tdscanuck From Canada, joined Jan 2006, 12710 posts, RR: 80
Reply 1, posted (3 years 6 months 2 weeks 4 days 14 hours ago) and read 3196 times:
Quoting cubastar (Thread starter): It involves replacing the first stage turbine hub prematurely in 964 engines being used under US registry.
From the life limits in the flightglobal article, it looks like they pulled the life back by ~10%. That means this shouldn't trigger a spate of immediate replacements, just some replanning of the engine change schedules.
How often does a PW4000 come off for life limit, as opposed to EGT degradation? If it's mostly the latter then this AD might not actually influence the fleet much.
lightsaber From United States of America, joined Jan 2005, 14570 posts, RR: 100
Reply 2, posted (3 years 6 months 2 weeks 2 days 10 hours ago) and read 2470 times:
AIRLINERS.NET CREW FORUM MODERATOR
Quoting tdscanuck (Reply 1): How often does a PW4000 come off for life limit, as opposed to EGT degradation?
Ten years ago the #1 reason was deteriorating fuel burn. (All engines deteriorate fuel burn with wear. And yes, EGT and fuel burn are tied... Engines were being pulled before EGT limits as fuel burn was impacting payload.)
Now there have been improvements in the PW4000... I do not know what is driving the fleet today.