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Researchers To Build Underwater Airplane
coondoggie writes to tell us that DARPA seems to still be having fun with their funding and continues to aim for the "far out." The latest program, a submersible airplane, seems to have been pulled directly from science fiction. Hopefully this voyage to the bottom of the sea is of the non-permanent variety. "According to DARPA: 'The difficulty with developing such a craft come from the diametrically opposed requirements that exist for an airplane and a submarine. While the primary goal for airplane designers is to try and minimize weight, a submarine must be extremely heavy in order to submerge underwater. In addition, the flow conditions and the systems designed to control a submarine and an airplane are radically different, due to the order of magnitude difference in the densities of air and water.'"
Isn't this the same exact kinda thing that Steve Fossett et-al were building (completed?) - as covered previously on Slashdot?
This was Fossett's project I believe. They already have a design and partial prototype yes?
They're using their grammar skills there.
Airplanes underwater??? This is crazy talk! Next they will wants subs that fly!
to build a flying submarine - I mean after all, if we made a brick fly (an old saying about the F-4 Phantom).
I don't have anything to say, but everybody else is posting stuff with "Steve Fosset" as the title.
Sounds like a few too many people at DARPA liked 'The Phantom Menace' a little too much.
http://en.wikipedia.org/wiki/Image:Flying_Sub.jpg Someone's imagination is running wild. If DARPA is giving them money then it's time to turn them off.
http://www.imdb.com/title/tt0075648/
May be not as crazy as it looks.
Can't wait for the psychic schoolgirl commando anouncement.
Rocks sink, and Rocks Fly. Problem Solved!
and the wooorld of tomooorrrow!
Seriously, what kind of moron chooses gwyneth paltrow over angelina jolie, even one-eyed? Sheesh.
Between the densities of air and water at atmospheric pressure.
I'm not sure, but I believe those "underwater airplanes" already exist.. and are called "submarines".
MABASPLOOM!
we already solved this problem sometime in the 1980's...
http://ufoseries.com/movieClips/skyLaunch.wmv
http://www.youtube.com/watch%3Fv%3D63yhXg0bsfY&usg=AFQjCNFpfG0wXT4-4yM7QfqXByVLWtgxyg It's already been done. Seeing is believing
And how is the Fiery Phoenix mode working?
Well, so much for todays poll, I guess.
Who cares about boring old submarines and carriers when you can get a submersible airplane.
study up on flying fish and flying squid
then dabble in cormorants and water beetles
once again, mother nature was here first and has a lot to teach us about where to start
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
First thing that came to mind for me is from the old UFO series http://en.wikipedia.org/wiki/SkyDiver
The idea of JATO (or is that RATO) assisted launches from underwater would make for some interesting dynamics, yet I think that space borne items will be of far more value in the long term, its not like you can't drop from about anywhere up there and end up where you want to be while a submersible is subject to being easily interdicted
* Winners compare their achievements to their goals, losers compare theirs to that of others.
Before they go too far with the designs, DARPA might want to check their figures for the densities of water and air. Last time I checked they differed by a lot more than "an order of magnitude" and I'd think this might be important.
Airplane is in the air, this should be called a Submersible craft.
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http://www.tomswift.info/homepage/diving.html
This game was called X-COM 2 : Terror from the Deep.
http://validator.w3.org/check?uri=http%3A%2F%2Fwww.slashdot.org Errors found while checking this document as HTML5!
Did they mod MS Flight Simulator for that video in TFA?
Anyhow, I'm guessing they're not planning any paratroopers. They've got the door on the back between the exhaust of the turbines. Can you say barbecue!? Not to mention that you'd probably snap your neck once you got thrown by the output of those things.
-
Jim, you're WAY off your landing mark, you're going to have to... Jim?! JIMMMMMMMMMMM!!!
Planes are designed to soar as high as possible with the least amount of energy and to be very aerodynamic. Underwater craft are not designed to soar, or to go deep in order to achieve the best performance.
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Supercavitation would allow submarines to move at supersonic (with reference to water) speeds while submerged, and dogfight underwater like WWI aircraft did in the air. If they can come to a complete stop they'd be silent and invisible, just floating there, then fire up the engines and go back to moving faster than ship-based sonar would be able to detect them. There's already a supercavitating torpedo. People who design targets -- I mean aircraft carriers and destroyers -- must be worrying about this.
