Could a replica Gotha-229 be produced in this day and age?
Prowlus
tested , is it possible for a team of warbird enthusiast to
reconstruct a full scale flying replica of the Gotha-229? It seems all
the Gotha needed was a modern flight control system . They could
easily use lightweight composites for the airframe and the same
engines that power the me-262 replicas.
Does anyone here think it would be a project that would fittingly
honor the b-2s heritage and design?
ORVAL FAIRBAIRN
bfo...@hotmail.com (Prowlus) wrote:
Actually, there already IS an aircraft flying that honors he B-2's
heritage and design: the Northrop N9M. It served as a proof-of-concept
craft for the XB-35 and the later YB-49. Planes of Fame regularly flies
it at West Coast airshows.
--
Remove _'s from email address to talk to me.
Eunometic
Prowlus wrote:
> Since that theres already new airworthy examples of the ME-262 being
> tested , is it possible for a team of warbird enthusiast to
> reconstruct a full scale flying replica of the Gotha-229?
A Ho 229 is still packed away in the US somewhere and I expect plans
are still extant. Given that it was constructed mainly of wood it
should be possible to reconstruct without a sheet metal shop.
> It seems all
> the Gotha needed was a modern flight control system .
The Hortens had developed handling to a high art on their designes;
remember they built up to 20 experimental flying wing designes. The
latter ones were both stall resistent (tended to simply mush forward)
and spin resistent.
The bat wing tail added considerably to stabillity and it is to be
noted that while the B-2 spirit has a twin bat like tail non of Jack
Northrops designes did. The YB-49 needed an autopilot to become a
stable bomb platform.
The noted crash of the ho 229 piloted by Erwin Ziller had a number of
factors:
1 Engine Failure.
2 Pilot Deployed undercarriage too early against advice. It was
advised to delay undercarriage deployment to just before landing in the
case of a single engine failure as this made handling even more
difficult when the remaining engine was on full power.
3 the engine that failed opperated the hydraulics. Therefor Ziller
used the emergency compressed air undercarriage deployment, however
this failed to deploy both wheels; hence the Ho 229 was left with one
failed engine and an undercarriage extended only on the failed side.
It was impossible to control and Ziller lost his life.
Rob Arndt
much more related to the Go-229; so much in fact, that Northrop took a
look at the stored Go-229 and analysed it thoroughly before the B-2 was
built.
And NO, its just not made of wood. The Hortens used impregnated
materials in its construction to make it anti-radar.
I think that if a historical foundation or Northrop invested in such a
project that it would indeed be a fitting tribute.
The Hortens were way ahead of Northrop in design and concepts- so much
in fact that they were secretly taken to Wright Field after the war and
participated in design research for exotics.
The famous Rhodes 1947 UFO pic (which clearly shows a parabolic disc)
is believed by many to be of Horten origin and possibly the craft that
crashed at Roswell. Same year, same location- New Mexico (where a
variety of German secret weapons testing went on postwar).
Rob
p.s. Please don't bring up the Hortens account of their postwar life.
What was done was done in secret and they can't account for the gap
between British confinement and Argentina except to say they were in
Germany. No one would have left these experts in flying wing design
just sit in Germany when every major Allied player was snatching up
every German scientist, technician, and specialist they could find.
Jim Wilson of Popular Mechanics researched the FOIA documents and the
Hortens were a top military priority. They were released from British
custody to US custody.
Krztalizer
the replicated Me 262s is also a fan of the Go 229 and asked to borrow
the plans we found at the PRO. He is very interested in doing exactly
what you suggest. We're had several conversations about what a good
follow on project to their 262s might be, with a copy of a Go 229 being
the front runner.
v/r
Gordon
Peter Stickney
bfo...@hotmail.com (Prowlus) writes:
> Since that theres already new airworthy examples of the ME-262 being
> tested , is it possible for a team of warbird enthusiast to
> reconstruct a full scale flying replica of the Gotha-229? It seems all
> the Gotha needed was a modern flight control system . They could
> easily use lightweight composites for the airframe and the same
> engines that power the me-262 replicas.
