Hello HighIron. Not knowing which 3 aircraft you have this problem with makes it difficult. Some 3rd party weapons can cause CTD but this would be the same in Free Flight. As this only seems to happen in QC it might be the enemy aircraft & not the player aircraft causing the problem. It's also possible this could be caused by 3rd party scenery.

OK. The is4g aircraft should be fine. These were SCASM edited by the best in the business. Make sure any 3rd party weapons are installed correctly. Some aircraft seem to cause problems on certain systems & I never did find out the answer. It could also depend on your OS. Some aircraft that work fine on Win98Hagar give problems on WinXP. There are so many variables these days. This could be a simple thing like texture formats or some other unknown conflict. The number of wingmen could also affect it. You could try these aircraft in QC without wingmen to confirm this.

I'm shooting in the dark & running out of ideas. Maybe someone else can suggest something.

One thing. It seems I'm a little out of date. The latest versions of some of the is4g aircraft appear to be Gmax. It might depend on which versions you have.

Sorry. I should have qualified that. Gmax is one of the applications used to create the aircraft visual models. When CFS2 was first released all 3rd party aircraft were created with a payware application, 99% of which would have been a program named FS Design Studio. While these worked fine they did not have all the features of the default aircraft. Some of the earlier designs had the conflict with WinXP that I mentioned although this could be fixed with a special utility.

When FS2002 was released it became possible to create arcraft with all these features using a freeware application named Gmax which was bundled with it. In theory, these should be better but this is not always the case. There should be no conflict with these aircraft & WinXP.

You mentioned that you don't have a problem on your system with the is4g C205 Veltro. It occurred to me that this might have been created with a different application to the others. This might be worth looking into.

PS. I should point out that FS Design Studio has since been updated to version 2 which has similar features to Gmax. I use FSDS2 to create all my own CFS2 aircraft. I find these are actually better than Gmax designs for use in missions & campaigns. I would not expect it of the is4g aircraft but I have had a few problems with Gmax designs in CFS2 on my own system.

Thanks to all for the extra leads on troubleshooting info...I guess that's all I can do:  Get in and dissect folders and find commonalities with A/C exhibiting odd behavior and experimenting.

After my my 1st add-on downloads a few months ago, I'm finding there's a lot lot more than just copying and pasting a couple of files...that's for sure