This question is going to continue to come up as more SF2 only releases are made available, so I figured I'd start a thread designed to help those who haven't made the jump for whatever reason to be able to enjoy creations made for the SF2 series. Now, realize this list only applies to third party aircraft. Stock SF2 aircraft LODs use different code, and so are NOT backwards compatable, period.   This list will assume several things:   1. That any Gen 1 install is patched to at least the Oct 08 patch level. 2. That you are intimately familiar with ini files (data, weapondata, gundata, etc) and how to change them. 3. That you are intimately familiar with the Gen 1 directory layout. 4. That you have good skills with the 'search' function. 5. That you have a good understanding of the various terms used in this list.   If any one of these statements is untrue, you will need to fix it before you can start making stuff backwards compatible. The modders will increasingly not have the time to be able to make 2 versions of the release.   Realize this list is only valid as of 30 Jun 09...any SF2 changes after that may continue to cause the generations of TW sims to deviate from each other, so continue to consult additional sources.   I would ask others to contribute to this list as they see fit. Realize, this isn't a 'step by step' list, merely a 'checklist' of what needs to be changed to use a SF2 aircraft.