unmanned transport
I hadn't looked at this thread for a while. You assembled a lot of good and interesting information in your most recent post as well as your #139 post.
One other advantage of a two spool engine is its more rapid air start time verses a three spool engine. There was an incident years ago involving a Delta Boeing 767-200 (GE CF6-80A engines) departing LAX for CVG where this advantage became very important.
30 June 1987; Delta Air Lines 767-200; Los Angeles, CA: The engines were inadvertently shut off during climb at about 2,000 feet. The crew was able to restart the engines at about 500 feet and continued to their original destination of Cincinnati.
I recall seeing data (think it was in Aviation Weekly) regarding the time to start GE, Pratt and RR engines after a flameout and both GE and Pratt engines had the shortest restart times by quite a bit verses the RR three spool engine (RB211).
TD