What happens when Boeing runs out of numbers?

Boeing uses 7Letter7 designations during the early stages. The 7E7 became the 787. the 7N7 became the 757, the 7X7 became the 767, and the 7J7 was canceled while still in the design phase. Notice the letters didn’t increase sequentially.

And why are Boeing jets all 7-something? Because that was the series designated for commercial jet aircraft. Supposedly the marketing people added the 7 on the end because it sounded snappier. (Let us bow our heads for the poor 720.)

I’d like to see Boeing ditch numbers and use the car manufacturer approach, giving each new jet a unique product name, like how it floated the Sonic Cruiser concept 20 years ago.

Or do what the carmakers do, and assign old names (numbers, for the aircraft) for an entirely different vehicle.

This approach is out of favor in the auto world. Almost none of the leaders in the space do this any more. Even old standards like Cadillac have mostly dropped the standard. Some key examples: Ford F150, Tesla Model 3/Y/S/X, BMX 3-series, 5-series, X-series etc, Mercedes E-class, S-class etc., Audi S7, A5, Q7, Infiniti Q50, QX55 etc., Lexus LS, Is, RX, UX, etc. Cadillac CT5, XT6 etc., Mazda 3, 6, CX-30 etc.

Of course some of the old standards still use the old naming convention but that’s mostly because they have brands with a lot of name recognition and fans like the Accord, Camry, Escalade, Tahoe, Wrangler, Jetta, Golf and others but the majority of these brands are targeting a decidedly non-enthusiast buyer. This is a long way of saying that for much of the industry names = mainstream/budget cars, letters & numbers = performance/luxury cars. Boeing is not going to go that direction for their planes.

I wonder if that would run afoul of any FAA regulations, though. I don’t know for sure, but I have a feeling they wouldn’t be too happy about a “New 707” that has nothing in common with the original 707. Unless, perhaps, they retired the type certificate for the old 707 first, which would mean any old 707s still in existence couldn’t legally fly anymore.

Can’t they name their airplanes whatever numbers/letters they choose?

They can name the aircraft anything they want, but they could not use the same type certificate. For example, some Cessna 172 Skyhawks are certified under the Cessna 175 type certificate. (NB: The 172 and 175 are mostly the same; unlike, say a 2021 Chevrolet Camaro and a 1968 Chevrolet Camaro.)

Airbus has been using the Neo (“New Engine Option”)suffix since 2010, while the old versions have been renamed CEO (“Current Engine Option”). It does have a different suffix. The 330neo has a 800 and 900 variant vs 200/300 original.

So the FAA would happily issue a type certificate for a new plane designated “707”, and also allow the type certificate for the old 707 to continue to exist? It just seems like that would cause potential for confusion.

The whole 737 Max fiasco is a recent example where Boeing is already doing this. It’s not prohibited and has been a pattern for a while. A 737 on approach could be one of a few very different airframes right now.

I’m aware of that, but both of those planes are ostensibly just new variants of the earlier A330 and 737. I’m sure Boeing could theoretically build a 707-Max with four engines and a single aisle cabin. But I’m talking about a completely clean sheet design with absolutely no commonality with the original whatsoever.

7 \pi 7 , 7 \varphi 7, 7 \gamma 7, 7 \Omega 7, etc…

That’s what Boeing wanted us to think. Boeing framed the 737 Max as a variant to dodge a bunch of paperwork and re-training that would have been required for a new airframe. Yet in reality it’s essentially a new plane and the MCAS system is one of the workarounds they implemented to keep up that façade.

The point is that it’s up to the manufactures what they call the planes. There’s a lot of below-the-fold stuff that actually dictates how the FAA’s regulations get applied from model to model.

I agree that they can call it whatever they want for marketing purposes, yes. But on the official FAA documents, I am less sure.

And the Max certainly wasn’t a clean-sheet design. The entire reason Boeing developed the 737-Max as opposed to a totally new plane was because it quicker and cheaper to make a few upgrades to the existing 737 airframe than to design a new one from scratch. A big part of why the 737-Max was so… sub-optimal was they were trying to squeeze more life out of the old 737 design rather than just biting the bullet and designing a whole new plane.

But we’re digressing from my original question. Whether or not you think it should have been allowed, all the 737 variants are on the same type certificate. My question was whether or not the FAA would issue two type certificates for two planes with the same designation.

No. An aircraft that is not an actual development of the type-certificated aircraft would require a new type certificate. The confusion would be on the customer end.

It’s not a big deal. Lockheed had two different types named “Electra.” Boeing could simply give the new plane an official (i.e., paperwork) name but call it whatever it wants. Boeing called the 307 the Stratoliner, and the 377 the Stratocruiser.

They could ask Microsoft’s marketing department for assistance with naming conventions.

The successor to the 747 will be the 747 360. After that is the 747 One, then the 747 One S, then the 747 One X, then the 747 Series X One S, then the 747 Series X1 360 … Makes perfect sense!

IBM had a somewhat similar problem back in the day when all products had three-digit model numbers. Their solution was to move to four-digit model numbers, which also gave them the opportunity in some cases to express the relationship to the product of a prior generation. Thus, they had a vacuum-tube mainframe computer intended for scientific applications called the IBM 704. The second-generation solid-state successor became the IBM 7040. A faster version was designated the 7044. Similarly, the IBM 7090, a different architecture also intended for the scientific market, was an evolution of the 709, and a faster version became the 7094.

If Boeing followed this practice, the next airplane after the 797 might be the 7070, with 7071, 7072, etc. representing variants.

I look forward to the expensively branded new plane with the car-style name landing somewhere where it means ‘wanker’.

Cue obligatory Mitsubishi Pajero link.

Sure, hexadecimal would work for a while. But what happens after the 7F7?