The First Stealth Flying Wing

June 24, 2009 1:12 PM

Though the B-2 Spirit is perhaps the best-known of the flying wing designs, its creation came almost 50 years after the earliest attempts at creating fixed-wing aircraft with no definite fuselage. The first prototypes of Frenchman Charles Fauvel's flying wings followed the patent on his formula for the flying wing in 1929. Jack Northrop's newly formed Northrop Aircraft Co. created the first flying wing for the United States in 1940, dubbed Northrom N-1M "Jeep". But it was the Horten Brothers, German aircraft pilots and enthusiasts, who created the first fully-functional stealth flying wing: the Horten Ho IX.

The brothers were first interested in flying wings as a design for gliders. The German government was funding glider clubs at the time because production of military aircraft was forbidden by the Treaty of Versailles after World War I. Walter and Reimar Horten initially entered the Luftwaffe as pilots, but submitted their flying wing glider design for a long-range bomber design request.

The Ho IX (link via) is often called Gotha Go 229 or Ho 229 due to the identity of the chosen manufacturer of the aircraft. The craft was of mixed construction, with the center pod made from welded steel tube and wing spars built from wood. The wings were made from two thin, carbon-impregnated plywood panels glued together with a charcoal and sawdust mixture (utilized as a porous filler to lighten the composite formed parts). Control was achieved with elevons and spoilers. The aircraft utilized retractable tricycle landing gear, with the nosewheel coming from an He 177's main gear. A brake parachute slowed the aircraft upon landing. The pilot sat on a primitive ejection seat.

During the final stages of the war, the US military captured a Horten glider and the Ho 229 V3, which was undergoing final assembly, and sent them to Northrop Corporation in the United States for evaluation. Five partial airframes found at the Gothaer Wagonfabrik factory assembly line were destroyed by soldiers. The only surviving Ho 229 airframe, the V3, is located at the National Air and Space Museum. A full-scale replica was recently created and tested by Northrop Grumman for a National Geographic special entitled "Hitler's Stealth Fighter."

The stealth capabilities of the craft were not fully understood or known when first flown. Though the Kriegsmarine, by 1944, had developed and tested radar-absorbing materials which were applied to the parts of submarines exposed above the water in order to prevent their detection by ASV radar, it appears that the radar-absorbing properties of carbon had not been known to Reimar before the late 1970s, when materials working on similar principles were created in the USA. Still, rumors of stealth capabilities circulated around the HO IX, which lead to replication of and documentary on the Ho IX. The fact that the Ho IX can now be called the first stealth aircraft may have been partially due to luck in design.

The Horton Ho 229 V3 replica is on display at the San Diego Air & Space Museum, opening today. For those wondering about the nitty-gritty specifics, an advanced projects engineer/manager at Northrop Grumman Aerospace Systems who was involved with the recreation and documentary joined a discussion on the recreation efforts, and provided a lot of details the differences from the original craft from 1940 and the modern day replica.

posted by filthy light thief (32 comments total)

At first I thought this was the plane featured in Raiders of the Lost Ark, but the Horten didn't exist until many years later.
posted by tommasz at 1:22 PM on June 24 [3 favorites has favorites]

You forgot the most important link of all.
posted by Artw at 1:24 PM on June 24

Bah, beaten!
posted by Artw at 1:24 PM on June 24

Good post!
posted by hortense at 1:27 PM on June 24

Buried in this page is a comparison of the Raiders design and the actual Horten designs. Scroll down for still images, though lacking the pizazz of video.
posted by filthy light thief at 1:28 PM on June 24 [1 favorite has favorites]

Of course the Nazis built a more advanced model but Indiana Jones blew it up.
posted by crapmatic at 1:30 PM on June 24

The Nazis built wonderful super-weapons by the dozen. The Americans and Soviets built below-average weapons... by the million... and figured out how to ship, deploy, fuel and feed whole armies across continents. The Jeep did more than the Sherman Tank to win the war.

The real Allied super-weapons were in Bletchley Park. Colossus was more powerful than the V2 or A-Bomb, believe it.
posted by Slap*Happy at 1:31 PM on June 24 [3 favorites has favorites]

Nice post FLT, thanks.
posted by doctor_negative at 1:32 PM on June 24

Horten Hears a Ho?
posted by bz at 1:32 PM on June 24 [2 favorites has favorites]

Holy shit, cool plane. And holy shit, nice post.
posted by COBRA! at 1:37 PM on June 24

Thanks for the link, tommasz. I had been meaning to post an AskMe for a while to ask what the hell that awesome plane was.
posted by dunkadunc at 1:47 PM on June 24

The Nazis built wonderful super-weapons by the dozen. The Americans and Soviets built below-average weapons... by the million....