Nostalgia's not what it used to be.
How about this, a rear propulsion planwhich the pilot operates in a counterbalanced globe at the nose. The airplane slows down to a minimum airspeed and inserts the nose and flips over, the pilot's globe rights itself and the planes control surfaces are inverted. The fusalage takes on water to neutral bouyancy and the plan controls as if it were upside down. I'm sure this is completely unfeasible and I hope someone will explain why. The main problems I see are 1.) Slowing the plane enough that 'insertion' doesn't rip it apart. 2.) The pilot seizing up during this maneuver which would go against all of their piloting instincts. 3.) Control systems designed for air travel would be completely inefficient/infeasable in an aquatic environment. Did I forget anything else?
-=Bang Bang=-
Well, the "flying" submarine bit has been around for awhile, but adding the air part certainly does add a twist.
If brevity is the soul of wit, then how does one explain Twitter?
or waterplane?
Let's not be illiterate.
Hail Eris, full of mischief...
E pluribus sanguinem
I then put two and two together and got five, because I realised that the disagreement arose because the interviewer did not expect the operating temperature range of the hardware to exceed more than about 25 degrees C - which made sense if it was for use in sea water.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
Hey, I can make any plane a submersible. Granted, there's not much you can do with it after that point but hey, you were the one who were vague about the specifics!
Anyone else getting flashbacks to that old game Subwar 2050?
Kwisatz Haderach
Sell the spice to CHOAM
This Mahdi took Shaddam's Throne
http://en.wikipedia.org/wiki/X-COM:_Terror_from_the_Deep Ok, the idea of a flying sub is kinda cool, I'll give it that, but whats the practical use? I mean when are you ever going to need a sub and a plane and not have time to switch between the other two? Unless we are fighting a terror from the deep (puts on tin foil hat)
-Ours is the wisdom of Solomon, the magic of Merlyn, the fall of Icaris.
puddlejumper (you know, from Stargate :)
Why am I paying my tax money for this? Can someone explain? They rip off the taxpayer to the tune of $500 billion every year (although only a fraction of that is DARPA) and then build something ridiculous with no prospect of adoption, ever, or wage wars under false pretenses.
Is that like Tuna, chicken of the sea?
JS signing off.
"We're taking over 150 atmospheres of pressure!"
"How many atmospheres can this ship take?"
"Well, it's a spaceship, so I'd say anywhere between 0 and 1."
Eek!
All I can say is "Why?" - This really does sound like a stupid(tm) idea to throw money at...
Note - I'm not being rhetorical, I'd really like a [good] answer...
-Space for rent
I don't have anything to say either.
Someone has been watching re-runs of Voyage to the Bottom of the Sea
There is no "-1 offended" or "-1 you don't agree with me" mod options for a reason.
I'm waiting for the sonic boom.
now we need to go OSS in diesel cars
since when is "fuckofftags" a useful tag?
They're saying how the requirements for submersibles and aircraft are diametrically opposed. That's good! If they were only kinda in opposite directions, that'd be a challenge. But calling on my vast electrical engineering knowledge (and what is mechanical engineering but electrical engineering with molecules instead of electrons?), I can tell you this is easy. What do you do if you discover that your current is diametrically opposed to what you want? That's right, you flip the terminals around, and bam your current is spot on!
So, using the same principle. In air you want the plane light and lift high because gravity means the natural tendency of the plane is to go downward and you want to go up. Underwater, gravity turns into buoyancy and your plane would naturally want to go up when you want it to go down. This sounds like our current problem -- we have a plane that flies perfectly in air, but in water goes the opposite direction of what we want. So what do we do? Yeah, we just flip it. Now the "lift" of the wings is pointed down. All you need then is an engine that works in air and water, and either a crew compartment that rotates to stay vertical, or sturdy straps and training for pilots to maneuver while upside-down. Done!
I just but the reversed-wing thing is actually used in some high speed submersible. Exercise on how to make it work in either direction above/below water left as an exercise for the DARPA grantee.
