This is in ETO with 1.0, 1.2, and bombers, all installed
it happens to whatever I plane I am in when I come to the main menu area. It happens at any airfield, I cant name them though. For example, I reinstalled everything and I booted up ETO for the first time on era 5, and as soon as I hit the main menu the plane that was sitting there goes BOOM!!! (I think It was a P-47D). However when I go into quick flight, I cycle through the planes there and they dont explode. Until after I come back to the main menu after the quick flight, then boom! the plane i just flew in explodes, and it doesnt matter what plane i chose. This happens to kill my pilot in any campaign as soon as I create my character and make it to his campaign menu. Doesn't matter what nationality or plane chosen.
I started with CFS3 Firepower v1.08, then ETO 1.0, then 1.20, then the bombers pack.

LastPanic, I think I just found your problem. ETO was neither designed nor tested with FirePower. This may well have messed up your install. You need a clean, fully-updated (3.1 and 3.1a) vanilla install of CFS3 in order to install ETO Expansion 1.0, then ETO Expansion Cumulative Update 1.20.
This solution should have you up and running, give you a vanilla CFS3 install for installing other CFS3-based add-on standalone theaters (MAW, PTO, etc), and retain your FirePower install.
Before you do anything else , do this. To save time, go into your CSF3 ETO Expansion main game folder and look for this file: MultiCFS3.exe. Copy this file to a safe location.
Follow these steps exactly:
1. Delete, not uninstall, your ETO install completely. This should be in C:\Program Files\Microsoft Games, unless you installed it elsewhere. This includes deleting the two folders that are named "Combat Flight Simulator 3.0" that are found in these two locations:
For Windows XP:
A. C:\Documents and Settings\User Name (Your Name)\Application Data\Microsoft
B. C:\Documents and Settings\Kasey\My Documents
For Windows Vista:
A.
C:\Users\\AppData\Roaming\Microsoft
B. C:\Users\\Documents
While you are at it, delete the two folders named Combat Flight Simulator 3.0 that are in these locations.
2. Delete all desktop icons relating to CFS3 and ETO.
3. Now, re-name the Combat Flight Simulator 3 folder that is in Program Files/Microsoft Games to reflect that it contains FirePower. Afterward, drop in a copy of the Multicfs3.exe that you saved elsewhere, and run it. Use it to re-name the CFS3 install to reflect FirePower. After you have done this, go back into the newly re-named install that contains FirePower, and look for the file named "cfse.exe". Right-click on it and send it to desktop as a shortcut. Go to the desktop and re-name this new icon to reflect FirePower. Start this game up and exit. You now have two new folders in Application Data/Microsoft and My Documenets for the FP install.
4. Now simply re-install CFS3 normally, and apply the two updates (3.1 and 3.1a). You will now have a new CFS3 icon on your desktop. Leave this alone, as you will need it to start this new vanilla install. When you start up with this icon, you will have two new folders in Application Data/Microsoft and My Documents named Combat Flight Simulator 3.0. You vanilla install is now ready for installing any CFS3-based add-on standalone theater, such as PTO, ETO, MAW, etc.
5. Install the CFS3 ETO Expansion 1.0 through your new vanilla install. Start it up and set everything inside the way you want it, as normal. Then exit.
Note: Start ETO in Era 1 and exit, then set the ETO Spawn Selector to 1 before installing CFS3 ETO Expansion Cumulative Update 1.20.
6. Finally, you can now safely install the 1.20 update. After this, all should work just fine.
I hope that this helps.:d