Unfortunately, the bottom line is that you should ave bought IL2 1946.  
It is sold online for the same $9.99 price as (and this is a scam) the original IL2 Forgotten Battles (FB) OR Pacific Fighters (PF). 
You can browse for those titles at "Direct to drive" for examples: http://www.direct2drive.com/3021/product/Buy-IL-2-Sturmovik:-1946-Download 
What this particular retailer does not tell you (that is where the scam is) is that IL2 1946 contains IL2 FB+PF+all the patches and new airplanes until version 4.07m. 
  
I do not remember if PF is patchable to version 4.XX or over but I strongly encourage you to buy IL2 1946 (and possibly return PF if it is a physical version). 
  
To summarize for anybody that would want to purchase any of the IL2 titles: DO NOT let them trick you by price maneuvering! ONLY BUY IL2 1946 and you get ALL the series titles. 
  
From the IGN review: "IL-2 1946 is a collection of all things IL-2 up until this point in time: every add-on, every campaign and every plane, over 300 of the things by the last count. It also contains three new expansions of its own: PE-2, Sturmoviks Over Manchuria, and 46 (after which the collection is half-named, confusingly) - all mercifully merged into a single installation" (Sam Nolan; http://pc.ign.com/articles/751/751000p1.html)