The enemies of Democracy are
It's completely ass-backwards that the big funders for ideas like this are military rather than domestic or commercial, that a "national security" gets first dibs at any technology that might come of this.
Would the internet be around if the military hadn't decided the way to keep wired communications going through a nuclear attack was to make it free and widely available? Unlikely.
Any submersible technology is worth developing/exploring for the obvious reason that the planet is getting overpopulated.
underwater dirigibles. They use water tanks for ballast and trim similar to the dirigibles used gas bags for lift and trim.
Okay - so it's a submersible aircraft rather than a flying sub. Slightly easier.
Not sure if it's acceptable for the passengers to require wetsuits. Since we're only after shallow depths pressure isn't going to be a big problem. Modern materials should be able to handle depths of a few feet. Weight is. Flooding the thing will mean less force required to keep it under.
Wings can be used as hydrofoils. They'll be a bot too good though. Perhaps they need to fold out of the way entirely or something. Extra front and back fins can be added which will provide some lift in the air and ability to keep the vehicle underwater as long as it's moving at a reasonable speed.
Perhaps a plane is the wrong way to go. Ground effect craft would have a lot of the advantages and can be made heavier without as much impact.
All it needs is nuclear power and a cool shape...
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
I remember seeing a mini sub that was neutrally buoyant and used its 'wings' to 'fly' in the water.
Sounds like proven tech to me.
---- Booth was a patriot ----
Nah, he was just trying to replicate the results of the experiments of the decorated scientist 'Buckaroo Bonzai'.
Too bad he didn't realize his work was obsfucated for national security reasons.
---- Booth was a patriot ----
and I could live without Tasers. My issue is when they spend my money on ridiculous crap like this.
This reminds me of the final fantasy games I used to play.
Basically every game had an airship, which was a sea vessel that looked similar to a pirate ship.
It would become airborne via aid of a blimp or helicopter style blades.
It wasn't submersible, but the ship was definitely not lightweight.
One of my dreams is to become an eccentric billionaire and build one to throw sky parties.
If it ever happens, you're all invited!
Does it come with Angelina Jolie wearing an eyepatch? Are they going to do helicarriers next?
[Insert pithy quote here]
Why is everyone going on about Fossett when this thing isn't too far off from the Nightowl's magical flying machine?
"We shall grapple with the ineffable, and see if we may not eff it after all." - Douglas Adams
It's an interesting capability, but rather specialized.
What DARPA apparently wants is an aircraft with modest underwater capability, just enough to submerge to snorkel depth. It's intended to carry a Navy SEAL team. (They use the term "operators", which includes a range of special-ops people, but if it's an open-ocean job, they'll probably be SEALs.)
SEALs already have various rubber boats and mini-subs, and those can be deployed from helicopters, existing submarines, and surface craft. So why the need for this specialized craft?
It would have to be for a place where the U.S. Navy couldn't operate offshore, even with submarines. Now where would that be? The Black Sea and the Caspian Sea are probably the only such bodies of water of military interest. The Black Sea is considered a "Russian lake"; no US vessel is going to get through the Bosphorus. The Caspian Sea is inland, and borders on northern Iran, but isn't a useful route for an special-forces attack on Iran.
But the Black Sea port of Poti, in Georgia, is of current military interest. During the war in South Ossetta, the Russians took over Poti and the road/rail links to Gori, so that they'd have an escape/supply route in case somebody took out the Roki Tunnel, their only other access route. (Read, or see, "A Bridge Too Far", for what happens to an armored assault force out at the end of a long, thin string the enemy can cut.) If Russia wants to move into Georgia in force, they'll need sea access at Poti, or somewhere along the Black Sea coast. The US might want to do something about that, something short of full-scale military confrontation with Russia.
So that's what this is good for.
