AC320tech From Canada, joined Jul 2006, 197 posts, RR: 1 Reply 4, posted (7 years 4 months 3 weeks 3 hours ago) and read 2962 times:
All the 707-120 and -320's have JT3C's and when you see pictures of it, is one whole engine with no LP bypass (thats open, because the JT3C is a turbojet) like on the JT3D, so the C should probibly stand for Closed.
Hahahaha at Kevin, it should be, considering RR them selves are not pleased with the fuel consmption of those engines.
Kaddyuk From Wallis and Futuna, joined Nov 2001, 4126 posts, RR: 27 Reply 9, posted (7 years 4 months 3 weeks 1 hour ago) and read 2929 times:
Quoting AC320tech (Reply 8): Kevin, do you have any trouble with the tripple spool?
The shaft protection can be a pain (the system that detects if any of the shafts have sheared). Causes some troubles at time however normally a reset and functional test of the EEC fixes the problem. Operationally the engine causes little trouble, but it can make for awkward delays... Most engine issues i see are with items attatched to the powerplant (Hyds, Elecs, Bleed etc...)
[Edited 2006-08-03 03:47:36]
Whoever said "laughter is the best medicine" never had Gonorrhea
Jetlife2 From United States of America, joined Jul 2006, 217 posts, RR: 25 Reply 10, posted (7 years 4 months 2 weeks 6 days 23 hours ago) and read 2908 times:
RB = Rolls Barnoldswick
CF = Commercial Fan
CJ = Commercial Jet
CFM = Commercial Fan Moteur
Sub-naming conventions for GE:
major models are, for example, Commercial Fan 6 (CF6).
This becomes a family name - and now has acquired a "Brand" value. So quite a range of engines are designated under the "CF6" family name, even though this spans CF6-6 up through CF6-80, where you could have easily designated them CF6, CF7, etc.
Simlarly CFM56 was named using part GE, part SNECMA methods. SN designates in sequence "Moteur 56", "Moteur 88" etc. So we have
CFM56 = Commercial Fan Moteur 56
The CFM56 is now a brand so it acquired sub types CFM56-2, -3, -5, etc. The missing numbers (-1, -4) did exist as studies. Extra credit if you know which applications they could have been. The -6 was not used to avoid possible confusion with CF6.
Further models within a family have names that designate the basic engine, such as
These are just the start....
suffix B - Boeing, A - Airbus, D - Douglas
sometimes suffix F means FADEC (vs PMC) but this is so common now, so no longer used for new programs.
first example CF6-80C2D1F is a "CF6-80C2" engine built for the first Douglas installation (D1) with a FADEC
2nd example CF6-80C2B6F is a "CF6-80C2" engine for the 6th Boeing application (B6) with FADEC. Why 6? Different thrust ratings for Boeing would be counted B1, B2, etc.
3rd example CF6-80E1A1 is a "CF6-80E1" engine for the first Airbus application (A1).
AC320tech From Canada, joined Jul 2006, 197 posts, RR: 1 Reply 11, posted (7 years 4 months 2 weeks 6 days 22 hours ago) and read 2900 times:
Quoting Kaddyuk (Reply 9): Most engine issues i see are with items attatched to the powerplant (Hyds, Elecs, Bleed etc...)
The Embraer E-Jets have lots of "sensor" issues and bleed issues on the CF34. These sensor issues are common, and can be fixed by simply "resetting" the aircraft (IE powering it all down, or resetting the FADEC) which can take upwards of 15 minutes.
DarkBlue From United States of America, joined Sep 2003, 233 posts, RR: 10 Reply 13, posted (7 years 4 months 2 weeks 6 days 9 hours ago) and read 2812 times:
Quoting Jetlife2 (Reply 10): 2nd example CF6-80C2B6F is a "CF6-80C2" engine for the 6th Boeing application (B6) with FADEC. Why 6? Different thrust ratings for Boeing would be counted B1, B2, etc.
Boeing has 2 aircraft that both carry CF6-80C2 (747 and 767) and for the most part, the engine is only differentiated by thrust rating. However, I've noticed something that helps me remember which rating goes on which aircraft. I'm sure this was entirely unintentional, but odd ratings (B1F, B3F, B5F) are on the 747, while even ratings (B2F, B4F, B6F, B8F) are on the 767. The one except to my dumb little rule is the B7F which is on the 767.
Quoting Jetlife2 (Reply 10): These are just the start....
suffix B - Boeing, A - Airbus, D - Douglas
and i'll carry on in the CF6 family with:
L - Lockheed, K - Kawasaki (for the CF6-80C2L1F and K1F models)
E - Embraer, A - ACAC (CF34-10E & CF34-10A)
GEnx family, GE has used the same nomenclature for airframer:
A - Airbus, B - Boeing (GEnx-1A, GEnx-1B)
Multiple aircraft within the same airframer is noted by the first number:
GEnx-1B (787), GEnx-2B (747-8)
Finally takeoff thrust rating is noted by a number after the letter to give you a rough idea of takeoff thrust:
Jetlagged From United Kingdom, joined Jan 2005, 2509 posts, RR: 24 Reply 14, posted (7 years 4 months 2 weeks 5 days 13 hours ago) and read 2729 times:
On the CF6-50 series, the -50C2 was the Airbus A300 version and the -50E2 was the Boeing 747 version of the same engine, so the suffixes (at least at that time) were issued in sequence, rather than A for Airbus, B for Boeing.
There was also a CF6-45A (for the 747SP I think), again it was the same basic engine as the CF6-50, probably with a reduced thrust rating. As the "50" probably represented the TO thrust rating (which is in the 50,000 lbs range) the -45 was probably derated to around 45,000 lbs.
Not sure why GE chose the CF6-80 designation, maybe they thought it would grow to 80,000 thrust? Possibly it was because 8 is a lucky number in the Far East?
Around the time the CF6-80 came out engine designations were getting out of hand, being more like a part number trying to represent everything in one. PW "rationalised" this by adopting its new numbering system, replacing JT9D-7R4xx with the new PW4000 series, where the last two digits represented thrust rating. It wasn't long before the suffixes started to appear again though!
I suspect RR adopted the name Trent (the engine is still officially an RB211) as the numbers were getting out of hand, also as a marketing brand re-launch.
As for the JT3C, JT3D issue the JT3C came first, so I suspect the fan version was named JT3D simply because D comes after C alphabetically, so it was the next designation in sequence. If the letter was to mean something, F would have made more sense. Of course the D suffix then stuck as meaning turbofan on the JT8D, JT9D, etc., even though there was no turbojet equivalent. So "D for ducted" probably came later. The C in JT3C certainly doesn't stand for "closed" as was suggested earlier.
The glass isn't half empty, or half full, it's twice as big as it needs to be.