# Horten Ho 229



## Monkeyfume (Nov 15, 2014)

I was reading about the Horten Ho 229 flying-wing jet bomber recently. Is it really as good as it sounds? The 3x1000 requirement seems pretty tough, and although it didn't make it, it was "close" (the only prototype that came anywhere near to it). Then again, despite all the hype the Arado Ar 234 seems superior to it in every way. Is there something I'm missing?

Stats Ho 229 / Ar 234
Max speed EDIT: 607 / 461 mph (sorry for the error)
Range 620 / 1240 miles
Payload 2200 / 2200 lb

Apparently the Horten Ho 229 V3 was taken from its factory by U.S. forces to the RAE site to see if Derwent I engines could fit inside it (they could not)? I did not know this, it is correct?


EDIT: Main advantage of the Ho 229 over the Ar 234 seems to be that it's faster while still being able to carry the same payload.


----------



## wuzak (Nov 15, 2014)

I don't believe that the Ho 229 was to be a bomber. Rather it was a fighter.

There is something wrong with your numbers for the Ar 234 - the speed of sound at sea level is 761mph, so your numbers have the Ar 234 being supersonic.


----------



## FLYBOYJ (Nov 15, 2014)

Horten Ho 229 - Wikipedia, the free encyclopedia

_"The Horten H.IX, RLM designation Ho 229 (often called Gotha Go 229 because of the identity of the chosen manufacturer of the aircraft) was a German prototype *fighter/bomber *designed by Reimar and Walter Horten and built by Gothaer Waggonfabrik late in World War II. It was the first pure flying wing powered by jet engines."_


----------



## GrauGeist (Nov 15, 2014)

Monkeyfume said:


> Stats Ho 229 / Ar 234
> Max speed *620 / 780 mph*
> Range 620 / 1240 miles
> Payload 2200 / 2200 lb


Did you perhaps mean KPH for those speed quotes?

The Ar234's Max. Speed at 20,000 feet was 742kph = 461mph

Also, the data for the Ho229V3 is estimated, it never flew. Only the V2 flew, but suffered an engine failure, caught fire and crashed before it was able to demonstrate it's full abilities.


----------



## Capt. Vick (Nov 15, 2014)

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


----------



## GrauGeist (Nov 15, 2014)

Capt. Vick said:


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


V2 was supposed to be equipped with the BMW003 but ended up using the Jumo004. Also, the V2 itself, was slighly smaller than the V3 airframe.

The V3 had Jumo004B engines installed, although it was intended to have the Jumo004C as standard equipment.


----------



## Monkeyfume (Nov 15, 2014)

GrauGeist said:


> Did you perhaps mean KPH for those speed quotes?
> 
> The Ar234's Max. Speed at 20,000 feet was 742kph = 461mph
> 
> Also, the data for the Ho229V3 is estimated, it never flew. Only the V2 flew, but suffered an engine failure, caught fire and crashed before it was able to demonstrate it's full abilities.



Then the Ho 229 only went 385 mph? Unless I'm doing something wrong, that's weak.

EDIT: Out of curiousity, _could_ it have flown if it had to, just the Germans ran out of supplies and/or time before they could do so?


----------



## GrauGeist (Nov 16, 2014)

V3 was VERY close to flight by the time the factory got over-run, V4 was under construction, but only the fuselage framing had been completed.

Understand that the Ho229 was still a long way from being a production aircraft. Perhaps another 6 months would have seen them arriving at the front in limited numbers, but time had simply run out.

As far as projected speed, the Ho229 was estimated to have a Max. speed of 607mph (977kph) at 39,000 feet. While 607 doesn't sound like much in today's terms, that was wicked fast for an aircraft of the day and was on the envelope of Mach flight.

Reactions: Like Like:
1 | Like List reactions


----------



## l'Omnivore Sobriquet (Nov 16, 2014)

The Arado had a full bombsight equipment that the Ho could'nt carry, nor use. It had room in the cokpit and downward vision. It was a real bomber even if light.
Also it stood ready for a 4 engine upgrade which the Horten forbid, save for a complete redesign.

The Ho IX / Go 229 was certainly an exciting aircraft with a good potential to 'do things', carry bombs and drop them at a minimum, a good card the Germans would have thrown in the arena when its time was to come.
The Horten designer was confident about stability and possible controllability issues, and he had exceptionnal experience to back this.
The Ho was also the only German jet to feature airbrakes.
With good range it could have been a noted 'strategic harrasment' aircraft of some sort, probably replacing the Do-335 in the role.

I'm quite certain that the pair of MK-108 canons placed right next to the turbojet's air intake would have shown unpractical at testing stages.

