Double back,
Way back when, that would have cost the FEO a lot of beer at the next slip.
A vague memory about variable inlet guide vanes which were driven by fuel pressure from the high pressure fuel pump ---- does that ring a bell ---- it's a long time ago since I played with JT9D-3A/7/7F-J etc.
Fortunately, the -7RE was a big improvement, but VIGVs and those pesky HP fuel pumps still caused problems from time to time.
I concur about the CF6, in my case the CF6-80C2 mostly, great engine.
Tootle pip!!