Aging ski infrastructure

[bigdude2468]

Yes. There are many 757s, 767s, and A320s built before 1991 still in passenger service at the majors in the US. 737s and MD80s built in the 80s still fly at some smaller companies. And if you look at night freight, remote areas, and third world, you'll see airplanes dating back to WWII still in commercial service.

Delta Airlines retired its last DC-9 in 2014, 36 years old. The plane was delivered in 1978 to North Central Airlines. Through merger it was flown then flown by Republic, then Northwest before Delta acquired Northwest. While the interior had been refurbished the flight controls were essentially unchanged with all analog gauges.

[Ted Striker]

Because it's not written into Federal legislation.

It's actually the manufacturers who mandate the inspections and replacement of bolts aka "heavy checks" aka "C" and "D" checks. The feds essentially audit to ensure compliance.

As others said, the actual airframe is never replaced.

Maybe not quite apples to apples, but it isn't a whole lot different than chairlifts. There is always some government body that oversees the operators.

Delta Airlines...

They are a great example of keeping older airplanes in the sky. They have somewhere in the neighborhood of 200 75/76s and another 200ish mad dogs.

[old goat]

Delta Airlines retired its last DC-9 in 2014, 36 years old. The plane was delivered in 1978 to North Central Airlines. Through merger it was flown then flown by Republic, then Northwest before Delta acquired Northwest. While the interior had been refurbished the flight controls were essentially unchanged with all analog gauges.

Let's not forget the B52--last one was built in 1962 and 76 of them are still flying. Expected to fly to 2040. But even older is my personal skiing infrastructure, which seems unlikely to last past the end of the current decade.

[Benny Profane]

Well, if the "feds [didn't] essentially audit to ensure compliance", do you really think those regular tests and replacements would be done?
Name me another industry outside of nuclear energy that is so heavily regulated. Which is good.

Here, I was just reading this today. http://www.vanityfair.com/news/1998/...fstream-199810 Didn't get through it all, because I got to a what the fuck am I reading this for moment, but, this stuck out early:

"I learned that every important part of a jet is inspected religiously, documented extensively, and then replaced long before age or wear could be a problem. Some get replaced on calendar time, some after a set number of takeoffs or landings, and others based on how many hours you have been in the air. These schedules are constantly refined, because every plane of the same model is turning in data all the time. If a part turns out to be wearing faster than expected, a bulletin is issued and everybody’s schedule is updated. In a sense, there are really no old planes. Most parts have been either recently replaced or certified as being in new condition. The F.A.A. has, statistically speaking, won the mechanical battle, which is why it is safe to buy a used plane. Pilot error is more likely to kill you than any equipment problem. When a mechanical problem does occur, it is almost always the result of a human error—some overworked mechanic forgot to tighten a bolt."

[boltonoutlaw]

Of interest re old airliners: http://www.airliners.net/forum/viewtopic.php?t=533999

[old goat]

Aren't there tests that can be done to test for metal fatigue and internal cracks? I don't know if they're practical to do for lift towers.

[Buster Highmen]

Aren't there tests that can be done to test for metal fatigue and internal cracks? I don't know if they're practical to do for lift towers.

I'm aware of infrared testing devices to check metal fatigue not only in the lift towers but also for the cable.

For example: https://app.aws.org/wj/supplement/wj0910-195.pdf

[Norseman]

Also: dye penetrant...mag particle maybe

[#######]

Also: dye penetrant...mag particle maybe

NDT (Non-Destructive Testing). Laws vary by state but when I was a monkey it was 20% of the carriers annually.

Wet/Dye coil magnet/blacklight on the grips/grip parts. Dry/handheld magnet w/powder on critical chair welds. Visual/Super Fancy Computer Magnetic rope inspection by splicer performed annual/pre-operation. Insurance/Forest Service/UDOT performed two inspections annually, usually pre-operation and on any given day during the season.

[Norseman]

Thanks for the educated response to my surmising.

[Buster Highmen]

My right knee is requiring a lot of maintenance; don't need the NDT.

[Ted Striker]

Magnaflux is used for aircraft part inspection and chairlift haul ropes.

edit: sicktird beat me to it

[abraham]

NDT (Non-Destructive Testing). Laws vary by state but when I was a monkey it was 20% of the carriers annually.

Wet/Dye coil magnet/blacklight on the grips/grip parts. Dry/handheld magnet w/powder on critical chair welds. Visual/Super Fancy Computer Magnetic rope inspection by splicer performed annual/pre-operation. Insurance/Forest Service/UDOT performed two inspections annually, usually pre-operation and on any given day during the season.

There must be some applicable ultrasonic methods as well? I know they are used for things like pipeline and weld inspection.

A year or two ago I was visiting a company that builds oil pumps and test rigs for lifecycle testing. They had a bracket for a roller coaster, maybe a rail support(?), that was being tested because the designers were switching from steel to aluminum. It was in a non stop test for 5-10 million loading cycles to convince the company it was a safe replacement. I think the technician mentioned that in the field the parts get replaced after about 2-3 million cycles

[#######]

^^^ Yeah, now that I recall the rope inspection was visual on the splice(s) and tucks and then a full ultrasonic scan.

[Shred Baron]

^^^ Yeah, now that I recall the rope inspection was visual on the splice(s) and tucks and then a full ultrasonic scan.

Haul ropes get an MRT (magnetic resonance test), not quite UT. Detects amount of steel in one spot, pretty good at finding broken wires. Grip, brake bullwheel and other major parts have regualrly scheduled mag particle inspection. Ultrasonic isn't too common, but it can find things that aren't visible at the surface. Schedules are determined by manufacturer and ansi b 77.1, which isn't enforced by all states. Code also required periodic rebuilds, and thorough inspections of major systems periodically.