It has been underlined already that the type would have required time to become an operationnal tool. I would leave two thoughts about this :
- The Horten Company was a tiny familial structure with no experience whatsoever in operationnal requirements for a service aeroplane, nor with mass industry. One of the brother was an experienced fighter pilot but this alone is not enough.
The Ho IX can very well be seen as an 'amateur' or 'week-end' builder's model scaled 1. Even if, again, the Horten designer mastered very well the aerodynamics of his 'home product', with years of work and testing on multiple models. This is why the whole thing was quite wisely transferred to the Gotha(/Zeppelin?) concern. Which in turn had its own views, rather looking down from up, on the concept. Yes it would have taken some time to translate all this into a series produced field weapon.

- Doubtlessly however, in any what-if scenario allowing to show its qualities in warfare, the Ho IX would have been hurried in a still crude form into combat. This is no Republic Thunderstreak program here... Have those two bombs safely fitted underneath and throw them well into the Allied camp. Some sort of 'Volksbomber' scheme without even the name.

I like the Horten IX very much because I'm an aviation enthousiast. Would have liked to see it come to, some life, in some numbers.
It is also a fine familial/entrepreneur story...
To equip a Lufwaffe have the Me-262, Arado 234, and Do-335 (yes!), which were the more serious stuff. Even the Henschel 132 was more thouroughtly concieved as a weapon.

Reactions: Like Like:
1 | Like List reactions


----------



## stona (Nov 16, 2014)

Monkeyfume said:


> Apparently the Horten Ho 229 V3 was taken from its factory by U.S. forces to the RAE site to see if Derwent I engines could fit inside it (they could not)? I did not know this, it is correct?



No, that is incorrect.

The Ho 229 V3 was shipped to the US on board _SS Richard J Gatling_, departing Cherbourg on 12th July 1945.

The airframe that went to Farnborough was the remains of the earlier prototype H IX V2. It was flown to The Royal Aircraft Establishment from Binders airfield in a captured Ar 232 piloted (almost inevitably) by Eric Brown.
The possibility of flying the aircraft with Avon turbojets was discussed as for reasons I don't have time to type here the British test pilots refused to fly the machine with Jumo engines, of which they already had some experience.
It was soon established that the Rolls Royce engines would not fit without considerable modification to the airframe due to the British engines larger cross-section. This was considered pointless as the expected performance of the Ho 229 was not expected to warrant the effort and the programme was abandoned.

Incidentally it has been generally assumed that the V3 aircraft which went to the US was never assembled, but this is not so. It did have the wings attached for display purposes and there is a photograph of it in this state taken at the Douglas factory in Chicago.

Cheers

Steve


----------



## Siddley (Nov 16, 2014)

I don't think we will ever know the potential of the Ho 229 but given the poor stability and handling characteristics of contemporary ( and post war ) flying wing designs my personal feeling is that it probably had some nasty surprises waiting for it's pilots.

Reactions: Like Like:
1 | Like List reactions


----------



## stona (Nov 16, 2014)

There were many unsolved problems with the Horten design. Aside from the stability problems and control harmonisation specified in a July 1944 DVL report there were fundamental design problems associated with an all wing design that were never solved. Lippisch solved them with a vertical fin on his Me 163 and Walter Horten wanted to do the same on one of the early prototypes (can't remember which) but was overruled. CoG problems meant that the V2 carried 232 Kg of lead ballast.
Both brothers pretended to be unaware of Lippisch's work, despite the testing of his models in the Gottingen wind tunnels, the data from which the Hortens had access to.

I think any idea that an operational version of an Ho 229 was even on the horizon for 1946 is a bit optimistic. After the successful V2 flights (unless your name was Ziller) the RLM ordered three more prototypes (V3-V5) and ten 'zerstorer' prototypes (V6-V15) to be followed by 40 8-229 A-0 aircraft. The first of all these prototypes was not scheduled to fly until_ November 1945 _.

Finally it is worth remembering that NO Horten aircraft was ever fitted with armament of any type. Their impact on WW2, even had it lasted for another year, was and would have been precisely zero.

Cheers

Steve

Reactions: Like Like:
1 | Like List reactions


----------



## Capt. Vick (Nov 16, 2014)

Steve,

Are you sure you don't mean the Ho IX V1, the glider? I can't imagine there was much left of the V2 after the crash.

Jim


----------



## fastmongrel (Nov 16, 2014)

How far along was the micro processor controlled fly by wire control system before the war brought development to a halt. Everything I have read on flying wings says they were an accident waiting to happen for anything other than flying straight and level and are only feasible with computer controls.


----------



## stona (Nov 16, 2014)

No, I mean the remains of the H IX V2. It was this that was flown to Farnborough from Binders airfield, near Erfurt.

Once the programme was cancelled and any possibility of rebuilding the aircraft with Rolls Royce engines abandoned the remains were displayed in the German Aircraft Exhibition in the 'A' Hangar at Farnborough. Contemporary photographs show that the cockpit in which Ziller met his demise was demolished and one wing was very badly damaged. There were no engines fitted.

The British did test fly a Horten glider, the H IV, W.Nr. 25. This was given the RAF serial VP543 and flown, towed by a captured Fi 156 (RAF serial VP546) until 1950.