It certainly would be feasible. You don't need to fool with Fly By
Wire or composite materials, either - the basic structure of the 229
was plywood over steel tube - not that much different than most
homebuilts, and more than up to the task. He Horten flying wings
didn't have any handling problems that would require any control
system gimmickry to sort out.
It might just be easier to do than the replice Me 262s, modulo the
better documentation that exists for the Messerschmitt.
There is an almost complete 229 in the Smithsonian's collection.
(Third prototype, not flown.)
> Does anyone here think it would be a project that would fittingly
> honor the b-2s heritage and design?
Actually, that's best represented by hte currently flying Northrop N9M
The thing to do would be to follow up the Mo 229 with a replica XP-79
(Northrop's Flying Wing jet fighter), and see how they stack up.
--
Pete Stickney
p-sti...@nospam.adelphia.net
Without data, all you have are opinions
Eunometic
Rob Arndt wrote:
> Northrop's early flying wings are NOT the basis for the B-2, which is
> much more related to the Go-229; so much in fact, that Northrop took
a
> look at the stored Go-229 and analysed it thoroughly before the B-2
was
> built.
Jack Northrop was out of his company by this stage and you obviously
refer to the Northrop company.
I would say the B-2 borrowed from all and every piece of information
regarding flying wings and then went through extensive computer
simulation and analysis to come up with the B-2 design; which went a
little in the way of the latter Horten designes in having a 'bat tail'
albeit a twin tail rather than a single more stingray style tail as on
the Ho 229.
> And NO, its just not made of wood. The Hortens used impregnated
> materials in its construction to make it anti-radar.
The prototypes were NOT made of this material because it was a rush
job. Part of the RAM (radar absorbant materials) were supposed to be a
1 inch thick plywood with a graphite/saw wood/glue composite filler
with some basic re-entrant structures. Absence of raw materials was a
huge problem for the Germans. Cardboard was a material used in several
of their missile fins such as the X-4.
The fuel tanks were supposed to be integral with the wooden wings using
a special fuel resistent glue but again not on the prototypes. This
fuel resistent glue was used on the Heinkel He 162 wings and also on
the Ta 152 H-1 (the Ta 152 H-0 didn't have the glue available yet) and
it abviously heled to reduce radar cross-section.
If you look at all of the work and the many photographs of RAM coatings
on snorkels and periscope in German subs it is clear that the Germans
had evolved a fairly effective anti-radar 'stealth capabillity' and
knowledge using ferrites and graphite, though I wouldn't suggest it is
anywhere near as effective as the current technology and state of
knowledge.
I believe a reduction in detection range of 30%-50% was achieved in the
first generation of RAM coating retro-fits to sub conning towers and
persicopes and possibly better on the advanced type XXI subs. conning
towers were also coated and a rubber sonar absorbing material was also
used on some German subs that was effective over certain frequency
ranges.
I've also come across accounts by German WW2 submariners manually
erecting radar screens around their conning towers when they surfaced
to reduce their radar profile.
> I think that if a historical foundation or Northrop invested in such
a
> project that it would indeed be a fitting tribute.
> The Hortens were way ahead of Northrop in design and concepts- so
much
> in fact that they were secretly taken to Wright Field after the war
and
> participated in design research for exotics.
I wouldn't say they were 'way ahead' but they seemed slightly ahead in
some areas.
Towards the end of the war the Hortens started moving away from pure
flying wing designes and adding a keel fin. In part this was because
the draglerons created shockwaves at transonic speeds and in part
becuase they were heading towards sweep backs of up to 60 degrees which
also reduced the effect of draglerons. In part it was becuase the 86
year old professor Prandtle (or was it Betz) argued with them against
flying wings becuase of this issue.
I really don't know how the B-2 deals with these shock wave issues?
The final Horten bomber of the wars was the Ho XVIII B-2 which had a
huge keel fin.
It was supposed to bomb the USA and was made of steel tube, plywood
combosite scrap and fabric.
This is the only image of it on the net, in Italian I believe:
http://www.europa1939.com/luftwaffe/proyectos/xviii.html
It was to be an impressive aircaft with in flight refueling capillity
and in theory was up to the task of bombing the USA even without in
flight refueling, apparently it was ordered into 'production in march
1045'
The issue is dealt with in Manfred Griels "The Luftwaffe over America"
(I'll be reviewing this book on r.a.m soon.)
