3rd turbine in the tail?
This is probably the first time I've posted on this forum, but had a curiousity that I wanted to lay to rest. On some aircraft there is a 3rd turbine in the tail section of the airplane.. I've heard (from where, I can't remember) that this is primarily used to generate power for the aircraft, and is not necessarily used for thrust. Is this just myth or is it actually used to power the aircraft while in flight, etc? Thanks in advance!
Joel