The British also acquired the rather strange Horten H VIII. What happened to it is not known though it may have been shipped to the US.

The H IX V2 did find its way to the US in late 1945 or early 1946, after the Farnborough exhibition, according to Eric Brown writing in 1982. Anyone know what happened to it?

Cheers

Steve


----------



## wuzak (Nov 16, 2014)

stona said:


> The possibility of flying the aircraft with Avon turbojets was discussed as for reasons I don't have time to type here the British test pilots refused to fly the machine with Jumo engines, of which they already had some experience.



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.

The Avon was slightly larger in diameter than the Jumo but smaller than the cntrifugal types. It was shorter, heavier and some 2-3 times more powerful than the Jumo.

The likely engine was the Derwent V.

Another alternative may have been the Metrovicks F.2. The F./1 had flown in the Meteor in 1043, while the F.2/2 and F.2/3 had flown in a Lancaster test bed, the latter solving many of the reliability issues. The F.2/3 was similar in size and weight to the Jumo, and only slightly more powerful.


----------



## swampyankee (Nov 16, 2014)

fastmongrel said:


> How far along was the micro processor controlled fly by wire control system before the war brought development to a halt. Everything I have read on flying wings says they were an accident waiting to happen for anything other than flying straight and level and are only feasible with computer controls.



The Luftwaffe's unter-, I mean ubermencsh pilots didn't need no stinking stability augmentation systems!

Out of snark mode:

It is not terribly difficult to make stable flying wings. It was done by, among others, Northrop and Fauvel. They do tend to have poor damping in pitch and yaw, which may cause problems (it did with the YB-49), and it can be difficult giving them decent low-speed handling (see: A-X program). It's also a bit difficult to find enough volume for any kind of payload, which is why just about the only flying wings in service are very expensive bombers. There are a few Fauvel sailplanes, but their payload is nil.


----------



## Shortround6 (Nov 16, 2014)

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.


----------



## KiwiBiggles (Nov 16, 2014)

swampyankee said:


> It's also a bit difficult to find enough volume for any kind of payload



And here Swampyankee gets right to the heart of the flying wing. They're an aerodynamicist's idea of a plane, not an engineer's. To the aerodynamicist, the fuselage is just the stick that keeps the wing and empennage flying in formation. To the engineer, the fuselage is the whole point of the plane; it's where you put the bits that matter, like guns and bombs, cargo and cameras, passengers and pilots. All the other bits like wings etc are just there to get the important bits where they need to be.

The flying wing starts from the position that, if we could just lose all the bulky parts, the wing could be pure and beautiful, a piece of art. Unfortunately, aeroplanes need to do something other than just fly - they have a job of work to do. And for that you need a fuselage. And it has to be stable when you want it to be, damped enough to be controllable, responsive when you need it to be; and for that you need a separate empennage.

Flying wings make good toys for the very rich. We should be glad the Germans wasted resources on them.

Reactions: Like Like:
1 | Like List reactions


----------



## Capt. Vick (Nov 16, 2014)

stona said:


> No, I mean the remains of the H IX V2. It was this that was flown to Farnborough from Binders airfield, near Erfurt.
> 
> Once the programme was cancelled and any possibility of rebuilding the aircraft with Rolls Royce engines abandoned the remains were displayed in the German Aircraft Exhibition in the 'A' Hangar at Farnborough. Contemporary photographs show that the cockpit in which Ziller met his demise was demolished and one wing was very badly damaged. There were no engines fitted.
> 
> ...



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


----------



## GrauGeist (Nov 16, 2014)

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 (Nov 16, 2014)

Capt. Vick said:


> 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 (Nov 16, 2014)

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 (Nov 16, 2014)

Monkeyfume said:


> 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 (Nov 17, 2014)

wuzak said:


> 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 (Nov 17, 2014)

Shortround6 said:


> 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 (Nov 17, 2014)

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 (Nov 17, 2014)

Capt. Vick said:


> 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 (Nov 17, 2014)

Capt. Vick said:


> 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 (Nov 17, 2014)

stona said:


> 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 (Nov 22, 2014)

Shortround6 said:


> 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 (Nov 22, 2014)

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 (Nov 22, 2014)

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 (Nov 22, 2014)

swampyankee said:


> 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 (Nov 22, 2014)

Graeme said:


> 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 !

Reactions: Like Like:
1 | Like List reactions


----------



## gumbyk (Nov 23, 2014)

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 (Nov 23, 2014)

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 (Nov 24, 2014)

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 (Nov 24, 2014)

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......

Reactions: Like Like:
1 | Like List reactions


----------



## Milosh (Nov 24, 2014)

> 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.


----------



## davparlr (Nov 24, 2014)

GregP said:


> Some fighters are not recommended for certain maneuvers.



