DARPA's new X-76
darpa.mil121 points by newer_vienna 6 hours ago
121 points by newer_vienna 6 hours ago
To be clear, this is not a power-point program but a continuation of a long-standing design work with Bell.
Two articles that cover this in depth are: 1. Revised Fold-Away Rotor Aircraft Concepts Emerge From Special Operations X-Plane Program. December 2024: https://www.twz.com/air/revised-fold-away-rotor-aircraft-con...
2. Bell’s Plan To Finally Realize A Rotorcraft That Flies Like A Jet But Hovers Like A Helicopter. September 2021: https://www.twz.com/41997/bells-plan-to-finally-realize-a-ro...
The second article covers decades of prior wind tunnel testing on the folding rotor concept.
> continuation of a long-standing design work with Bell.
sunk investment. The success - it made into production in meaningful numbers - of V-22 means that design will beaten to death.
Even though Bell X-22 (https://www.youtube.com/watch?v=lFdV5CVXGGw) was much better as prop VTOL than V-22 and for jet VTOL Ryan XV-5 Vertifan (look how great it is flying https://www.youtube.com/watch?v=HwvkjFIYWR8 ) was much better than F-35 has been and X-76 will be.
>decades of prior wind tunnel testing on the folding rotor concept
Oof, I wish I had a job like that.
Design remings me of something...
https://en.wikipedia.org/wiki/Accidents_and_incidents_involv...
The Osprey has a reputation, for sure, but it's mid-pack. They called the F-104 the widow maker for a reason, for example. And the F-16 has a fairly high accident rate, too, slightly higher than the Osprey. Though I think the F-16's history is a bit more lopsided, they made some changes after early production airframes proved pretty accident prone.
The Osprey's accident rate is not that bad, and the US Army have ordered a new smaller tiltrotor, the v280.
The next generations of accidents are going to be even more looney-tunes in nature.
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Any time there are planetaries or splines attached to jet engines, it's a really weak spot. This holds for ordinary turboprops too.
It looks like a maintenance nightmare with those clutches to decouple the blades and the mechanisms to have them folded during cruising. Does it even improve substantially in anh metric over the V280 to put money into it?
The V280 is designed to be cheap (a very relative term here).
Reading between the lines, I suspect "fast, but also expensive" was a design option that popped up and was not chosen earlier in the V280 program and now Darpa wants to pay to see where it goes.
Hard to be more expensive than F-35B.
The F-35 is cheaper then some new production 4th generation fighters at this point.
I've had to eat some humble pie and moderate my assessment of the F-35. It still does have a lot of issues, for sure, but it turns out if you divide an eye wateringly large number by another impressively large number, the result can be a lot better than I thought it would be.
It's lot more about operational costs and project deliverables than plain sticker shock, and it is turning out to be a capable platform.
all these cost assessments are numbers on a spreadsheet. let's see what the numbers look like after 20 years on the line, with SrA mechanics and most flight hours by new Lt's and Captains. if they over-estimate the engine rebuild time, or if it really takes 2 hours instead of 30 minutes to remove and replace an avionics box (as was forecast), the calculation can veer in the other direction quickly. i predict the F35 will be the most expensive by flying hour of any (line) aircraft that has come before it.
> I've had to eat some humble pie and moderate my assessment of the F-35
Same for me. I was surprised to hear that it actually competes favorably on price. And aside from early griping that it couldn't beat an ancient F-16 in a dogfight, it seems pretty capable in that regard too. Saw a demo at the last airshow I went to and that plane was defying physics. I love the 16, always will, but I definitely don't think it would hang with an F-35.
In a real fight, the F-35 smokes the F-16 beyond visual range before the F-16 even knows there is a problem. The radar and electronic warfare capabilities are incredible.
The sticker price is competitive but the cost per flight hour and the availability factor is pretty horrifying. Factoring in the cost of flying and the availability makes the Grippen about half the cost.
I wonder if the flight hour cost of F 35 includes the maintenance it's undergoing when it's not available.
4th generation platforms like Grippen are not survivable in a modern air defense environment without complementary 5th generation platforms to establish air superiority. You can't avoid having a fleet of something like F-35 to gain control of the airspace.
> modern air defense environment
Wildly dependent on your definition of "modern", which mostly depends on your potential adversary. The Russia/Ukraine, and the new war in the Gulf have shown numerous ways in which 4th generation jets, and more importantly cheaper missiles and even more cheap drones can perform supression of enemy air defences and/or air support. Unless you're fighting the US or China, 4th gen jets are plenty. And even against US and US defended locations, cheap drones and missiles have been able to influct some pretty serious damage to critical infrastructure (like extremely expensive and rare radar systems). An adversary not crippled by extreme sanctions and corruption for decades might have been able to achieve even more, even with the total lack of airpower.
4th generation aircraft are not sustainable in modern combat without a wide array of assistance from EW etc. The losses of aircraft in Ukraine on both sides are horrifying. The only reasons the Ukrainians persist is because they have no choice. The Russians can sit outside of the Ukrainian engagement range and lob semi-smart bombs, or air to air missiles at any Ukrainian aircraft that show up on their radar.
The real reason stealth is needed is as a counter to GBAD. Modern anti-aircraft missiles are incredible lethal.
"4th generation aircraft are not sustainable in modern combat without a wide array of assistance from EW etc. "
But isn't that true of the F35 as well?
On it's own, I doubt it would survive much longer on the eastern front in Ukraine.
In Iran the F-35 also did not fly around freely while the ground radars were active. They had to be taken out first. For that stealth was probably useful (and in general it is).
But it is not making them invisible - and cheap sensors and AI is likely to counter it soon. Because sensors and analysis will get better over time and sensors also better and cheaper. But the stealth will remain largely the same. It cannot really be upgraded for existing jets.
> "modern combat"
> have no choice
That's my point. Any battlefield today is "modern", but militaries operate with what they have. From Russia to the Houthis passing via the Houthis, we've seen insane amounts of damage done on "a modern battlefield" with anything from Cold War era equipment to cheap drones assembled by a terrorist group living in the mountains with no industrial base.
Yes, if the US wants to fight China, and vice versa, it needs 5th gen jets. Everyone else doesn't need them. They're nice to have to make your job easier (like Israel vs Iran), but don't guarantee you anything (like Israel vs Iran).
Russia/Ukraine war shows that 4th generation jets are not survivable in any current as of 2026 air defense environment.
Presuming that state of affairs will persist though is fraught.
It's quite likely that in about 5 years most military installations will have a mix of weapons to intercept those systems - and depending on a number of factors you could easily end up back at low performance drones being so reliably intercepted as to be a waste of munitions to deploy.
WW1 after all was based on exactly this thinking: surely the volume of an army would overcome the machine gun.
> It's quite likely that in about 5 years most military installations will have a mix of weapons to intercept those systems - and depending on a number of factors you could easily end up back at low performance drones being so reliably intercepted as to be a waste of munitions to deploy.
That's unlikely. Anti-drone defences will only improve, yes, but autonomous drone swarms numbering in the thousands to tens of thousands are doable today, and few weapons systems can handle the rate of launch/fire required to combat that. Especially if there are follow-up waves mixing drones and heavy missiles against which your anti-drone defences wouldn't be enough.
> WW1 after all was based on exactly this thinking: surely the volume of an army would overcome the machine gun.
But building a cheap kamikaze drone costs much less than building a human.