It would be interesting to see a comparison of innovation in a fascist, capitalist, and communist states. How does it affect the process of invention and innovation? Is it more about the direction/approval structures, the psychological mindset of the R&D team, the choice of singular massive creations or hordes of smaller creations?

I would love to see it in a Jared M. Diamond (Germs, Guns and Steel) mixed with the sensibility and delivery of James Burke (Connections, Innovation).

Damn, I need to be a doc producer. Get me their agents!!
posted by chambers at 1:47 PM on June 24 [2 favorites has favorites]

From what I've read, the conception of the Nazi state as being super-efficient is quite mistaken, actually. Because of the way political pull worked, you ended up having a whole lot of people doing a bunch of unnecessary duplication in the name of preserving their own political fiefdoms. And yes, I'm aware that the United States had all sorts of power struggles as well (are tanks cavalry? Are they artillery?), but ... look, the Luftwaffe had a 'paratrooper' panzer division!

There's a common conception that the Allies were not as 'technologically advanced' as the Germans, and really, I think that that's really because the Germans and the Allies had different needs. For example, in 1940 (IIRC), both the Western Allies and the Germans decided to look into these 'nuclear weapons' some physicists had been babbling on about. The German commission found that it was very unlikely that nuclear weapons would be developed before the war's end, and so funding for the nuclear weapons project (actually, the Germans had multiple nuclear weapons projects, see, inefficiency!) was a low priority. The Western Allies, in the other hand, decided that nuclear weapons could be developed before the end of the war, and therefore _had to be_, in case the Germans did it first. Hence, they poured money into it. Both sides actually turned out to be correct, as nuclear weapons were developed after the Soviets had taken Berlin.

Just tossing it out there, but maybe because the Nazi system was more "Oh, the Reichsmarshall loves your idea, here's a giant bag of money", the things that got made sounded more impressive. I mean, the Germans never developed the VT (radar) fuse. The Western Allies did.
posted by Comrade_robot at 2:32 PM on June 24 [3 favorites has favorites]

chambers, that'd be pretty neat, I think.

I work at NASM's Garber Preservation, Restoration & Storage Facility, where the surviving 229 is in roughly three parts (wing, wing, and "fuselage," which is basically the cockpit and engine assembly) and, like the poster on that forum from Northrop Grumman I'm sort of uncomfortable calling it a stealth fighter, and the reason is sitting right next to it in the warehouse where it's kept. The 229 is kept - like our Mosquito - in a special climate-controlled building because the whole thing is made of plywood. Every last bit, except for the engines, the pretty minimal frame holding them together to the cockpit, and the this-looks-too-small-oh-my-god-they-put-the-jet-that-close-to-the-wood exhaust deflection plates (they're the rusty area just under the exhaust). It's not stealthy because it's a flying wing, particularly, or even the charcoal-and-sawdust glue in the wings. It's just stealthy because there's nothing in it for radar to reflect off of. And while the radar-dodging might have been useful if they'd really intended it to be used as a bomber, the repurposing to interceptor - and the fact that it was way faster than any radar-carrying aircraft at the time - meant it wouldn't have even been particularly beneficial compared to the fact that it was just really fast.

Calling it "Hitler's Stealth Fighter" plays on the visual semblance to the F-117 and B-2 (and the F-19!) but misleads you from what they were trying to do - make a dirt-cheap high-performance jet fighter-bomber in a state with barely a resource to spare. Still, I'm looking forward to watching the documentary when I get a chance.
posted by The Bridge on the River Kai Ryssdal at 2:39 PM on June 24 [11 favorites has favorites]

Yeah, a King Tiger needed something on the order of a hundred thousand man-hours to make one of them... and by that time, the Hellcat was being rolled out a hundred at a time at $50k a pop (around a half-million in modern money.) The manufacturing technology needed to develop a mass-produced weapon that effective and that cheap is more impressive than micrometer tolerances.
posted by Slap*Happy at 2:54 PM on June 24

Fascists start off building good weapons platforms, but then get obsessed with size. Pretty soon, it's imperial star destroyer this, and super heavy blah blah that.
posted by BrotherCaine at 2:57 PM on June 24

The Soviets built the best tanks in WWII, in terms of logistics, economy and effectiveness.
posted by BrotherCaine at 3:04 PM on June 24

Of all the suggestions given to Fat, the one that seemed most promising came from Sherri, who still lingered on with us in a state of remission. "What you should do," she told Fat during one of his darker hours, "is get into studying the characteristics of the T-34." Fat asked what that was. It turned out that Sherri had read a book on Russian armor during World War Two. The T-34 tank had been the Soviet Union 's salvation and thereby the salvation of all the Allied Powers-and, by extension, Horse- lover Fat's, since without the T- 4 he would be speaking-not English or Latin or the koine-but German.

