DARPA wants to combine traditional sealift and airlift | Hacker News Reader

DARPA wants to combine traditional sealift and airlift

spectrum.ieee.org

86 pointsRafelMri49 comments

If you want to see what's left of the Ekranoplan: https://www.youtube.com/watch?v=rozqIdT6lLQ

That’s too bad. Wish it was in a museum instead.

Indeed, it's a real waste. Such a unique machine. What you can't really tell from the video is how high that thing is, the tail is incredibly high up.

Apparently it was on its way to a museum when it “escaped” it’s water-tow and ended up permanently beached. Someone in another comment posted this which has the details from 2020:

I was trying to find it on Google maps but could not.

https://www.google.com/maps/@41.940745,48.3794887,18z

Thank you!

Same with their Buran space shuttles. They're just sitting in decaying facilities.

https://www.youtube.com/watch?v=-q7ZVXOU3kM

It's the ultimate example of 'you can buy it but you can't afford it'.

It doesn't even make sense; clean them up and move to a nice museum hangar and it would basically be free money. I expect they profit quite nicely already from fines and bribes from all people that go to visit the shuttle anyway.

IT BELONGS IN A MUSEUM

honestly DARPA would do better to just buy or license the Lun-class ekranoplan designs. The Lun makes the Boeing Pelican look like a grift. Lun is a far more capable and fully developed offering.

Aside: Many years ago I had an idea for something, which may or may not be plausible, and even bought a couple of books on invention and patenting, so I could perhaps develop it. I never did. Not my realm. BUT. My thought was:

Could you have inflateable control surfaces on lowish-speed wings and aerodynamic surfaces, such that instead of bending and extending using hard surfaces, areas could instead be inflated or deflated to change the dynamic of the overall lifting surface? frontal edges, top and bottom, some trailing surfaces. Wings could become thicker or thinner, at different points.

Only seems to make sense on slower, prop-driven haulages, such as here.

inflatable surfaces already exist today, although not for control surfaces. De-icing boots are common in GA and some larger aircraft.

Were you thinking to change the shape of an airfoil to affect the aerodynamics? that seems really risky and potentially unnecessary. For control surfaces, hard to picture something else than moving parts over a hinge, except maybe flaps that already change the shape of the wing.

Aeroelastic surfaces have been studied for some time, though I don't know of any production applications (yet). Here's a NASA F-18 fitted with them:

https://www.nasa.gov/centers/armstrong/news/FactSheets/FS-06...

Are you referring to the ballpark "specifications" in the article? If so, I don't know of any material that can withstand the stresses of the weights and speeds mentioned in it ... unless you are going for really low wing loading (think dirigible).

This you?

http://inflatedwingsails.com/en/concept/

I wish!

"IWS behaves like a muscle" is sort of what I was thinking though.

Small deep cells, intermediate wide cells, large, flat sub-dermal cells, outer skin. All the cells being somewhat indivdually addressable in terms of pressure.

How would this thing behave in bad weather?

Also read recently that european armies were relying on ukrainian cargo plans for transporting large items that A400M can't handle. And are now considering developping their own large cargo plane. These things are rare and apart!

Bad weather is the most significant hurdle here. The article references a few of the Soviet GEVs that were successfully developed, but it looks like they only operated regularly in the Caspian Sea and Black Sea (relatively calm water). Overall, major challenges to development are summarized pretty well here: https://en.wikipedia.org/wiki/Ground-effect_vehicle#Advantag...

Sounds like one big step already taken is in low altitude altimeter development. These folks did a good study on radio altimeter integration in GEVs: https://www.sciencedirect.com/science/article/pii/S147466701...

Very poorly. If a wing hits the water, it's game over - the plane immediately cartwheels and aerodynamic forces rip everything to shreds.

This is DARPA and some defense contractor wanting to cash in on Biden's big increase in military spending.

How low do you think this thing will be flying?

In the embedded video it is said that they want the plane to be able to operate in high sea states and even to sustain flight at up to 10000 feet.

https://youtu.be/IOnLpXVkkTU?t=50

To be fair bad weather is a hard problem for existing sea and air lift.

This is not a pure Ekranoplan and can fly high enough to avoid most mountains, let alone large waves. It's most efficient flying lower but it can act more like a normal plane if necessary.

There's already a startup developing an electric passenger ground-effect seaplane, perhaps the design will scale?

https://www.regentcraft.com/

The problem with batteries is they don't lose weight as they discharge[1]. With fuel powered aircraft the fuel is used up over the course of a flight, so that the average weight of the aircraft is substantially less than the starting weight. This means that as flight times increase the advantage shifts more heavily towards fuel powered aircraft.

[1]: actually they do but it's a trivial amount.

> actually they do but it's a trivial amount.

That depends on the type of battery. There are battery technologies that aren't closed systems (e.g. iron-air batteries are pure iron when charged, and iron oxide when discharged, pulling the oxygen from external air).

The problem with ground effect planes is that flying at 1000km/h a few meters above ground (or sea) is never going to be safe. Terrain (and even worse, sea) is unpredictable. It might make sense for the military but not for commercial passenger flights.

I believe an electric, ground-effect ferry is being planned for Hawaii

Found this, very recent, May 11th: https://www.flightglobal.com/strategy/hawaiian-invests-in-re...

I definitely think the commercial application of wing-in-ground / wing-in-sea is the most interesting. Plowing through water takes a ton of energy. Reducing the energy input it takes to stay in the air sounds wonderful.

Or you can just use hydrofoils, which are an established, proven technology and have been for half a century.