Indeed! It is not unusual for aircraft, including fighters, to have a limited operating envelope for various operational configurations, certainly with external stores including fuel. The F-4 was notorious for departing when maneuvering with certain store configurations. Generally speaking, external stores are jettisoned prior to engaging in combat (F-86 procedures required retuning to base if external fuel was not jettisonable). If we address the aft tank of the P-51 as similar to external stores, then a limited performance envelope until burn off to a stable configuration is reasonable and equivalent to jettisoning tanks prior to combat.

Reactions: Bacon Bacon:
1 | Like List reactions


----------



## davparlr (Nov 24, 2014)

tyrodtom said:


> 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.



Maintainability of the RCS coatings of the B-2 have been an on-going issue for a long time and I think they have implemented an upgrade to mitigate that (it's been a long time since I was on the program). It does not hamper operational effectiveness. In Kosovo, in miserable weather that grounded Navy and AF aircraft, the B-2 was able to destroy 40% of the identified targets with only 10% of the missions.


----------



## stona (Nov 24, 2014)

swampyankee said:


> 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, ....)



The Horten aircraft were finished in standard aircraft lacquers.

Cheers

Steve


----------



## Monkeyfume (Nov 24, 2014)

pattern14 said:


> 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......



E.555 was cancelled in '44 as it was too complicated/expensive. H-IX was still being developed at the end of the war and we realistically can only guess as to what it _could_ have become.


----------



## Monkeyfume (Nov 24, 2014)

stona said:


> The Horten aircraft were finished in standard aircraft lacquers.



From Wikipedia:
_After the war, Reimar Horten said he mixed charcoal dust in with the wood glue to absorb electromagnetic waves (radar), which he believed could shield the aircraft from detection by British early warning ground-based radar that operated at 20 to 30 MHz (top end of the HF band), known as Chain Home._

Never used, but potentially could have been.


----------



## Capt. Vick (Nov 24, 2014)

I have always thought of this as bunk! But couldn't it be answered with a simple test by the Smithsonian? Let's put this to bed already.


----------



## GrauGeist (Nov 24, 2014)

Capt. Vick said:


> I have always thought of this as bunk! But couldn't it be answered with a simple test by the Smithsonian? Let's put this to bed already.


When tests were conducted on the Ho229 at the Smithsonian, it was found to contain graphite embedded in the surface laminate. They also tested the original airframe with WWII era radar and it did return a low signature.

You may recall that they built a 1:1 scale replica based on original blueprints and rebuilt it as close to original as possible. This was tested at Northrup's facility and found that the Ho229's design did indeed have a reduced signature. So, for example, had the Ho229 crossed the channel on a mission, the British radar would have about a 20% reduction in detection, allowing the Ho229 to get closer than a conventional inbound enemy aircraft before it's signature was detected.

So it's not bunk, it is real! Here's a link to NatGeo's page for all the details: "Hitler's Stealth Fighter" Re-created


----------



## davparlr (Nov 25, 2014)

GrauGeist said:


> When tests were conducted on the Ho229 at the Smithsonian, it was found to contain graphite embedded in the surface laminate. They also tested the original airframe with WWII era radar and it did return a low signature.



The B-49 was shown to disappear from radar in certain attitudes and it was certainly not designed for radar avoidance. The very shape of the Ho 229 could show reduced RCS. With the front mounted engines with straight inlets, the compressor blades, which act as rotating radar reflectors, would light up a radar scope from the forward quadrant. So too, maybe with a bit less reflectivity, turbine blades buried deeper, would the the rear quadrant. Putting on special paint to reduce radar reflectivity would be like a hunter dressing up in camouflage and then putting on a day-glo vest for protection.


----------



## GrauGeist (Nov 25, 2014)

Reimar was onto something, there's no doubt about it. He spent a great deal of time with Naval engineers, in an attempt to defeat radar detection.

I agree that the very profile of the Ho229 presents a low RCS by virtue of design, however, how sensitive was WWII era radar in respect to the turbojet inlets, versus what we know and use in modern radar technology/stealth profiles?

In otherwords, technology has taken a quantum leap in the 70 years or so since that technology was employed. Back then, a U-Boat could talk to Berlin on it's two-way with an antenna that was the length of the boat and required a great deal of power. Now, we can do the same thing with a hand-held device using only a few volts and an antenna that's less than an inch.

So radar technology today is highly sophisticated, extremely sensitive and has a broad range of counter-measures versus the archaic "analog" systems of WWII.


----------



## thedab (Nov 25, 2014)

it is bunk,that test was with the 1940 chain-home radar using 22-25 MHz from about 42 the British were using centimetric radar working on 3GHz of 10cm wavelength,like what they had on the H2S radar


----------



## GrauGeist (Nov 25, 2014)

CHEL had an extremely short range and was used in conjunction with CHL which had the range, but not the low altitude detection of CHEL...

And I am willing to guess that the engineers at Northrup-Grumman were well aware of the various frequencies used during the late war period.


