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Double Back
4th Jun 2018, 10:22
Was talking this week about an "experience" I had, long time ago when still F/O on the B747 200-300 series, that is with a F/E for the magenta drivers.
Our 200's were equipped wit P&W engines, and one of the features it lacked was the automatic fuel heat, besides having no auto throttle!
During cold nights the F/E was kept awake by this more or less continuous monitoring.
On one occasion he must have dozed off because suddenly the engines started to accelerate beyond the cruise power lever setting we had selected. I grabbed the handful of throttles to stop the movement and the now wide awake F/O immediately switched on the Fuel Heat which solved all.
I cannot remember why the engines accelerated and not roll back because of the forming of ice crystals. Anybody a clue?

torghabe
5th Jun 2018, 10:18
Never heard about this problem with GE engines. Fortunately.

Double Back
5th Jun 2018, 11:13
Indeed, flew the magnificent CF6 on the 300 series and later as a Cpt on the -400 for 17 yrs. In all I must have flown over 22 yrs powered by CF6. I NEVER had an engine failure! (Imagine the cost reduction I could have generated without all of my N-1/-2-3-4 training :) :) :) ). It swallowed ice, hail, rain and birds without problem and took maxed out cold fuel.
It ran even w/o electric fuel pumps, tested that as I flew a few years as technical pilot, during flights after heavy maintenance which needed inflight shutdown testing and restart. So at one occasion, just for the heck of it, we left the throttle in cruise with pumps off (engine kept running normally) and put the start lever in off. After the compulsory 3 mins wait we just added fuel again and ignition. It lit up and went to idle where it hesitated a moment and went gently to the cruise power selected. still with pumps off. It was an almost boring event.
Great engine and a great plane. Both never let me down or bit me and I got to my retirement incident free, which after 10 years still gives a fantastic feeling. Sorry to see them slowly being decommissioned and move to the frying pan factories.

LeadSled
5th Jun 2018, 12:08
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!!