Thrust From United States of America, joined Sep 2003, 2686 posts, RR: 10 Posted (9 years 11 months 2 weeks 1 day 4 hours ago) and read 1392 times:
Just out of curiousity, I was wondering why Delta did not retire their aircraft based on their age. They took the youngest MD-11s, like N813DE, out of service far before some of the oldest, like N801DE and N802DE. Why did they do that? Wouldn't it cost more to maintain an older MD-11 than a newer one? Or do they replace the engines during maintenance so that the age of the aircraft doesn't affect fuel-efficiency, etc. Why do airlines pick certain registrations of an aircraft they are phasing out to be retired first or retired last? In my thinking it would make more sense to retire the youngest aircraft last and the oldest first.
Ual727222 From United States of America, joined Dec 2003, 61 posts, RR: 0 Reply 1, posted (9 years 11 months 2 weeks 1 day 4 hours ago) and read 1353 times:
I am not sure about Delta's situation, but usually, when an airline gradually retires a fleet type, it retires those that are due for "C" check first. So, if N813DE is scheduled for its C check prior to N807DE (and I am just making a hypothetical scenario), it would retire 813 first rather than spend the money on its inspection, since the airline is planning to retire the fleet type in a definite period of time anyway. 807 might keep flying past 813, even though it is older, if its C check date is later.
Now, all things being equal, there is no magic formula, etched in stone to make these determinations. An airline may decide to retire certain aircraft first if such aircraft have more airframe hours or have had more maintenance issues of late. Even a fleet of the same aircraft type has its top and low performers. For instance, I am a 747 pilot (744 currently), although I also flew the 100s and 200s when they were in service. And I recall that a few specific aircraft had little quirks and were more prone to needing the mechanic's wrench than others. So, if an airline is deciding to retire a fleet type, it could pick the one or two annoying machines to go first. But I would imagine most airlines use the C check dates as a guide for choosing which ones go first.
DeltaGuy From , joined Dec 1969, posts, RR: Reply 2, posted (9 years 11 months 2 weeks 1 day 3 hours ago) and read 1304 times:
Right on UAL727...
I know DL used this theory for the 727 and L10 retirements, and I'd bet for the MD-11's too. That's why you'd see newly painted 727's out in the desert, while some OC ones were still going..just depends really. I know the L10's were retired bout the time they were because they were in need of a D check, IIRC.