This story is straight out of a mid-90's PC game I used to enjoy.
http://images.google.com/imgres?imgurl=http://content.answers.com/main/content/img/amg/games/drg000/g007/g00722gkojg.jpg&imgrefurl=http://www.answers.com/topic/terror-from-the-deep&h=228&w=200&sz=12&hl=en&start=2&um=1&usg=___hGQhc8r1nEyaxg_QoYiGjqe6iU=&tbnid=Ys_aeCK132xEbM:&tbnh=108&tbnw=95&prev=/images%3Fq%3Dx%2Bcom2%2Bterror%26um%3D1%26hl%3Den%26rls%3Dcom.microsoft:en-us%26sa%3DN
I like it because it removes the danger from the notion of "in the event of a water landing..."
(Can somebody please tag this "skycaptain"?)
Now DARPA have plans for this new gadjet, but yet I cant pick one from the /. poll
I call this slackery!
A sub with a Warp Engine...Beam me up Scottie there's no intelligent life left on earth!
Well, i have lots to say!
I just don't feel like saying it.
-Taylor
Worldwide Military budgets: $2100 billion. Worldwide Space Exploration budgets: $38 billion. Really, world? Really?
Movie != Reality
Stop bringing ancient movies up into discussions about reality, please. We don't fucking care of someone made up a story remotely similar to the topic.
Who needs to imagine anything?
Please mod parent way up - not only remembered it, found pictures for it.
Pathological kinda promises Path + Logical - but instead, you get stuck with pathetic.
http://www.susanscott.net/Oceanwatch2002/jan04-02.html
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
When I was in the Navy, my Captain was a submariner and my XO (2nd in command) was a helicopter pilot.
These two guys didn't get along.
In one (of many) knock down drag 'em out verbal exchanges the two had, the Captain yelled at the XO,
"There are more helicopters at the bottom of the sea then there are submarines in the sky!!"
http://www.htcherocentral.com
Didn't G.I. Joe already do this, more than 20 years ago? Why's DARPA doing this again, now?
http://gijoe.wikia.com/wiki/S.H.A.R.C.
http://www.yojoe.com/vehicles/84/sharc/
http://www.technohol.com/gijoe/84j-gear/index.asp
"Those who would sacrifice essential liberty for temporary safety deserve neither liberty nor safety."
Sounds like a few too many people at DARPA liked 'The Phantom Menace' a little too much.
More like "The Incredibles".
In particular: The scene where Mr Incredible is being flown to Syndrome's island-of-military-tech-fabrication in an automated plane which (for no discernible reason) lands by smoothly "flying" into the water and cruises underwater into an underground/underwater hanger which drains and fills with air.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Submarines are difficult thingies to get working ... so are thingies that fly.
Cars, on the other hand, can be slapped up by any soap-box derby kid.
So I think a better engineering strategy would be to get a decent car/submarine and car/plane concept working.
Then you fork/fudge/re-factor the interfaces to deprecate the car stuff, and then you get a submarine/plane!
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
I really did want to be Tom Swift Jr. when I was young. Unfortunately I ended up looking more like Chow Winkler.
I don't really know who were part of the team that was Victor Appleton III, but they came up with a lot of intriguing gadgets and ideas to wrap the book's formula around when I was in the 6th grade. Jet submarines, flying cars ("Ultrasonic Cycloplane", lovely great words you could chew on), giant robots, quite a range really. Think in terms of the more imaginative Modern Mechanix covers written to appeal to the impressionable grade school demographic, and you have a lot of mind food for the proto-geek.
Do not mock my vision of impractical footwear
This whole line of thought is entertaining to me, as one of the "wrecks" in the quarry I dove this weekend was an F-4. (They "feel" much bigger underwater. Sadly, its wings were detached and lying nearby, so even if I could get some thrust into it, I probably couldn't fly it.)
The USA has had INVISIBLE Isreali-piloted submarine planes since the early 1980s. The BOLSHEVIKS in Washington were only stymied in their plans for world DOMINATION by the use of PSYCHO-KINETIC RANGE FINDING.
This was all revealed in detail by Dr. Peter Beter in his series of Audio Letters in 1981 - 1982.
Oh yeah? Think I'm just trying to be funny, do ya? HA! Take this:
http://www.peterdavidbeter.com/
And THIS:
http://members.aol.com/rem547/
http://bcliffe.com/subs/FS1.html
I need one of those models...
There exists no way of exchanging information without making judgments. --Bene Gesserit Axiom
a screen door that can be used both submerged and airborne.
