[agracier]

Uberdood, as far as I know, you shouldn't have a 3do folder in your STD folder.
Unless this is a new development with UI 1.2, which I don't have, the STD folder is only supposed to have a 'com' and 'i18n' folder inside, in which you find the air.ini, plane_ru.properties and weapons_ru.properties files.

Hmmm ... I happen to have a 3do folder inside my STD folder. I remember installing it for a set of objects mods I believe.

The 3do subfolder is buildings/ToW ... and then a whole bunch of further subdirectories like watertower, telegraph_pole, sentry_box and so on .... all obviously objects ...

Of course, it doesn't have anything to do with installing aircraft, but apparently there is a mod that ended up being placed in STD/3do ...