"The T-34," Sherri explained, "moved very rapidly. At Kursk they knocked out even Porsche Elefants. You have no idea what they did to the Fourth Panzer Army." She then started drawing sketches of the situation at Kursk in 1943, giving figures. Fat and the rest of us were mystified. This was a side of Sherri we hadn't known. "It took Zhukov himself to turn the tide against the Panzers," Sherri wheezed on. "Vatutin screwed up. He was later murdered by pro-Nazi partisans. Now, consider the Tiger tank the Germans had and their Panthers." She showed us photographs of various tanks and related with relish how General Koniev had successfully crossed the Dniester and Prut Rivers by March twenty-sixth.
posted by Artw at 3:09 PM on June 24

My dad worked with a guy once who had been a photographer on a reconnaissance Mosquito during the war, doing bomb-damage assessment. He brought in some pictures he'd taken once, my dad told me. Said his job consisted of lying flat in the belly of the aircraft and pressing the film button when the pilot said to.

The pictures, he said, were taken with three cameras, one directly out each side, and one straight down. My dad said the pictures he saw, from the side cameras, were looking up at a slight angle into second-story rooms from somewhere near street level.

At three hundred miles an hour.
posted by atchafalaya at 3:42 PM on June 24 [2 favorites has favorites]

Great stuff. I was a WWII aviation buff in my adolescence, but I'd never heard of this thing.
posted by Devils Rancher at 4:13 PM on June 24

If I may suggest, if these and other WWII "dream weapons" interest anyone, My Tank is Fight, a look at some of the most terryfying weapons of WWII, had they been made/finsihed, such as the P. 1000 "Ratte" - A German super tank so large that it used a cruiser turret with two huge naval cannons.
posted by chambers at 4:23 PM on June 24

I used to love flying this plane.
posted by Tenuki at 4:48 PM on June 24 [1 favorite has favorites]

Far and away my favorite flying wing is this one -- Nausicaa's. And I can't be the only one who thinks it's overwhelmingly cool because at one point there was a group trying with some success to build one for real. There are some pics of the full size mock-up on this page and a video of some test flights as an engineless glider. (I can't find any further news of the for-real Mehve. Last rumor I heard they were looking for a female test pilot. Small, light, suicidal.)
posted by jfuller at 5:16 PM on June 24 [1 favorite has favorites]

Just finished an interesting book entitled, "The Wages of Destruction" a super detailed account of the Nazi economy in the run up and during WWII. The Nazi's were not models of efficiency; but they were very good at scheming and figuring out how to keep the whole bubble going until near the very end. The author demonstrates that the vaunted blitzkreig was mostly smoke and mirrors. The myth of the automated Nazi war machine and industrial superiority was mostly simply propaganda. I'm sure they had a few super weapons but they could never manufacture them at a scale necessary to make a strategic difference. The US, USSR and Great Britain also had a number of super weapons. Like computers, the atom bomb, etc.
posted by humanfont at 7:06 PM on June 24

You can see similar glider designs at the Smithsonian Udar Huzy site by Dulles.
posted by garlic at 8:54 PM on June 24

The Bridge on the River Kai Ryssdal : Calling it "Hitler's Stealth Fighter" plays on the visual semblance to the F-117 and B-2

Nah. The Wiki article mentions that they mixed coal and glue to put on the wings so that it would absorb radar. It was built to be stealthy, way ahead of its time.

Read a book on the F-117 once (can't remember the name) and it said that a former-Russian researcher working for Lockheed Skunk Works found this Russian article on geometric shapes that could be used to predict radar reflections, and he realized (even though the Russians didn't) that this mathematics could be used to build a stealthy plane. The F-117 looks weird not because it is the best stealthy design, but because it is the only design that can be predicted to be stealthy based on this new mathematics. Word in the industry (unsubstantiated) is that when Northrup designed the B-2, they asked Lockheed for help in making it stealthy, and Lockheed refused. The net result is that it was a lot less stealthy than they had wanted it to be.

Other than adding certain shapes, the other way to make something stealthy is to actually absorb the radar, which is what the Horton Ho actually did, so long ago.


Ran across this other old weird winged plane the other day.
posted by eye of newt at 9:58 PM on June 24 [1 favorite has favorites]

eye of newt - The Wiki article mentions that they mixed coal and glue to put on the wings so that it would absorb radar. It was built to be stealthy, way ahead of its time.

I think the wiki page is pulling from recent discussions and descriptions. As I linked in the FPP itself, Michael Jorgensen wrote a letter to a curator at the facility inquiring about the rumored stealth properties of the Ho 229 aircraft and received a detailed response:

"I have examined the aircraft and many primary and secondary sources of information about the Hortens' work, and I have found no reliable evidence to confirm this idea. Reimar Horten described these low RCS [radar cross section] techniques during the early 1980s as news reports began to appear that described the stealth qualities of the Northrop B-2 bomber. I have examined the Ho 229 V3 numerous times and found no evidence of a "mixture of charcoal and glue" applied to the skin that would lower the RCS. I believe Horten 'invented' the notion of the stealthy Ho 229 to draw attention to other interesting and innovative aspects of his work."

