I'm sorry I can't spend as much time as I wish I could on IL-2 right now, but I am working on a complete overhaul of the Battle of Britain segment, that will hopefully take care of this VERY annoying bug, that some people has fallen victim to, with their aircraft exploding on start on the runway...
Mind you, the campaign seems to work without snags for most people. The reason why some encounter this can be one of the following three (or a combination): Firstly a clash of installed mods, secondly a load-out problem, and thirdly a map bug. Cannons Beta Channel is pretty old, has its share of bugs and can be tricky to use. For instance: if you use the damage paint brush on the map, the front line markers will disappear. And if they are gone you will have the phenomenon of the mission saving forever in FMB. If you want to use the front line markers and avoid the saving for ever, you must lose all destruction on the map.
Anyway: as mentioned above a way to fix this is to load the mission in question in FMB, save it,
just save it, no changes needed, then have a go. But this will hopefully not be needed
with the forthcoming version 1.2, where the entire BoB-segment has been overhauled.
Sorry about this
EDIT: Version 1.2 now up. See post 1.