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> combination of the manufacturer, make and serial number.

> patent that involves defining that as a unique identifier for aircraft.

Now i got mighty curious what makes this novel enough to be a patent.

Maybe its right-click level of patent.

You burrow this simple idea in pages and pages of obfuscated tedium, and that's good enough that everyone is happy. Patent office gets their fee, lawyers get paid, company can say it has a supercharged patented innovation.

It's a unique identifier but now "not on a computer".

I was wondering the same thing. I've had to derive unique identifiers from hundreds of different data sets over the years. What makes it special when it's a plane?

>> it’s on a plane.

Exactly this. The domain space and a couple of good lawyers makes it patentable today.

Go work at a big company. The patent lawyers come around and ask what you've been working on, and a month or two later, your name's on 10 patents, none of which make any sense whatsoever. If you're very lucky you might get a dollar bill for each.

For a while at google you would get $5k per patent submission and $10k for each approved(?) one. Given how easy it was, I could have matched my annual salary. It's depressing how easy it is to get a system architecture (unimplemented) patented at bigco.

When I was at Microsoft, years ago, it took more effort to avoid having my name end up on a patent than I'd have had to exert if I'd actually wanted one.

Reminds me of the ship of Theseus: https://en.wikipedia.org/wiki/Ship_of_Theseus

The “real” unique identifier is such a common problem. And the solution is almost always “model, make, and serial number.”

Plus year of production if necessary.

I’ve seen programmers attempt deduplicate humans by language spoken.

I know about systems who had two types of serial numbers which ought to be the same, but weren‘t because they had been programmed at different eol stages, when daylight savings time kicked in. One of the system run in utc the other in local time. Date was part of the serial.

Parallel production lines with overlapping sequences also cause this, especially in aerospace- it is widely known that Airbus does it, for example.

Very interesting thread.

Noob me would have guessed the "source of truth" would be whatever identifier(s) is recorded by the insurance company. Or maybe the service and maintenance agreements.

Failing that, I would have guessed some kind of (natural) compound key derived from the transfer(s) of ownership (Airplane Purchase Agreement? Bill of Sale?) noting the unique major components like airframe, interior, and engines? And maybe wings?

Sounds like a fun problem. Thanks for sharing.

How does "model, make and serial number" translate to humans?

(No racist intentions here, but you bring up both points and I thought that to be interesting)

Johnson Smith

The son of John who is a smith

I'm only joking a little. Funny thing, surnames aren't actually that old for Europeans. Most of history there'd be maybe two people with the same name. They solved it back then very much the same way we solve it now.

https://en.wikipedia.org/wiki/Category:Occupational_surnames

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

Even worse in other languages. The three surnames Kim, Lee, and Park cover about 50% of Koreans.

You should see Vietnamese! It's decreasing, but it used to be ~40%! Now it's closer to 30[0].

And don't forget that there's Lee[1], Lee[2], Lee[3], Lee[4], and Lee[5]! Which are all different

[0] https://en.wikipedia.org/wiki/Vietnamese_name

[1] https://en.wikipedia.org/wiki/Lee_(English_surname)

[2] https://en.wikipedia.org/wiki/L%C3%BD_(Vietnamese_surname)

[3] https://en.wikipedia.org/wiki/Lee_(Korean_surname)

[4] https://en.wikipedia.org/wiki/Li_(surname_%E6%9D%8E)

[5] https://en.wikipedia.org/wiki/Li_(surname_%E5%88%A9)

Besides the two you mention, there are ten other Chinese surnames that could be anglicized as Lee, namely 力, 勵, 厲, 栗, 澧, 禮, 立, 酈, 離, and 黎.

To be fair, that's probably still "good enough" these days.

"Abel Davidson Carpenter of Helsinki born in the year 2020" is probably good enough an identifier.

Obviously has some issues, but it's interesting to see that this "ancient" scheme would still hold up these days.

Funnily enough, my "full id" (full name, city, profession plus year) isn't unique to me unless you add a date of birth. Maybe it's not unique with a date of birth either, but statistically it should be.

It's a regional thing, but roughly translates to "John Smith, programmer from NY, born 1995"

Make = who made the thing

Model = what is the type of the thing

Serial Number = was supposed to be what order the things were made in (e.g. the number of the serial order), but this is often obfuscated or often repeats [1].

In cars, make would be like Ford. Model would be like Focus, serial number would be VIN (vehicle identification number - in cars, those are generally unique!).

Ford Focus + VIN, basically.

There is a theoretical concept of a unique identifier for everything... including people from ISO under ISO 8000.. combining a natural location identifier (eNLI)[2] and an ISO8601 timestamp - to represent "where and when a thing is considered to be born" - a point in time and space the thing is considered to come into existence.

I think the idea is called "natural person identifier" for humans.

This ID has to be assigned but I think you can see the idea at least.