Actually, the Japanese built and used several of these in WWII (they had to surface to launch); link.
Impressive, but probably not worth the cost and resources...
...of the undeniable fact that there's nothing under the sun that man cannot conceive, that Gerry Anderson hasn't thought of already.
Any technology distinguishable from magic is insufficiently advanced.
First thing that came to mind for me is from the old UFO series http://en.wikipedia.org/wiki/SkyDiver
Gerry Anderson also used the same concept in Thunderbirds.
DARPA's model, though, looks more like Irwin Allen's Flying Sub from "Voyage to the Bottom of the Sea". This makes it a bad idea - it'll be prone to rocking violently back and forth while shooting sparks all over the cockpit at the slightest problem.
I once visited the aquarium in Monterey, California. The main fish tank is open to the air and has the same kinds of fish that inhabit Monterey Bay.
I happened to be there when the fish were being fed. I was treated to the sight of birds flying around in the tank and challenging the fish for the food. I mentioned it to a colleague at work and he said that he skin dives and sees that all the time. I have visited other aquariums and have never seen anything like that anywhere else
If birds can fly underwater, why not airplanes?
in Soviet Russia, no less. The Ushakov LPL was a WW2-era design for a flying submarine. It didn't progress beyond a paper project.
In the '60s, hobbyist Donald Reid succeeded to some extent. His homebuilt craft was underpowered but did fly (briefly).
I don't understand the assumption that a submarine-aircraft would have to be made heavy and thus be too heavy to fly. Therefore the idea is suggested to be not likely to work at all or will be too compromised to be good at either role.
Rather than resisting water pressure with a heavy pressure hull, it is only necessary to equalize pressure internally and externally. Also consider that humans can readily withstand pressure to a depth of 20-30 metres (just don't try surface in a hurry).
It then becomes not necessary to reinforce all but a few sensitive systems against pressure at depth. That said it's not as simple as taking a F-22 and filling the avionics full of scotch guard and drilling some drain holes. But landing say a helicopter on water, flooding it and having it perform adequately underwater is not a monumental engineering challenge.
In such a craft you could still have a small pressure vessel for crew and sensitive systems, while the rest of the vechicle is filled with ballast water and the resulting compressed air. We are still talking about weight penalties in additional systems and design, so it's still a vehicle that's neither a good aircraft nor a good submarine.
I also think Darpa would be better off with a some VTOL design considering the difficulties in taking off from water. Something like a submarine apache would be quite an achievement. I'm forgetting that the F-22 design is VTOL capable, now that would be a scary machine for any enemy to go up against.
After logging in slashdot still does not take you back to the page you were on. It's been that way for 20 years.
The definition of flight, as I studied at flight mechanics, is the motion through a single media or lack of media. :P ), since their motion is between two media.
Airplanes fly through the air
Zeppelins and balloons fly through the air
Submarines fly through the water
Space-ships fly out of atmosphere
Ships do not fly because their motion is in between two media
Cars do not fly (except for some instants, as it is the case of Rally cars jumping
From an engineering point of view, submarines use buoyancy forces mainly besides hidrodynamic lift at controls. There are interesting projects around about small submarines using mostly hidrodynamic lift to move around. However, being buoyancy so cheap and independent of the speed of the sub, makes it so interesting for a sub. In aviation, however, in order to obtain good buoyancy you need so much volume that makes it impractical (Zeppelin) and smarter approach is required (aerodynamic lift) with a penalty (minimum speed required).
Check out the U.S.S. Ohio (SSGN-726). I'd bet that one of these submersible aircraft will be designed to fit/fold-up into a D5 missile tube. Eight operators and their gear? Sounds like a SEAL team to me... I think that Skunk Works has a video of the Cormorant drone which is a similar concept.
I seem to recall reading a science fiction story from the late 70's or early 80's involving so called negative bouyancy submarines. The idea was that they were more like underwater fighter planes than blimps.
Of course, if you had a propulsion failure, you would end up on the bottom of the ocean.
airplanes "fly" by making the air they're going through go through a longer route on their top side, /--\, than their bottom side, ___, but in the same amount of time, thereby creating lower pressure above them: the pressure difference raises them. Problem is you need to keep moving.
