Horten Ho 229

[GrauGeist]

I've always wondered about how the RAF was going to evaluate V2, since it hit so hard on impact, both engines were ejected quite some distance, landing in a ravine. The pilot was found not far from where the engines came to rest.

I do have a photo somewhere of V4 under construction, I'll see if I can find that one, at least.

 

[wuzak]

Might you know where I could get a copy of this photo? Can't find it in any of my books.

This might be it:
http://airandspace.si.edu/webimages/highres/WEB12026-2011h.jpg

The book Amazon.com: Horten Ho 229 Spirit of Thuringia: The Horten All-Wing Jet Fighter (9781903223666): Andrei Shepelev, Huib Ottens: Books has the picture of the V3 assembled in the USA.

 

[Monkeyfume]

http://www.ww2aircraft.net/forum/aircraft-requests/horton-brothers-flying-wings-3618.html
Take a look at that.

Great pictures in #9 and #10. And the guy who posted them goes on about the story.

 

[GrauGeist]

http://www.ww2aircraft.net/forum/aircraft-requests/horton-brothers-flying-wings-3618.html
Take a look at that.

Great pictures in #9 and #10. And the guy who posted them goes on about the story.

Then follow up with this thread to come full circle: www.ww2aircraft.net/forum/aircraft-pictures/german-flying-wings-15300.html

 

[stona]

I know Shepelev and Ottens identified the Avon as the engine suggested for use with the Ho 229 V2, but I think this is unlikely. For one they identified the engine as a centrifguagl type, which the Avon is not.

Also, the Avon first ran in 1946 on the test bench, so would be unlikely to be considered as a replacement engine for a highly experimental captured aircraft.

Quite possibly, but bearing in mind the need to virtually rebuild the badly damaged V2 I think this was only ever a proposed programme and actual flight was something that was going to happen well into the future. It was rapidly abandoned in any case not long after the remains of V2 arrived.

It took the French more than two years to complete a partially built Do 335 prototype, but they persevered and even flew it for a few hours.

Cheers

Steve

 

[stona]

With a bomber you may get by with a design that is "stable". With fighters you want the ability to switch back and forth. You want a fighter that is stable when you want it to be and unstable when you are trying to get it to change direction in a hurry, followed by a return to stable very quickly. Fighters have to able to return to a somewhat stable flight condition AFTER some rather gross changes in pitch and yaw. IF the wing/control system becomes ineffective past certain limits of angle of attack or yaw you may loose the aircraft. Bombers/transports seldom (if ever) operate at the angles of attack or yaw that fighters will. And fighters have to be careful with yaw. That is what caused the loss of some of the early F-100s, among others.

Turning a 'flying wing' was one of the fundamental aerodynamic problems that the Hortens struggled with. They adopted the rather inelegant solution of drag rudders which worked, after a fashion.

Cheers

Steve

 

[Capt. Vick]

Nope, still no pictures of the V2 wreckage. I'm sorry, despite the story, I still think it unlikely that it was scraped up and shipped to England. A gut feeling brought on by the myths and lies surrounding this futuristic aircraft.

 

[Koopernic]

And the V2 flew with different, smaller, lower powered engines than the V3 was equipped with.

Apparently the prototypes had been conceived around the BMW 003, the requirement then switched to the bigger Jumo 004. When the 'test engines' arrived an accessories gearbox cam with the engine that the Hortens hadn't bee told about. This got in the way of a spar hence the centre section of the wing had to be thickened which lead to Mach concerns, the solution was to scale the whole flying wing up a little for the production version. Hence the V1/V2 were more test beds.

Despite the grand and expensive National Geographic Channel / Northrop radar cross section measurements they are invalid in my view. The production or V3 versions was not only bigger but used a different form of wooden construction: the plastic-wood filler heavily doped with carbon black. Carbon black is of course semiconducting and a reasonably radar absorber. The 'experiment' or simulation did not take this into account. To get high quality radar absorption the conductivity must increase in exponential fashion and be around 1/4 to 1/2 wavelength. This type of absorber was known to the Germans, in fact invented by one (Jaumann absorber) and used on uboat masts by lamination of different conductivities but the 'filler' in the Ho 229 was probably not exponentially 'doped' though it would have been possible as only about 5 plys in the 1 inch filler would have been required.

The HO 229 had a slight pitch 'snaking'. Though not impactful on the aircrafts bomber role it was thought a problem for gunnery. The improvised solution was to extend small airbrakes during firing to damp out the motion. The Germans had developed a gyroscopic yaw damper for the Me 262 and I expect it could have been adapted to control pitch.

Take your choice: yaw or pitch based snaking.

