Airxliban From Lebanon, joined Oct 2003, 4495 posts, RR: 54 Posted (3 years 5 months 1 week 6 days 1 hour ago) and read 3720 times:
Can someone tell me what the overhaul intervals are for the following engines?
CFM56-3, -5, -7
I have some data which suggests that overhaul for the CFM56 is every 10,000 hours, but that sounds quite low to me and I'm also not sure whether the same interval would apply for the -3 and the -7 which as I understand it are rather different engines. If the interval is every 10,000 hours I guess that means that an engine for a big carrier like Southwest which must do 3,000 hours a year would go for overhaul in every 3-4 years, which strikes me as being too frequent.
The -7 is on an MSG3 maintenance program (I suspect the -5 is as well, but I'm not positive), so it doesn't have *an* overhaul interval, it's just got a ton of tasks with different intervals. They range everywhere from 50 hours to the lift limits on some of the parts. Major blocks of tasks come due at 1200/1600/2400/5000/6000/7500 hours.
The first thing that would require you to pull the engine, assuming you can pass all the intervening inspections, is the first buried part with a life limit.
MarkC From United States of America, joined Apr 2006, 259 posts, RR: 0 Reply 2, posted (3 years 5 months 1 week 5 days 5 hours ago) and read 3601 times:
You're talking about an engine shop visit, right? This is where the engine is removed from the wing and sent to an overhaul shop. Its based on cycles, not necessarily hours. And, you are correct, I would say the CFMs on Southwest are going to be about every 3 - 4 years. The only CFMs I have worked on were from an atypical operator, and had longer intervals at the tradeoff of a much higher overhaul cost. PW4000's on longhaul aircraft go about 2,000 - 2,500 cycles between shop visits (baring an AD or parts failure). But, that could be many years.
rmm From Australia, joined Feb 2001, 521 posts, RR: 1 Reply 3, posted (3 years 5 months 1 week 3 days 9 hours ago) and read 3481 times:
When I worked in the shop (many years ago) on the CFM56-3 the first cyclic lifed item was the HPT front shaft. On early models it was changed IIRC at 12,800 cycles although only one engine was actually removed when I worked on the shop floor due to the time expired part, most others ran out of EGT margin before making 12,800 cycles.