----------



## stona (Nov 25, 2014)

GrauGeist said:


> When tests were conducted on the Ho229 at the Smithsonian, it was found to contain graphite embedded in the surface laminate. They also tested the original airframe with WWII era radar and it did return a low signature.[/url]



The tests were conducted only on the nose cone, not the entire structure. If I tested the air dam on the front of my car I might conclude that the entire body was constructed of composite materials, but it isn't.

The Ho 229s low radar signature is due to it's lack of two of the structures which caused a large component of the radar reflection of more conventional aircraft of the day, a vertical fin(s) and a propeller disc(s). It is not due to any intentionally built in stealth.

A large contribution to the stealth of modern aircraft is in the careful design of their geometric shape, to minimise reflection. The shape of the various Horten projects owes absolutely nothing to this consideration, and everything to attempting to make them fly controllably. Any stealth properties of the aircrafts' shapes were purely coincidental. 

The first time that either of the Hortens implied that there was some kind of stealthy aspect in the design of their aircraft was Reimar in the 1960s, when such technology was being seriously developed. The pertinent question is why he, who was still involved in aircraft design and was chasing contracts, might say such a thing with the benefit of hindsight?

Cheers

Steve


----------



## Milosh (Nov 25, 2014)

Wasn't the Mosquito hard to detect with radar?


----------



## Capt. Vick (Nov 25, 2014)

Why would the Horten brothers have bothered putting RAM of what was essentially a POC airframe? I think the jury is still out on this point at least. Just my gut feeling.


----------



## Monkeyfume (Nov 25, 2014)

Milosh said:


> Wasn't the Mosquito hard to detect with radar?



No.


----------



## FLYBOYJ (Nov 26, 2014)

Milosh said:


> Wasn't the Mosquito hard to detect with radar?





Monkeyfume said:


> No.



Actually the Mosquito did present a lower RCS than other aircraft of the same shape and size and I believe the Mosquito carried a taylored transponder (IFF) to address this. It wasn't invisible, just a little harder to see at times, if one was to see an old radar screen and how targests were acquired this would be apparent, especially if dealing with any kind of clutter or interferance. I think if you search older posts this was discussed in length.




stona said:


> The tests were conducted only on the nose cone, not the entire structure. If I tested the air dam on the front of my car I might conclude that the entire body was constructed of composite materials, but it isn't.


I think the Northrop team that constructed the replica found there was graphite impregnated in other parts of the structure as well


stona said:


> The Ho 229s low radar signature is due to it's lack of two of the structures which caused a large component of the radar reflection of more conventional aircraft of the day, a vertical fin(s) and a propeller disc(s). It is not due to any intentionally built in stealth.
> 
> A large contribution to the stealth of modern aircraft is in the careful design of their geometric shape, to minimise reflection. The shape of the various Horten projects owes absolutely nothing to this consideration, and everything to attempting to make them fly controllably. Any stealth properties of the aircrafts' shapes were purely coincidental.
> 
> ...



Agree 100% Stealth technology is not one or two technologies applied to aircraft construction but a combination of technologies that took years to develop and evolve into what we have today. Along the way, some designs revealed a piece of the puzzle (the Mosquito low RCS, the low RCS encountered on flying wings, etc.) 

Although this technology is not foolproof, it is a game changer. The Hortens may have been on the right track in their thinking but were still years away from developing a true stealth aircraft.

Reactions: Like Like:
2 | Like List reactions


----------



## swampyankee (Nov 26, 2014)

Monkeyfume said:


> From Wikipedia:
> _After the war, Reimar Horten said he mixed charcoal dust in with the wood glue to absorb electromagnetic waves (radar), *which he believed* could shield the aircraft from detection by British early warning ground-based radar that operated at 20 to 30 MHz (top end of the HF band), known as Chain Home._
> 
> Never used, but potentially could have been.



Belief is cheap; ask any body who's a fan of the Chicago Cubs. In any case, working radar-absorbing materials don't use charcoal.


----------



## Capt. Vick (Nov 26, 2014)

Yeah. This makes sense. Let me mix a little charcoal in with the wood glue that holds the plane skins together. Never mind the unknown consequence this might have on it's bonding ability, and let's ignore the fact that the Tego Film factory was bombed and the replacement glues failed spectacularly during a high profile He 162 fly over. Really? REALLY? Does anyone else feel that hearsay, unspecified sources and just plain bunkery have made the uncompleted V3 and to some degree the V2 prototypes into something that was more wished than reality-based? 

Questions (to my mind) that need to be answered

1) Was RAM, in any way, shape or form used in the construction of the jet powered Horten flying wings, through direct analysis of the (apparently) only surviving article.

2) Review of the transcript of the National Geographic "documentary" in order to specify the claims made in it and systematically judging their merit based on known facts or in lieu of that an educated guess.

3) Confirmation about what happened to the remains of the V2 after it's fatal crash.


