MarkC From United States of America, joined Apr 2006, 259 posts, RR: 0 Reply 2, posted (7 years 4 months 7 hours ago) and read 3004 times:
That is what they are. That is where they are. I see these on a daily basis. The other ones are removed in your picture. They go around the circumference of the Fan Exit Rear Case just like the one shown.
Fr8Mech From United States of America, joined Sep 2005, 4738 posts, RR: 12 Reply 7, posted (7 years 3 months 4 weeks 17 hours ago) and read 2741 times:
Quoting AC320tech (Reply 6): But if that is true, wouldent we be able to see the guide stop outlines on the cowling?
Guide stops? Not sure what you're asking here.
Here's a brief anatomy of what we're seeing:
-At the very top, fwd of the pylon is the thrust reverser air motor (just visible).
-Below that, as discussed is a cascade segment.
-The green ring the segment is attached to (fwd) is the translating ring. This ring moves fore and aft and is continuous from the top of the engine to the other side. If I had to guess, about 320 degrees.
-The cascade segment is attached, at its aft mount, to the translating sleeve. Housed in the sleeve, inner, out of our view, are the blocker doors and the operating links.
-Forward of the ring, are 2 of the TR gearboxes and their jackscrews. These are linked together, in series, with 2 more on the other side, by shafts (heavy cables) to the TR air motor.
I don't see any other TR component from this view. Incidently, the fixtue on the engine fan case about half way up, is the attach point for the engine change equipment.
Yes, the engine was (is) maintenance intensive. Chapter 75 is a bear on the -7A/AH's and only marginally better on the -7Q. The reverser is always locking up. The early engines leaked oil and the fuel leaks on the -7Q would clean off the oil. The core cowl could kill you if you're not careful.
Fr8Mech From United States of America, joined Sep 2005, 4738 posts, RR: 12 Reply 13, posted (7 years 3 months 3 weeks 5 days 23 hours ago) and read 2547 times:
Minor improvments, but no real change. The engine doesn't really leak much oil, but the breather/cowl interface isn't the best and you always get a film of oil under the cowl. The engine uses a horrendous amount of oil compared to today's standards. I believe our limit is 1.25 qts/hour.
Fr8Mech From United States of America, joined Sep 2005, 4738 posts, RR: 12 Reply 15, posted (7 years 3 months 3 weeks 5 days 7 hours ago) and read 2476 times:
The B747-2XX normally has -7Q engines (if PW equipped) though I know of at least one tail that had a set of -7J engines installed.
As for the fairings; I think there are a couple of -1XX that have the high speed fairings installed, I don't believe it's a -2XX installation only. I'll keep on eye on our birds as they cycle through to confirm.