The maintenance cost associated with end-of-life commercial flight equipment quickly outpaces the cost of buying a new platform. Without maintenance, the avionics (and everything else on the plane) is barely worth its weight in scrap metal (because even scrapping is expensive).

This is a massive factor in marine economics too.

Because the disposal costs are so high, and recycling of specialist equipment and wiring so complex the point at which a vessel turns from an asset to a liability may be hard to anticipate.

There are lots of "luxury" yachts and "Gin palaces" out there that seem to be worth millions on paper, but are worth net zero. Many have embedded trackers deep in fibreglass mouldings, and large vessels are satellite tracked so simply scuppering them is no longer an option.

During the pandemic there was lots of talk of mooring many cruise ships along the south coast and turning them into permanent hotels. Ships often end up as nightclubs or restaurants.

> Many have embedded trackers deep in fibreglass mouldings, and large vessels are satellite tracked so simply scuppering them is no longer an option.

Could you elaborate a bit on this part? Intentional sinking for insurance purposes, or to avoid having to pay for it to be scrapped?

I recall there’s some ship graveyards on the Turkish coast where they intentionally ram large cruise-liners into shore so they can scrap em. But I guess that’s more relevant for bigger ships with more steel etc?

> Could you elaborate a bit on this part? Intentional sinking for insurance purposes, or to avoid having to pay for it to be scrapped?

Sorry for late reply. Yeah, I was thinking of the latter, though both might be possible. Contriving a marine accident, collision, fire. loss in a storm etc would be physically dangerous and legally very risky. A less serious but still illegal caper would be dodging the scrapage costs by holing it. But when a registered vessel "disappears" that can trigger serious investigations for all sorts of reasons I am sure you can imagine.

It's illegal in most of Europe, at least, to transport hazardous waste for disposal to places where it would get done inappropriately.

Usually this is dealt with through finding a company that can claim to use the ship for something but actually scraps it.

One now defunct company almost failed this kind of dance by admitting it sold a ship for scrapping. https://en.wikipedia.org/wiki/MS_Fennia

Toronto faced a similar issue of antiquated electronics with its last set of retired street cars which used (1970s) state-of-the-art silicon-controlled rectifiers for propulsion. However, replacement parts stopped being made into the 1990s and 2000s. In the last days of operation, some units were cannibilized to get other broken down units going as replacement electronics were simply not available and could not be jerry-rigged from other off-the-shelf parts.

(1) https://stevemunro.ca/2018/06/07/will-toronto-get-more-new-s...

The Hague purchased old trams from Marseille for parts, as they had this exact problem with the old (red) GTL-8 trams. [1]

Some GTL-8s are actually still in service to this day, though they're being replaced by new Siemens Avenios as time goes on.

[1] https://nl.wikipedia.org/wiki/Gelede_Tram_Lang

Do most cities design and build their own buses and trams?

In the face of the mid-century GM streetcar conspiracy in North America, there were very few options for off-the-shelf streetcars. Toronto ended up working with a provincial agency (UTDC) to develop a design that would meet contemporary needs. It was really a world-class effort: the prototypes were built in Switzerland, adjusted for Toronto track gauge and marketed to Boston (who ended up going with a Boeing design).

In a very oversimplified explanation, most major rail manufacturers now offer something that’s like a kit: cities pick length, types of operation (street running or separate grade), front-end and back-end design and that’s it.

Had no idea such a thing had ever happened. Interesting article.

General Motors streetcar conspiracy

https://en.wikipedia.org/wiki/General_Motors_streetcar_consp...

At least with rail vehicles (trams, metros and trains), I think custom designs used to be more common in the past. Perhaps the consolidation of all sorts of independent rolling stock manufacturers into Alstom has played a part in making it less common these days.

Assuming they weren't upgraded, the plane was 30+ years old when it was decommissioned. Normally, I'd say the market for equipment that old is third-world countries, and the old planes need old parts, but the 747 is a big plane. The other buyers of old airplanes are companies like UPS and DHL, but I'm not sure they want them that old, and they'd probably upgrade the avionics.

From what I understand (admittedly little) the engines are the most valuable part of a eol airliner

Wouldn't surprise me. The lifespan of an airframe is far longer than that of an engine, and they're designed to be swapped out. They can even be transported under-wing: https://www.flightradar24.com/blog/how-qantas-ferried-an-eng...

The engine is basically a collection of life limited parts, so the range of value in the engines depends hugely on how many engine hours flown since the engine was last rebuilt. They can be worth a few million dollars removed from an aircraft that's otherwise unsaleable (to swap onto the remaining aircraft still in service) or of negligble value themselves.