> The famous Rhodes 1947 UFO pic (which clearly shows a parabolic disc)
> is believed by many to be of Horten origin and possibly the craft
that
> crashed at Roswell. Same year, same location- New Mexico (where a
> variety of German secret weapons testing went on postwar).
>
> Rob
>
> p.s. Please don't bring up the Hortens account of their postwar life.
> What was done was done in secret and they can't account for the gap
> between British confinement and Argentina except to say they were in
> Germany. No one would have left these experts in flying wing design
> just sit in Germany when every major Allied player was snatching up
> every German scientist, technician, and specialist they could find.
> Jim Wilson of Popular Mechanics researched the FOIA documents and the
> Hortens were a top military priority. They were released from British
> custody to US custody.
I've seen correspondence between one of the Hortens and Jack Northrope.
Horten was basically applying for help from Northrop in order to
secure a job in the USA. If they were in the USA they were thoroughly
debriefed and let go or simply unhappy there. The brothers were quite
argumentative with each other.
A lot of German Scientists and Engineers WANTED to go and work in the
USA and many were rejected. It was better than facing the Soviets or
food privation. Seems to have been mainly Jet Engine, Rocket and
rocket Guidence but also materials, chemisty and radar experts. There
is a list somewhere on the net and it is several thousands names long.
Rob Arndt
and the one you posted is one of many. The first version:
http://www.samoloty.ow.pl/rys/rys030.jpg
An alternate was a contra-prop bomber. The final design was authorized
on 3/23/45 and work commenced on it at Kahla on 4/1/45.
Rob
Rob Arndt
glue, charcoal, and soot. A further anti-stealth paint called
"Schornsteinfeger" (Chimney Sweep) was to be applied to the fuselage.
Rob
Eunometic
into production by H Goering.
http://www.europa1939.com/luftwaffe/proyectos/xviii.html
This doesn't include a committee designed aircraft by junkers and the
Hortons.
The efficiency of the flying wing concept theoretically gave enough
performance to complete a bombing mission to the east coast of the USA
on the primitive fuel hungry jet engines of the day.
"Schornsteinfeger" (Chimney Sweep) probably refers to the use of the
graphite as a component of the radar absorbing material. Rather a
dangerous practice to include a clue in code names.
Rob Arndt
Go-229's construction materials. You really don't know much about
German secret weapons, do you?
It also was the idea that produced US "Ironball" paint for the U-2
postwar.
Rob
Dan, U.S. Air Force, retired
> There are plenty of drawings and artworks for the Horten XVIII online
> and the one you posted is one of many. The first version:
>
> http://www.samoloty.ow.pl/rys/rys030.jpg
Ooh, a pretty drawing.
Dan, U.S. Air Force, retired
Dan, U.S. Air Force, retired
<snip>
>
> The final Horten bomber of the wars was the Ho XVIII B-2 which had a
> huge keel fin.
>
> It was supposed to bomb the USA and was made of steel tube, plywood
> combosite scrap and fabric.
>
> This is the only image of it on the net, in Italian I believe:
> http://www.europa1939.com/luftwaffe/proyectos/xviii.html
>
Interesting design. Pity the artist's rendering exaggerates the vertical
stab when compaired to the 3 view. Seeing a flight of those over the
Eastern Seaboard could be a tad unerving. It would have been nice to
have the Nazis waste valuable rescources building it. The war might have
ended sooner.
renab...@aol.com
Arndt the Clueless wrote:
> Northrop's early flying wings are NOT the basis for the B-2, which is
> much more related to the Go-229; so much in fact, that Northrop took
a
> look at the stored Go-229 and analysed it thoroughly before the B-2
was
> built.
> And NO, its just not made of wood. The Hortens used impregnated
> materials
SNIP
As Lavochkin had previously done with his LaGG-3, La-5 & La-7 (resin
impregnated birch called "delta wood" by the Russians)and IIRC
Dehavilland had used for his line of wooden aircraft to include the
racing Comet and the Mosquito.
in its construction to make it anti-radar.
SNIP
Nice side effect, if it worked, but much more likely that the primary
reason was that the use of ersatz materials in Germany had become
imperative as strategic material supplies dried up.
