This entire comment chain is bewildering, we're attacking strawmen. Did anyone read this article and leave assuming no further work was done after approval? Was this HN comment chain enlightening to anyone? Who are we writing this for?
For my aerospace engineering undergrad we also had to create a conceptual design for a new aircraft. And of course, as university projects go, we basically did it in five days. But I won't tell you how many iterations we would've had to go through until we had an optimum configuration ready to be sent to detail design
The headline makes it look like their design was a definite one. Then you actually read the article and it says it took another four years before the first one would fly. Which is actually to me the more impressive part of the story, considering the amount of time it takes aircraft manufacturers to go from concept to production these days (e.g. the A380 was first conceptualised in the 1980s and its first flight was in 2005)
The problem people have is that designed is a very flexible word that can mean a great many different things, and because of that it's being used here in a way that means something akin to conceptualized, but also used in the title in this way specifically because it will suggest to people that all the design work was finalized in that period.
That's click-baity in that it plays with people expectations, and not in a way they generally enjoy, so they're annoyed. If you don't like click-bait, the appropriate thing to do is to complain or abstain, otherwise you're just reinforcing their decision to communicate in that way.
Also, Nazi Germany had a few designs that took way shorter than that to go from idea to first flight. An extreme example is https://en.wikipedia.org/wiki/Heinkel_He_162#Prototypes:
“The He 162 V1 first prototype flew within an astoundingly short period of time: the design was chosen on 25 September 1944 and first flew on 6 December, less than 90 days later”
They did have to cut ‘some’ corners to get there, though. That Wikipedia page mentions that it used a highly acidic glue that would disintegrate the wooden parts it was intended to be fastening, that that caused problems on the first flight and a deadly crash on the second, but that it wasn’t considered important enough to hold up the production schedule for even a day.
Ask yourself, how long does this normally take to go from A to B?
One day you've got top engineers with a contemporary concept, but the military says nah we've got to have something way better.
So they really go to work on it until they can confidently deliver a 33-page futuristic well-engineered proposal with a prototype scale model and then the military says yes right away.
What's normal here, weeks, months, even years?
That's what's impressive in 48 hours, nobody could expect a complete set of blueprints, they had to first determine if prints would even be realistically possible.
You know their slide rules were flying like few could do.
With engineers like this why would you use anyone else?
For example, let's look at the concept/design of a helicopter:
DL1 (idea phase): a flying machine that can go straight up and hover
DL2 (concept with basic working principle): a vehicle with a rotor which acts like wings moving in a circle to move air down and by reaction push the vehicle up
DL3 (concept with important details attached): as DL2 but with a tail rotor to allow for axial control and differential tilting of the airfoils to allow forward thrust
DL4 (concept with specifications that drive requirements for other specs): as DL3 with rotor lengths of 3.3 m and a NACA 0018 cross section made of 6061-T6 aluminum
DL5 (concept with full specs): as DL4 but also etc.
Is anyone aware of better nomenclature like this for the concept/design phase? It would help for more important things than this discussion alone. Like when discussing which is more important, idea or execution: so which level idea are we talking about? Also, the root cause of a lot of software problems is in the spec. It would be nice to be able to go back and say, "this spec is only spec level 3, can I please have a spec level 5"?
This discussion is happening because "they designed it over a weekend" is really vague. It would be nice to have a quick way to make it not-vague.