But imagine for a moment if instead of the airplane we turned to ... the dirigible.
Imagine if you could change the average density of the WHOLE body to be less than the surrounding "air" (water).
You would have to somehow find something that weighed less than water.
In a normal dirigible, where you have to find something lighter than the surrounding air, you fill it with helium/hydrogen/or hot air (which is less dense). But for an "underwater" dirigible?
Well since AIR is ligher than water, imagine if you had hollow sections filled with AIR!
You could have balloons of air, let's call these "ballasts". If you wanted to go lower in the water, you would fill these "ballasts", with seawater from "outside", and when you need to "ascend" again you could drive the water back out (filling the "ballast" from tanks of compressed air).
It might just be crazy enough to work!
While the primary goal for airplane designers is to try and minimize weight, a submarine must be extremely heavy in order to submerge underwater.
Bah! 19th-century thinking! Submarines fly like zeppelins: they try to match the density of the fluid around them. But as the Wright Brothers proved, you don't have to match the density of your medium to fly.
Picture something like an airplane, very much lighter than water, but with an inverted airfoil wing, which generates downward "lift" as it moves through the water. Just like an airplane, so long as it keeps moving forward, it can maintain level flight.
The power required to stay underwater using inverted wings is probably pretty high, but TFA says this vehicle's day job is as a military aircraft. If your power plant can manage Mach 2 in air, you can do just about anything underwater.
What? Oh sorry, wrong door.
I love the self-assurance of the ignorant. Quite cute, really...
I work with ex-submariners. One of the reasons that they hated and feared a real reactor SCRAM was that the sub was essentially relying on its forward motion to maintain it's depth.
Yes, it was negatively buoyant, but the slight upward pitch of its planes enabled it to "fly" through the water. Supposedly, you get much more responsive control that way, rather than wallowing in the water while you wait for tanks to fill or empty. Very important, when you're trailing an aggressive Russian sub...
When the reactor shuts down and the screw stops turning, the damn thing will sink until the control team get the tanks set for neutral or positive buoyancy. Not a comfortable time as the boat heads down and the hull groans and creaks and everyone starts to wonder if there's enough high pressure air in reserve to blow the tanks.
Mainly OT, but by God and by golly, major navies do FLY their subs.
Political language
They might also want to check with someone who knows something about submarines, even an enthusiastic amateur...
Submarines want to be dense enough to dive, yet light enough to surface. (Yes, I know the difference between density and weight, but in submarine design and operational calculations you use both depending on the angle you're viewing the problem from.) Optimizing displacement to the narrow range where weight and density are in balance is a complicated problem. (The lack of a solution to which killed many an early submarine crewman until John Holland had a flash of brilliance and separated the ballast and trim systems from each other.)
no text to see here, move along
I imagine he'll be escaping from a rapidly surfacing submarine by cunning use of a parachute after the pilots bail with the last of the inflatable rafts. Wait...what?
http://en.wikipedia.org/wiki/Fictional_submarine_aircraft_carriers
14 listings.... vttbots is only one of the 14,.,,
every day http://en.wikipedia.org/wiki/Special:Random
Next they'll be requiring dive-bombing capacity in their passenger jets! And ejection seats in submarines!
Facetiously, fast aerial transport needs fuel with a high MMBTU and a light weight. A non-nuclear submarine needs a lot of batteries to move underwater for any reasonable length of time.
That number of batteries constitutes a weight penalty for an aircraft. That quantity of light jet fuel constitutes a massive buoyancy chamber for a submarine. And burning off the fuel to permit their use as ballast tanks in order to submerge ... sends a terror-induced shiver up my spine. It puts a new meaning into Overuse Syndrome.
To be blunt, it's a non-starter.
"I his bow, and spun and wove, likes you." Vere de Vere out of my mould's mouth dragged me of the voluntary apes.
No, but it's all really taking me back. It got me thinking about Supercar, Fireball XL5 and Stingray - I watched those as a kid in the '60s.
http://en.wikipedia.org/wiki/Supermarionation
I'm trying to remember if those included flying subs.
Anything to avoid my latest Sarah Palin spam email.