----------



## blueskies (Nov 26, 2014)

Capt. Vick said:


> Yeah. This makes sense. Let me mix a little charcoal in with the wood glue that holds the plane skins together. Never mind the unknown consequence this might have on it's bonding ability, and let's ignore the fact that the Tego Film factory was bombed and the replacement glues failed spectacularly during a high profile He 162 fly over. Really? REALLY? Does anyone else feel that hearsay, unspecified sources and just plain bunkery have made the uncompleted V3 and to some degree the V2 prototypes into something that was more wished than reality-based?
> 
> Questions (to my mind) that need to be answered
> 
> ...



Adding charcoal was hardly some unknown. 

If you have a formaldehyde resin then the addition of charcoal will improve curing times with the addditional benefit of slightly improving strength. 

Imho this is by far the most likely reason for charcoal being present in the 229.


----------



## GrauGeist (Nov 26, 2014)

The Tego film was a very reliable laminate adhesive used worldwide before the war and was on a par with the laminate adhesives used by the Allies for their aircraft construction.

It was the alternate laminate adhesive, manufactured by Dynamit after Golmand's factory was bombed, that was the culprite behind the delamination failures on several Luftwaffe aircraft. It was due to a corrosive reaction to the wood after it had cured, that caused catostrophic failure under stress.

Reactions: Like Like:
1 | Like List reactions


----------



## Capt. Vick (Nov 27, 2014)

Excellent. So if charcoal is present in the adhesive at all, there may be an alternate reason for it. Would this have been added by the manufacturer or would it have been an old wood workers trick?

Yes, I have read the same about Tego and the corrosive effects of its replacement. Obviously this is what I was alluding to in my previous post. Perhaps, if it is present at all, this was why charcoal was mixed with it, and NOT for its assumed RAM properties? To cut the acidity? More questions... I love these thought experiments.


----------



## stona (Nov 27, 2014)

What adhesive was used on the Ho 229 would be the pertinent question? Did the less than exhaustive testing done on the extant Ho 229 even answer this basic question, or was it just attempting to grab a headline for a second rate TV show?
It's not a difficult question. There were only three or four systems for bonding laminates in use at the time as far as I can tell. The Germans must have been using a version of one of them.

I assume it wasn't the TEGO film as the factory had been bombed in early 1943 and anyway the process was a 'dry' process using heat and impregnated paper. Without going all chemist I can't imagine why you'd add charcoal to this 'base catalysed' reaction, even if it was possible.

There may be a reason it was done during whatever process the Hortens were using in 1944/5.

Cheers

Steve

Reactions: Like Like:
1 | Like List reactions


----------



## Graeme (Nov 27, 2014)

If you go to the "Talk" section of the Wikipedia article on the Gotha 229, some guy/gal wrote this...



> With regards to "but it has carbon loaded glue; that makes little sense except for stealth" - simply put nothing could be farther from the truth.
> 
> When the 229 was under construction there was a dire lack of resin wood glues to work with, since pretty much all the factories producing resin were no longer in operation. So what were the Hortons to do? Adding charcoal to wood glue is a very old, simple and cheap method of improving the strength of wood glue. I believe this is the primary, if not sole reason for the presence of carbon in the wood glue.
> 
> ...


----------



## stona (Nov 27, 2014)

Exactly. As I posted some way back up the thread, the first claim for any kind of stealth capability for the Ho 229 was made by Reimar long after the war at a time when stealth technology for aircraft was firmly on the agenda.

The claims that the Ho 229 or any other of the brothers' designs were *intentionally* stealthy are not supported by any evidence at all. 

It's a red herring, about as plausible as German nuclear tests or flying saucers launched from bases in Antarctica. It did grab enough attention to promote more than one television show and several articles.

Cheers

Steve

Reactions: Like Like:
2 | Like List reactions


----------



## Capt. Vick (Nov 27, 2014)

Busted then? I think so, without going to the original source material that is.


----------



## stona (Nov 27, 2014)

I think so. 

*'Hitler's Stealth Fighter' *sounds a lot better than* 'Hitler's prototype flying wing'*. At least the National Geographic channel thought so particularly when backed up with utter BS like this:

_'In the final months of WWII a jet powered flying wing made its first test flight from a remote airfield deep inside Nazi Germany. Generations ahead of its time, the Horten 229 had been designed to be a lethal fighter bomber and more importantly, virtually undetectable to Allied radar.'_

There's not much that is actually true in those first two sentences from Nat Geo's promotional blurb 

"first test flight from a remote airfield deep inside Nazi Germany"...nope, Oranienburg, near Berlin, about 25 miles from the capital of the 3rd Reich. I wouldn't call that 'remote'.

"Generations ahead of its time"...nope, nothing new about the concept of flying wings and other aircraft were already flying with turbo-jets. The construction techniques used on the Horten aircraft are actually quite primitive for the day.

"the Horten 229 had been designed to be a lethal fighter bomber and more importantly, virtually undetectable to Allied radar"... the first bit is wishful thinking, the second simply not true.

Cheers

Steve

Reactions: Like Like:
1 | Like List reactions


----------



## Capt. Vick (Nov 27, 2014)

Yeah baby!


