Boeing has hinted several times that they want to look at a Blended Wing Body (BWB) design for the next generation of planes. That time may be now.
Safety requirements have evolved massively since then, but if you keep making the same engine with modest changes it can grandfathered. Kind of makes you wonder if grandfathering should have a limit (e.g. 50 years?).
The craziest aspect of the Soyuz that makes it obvious how legacy it is is how its engines are ignited: https://www.popularmechanics.com/space/rockets/a19966/russia...
You literally put something not too dissimilar from a wooden chair directly beneath the rocket nozzles, then set it on fire right before launch. When the rocket's engines start up, the fuel is ignited by the fire from the burning wood, and combustion begins. Now that's legacy. It's also reliable enough that they've never had to redesign it.
Yeah, the bulk of the device, and its combustible material, is made of wood. But it's also got two igniters (for redundancy) and a sensor for ensuring that the device has successfully ignited. Some engineering thought went into this. Comparing it to putting a burning piece of furniture under the rocket nozzles makes the whole design sound a lot more jerry-rigged than it really is.
“This setup is not as simple as a regular match, but it is surprisingly reliable and has worked for six decades on hundreds of rockets”
So why attempt to fix such a safety critical thing?
I'm no rocket engineer, but my guess would be that, if you're shutting down an engine at that stage in the flight, your only realistic options are going to be redirecting fuel to the remaining engines for a longer burn, or cutting all engines and activating the launch escape system. I can't imagine there's any practical reason to plan on shutting down and re-igniting engines during the first stage of a launch, and I also can't imagine trying to decide whether an engine is safe to re-light during the few seconds you'll have between when you executed the emergency shutdown and when it's time to jettison the first stage entirely.
That's not grandfathering. Grandfathering is "This engine was built before we made the law, so you can keep using it until it breaks."; what you're describing is just blatant selective enforcement.
It's similar to how I can continue to drive an old car that doesn't have ABS, since ABS wasn't required or invented when the car was built.
The difference of course is with cars we update the rules and apply them to all new cars as of a certain date. We don't allow someone to keep making cars using a design from 1967, at least not without including current safety features.
The reason it exists is otherwise the FAA could release a new requirement that would halt a pre-existing production line that didn't meet it.
> Because part 135 operators will have limited ETOPS operations, the FAA has decided to grandfather from today's rule all part 135 airplanes manufactured up to 8 years from the effective date of the rule. For purposes of airworthiness requirements, part 135 operators may use these airplanes in ETOPS without certification under § 25.1535. This is a change from the NPRM, which proposed grandfathering only those airplanes that were on an operator's operations specifications up to 8 years after the rule. Under the NPRM, they would then have had to remain on the operator's operations specifications to continue to operate ETOPS.
https://www.federalregister.gov/documents/2007/01/16/07-39/e...
> b. This Advisory Circular (AC) provides guidance to affected U.S. operators that operate aircraft outside the United States with aircraft that were never required to be noise certified. If you have such an aircraft, this AC outlines the noise certification requirement dates so you can confirm that your aircraft indeed pre-dates the requirements and should be considered acceptable. We use the term “grandfathered” for these aircraft. We strongly recommend operators of such aircraft to use the FAA form in Appendix 1 that includes a grandfather clause.
https://www.faa.gov/regulations_policies/advisory_circulars/...
> These seats should provide adequate vision to the pilot's panel and forward windows in visual system models. "Grandfather rights" prevail on previously approved simulators; however, efforts should be made to improve surveillance visibility. These observer seats need not represent the aircraft seats.
https://www.faa.gov/documentLibrary/media/Advisory_Circular/...
0: or not-technically-criminally if they planned ahead well enough.
Which is both fair and appropriate and proportional if it means that people don't die.
Imagine if all of the cloud computing data centers ran off legacy IBM mainframes -- then it'd be a more akin situation.
These comparisons are off a bit, though, because development lifecycles in airplanes are longer than for computer hardware.
It’s not a perfect anology, but probably better than systems that aren’t really changing much anymore.
Practically speaking, for the flavors of UNIX like systems most will work with this is equivalent to streams of 8 bit, clean-transferred, characters.
Any other kind of transfer system that you might want to build can be built on top of that. This interlinking design is the minimum viable product, and also the lowest level one. Comparing to a more recent design, such as PowerShell, transfer of objects limits flexibility and requires more shared infrastructure.
The key difference here, I think, is that there haven't been radical new improvements in firearms. You can clearly point out where the faults in, say, legacy airplanes lie, but guns (at least in civilian uses) haven't changed as much. Now, granted, for military uses, the modern assault rifle is a far cry from the aforementioned guns.
Just looking at the diagrams in that page, I doubt that measurements were defined with a 0.001 inch accuracy in 1921.
The technology was pretty mature in 1921, there were a few rounds of refinement before that. Machinists definitely talked about "one thou" back then. The same M2s which fire these things have been in production for over 80 years. I'm sure there have been small tweaks, special versions, etc, but basic compatibility has remained.