Pathological kinda promises Path + Logical - but instead, you get stuck with pathetic.
When I first looked at the video, I thought it was a rerun of a Voyage to the Bottom of the Sea episode...
I guess the Atlantis puddle-jumpers aren't a practical prototype with the need for a forcefield and anti-grav technology.
Just make a submersible with flip-out jet engines. If the jet engines are big enough, it will fly. See previous comment about F-4, also referred to as "a triumph of thrust over aerodynamics".
Underwater airplane??
How about a flying submarine while you're at it?
This is similar to an idea that I had years ago: the submacopter. It is basically a cross between a helicopter and a submarine. It flies like a chopper until it is time to submerge, then the wings fold up into a special cavity on the roof (like the landing gear for an aeroplane) and the tail rotor turns 90 so that it is perpendicular to the vehicle. Easy! I'll build one this afternoon!
I like my coffee the way I like my women - roasted and ground up into little tiny pieces.
or less?
A submersible (the device described in TFA is most definitely a submersible, not a submarine) can also dive underwater by making use of dynamic lift - use the wings to generate negative lift to hold it down. Just like modern submarines can "ride the planes" (meaning to use the bow/stern or sail/stern planes to keep the submarine in neutral buoyancy without actually making the thing displace exactly the amount of water it weighs.
Note that it's probably still a silly idea. If you can't go forty or fifty fathoms down, someone flying overhead is going to see you. And if you CAN got forty or fifty fathoms down, you probably weigh too much to take off from an airfield, much less from the ocean's surface. Pressure tight hulls don't come in lightweight versions.
Note further that someone flying overhead can probably see you at forty or fifty fathoms, come to that. That's not far below periscope depth, and subs at periscope depth were being spotted from airplanes in WW2 using the Mk1 Eyeball.
"I do not agree with what you say, but I will defend to the death your right to say it"
Sounds like a supersonic missile/torpedo hybrid would do the trick - don't know about carrying 8 people, not a bad idea for a weapons platform though! I believe modern torpedos exist that can travel in their own gas bubble at high subsonic speeds- and a fast moving 'cruise' missile might be able to be built strong and streamlined enough to make this a reality.
You can't fly airplanes underwater. Flying can only be done in the air. You might be able to build a swimming airplane, but then that would be a submarine. "Sub" as in "below" and "marine" as in "water".
Oh, I get it, they're building an amphibious vehicle that travels in the air and in the water. Interesting, but stupid. Since you would have to compromise the abilities of each and wind up with a mediocre compromise. Unless of course you have a way of altering the physical feature of the vehicle. I won't hold my breath on that one.
Although it may produce some very useful information on building subs that are superior to the current generation ones.
The device pictured in the video is not going to be practical.
It has a so called aspect ratio of about one (Width devided by length, if it were rectangular). This is inefficient. This is inefficient both in air and in water.
The low aspect ratio means it flies inefficient: I estimate it will fly at a glide ratio of about 1:3. So it requires a thrust of about a third of its weight to fly.
If it's going to go underwater, its going to have a specific weight that is comparable to water. That's not going to fly.
You need a higher aspect ratio to fly. At least to do so efficiently.
To be able to submerge, you need the specific weight to be about that of water. Normal submarines have a mixture of air and steel so that taking on some water makes them heavier than water. But their specific density needs to be quite close to that of water to have a little water make the difference between floating and sinking.
Having a specific density of water makes flying difficult.
The depicted vehicle with the door next to the jet engines has another disadvantage: you can't get off the plane for half an hour after landing... But thats just a practical issue that can be fixed easily....
that will fly like a lead zeppelin. What next? Roll-down windows for submarines?
Free, as in your money being freed from the confines of your account.
from the wikipedia-article:
"The missile controls its direction using four fins that skim the inner surface of the supercavitation envelope. To change direction, the fin or fins on the inside of the desired turn are extended, and the opposing fins are retracted"
unfortunately this is inconsistent with this statement later on:
"There are at least three variants:
VA-111 Shkval - Original variant; believed to be unguided (or perhaps tracking but not very maneuverable)
Shkval 2 - Current variant; believed to be guided, possibly via the use of vectored thrust, and with much longer range.