----------



## GregP (Nov 27, 2014)

You mean there aren't any flying saucers operating from the Antarctic? If that is true, where are they coming from?

Reactions: Like Like:
1 | Like List reactions


----------



## Capt. Vick (Nov 27, 2014)

Uranus?

Reactions: Like Like:
4 | Like List reactions


----------



## Monkeyfume (Nov 27, 2014)

GregP said:


> You mean there aren't any flying saucers operating from the Antarctic? If that is true, where are they coming from?



Outer space, you dumbass.


----------



## FLYBOYJ (Nov 27, 2014)

Capt. Vick said:


> Uranus?



There are only Klingons around Uranus!!!

Reactions: Like Like:
2 | Like List reactions


----------



## N4521U (Nov 28, 2014)

In the Navy they are referred to as Dinglberries!


----------



## Milosh (Nov 28, 2014)

Heard them called 'will knots'. Happens after passing lumpy gas.


----------



## Capt. Vick (Nov 28, 2014)

Oh man


----------



## GregP (Nov 29, 2014)

Crunchy peanut buter ... and it builds racing stripes on your underware. That's why they went to dark colors that are relatively impervious to brown additions.


----------



## GrauGeist (Nov 29, 2014)

Monkeyfume said:


> Outer space, you dumbass.


Not all "flying saucers" come from space, asswipe...

Reactions: Like Like:
1 | Like List reactions


----------



## Monkeyfume (Nov 30, 2014)

GrauGeist said:


> Not all "flying saucers" come from space, asswipe...
> 
> View attachment 277907
> 
> ...



Avro Canada Avrocar, it is really slow
Vought Flying Pancake, just a regular plane with fat wings
Something made by nazis, never seen it before but probably same as above.

They are not real flying saucers because they do not travel at light speed.


----------



## GrauGeist (Nov 30, 2014)

*Flying Saucer*: disc-shaped vehicle/craft capable of flight. This is pretty straight-foreward, the aircraft I posted up there meet the criteria of a "flying saucer".

As far as speed of light goes: "Light travels at a constant, finite speed of 186,000 mi/sec. A traveler, moving at the speed of light, would circum-navigate the equator approximately 7.5 times in one second. By comparison, a traveler in a jet aircraft, moving at a ground speed of 500 mph, would cross the continental U.S. once in 4 hours."

So if you've seen a flying saucer moving at the speed of light, you've got some damn-good eyesight...


----------



## davparlr (Nov 30, 2014)

GrauGeist said:


> I agree that the very profile of the Ho229 presents a low RCS by virtue of design, however, how sensitive was WWII era radar in respect to the turbojet inlets, versus what we know and use in modern radar technology/stealth profiles?
> 
> In otherwords, technology has taken a quantum leap in the 70 years or so since that technology was employed. Back then, a U-Boat could talk to Berlin on it's two-way with an antenna that was the length of the boat and required a great deal of power. Now, we can do the same thing with a hand-held device using only a few volts and an antenna that's less than an inch.
> 
> So radar technology today is highly sophisticated, extremely sensitive and has a broad range of counter-measures versus the archaic "analog" systems of WWII.



Radar reflectors are efficient reflectors of radar energy. Radar targets using radar reflectors can represent very large aircraft with a surprising small target. Variations in radar sensitivity would be proportionally equivalent. In other words they would have been equally effective with WWII technology as with modern technology.


----------



## stona (Dec 1, 2014)

Objects might reflect similar radar waves in similar ways but advances in how those return signals are received and_ much more importantly how they are processed_ have moved forward in ways unimaginable to WW2 engineers. 
Cheers
Steve

Reactions: Like Like:
2 | Like List reactions


----------



## davparlr (Dec 1, 2014)

stona said:


> Objects might reflect similar radar waves in similar ways but advances in how those return signals are received and_ much more importantly how they are processed_ have moved forward in ways unimaginable to WW2 engineers.
> Cheers
> Steve


No matter what the processing is, the return radar energy from the front of a row of compressor blades will be very high making insignificant any other RCS reductions available to the Horton Bros. WWII radar receivers would certainly be able to detect this large return if it could detect any aircraft.


----------



## stona (Dec 1, 2014)

davparlr said:


> No matter what the processing is, the return radar energy from the front of a row of compressor blades will be very high .



But less than a 10'-15' propeller disc.

Cheers

Steve


----------



## l'Omnivore Sobriquet (Dec 3, 2014)

[oops sorry, wrong thread.]


----------



## davparlr (Dec 5, 2014)

stona said:


> But less than a 10'-15' propeller disc.
> 
> Cheers
> 
> Steve



I don't think you can say that. That also avoids the point that since you have two big radar reflectors in the nose, other RCS reduction features are superfluous. Again, its akin to hunters putting on camouflage clothes and then putting on a dayglo vest to avoid being shot.


----------



## GregP (Dec 5, 2014)

The propeller is spinning at maybe 2,000 - 3,000 rpm.

