.
Purchasing it via Steam has been a much better experience than I thought it would be. The program file structure is familiar, I can launch RF from the taskbar, and Steam automatically updates the program. Additionally, I like to tweak things and experiment with program files, which means I occasionally screw things up beyond repair. Uninstalling an re-installing the program via Steam is just a few mouse clicks.