I suppose this doesn't include make/manufacturer but realistically that isn't needed for uniqueness in this scheme, only as descriptive metadata for things that have one.

[1] This is related to the fact that if serial numbers were truly serial, one could estimate the rate and quantity of production which is considered sensitive information by most manufacturers. This relates to "the German tank problem" - during WWII the allies were able to accurately estimate the production of German tanks by analyzing the serial numbers off captured tanks.

[2] https://eccma.org/enli-eccma-natural-location-identifier/

What does the standard say for folks whose date of birth is unknown? I’ve heard of immigrant heavy areas that have lots of people born on January 1.

Gender, Father and order of birth

Like Mary, first daughter of Henry VIII

> And the solution is almost always “model, make, and serial number.”

If you've ever spent time in old car forums, you learn that even this isn't enough because of production-line sloppiness.

Serial number re-use is rare, but it happens. Usually because a product had something detected that resulted in remanufacturing, but sometimes other things slip.

> I’ve seen programmers attempt deduplicate humans by language spoken.

How is that supposed to help? If two people have the same name, it's overwhelmingly likely that they also speak the same language.

> Personally, it boggled my mind that something as big as an aircraft did not have a simple time invariant unique identifier.

It boggles my mind that despite not having some sort of universal system things work as well as they do.

Aviation grew up relatively insular, and each country that had any sort of aircraft manufacturing did things their own way until fairly recently. Arguably, the first half of the history of aviation is a kind of free-for-all. The fact that we now have a globalized airline industry that mostly follows some kind of standards is the mind-blowing part to me. And I suspect if we weren't mostly down to a dozen or so manufacturers for the vast majority of airliners, even that wouldn't be the case.

Yeah but at some point countries started buying larger planes from only one or two manufacturers. At that point the manufacturers could standardize things.

Agreed!

Even runway IDs change over time: https://en.m.wikipedia.org/wiki/Runway#:~:text=Runway%20desi...

Those aren’t IDs though

Those are runway numbers. Which are the direction the runway is facing.

Aircraft of Theseus

Exactly!

The full Theseus treatment would need you to take [part of] the airframe that first plane discarded, then recertify it for use under its original serial number.

Is that allowed?

The way the Aircraft of Theseus is generally resolved is there’s a piece of metal called the “data plate”. This is the airplane as far as the FAA is concerned. I’ve been in a vintage biplane that was completely rebuilt from the data plate up. I think they got it for $40k.

It was worth it because without that, a home built airplane would have an experimental certificate and you couldn’t sell rides in it.

But does the data plate have an ID?

Yes, but it’s not necessarily unique like a VIN.

Does the data plate not limit the scope of what can be built around it?

In other words had Virgin Galactic built the VSS Enterprise around the data plate of a Cessna 172, would it then no longer have been an experimental aircraft?

It does limit, but I suspect a lot less for the rebuilt from ground up biplane, than for a certified for airline service aircraft (a commercial airliner).

The airplane has to match the data plate. Otherwise, it will fail inspections because of all those unauthorized modifications.

A unique identifier would've helped: https://viewfromthewing.com/american-airlines-flew-passenger...

Almost comical that it happened 1 day after this was posted.

> combination of the manufacturer, make and serial number

What if a new aircraft were made 50/50 from the parts of two older aircraft

It would depend on which side got the data plate.

I don't think it even matters. If what you're doing doesn't piss off any potential enforcers you're good to go. If whatever you're doing does then you're screwed (or will be tied up in court and paying tons of lawyers fees) regardless.

I would also say engine too.

Engines are actually changed fairly frequently because they're a wear component on most airplanes. They are also sometimes updated to a newer version or even an entirely different manufacturer. And often it's faster and cheaper to swap in a new engine that's ready to go rather than wait for the one that's attached to be overhauled, so the same engine might see service on multiple airframes.

> Engines are actually changed fairly frequently

A modern turbofan can run for 20,000+ hours on-wing before removal for overhaul. That's longer than many car engines last in total.

Most cars don't operate for >12 hours a day every day. Last time I randomly checked the flight history of a Ryanair 737 on flightradar24, it had spent over 18 and a half of the previous 24 hours airborne.

Same with trains. If they don’t run, they start to lose a lot of money for the operator really fast.

Thats why it should be tracked.

Engines are treated as their own thing separate to the airframe, with their own serial numbers.

And many commercial airliners are sold without engines at all.

The operators, such as Delta, do not actually own engines on the aircraft they fly, even though they own the aircraft. The engines are rented from e.g. Pratt & Whitney along with a maintenance contract. That said, that engines are in fact installed at the factory.

It’s a requirement that the airframe and engines are sold separately dating back to the original reason why United Airlines was named.

Which is not to say that commercial jets can take any old engine. Even something like this 767 that was split between GE and P&W have specific structures related to the original engine.