A lite version currently being exported to various world navies."
This might be true if you are looking at the "old" kind of submarines that stay out for months lurking around and waiting to launch their nuclear missiles?
This could well be the jetfighter-aequivalent for underwater. Imagine an aircraft-carrier with some of those (besides the conventional planes). They would not need power for months, but for hours only - just like jetfighters today. They could be used for covert strikes on marine installations, to approach costs unseen, to defend convoys against submarine threats or against small attack vessels, they would be able to outmaneuver every conventional fighter as long as the water below is deep enough...
Goin' ... down? ... and so obvious that nobody at /. saw it?
And supercavitation TORPEDOS?
OMFG it never ends
Hmmm.
RR
In order to fly an aeroplane has to have a relatively low wing loading - that is it's weight must be low with respect to its wing area. In order to submerge a submarine must be dense - that is its weight must be low with respect to its volume.
These factors are by no means diametrically opposed. A thin sheet has high area but low volume. I predict that the winning entries will be:
I'd also hazard a guess that it would be designed to be slightly buoyant, and would invert to dive, using the lift of its wings to pull it down. If propulsion failed it would automatically surface. The difficult design problems seem to me to minimise drag from the flying components when in the much denser underwater part of its range.
I'm old enough to remember when discussions on Slashdot were well informed.
This is a nice thing for a 6 year old to think about when he's bored but in the world of science it has no place. We have a submarine and we have an airplane, why combine them?
This type of object exists, we HAVE flying submaringes, they are called BIRDS. Diving birds are NOT constrained by their weight. Their problem is their lungs. Several spieces swim very well under water and can even go straight from flying to submerged.
If birds can do it, so can man.
The trick is to stop thinking of this object as an old fashioned submarine and accept that modern submarines FLY under water. They use their "wings" to control their movement, not their weight.
The biggest challence is re-configuring the wings. Birds can do this easily but swing-wing is out of fashion for a reason. A swing wing that can survive a dive is going to be a major piece of engineering.
Another challenge is getting from one method of propulsion to the other. Birds of course use the same engine and switch effortleslly between legs and wings for power, can humans do the same? Have a single engine that can power motion in air and underwater?
There is however one part of the requirement that might make it more difficult. I think this aircraft is intended for the insertion of seal units quickly without having to worry about air defences. For the seals to disbark from the aircraft underwater it would have to be going very slow or even be motionless. An aircraft that is light and uses negative lift to remain submerged would shoot up like a cork if it stopped.
Key problems:
Power source that can operate underwater.
Two modes of propulsion for air and water.
Switching quickly between modes and both modes not interfering with the other, for instance propellors would probabbly smash during a power dive.
Being able to remain motionless underwater and also submerged.
If it wasn't for the last requirement the trick would be fairly simple, "just" a plane that has positive lift in the air, negative lift under water, super-cavitation speeds to be able to shoot up out of the water with enough speed to remain airborne and a system to switch seamlessly between air and water propulsion.
Do-able. But remaining motionless underwater adds a whole new trick. Suddenly you can use your speed and re-use your wings to remain underwater, you need to alter your weight.
Mind you, I wonder if we at slashdot are not overcomplicating things. What DARPA is looking for is a way to insert seals with minimal detection.
What about an 'ordinary' sea plane that instead of sitting above its floaters can sink beneath them? Imagine an ordinary plane with floaters attacked sticking out the sides and below. It lands on the water as all seaplanes do but then the floaters rotate above the fuselage allowing to disappear beneath the waves. The fuselage opens, allowing sea-water inside removing most of its lift. The floaters act like miniature subs and can submerge to an extent. This aircraft is not about setting records, it has to operate near the coast anyway so can't go to deep in any case.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
Here are just two examples of people in the past trying this; to be fair, the first one isn't technically a flying submarine.
Submersible aircraft- http://blog.modernmechanix.com/mags/ModernMechanix/9-1930/submarine_plane/submarine_plane_1.jpg
Submarine aircraft carrier- http://en.wikipedia.org/wiki/Submarine_aircraft_carrier
No offense, but I've stopped responding to AC's.