I have been scratching my head over how to make a Lancaster bomber fly across the soundstage (don't ask!) and finally cracked it.

I'm so pleased that I simply must share it.

"For a mono track, duplicate the track and set one to the left channel and the other to the right channel. You can now use the volume envelope tool to control the levels of left and right independently.

For a stereo track, split the track into left and right tracks and again use the envelope tool to control the levels."

stevethefiddle - take a bow.

Full thread here.