Just check the video (not mine):
Was this an easter egg by Oleg? Or even TD?
Imagine the possibilities... Change the guns to something more realistic (like a Bofors), delete the missiles (but keep them for Korean war scenarios and later), and remove the engine sound.
I fully confirm that this works! The turret turn rate depends purely on the power setting, as long as the engine is on. Also, some funny effects when bailing out...