And an excerpt from Horten Ho 229 - Spirit of Thuringia on the Secret Projects forum:

Although the Ho 229 has been immediately identified as "stealthy" due to the characteristics of its overall configuration, neither of the Horten brothers ever claimed their aircraft had been designed with consideration to the way it deflects radar waves. In fact, the unique shape of the Ho 229 has evolved from the ten-year long aerodynamic research by the Hortens. What Reimar did claim as far back as 1950, was that the wooden construction of the Ho 229 would reflect very little of the incoming electromagnetic waves, thus making the aircraft "...barely visible on the radar."

...

While no wartime document is known to confirm any 'stealth' activities within the Luftwaffe, the Horten 229 can in any event be considered a precursor to the latest flying wing, the blended-wing-body and related devlopments, both military and civil - stealth or not. Thus seventy years on, the Hortens' vision is still at the forefront aeronautical progress.

The wikipedia article seems to have been hastily updated from unreliable sources.
posted by filthy light thief at 11:25 PM on June 24

As a (former) aero engineer: stealth is 80% shape and 20% radar-absorption. Basically, the shape of the aircraft must be such that radar reflection should be minimal from a defender's "point of view", i.e. typically the front and the sides. Since flying wings have a single leading edge (which has to be aerodynamic, i.e. curved, i.e. reflecting radar in a bunch of directions), and a thin side profile (no separate fuselage), the only things you really need to get a flying wing to be stealthy is getting the various angles just right, have a small vertical fin, and hide the engines inside the wing (which the Hortens seem to have done by accident).

eye of newt: the book you're referring to is probably this (excellent read BTW). The F-117 is the shape it is because computers at the time could calculate radar reflections using only so many polygons. So Lockheed just figured out how to make a polygon-based shape fly (answer: lots of power and smart flight controls; without its computers correcting the flight, the F-117 will drop like a brick). Contrast the F-117 with the F-22 which is (said to be) stealthier.
posted by costas at 2:23 AM on June 25 [2 favorites has favorites]

And let's not forget the other "near" flying wing the Germans fielded, which did make at least minor operational difference to Allied bombing near the end of the war, the rocket powered Me 163 Comet. Although it had a large vertical tail surface, and aerodynamic controls more like that of a delta wing aircraft than a true "flying wing," the Me 163's blended fuselage/wing shapes, very truncated empenage, and lack of seperate elevator surfaces were all design choices made in the same vein of reducing drag, that governed flying wing design.
posted by paulsc at 5:55 AM on June 25

I like the idea of a lifting canard to overcome the inherent control difficulties of a flying wing while still being more efficient than a conventional downforce-producing tail.

As alluded to by costas, to my knowledge a flying wing designs basically required fly-by-wire to be operable, but my faith in fly-by-wire is diminished by the recent and past Airbus accidents (albiet with scance evidence of a control system failure in the recent case) and, somewhat related, the DC metro crash.
posted by exogenous at 7:17 AM on June 25

Here's a scratch built model that's just appeared on Hyperscale
posted by mattoxic at 12:25 AM on June 26

The really interesting thing about the Me 163 was not its wing shape but the fact that it was rocket powered. The pilot could not slow down. That's right, seven and a half minutes at Mach 0.9, and then the pilot has to land it like a glider. Skidding to a safe stop was made difficult both by allied fighters and by the fact that the Me 163 was designed to leave its landing gear behind on takeoff. It was a manned surface to air missile.

One of the many problems with The Rocket Fighter That Couldn't Slow Down (tm) was that it flew too fast for the pilot to hit much of anything. One solution was the following:

- take a 50mm cannon
- mount it pointing straight up
- trigger it with a photocell, so it will fire automatically if it suddenly gets dark
- order the pilot to try to fly right underneath an allied bomber

The amazing thing is that this setup actually worked, or at least they got one kill out of it.

Meanwhile, the Russians were constantly trying to figure out how to incrementally reduce the cost of making a T-34. Guess who won.

-------------------------------------------

chambers, I like your idea. However, it's worth noting that democratic Britain's wonderweaponlust was almost as strong as Germany's. Radar and Colossus really were superweapons, but the British also produced lots of zany ideas like the "funny" tank with spinning chains to clear minefields. British superweapons would have done about as much good as the Me 262 if Britain had not had allies who knew the value of a well-oiled assembly line.
posted by justsomebodythatyouusedtoknow at 3:38 AM on June 26