DFWHeavy From United States of America, joined Jul 2011, 235 posts, RR: 0 Posted (3 months 3 weeks 3 days 3 hours ago) and read 2509 times:
The topic question says it all.
How many GE-90 (94B, 110B, 115B) can GE produce every month? How many do they actually produce? How long does it take from start to finish to build one?
jetlife2 From United States of America, joined Jul 2006, 187 posts, RR: 22 Reply 1, posted (3 months 3 weeks 3 days ago) and read 2428 times:
We are currently producing 180 per year, so 15 per month. This will increase next year to well over 200 because the 777 production rate is higher starting Feb 2013.
From start of assembly through test to delivery is typically 10 days.
tdscanuck From Canada, joined Jan 2006, 11033 posts, RR: 72 Reply 2, posted (3 months 3 weeks 2 days 13 hours ago) and read 2156 times:
Quoting DFWHeavy (Thread starter): How long does it take from start to finish to build one?
Quoting jetlife2 (Reply 1): From start of assembly through test to delivery is typically 10 days.
Given the amount of exotic alloys and forgings in a jet engine, I bet initial component build starts a long time before that. Probably at least 6 months, maybe more.
notaxonrotax From Netherlands, joined Mar 2011, 359 posts, RR: 0 Reply 3, posted (3 months 3 weeks 2 days 10 hours ago) and read 2069 times:
Quoting jetlife2 (Reply 1):
From start of assembly through test to delivery is typically 10 days.
Quoting tdscanuck (Reply 2):
Given the amount of exotic alloys and forgings in a jet engine, I bet initial component build starts a long time before that. Probably at least 6 months, maybe more.
I thought 10 days was awfully quick!!
Even assembling, testing and delivering it in 10 days seems incredibly fast, no?
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jetlife2 From United States of America, joined Jul 2006, 187 posts, RR: 22 Reply 4, posted (3 months 3 weeks 1 day 23 hours ago) and read 1870 times:
Tom is correct that raw material lead times can be 6 months or more for some parts. Those are on continuous order for years ahead so they are flowing in all the time at the necessary rate. For that reason it's always hard to answer "how long does it take", so I usually answer with the assembly and test time.
I agree 10 days is impressive. It's a testament to years of careful lean process work, which is continuing all the time. For example presenting the assembler with a fully kitted shadow box at the point of use, with every part and tool in the right sequence.
LHR27C From United Kingdom, joined Aug 2004, 1277 posts, RR: 21 Reply 6, posted (3 months 3 weeks 1 day 21 hours ago) and read 1777 times:
jetlife2 - do you know what the current production rate is on GEnx, and how that's expected to ramp this year? (eg what the rate would look like by December)
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imiakhtar From United Kingdom, joined Apr 2006, 543 posts, RR: 3 Reply 7, posted (3 months 3 weeks 1 day 15 hours ago) and read 1633 times:
Quoting jetlife2 (Reply 4): Tom is correct that raw material lead times can be 6 months or more for some parts. Those are on continuous order for years ahead so they are flowing in all the time at the necessary rate. For that reason it's always hard to answer "how long does it take", so I usually answer with the assembly and test time.
I agree 10 days is impressive. It's a testament to years of careful lean process work, which is continuing all the time. For example presenting the assembler with a fully kitted shadow box at the point of use, with every part and tool in the right sequence.
Great stuff. Could you give a quick overview of what testing a newly assembled engine entails (ie, a ground run-up?)
Quoting 2H4 (Reply 5): Are you able to say what part and/or material has the longest lead time?
I would hazard a guess and say the materials in the turbine or "hot" section require the longest lead time. Once you've got the right balance of materials (Nickel, Chromium, Cobalt and many more I'm sure), they need to be coated with heat barriers. A fascinating process, especially when you consider the preponderance of wrought materials (seems almost perverse ) in jet engines only five decades ago.
I often ponder how the jet engine pioneers, Frank Whittle and others would react if they saw a GE-90 today.
Tom is correct that raw material lead times can be 6 months or more for some parts.
Are you able to say what part and/or material has the longest lead time?
Rotating parts from forgings through finished parts are typically the longest. However the big static frames are complex so they are long lead too.
Quoting imiakhtar (Reply 7): Could you give a quick overview of what testing a newly assembled engine entails
The engine goes through a sequence of slow power sets to initialize all the rotating seals and get it ready for operation. Once this is accomplished it is put through a battery of performance tests covering thrust, fuel burn, accel and decel performance at a whole range of conditions such as idle, takeoff, cruise, etc. Many parameters are monitored and recorded. Each has expected values and each has a spec limit. All the data gathered is assembled into a report that forms part of the engine data package that goes to the customer, along with configuration details, etc. The engine is then weighed, bagged, paperwork closed, and delivered.
You might be interested in this video which covers some of the original development tests. Not what we do in production but you can see part of the facility.
Quoting LHR27C (Reply 6): do you know what the current production rate is on GEnx, and how that's expected to ramp this year? (eg what the rate would look like by December)
Sorry I do not. As a rule of thumb you could take the aircraft production rate and add 10% (for spare engines).
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