 

[stona]

Nope, still no pictures of the V2 wreckage. I'm sorry, despite the story, I still think it unlikely that it was scraped up and shipped to England. A gut feeling brought on by the myths and lies surrounding this futuristic aircraft.

The photograph was not reproduced in the book mentioned above, but the aircraft was listed in the aircraft of the German Aircraft Exhibition. It was retrieved by the Americans following information provided by the British who had interviewed/interrogated the Hotens in London during May 1945. Their is an American Intelligence Report to support this finding.

The absence of a published photo does not mean that the authors above haven't seen it. There are reasons why collectors might choose not to publish photographs, usually related to money.

Later Brown recalled the shipping to the US, and Shepelev and Ottens claim there is at least one document to support this, but if this was indeed the case nobody seems to know what happened to it and the 'Horten 8', presumably the H VIII, which the British had acquired in October 1945, also mentioned in this document.

Various gliders were found by British and American teams in the summer of 1945, indeed the brothers themselves were flown back to Germany to help with the search. There was a lot of interest in the aircraft initially, but this seems to have waned quite quickly.
The Hortens had less influence on post war aircraft than is commonly believed. Lippisch's delta wing research was far more influential and is evident in many designs of the 1950s and 1960s. Take a look at a F-102, F-106 or B-58 in the US or the British Vulcan or rather more experimental DH 108.

Cheers

Steve

 

[Koopernic]

Turning a 'flying wing' was one of the fundamental aerodynamic problems that the Hortens struggled with. They adopted the rather inelegant solution of drag rudders which worked, after a fashion.

Cheers

Steve

dragerlons are still the solution today and of course can serve the duel function of acting as an airbrake if deployed simultaneously. The units on the Horten look like wooden beams with holes drilled in them that extend out in linear fashion. They seem mainly of split trail type these days, better for avoiding shock wave related complexities on the trailing edge.

 

[swampyankee]

With a bomber you may get by with a design that is "stable". With fighters you want the ability to switch back and forth. You want a fighter that is stable when you want it to be and unstable when you are trying to get it to change direction in a hurry, followed by a return to stable very quickly. Fighters have to able to return to a somewhat stable flight condition AFTER some rather gross changes in pitch and yaw. IF the wing/control system becomes ineffective past certain limits of angle of attack or yaw you may loose the aircraft. Bombers/transports seldom (if ever) operate at the angles of attack or yaw that fighters will. And fighters have to be careful with yaw. That is what caused the loss of some of the early F-100s, among others.

What you say is very likely true today, but it was unlikely to be the case with most WW2-era aircraft, as most had straight wings: the AoA limits on bombers, fighters, and DC-3s were probably quite similar. Now, when fighters tend to have low aspect-ratio wings, with modifications to permit operation at very high angles of attack (I've read the F-14 could be flown controlled at AoAs from -30 to +70 degrees), this is no longer true. Bombers and transports need high cruise efficiency, which is, to a great extent, antithetic to ultra-high AoA, unless the aircraft designer is willing to pay the penalties of variable wing sweep.

Regarding stability, before fly-by-wire, fighters needed to be stable enough, but it was necessary to avoid most areas of negative stability* because these areas can quickly move aircraft into attitudes from which it's impossible to recover. The problem with the F-100 was unexpected, as the roll-yaw coupling it exhibited was just about impossible in a straight-winged, subsonic aircraft, because the roll-yaw coupling was caused by the relationship of mass distribution along the fuselage and the mass distribution along the wings. Other aircraft, like the F-104, exhibited different forms of flight control issues: the F-104 was subject to deep stall, a condition to which 727s were also prone. A classic example of an aircraft with a stability issue was the P-51, which was subject to pitch instability when one of the fuselage tanks behind the pilot was filled. The tank had to be emptied before combat, as the aircraft would likely do something unpleasant like go into a flat spin. NA's better experimental test pilots may have been able to recover from that, but I doubt if service pilots could.


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

* Most aircraft have a spiral instability mode, but its time constant is so long, on the order of tens of seconds, that it's easily controlled by a student pilot. I think most, if not all, swept-wing aircraft need yaw dampers to prevent Dutch roll, which is a form of instability. One problem with some of these modes is that they frequently have time constants on the order of a second, which means that the pilot's responses are going to be timed to amplify the instability, hence pilot-induced oscillations. I think that this phenomenon has been cited as the cause of several crashes of prototype fighter aircraft.

 

[Graeme]

Just on the subject of stealth, I understand the Gotha was suppose to be built with this in mind?

I wonder how well it would have stood up to the environment, especially when you read this from 1997 - was the B-2 also a delicate creature that didn't like moisture?

