Sampa737 From Brazil, joined May 2005, 637 posts, RR: 1 Posted (6 years 1 week 4 days 10 hours ago) and read 7336 times:
With stories of metal fatigue and other problems, just how long can a plane last with continual commercial use? I ask with reference to another post regarding the DC-8s of UPS but thought it better to begin a new topic.
NWAs DC-9s have been around forever. How long could FedEx use their MD-11s, DC-10s and 727s?
Kappel From Suriname, joined Jul 2005, 3533 posts, RR: 17
Reply 3, posted (6 years 1 week 4 days 10 hours ago) and read 7297 times:
It depends on how much the airline is willing to spend on maintenance. An aircraft can technically fly for a very long time, like the DC9's mentioned and of course the DC3, although the DC3 does not have a pressurized cabin.
Usually, after about 25 years it is no longer economically viable to operate an aircraft, due to MX costs and most likely a replacement aircraft that has been developed that uses less fuel.
There are exceptions of course. NW has operated the DC9 for a long time, because the extra maintenance and fuel costs were offset against the fact that they are owned and paid for. However, I believe they have now reached a point that they need to be replaces (thanks to current fuel costs). Thus they are speeding up phasing them out.
DALMD88 From United States of America, joined Jul 2000, 2540 posts, RR: 14
Reply 4, posted (6 years 1 week 4 days 9 hours ago) and read 7217 times:
It all comes down to how much money do you want to throw at it. If you can find the parts or better yet get approval to make the parts any airplane can fly forever. Of course after a point it might become a George Washington Axe. We had to replace the handle and the blade but it is the same axe George used to chop down the cherry tree.
Manfredj From United States of America, joined Mar 2007, 1132 posts, RR: 0
Reply 8, posted (6 years 1 week 4 days 7 hours ago) and read 6854 times:
Weren't these old birds built with heavier materials thus increasing their useful life? I would speculate that the newer the airplane, the more composites and what not are used. Doesn't carbon fibre break down over time? (naturally)
I think the 737, MD-90 Etc are the last of the older gen building style and therefore have a longer life than its competition.
VV701 From United Kingdom, joined Aug 2005, 7461 posts, RR: 17
Reply 9, posted (6 years 1 week 4 days 6 hours ago) and read 6684 times:
Quoting Kappel (Reply 3): An aircraft can technically fly for a very long time, like the DC9's mentioned and of course the DC3, although the DC3 does not have a pressurized cabin.
I believe that "the DC-3 does not have a pressurized cabin" is the key phrase. I do not think that national aviation authorities would allow the DC-3 to fly in their countries today if it had a pressurised cabin. I believe the dangers of metal fatigue with a pressurised aircraft are likely to limit its likely life to between 25 and 30 years depending on the cycles it has completed
Prebennorholm From Denmark, joined Mar 2000, 6420 posts, RR: 54
Reply 10, posted (6 years 1 week 4 days 5 hours ago) and read 6577 times:
Quoting Sampa737 (Thread starter):
With stories of metal fatigue and other problems, just how long can a plane last with continual commercial use? I ask with reference to another post regarding the DC-8s of UPS
Technically any plane can last forever. You just exchange all parts which fail due to wear, corrosion, fatigue or whatever reason.
It's a question about economics, comfort and noise.
A lot of planes have "died" due to noise, not least because the EU ruled against converting old fuel guzzlers with hush-kits making them barely legal noise wise and even more fuel guzzling.
It makes little sense to spend a lot of money on maintenance of a fuel guzzler, especially if you cannot fly it to a lot of places due to noise regulation.
That doesn't harm the DC-8-7x which is the only really successful re-engined old jet airliner with modern, fairly fuel efficient and noise compliant engines.
B727 also had some success with the 727-100 converted with 3 x RR Tay, and the the 727-200 converted with 2 x JT8D-2xx plus a hush-kitted center engine. I think that ends the story of successful re-engining.
With the very high number of 737-200s produced it may puzzle me that nobody ever attempted to put a low powered JT8D-2xx under their wings. Maybe it just proved wiser economy wise to sell them to less noise sensitive places on this planet and hush-kit or scrap the rest. Or maybe such a conversion called for extensive wing stucture modifications.
Always keep your number of landings equal to your number of take-offs, Preben Norholm
MMEPHX From , joined Dec 1969, posts, RR:
Reply 11, posted (6 years 1 week 4 days 4 hours ago) and read 6335 times:
many factors as mentioned:
1) How many pressurization cycles has the frame endured.
2) How much time/money do you want to spend on maintenance
3) How much are you prepared to spend on fuel
4) How can you support obselete technology.
5) How well built was the frame in the first place
NW DC9's are an anomaly unlikely to be repeated in aviation. Started with a very solid, well built frame, (some may argue over engineered) NW was prepared to invest in updating/maintaining them (remember they did look in the early 90's at replacing them) and they have the staff that knows how to maintain them. The aircraft is relatively simple compared to todays current generation of computer driven aircraft.
Like most things today, aircraft seem to be designed with much more of definitive life span in mind, so that once it reaches the milestone, while it may be technical feasible to maintain or upgrade the frame, the financials make it difficult to justify.
Jetjeanes From United States of America, joined Oct 2004, 1430 posts, RR: 1
Reply 14, posted (6 years 1 week 4 days 4 hours ago) and read 5963 times:
In theory forever. A felow told me they can replace everything but the planes shadow if they want to. Im sure there are older planes than the dc-3 but there has to be a point where cost
i would think would be worth it
GeorgeJetson From Bulgaria, joined Jun 2007, 169 posts, RR: 0
Reply 15, posted (6 years 1 week 4 days 3 hours ago) and read 5480 times:
Perhaps the Super DC-8s that UPS currently flies are what the DC-9s are to Northwest! Douglas (and McDonnell Douglas) built some awesome aircraft that were very durable and that stood the test of time. Although the company has been long gone, many of their aircraft are still flying, including some DC-3s from long, long ago!
Tonystan From Ireland, joined Jan 2006, 1423 posts, RR: 2
Reply 22, posted (6 years 1 week 3 days 23 hours ago) and read 3483 times:
Airliners tend to be built to withstand a certain number of "cycles". A single cycle would be a complete take off - pressurisation - landing. Once the aircraft reaches a certain number of cycles the aircraft must go in for certain maintenance checks (like your 5k, 20000k, 30000k checks for your car) and when it is coming to the end of its life cycle it is usually retired. However if an aircraft can be maintained well enough it may continue to fly. However the older the plane gets the heavier and more costly the maintenance becomes. Before 9/11 and the Concorde crash there were plans to extend the operational life of the aircraft so that it could continue to fly for another 10-15 years.
My views are my own and do not reflect any other person or organisation.
SNAFlyboy From United States of America, joined Oct 2007, 86 posts, RR: 0
Reply 23, posted (6 years 1 week 3 days 22 hours ago) and read 2974 times:
It would appear that, while an aircraft could be maintained for an incredibly long period of time theoretically speaking, the age of the aircraft is proportional to the amount of money you're willing to throw at it! In the end, possibly even the amount of time you're willing to spend working on it...
Hmm...what do you guys think? Could we make a nice parabolic curve with a graph of Cost vs. Age and watch the costs skyrocket?