The jet engine impeller is spinning at maybe 12,000 - 18,000 rpm.

BIG difference in reflectivity. The impeller will reflect a large percentage of incoming power. Anything that reads reflections will see the jet, assuming decent power to start with. The prop will be seen by anything that impinges enough power to pick up the small reflection percentage from the relatively slow-turning prop disc.


----------



## stona (Dec 6, 2014)

GregP said:


> BIG difference in reflectivity.



It's a far more complicated problem than that. Applying common sense to technical, scientific problems is always fraught with danger 

The reflections from a propeller disc (or discs) provide a substantial proportion of the return from such aircraft. The second highest RCS of typical aircraft, after the beam due to the relatively large area exposed, is nose-tail and this is due to the jet engines or propeller discs.

Cheers

Steve


----------



## stona (Jan 23, 2015)

I've just seen that the NASM team which is restoring the museums Ho 229 at the Udvar-Hazy facility has analysed the lacquers/coatings used on the aircraft (as you'd expect from professional restorers) and reports that _their is no evidence of any stealth 'coatings'. _

Cheers

Steve

Reactions: Like Like:
1 | Like List reactions


----------



## tomo pauk (Jan 23, 2015)

GregP said:


> The propeller is spinning at maybe 2,000 - 3,000 rpm.
> 
> The jet engine impeller is spinning at maybe 12,000 - 18,000 rpm.
> 
> BIG difference in reflectivity. The impeller will reflect a large percentage of incoming power. Anything that reads reflections will see the jet, assuming decent power to start with. The prop will be seen by anything that impinges enough power to pick up the small reflection percentage from the relatively slow-turning prop disc.



Could you please provide some source that will back up the quoted stuff?


----------



## Gixxerman (Jan 23, 2015)

I don't get the notion that the Ho229 was stealthy at all.
As far as I recall it was wooden covered steel tube construction (surely radar waves not 'seeing' the wood would 'see' the steel tube be reflected?) as said it had the most unstealthy engine intake (and exhaust) imaginable.
I also recall it being said that the cockpit is also a major point of return to airborne radar and there is absolutely nothing 'stealthy' about that Ho229's design there. 

This myth is a shame really, in my view there is an interesting tale of stealth from WW2. they (the Germans) did try a form of stealth.
But it was on U-boats in the form of anti-radar matting to cover masts such like.

Sadly the real stealth story just doesn't seem to be as 'sexy' as - I'm sorry to say (and I don't mean to offend anyone here) - idiotic notions that the Ho229 must have been 'stealthy' cos it looks a little bit like a B2 in shape (tho it shares nothing else in common - certainly not the billions of $ or the tens of thousands of hours super-computers worked on the actual shape, construction materials testing of the actual B2).

There was a TV show which followed the radar pole testing of the Ho229 (perfectly made, unlike 1945 German manufacturing) they reckoned it had a 20% smaller radar return than an Me109.
Not exactly a huge improvement certainly not 'invisible' to radar, not even the 1945 British radars which aimed the coastal batteries (which was bristling with effective proximity-fused guns thanks to the V1).
I wouldn't fancy the chances of any unit trying to attack targets inland having to get through (and return through) that lot. 

It all seems so silly to me frankly.

Reactions: Like Like:
2 | Like List reactions


----------



## wuzak (Jan 23, 2015)

GregP said:


> The propeller is spinning at maybe 2,000 - 3,000 rpm.
> 
> The jet engine impeller is spinning at maybe 12,000 - 18,000 rpm.
> 
> BIG difference in reflectivity. The impeller will reflect a large percentage of incoming power. Anything that reads reflections will see the jet, assuming decent power to start with. The prop will be seen by anything that impinges enough power to pick up the small reflection percentage from the relatively slow-turning prop disc.



The Rolls Royce Merlin XX had a normal maximum of 3,000rpm and a reduction ratio of 0.42:1, so prop speed was 1260rpm.
The Merlin 66 had a reduction gear of 0.477: for a prop speed of 1431rpm.
The Griffon 65 in the Spitfire XIV had a maximum speed of 2750rpm and reduction ratio of 0.51:1, prop speed 1402rpm.
Early V-1710s had reduction ratio of 0.5:1, engine speed 3000rpm, prop speed 1500rpm.
R-2800s commonly had 0.5:1 or 9:16 reduction on 2800rpm. Prop speed 1400rpm - 1575.
Sabres IIA and IIB revved to 3700rpm and had a reduction ratio of 0.274:1 for a prop speed of 1014rpm.

The Jumo 004B had a rated engine speed of 8700rpm. The BMW 003 had a rated engine speed of 9500rpm.

The Spitfire IX had a 10'9" (3.28m) diameter prop. The BMW 003 was 0.69m in diameter - so the compressor was even smaller than that.

I don't know what this means for RCS. Generally, the turbine compressor is a more solid target than a prop, but it is also much smaller in area.


----------