 

[swampyankee]

I believe that the weather-related problems of the B-2 are because of the radar-absorbent coating. The Germans are unlikely to have had RAM, although they probably had the theoretical knowledge to make them (so did the British, the Americans, the Japanese, the Russians, the Italians, ....)

 

[FLYBOYJ]

I believe that the weather-related problems of the B-2 are because of the radar-absorbent coating. The Germans are unlikely to have had RAM, although they probably had the theoretical knowledge to make them (so did the British, the Americans, the Japanese, the Russians, the Italians, ....)

Actually the Germans did try out a RAM on subs. From wiki

"The U-boat U-480 may have been the first stealth submarine. It featured an anechoic tile rubber coating, one layer of which contained circular air pockets to defeat ASDIC sonar.[8] Radar absorbent rubber/semiconductor composite paints and materials (codenames: "Sumpf", "Schornsteinfeger") were used by the Kriegsmarine on submarines in World War II. Tests showed they were effective in reducing radar signatures at both short (centimetres) and long (1.5 metre) wavelengths"

 

[tyrodtom]

Just on the subject of stealth, I understand the Gotha was suppose to be built with this in mind?

I wonder how well it would have stood up to the environment, especially when you read this from 1997 - was the B-2 also a delicate creature that didn't like moisture?

Any aircraft that can fly at 40,000+ feet is flying in severe climatic conditions every flight.

What does it do about clouds?? Avoid them !

 

[gumbyk]

You don't get much moisture adhering to the aircraft flying through clouds, and there isn't any appreciable moisture at 40k ft.
Severe conditions, but fairly stable, at least as far as moisture and temperature go.

 

[tyrodtom]

But they still have to climb to, and descend from that altitude, just like any other aircraft.
That in itself is exposing them to some pretty extreme climatic conditions.

Surely they don't have to restrict them to perfect weather missions only.

 

[GregP]

A fighter doesn't become unstable when it maneuvers, it maneuvers by means of control surfaces and the relative control surface area or the travel on fighters is much larger than the control surface area and/or travel on bombers or transports. The stability doesn't change because you are in a commanded roll , pitch or yaw.

While modern computer fly-by-wire fighters are all unstable on purpose and will rapidly depart controlled flight if the computer fails in-flight, WWII fighters were all stable or slightly positive of neutral stability by design.

Some fighters are not recommended for certain maneuvers. The P-51, for instance, is NOT cleared for intentional spins below about 10,000 feet or somewhat higher. If it begins to spin you can easily STOP the spin but, if it GETS into a fully-developed spin, you may need 10,000 - 15,000 feet to recover ... maybe not, depending on skill and luck. So, getting into a spin at 1,000 feet is mostly a death certificate, But the P-51 is NOT dangerous to fly, even near the limit.

Anyone who recognizes a a spin entry can stop one and , if you don't, then stay out of a P-51 cockpit in flight. It is a stable aircraft, too, with markedly LESS stability when the rear fuselage tank was full. In that condition since it was past the rear CG limit in that condition. It was neutrtal or slightly unstable, but it COULD get to Berlin and back and was out of the stability issue after flying for a relatively short time and the rear tank emptied. At a gallon a minute and a speed of 220 mph it would burn through the rear tank in some 90 minutes from startup. Considering how long it took to start up, taxi out, run up, take off, join up, find the bombers and join up again, it wasn't a really big issue.

Today, the P-51D is VERY stable because NOBODY flies them with the rear fuel tanks installed and full. Mostly they have a second seat and the passenger is much lighter than the old tank and fuel were.

 

[pattern14]

I've followed a number of these 'Luft 46" type aircraft with interest for some years, and the Gotha/Horten prototypes have recieved their fair share of attention. There was even a documentary a few years back where a replica prototype was made in the US. While the original example might be on display one day in a museum, it would have been extremely unlikely that this novel aircraft would have made it past the testing stage. Other advanced Luftwaffe jets were well and truly ahead of this one in terms of production readiness, and they never got their chance either. In my opinion, it is the "futuristic" appeal of the Ho-229 that maintains the interest generated in it, far apart from the practical or tactical application of what might have been. The Arado flying wing jet bombers had much more potential than this one, as did the designs of Dr Lippisch. However, the Red Skull in the "Captain America" movie had a flying wing that bore an uncanny resemblance to the Ho 229......

 

[Milosh]

Considering how long it took to start up, taxi out, run up, take off, join up, find the bombers and join up again, it wasn't a really big issue.

Except the manual says to use the LH tank for take-off and fly for 15 minutes before switching to another tank.