The thing I like about ground-effect over-sea vehicles is that, unlike hydrofoils, they're not majorly reliant on very fast blades chopping through whatever comes across their path in the topmost layer of the ocean, where life tends to dwell.

As a species, we really need to start considering our maritime-based cousins a bit better. The last few decades have been hellish for them, noise and all.

It depends on your requirements. This is the description from the Nemesis, a cost-is-no-concern ultra-yatch:

> The NEMESIS ONE will be the World’s Fastest Luxury Foiling Sailing Yacht, able to break the 50 knots speed barrier, while flying on computer controlled hydrofoils. [1]

So a breakthrough fantasy hydrofoil is trying to reach 50 knots. I suspect that, looking at significant figures & complexity of build, for anyone wanting to be able to get to 75 knots (88 mph) there'd be nearly no one justifying hydrofoils. Even at a reduced speed like 45 knots, I suspect the control problems & additional drag of running a foil start to be pretty unruly & inefficient, and that wing-in-ground very quickly gains appeal for simplicity & efficiency both.

Once we start thinking about wing-in-ground, with denser air, it makes even more sense to start looking at ideas we explored earlier in aviation, like lifting bodies, where we can reap yet more efficiency.

The best counter-example to myself I can come up with is the VT Halter Marine Mk Mod 2 High Speed Assault Craft[2], specs unknown. But I tend to think of hydrofoils as more like the 180t Sea Slice[3], powered by two 3840 hp diesel engines, capable of 30 knots. My eyes & intuition all tells me flying is more effective at speed, and that we have a lot of efficiency we could be gaining from wing-in-ground/sea.

[1] https://nemesisyachts.com/nemesis-one

[2] https://www.thedrive.com/the-war-zone/27350/the-u-s-navy-has...

[3] https://www.industrytap.com/lockheed-martins-naval-vessel-se...

> So a breakthrough fantasy hydrofoil is trying to reach 50 knots.

To be fair, no ekranoplane will hit 50kts without turning the engines on.

I wonder if someone from DARPA reads my tweets.. https://twitter.com/coenhyde/status/1443694051652423688

Started thinking about this to solve the port congestion problem, which they obviously are too. + emission reductions.

it's... not that radical of an idea...

As i hinted to in my second sentence. I was being facetious

Full scale conventional landwars in mainland Europe and seaplanes back in production. What century is it again?

It's a little late to be brainstorming low-cost platforms for sea-based logistics (read: Pacific-based).

First flight of a full-scale prototype by 2027? Not any of the legacy defense prime (Raytheon, Boeing, Lockheed, etc.). They probably stopped reading at "low-cost design" anyway.

Of the defense tech companies that CAN move fast enough and have the technical expertise (Anduril, Kratos, anyone else?), this is so far out of their wheelhouse and the $15M incentive is simply not worth it for the substantial chunk of their resources that they would need to stake on a large-scale program with no obvious path to operational relevance & Program of Record status.

It's a cool idea, and the history of similar platforms is fun, but it's tough to see how this becomes real.

Now we just need those hydro-fuel cell guys to wake up and drop a feed line somewhere hydro-dynamically convenient, and we can stop carrying fuel-tanks with us, forever ..

Just look at the Soviet "Looney" MD-160.

Osprey-style vehicles perform similar functions (move a lot of stuff or things up and then forward quickly enough)

Ospreys can land on a carrier, these need a friendly dock

This looks like someone trying to get on the cover of Popular Mechanics

What DARPA is looking for could carry a half dozen Ospreys without even noticing the weight - this argument is like saying trains don't need to exist because bike trailers do.

When ever the military get involved, its already too late.

There is already a seaplane capable of efficient theater-range transport of large payloads at speeds far exceeding existing sea lift platforms?

Because this is an article about DARPA asking for a new sea plane capable of efficient theater-range transport of large payloads at speeds far exceeding existing sea lift platforms.

Well, sometimes the hard part is the part _between_ "We got it to work a couple times in the Caspian Sea, kinda, sorta..." and "we carried this tracked anti-aircraft missile truck from Hawaii to Guam."

So military equipment has a constant, it keeps going up in weight so I'm not surprised they are asking for this, but the total equipment weights need to come down and nobody is seeing this. When the weights go up the effectiveness goes down. Thats why special forces can use what they want instead of standard issue equipment.

This image highlights this fact perfectly. https://www.thinkdefence.co.uk/2012/08/the-beach-recovery-ve...

The other thing you may not know is various military's will develop equipment for what if scenarios. The Hippo aka the Beach Recovery Vehicle in the link above is designed to push out assault landing craft that have got beached. One of the what if scenarios is a war which involves attacking from the sea. Now that Hippo is based down at Instow at the Royal Marines depot where its tested on Saunton Sands which is pretty good for surfing and thats where the photo was taken.

The contract the UK MOD agreed was so tight it put the manufacturer out of business which meant they had to be bought up because sometimes govt's can get value for money for taxpayers contrary to media reports.

So to answer your question, it depends on Crimea & Russia because Crimea has the 4th largest oil deposits on this planet so there might be a need, how soon is hard to tell, not that they make these things quickly, but they could if pushed. Now I cant help but notice that British oil companies have made record profits which will be useful for buying up foreign oil companies and investing overseas, me thinks there might be some investment going into Crimea soon but it depends on Russia and how that goes.

Come on hacker news, this is basically that big russian behemoth aircraft. It should be the first link in the comments.

So disappointed. HN let me down.

Joking aside, how do these compare?

Edit: jacquesm had it posted!

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