BTW, it using impregnated materials magically makes an aircraft a
steathly design, shouldn't honors go to Lavochkin and Dehavilland
(among others...)
> I think that if a historical foundation or Northrop invested in such
a
> project that it would indeed be a fitting tribute.
> The Hortens were way ahead of Northrop in design and concepts- so
much
> in fact that they were secretly taken to Wright Field after the war
and
> participated in design research for exotics.
SNIP
Prove it with citations to reputable works
> The famous Rhodes 1947 UFO pic (which clearly shows a parabolic disc)
> is believed by many
SNIP
Loons like Aren't
to be of Horten origin and possibly the craft that
> crashed at Roswell.
SNIP
Is there ANY lunatic story you don't buy into?
Same year, same location- New Mexico (where a
> variety of German secret weapons testing went on postwar).
SNIP
OK, V2's were being tested at White Sands by the Army with Von Braun's
team, so tell us (with citations) what other "secret weapons" were
being tested there in that period
> p.s. Please don't bring up the Hortens account of their postwar life.
> What was done was done in secret and they can't account for the gap
> between British confinement and Argentina except to say they were in
> Germany.
SNIP
So you are calling them liars?
Why would they have had any reason to lie about what they did post-war
when hundreds, if not thousands, of their countrymen did exactly what
you are saying they did quite openly and with no retalitaion?
No one would have left these experts in flying wing design
> just sit in Germany when every major Allied player was snatching up
> every German scientist, technician, and specialist they could find.
> Jim Wilson of Popular Mechanics researched the FOIA documents and the
> Hortens were a top military priority. They were released from British
> custody to US custody.
SNIP
Then interograted and released after being debriefed. The US and UK
weren't shangaiing anyone against their will. Many of the personnel who
immigrated looked at their prospects in a wrecked Germany and decided
they "prefered situations elsewhere".
Given the choice between the Hortens being liars and Aren't being any
idiot, the choice is obvious.
renab...@aol.com
Eunometic wrote:
>
> "Schornsteinfeger" (Chimney Sweep) probably refers to the use of the
> graphite as a component of the radar absorbing material. Rather a
> dangerous practice to include a clue in code names.
SNIP
One the Gremans were rather prone to. Operation Sea Lion is the classic
example. Another is the story of Freya. Dr R V Jones showed the value
of a classical eduaction when confronted with "Freya". He did some
research on Norse mythology and found that she was given the
Brisingamen necklace by Heimdall, guardian of th rainbow bridge to
Valhalla. Heimdall could see a hundred miles...so Jones concluded that
Freya was a radar set and had an idea of its range.
renab...@aol.com
SNIP
Which you can prove with appropriate citations, of course
renab...@aol.com
Eunometic wrote:
> The fuel tanks were supposed to be integral with the wooden wings
using
> a special fuel resistent glue but again not on the prototypes. This
> fuel resistent glue was used on the Heinkel He 162 wings and also on
> the Ta 152 H-1 (the Ta 152 H-0 didn't have the glue available yet)
and
> it abviously heled to reduce radar cross-section.
SNIP
I'm dumb, how would the glue reduce the RCS? By eliminating metal wimg
tanks (I presume rubber-based self-sealing tanks were out of the
question by then due to the limited availability of rubber). IIRC, the
Ta-152 had a wooden wing incorporating two steel spars, so even metal
wing tanks should not have made much of a diference.
> If you look at all of the work and the many photographs of RAM
coatings
> on snorkels and periscope in German subs it is clear that the Germans
> had evolved a fairly effective anti-radar 'stealth capabillity' and
> knowledge using ferrites and graphite, though I wouldn't suggest it
is
> anywhere near as effective as the current technology and state of
> knowledge.
>
> I believe a reduction in detection range of 30%-50% was achieved in
the
> first generation of RAM coating retro-fits to sub conning towers and
> persicopes and possibly better on the advanced type XXI subs.
SNIP
Do you have any references to read up on here? I was able to find one
on-line reference that stated the periscope/snorkel coating worked well
but was easily washed off...
conning
> towers were also coated and a rubber sonar absorbing material was
also
> used on some German subs that was effective over certain frequency
> ranges.
SNIP
I'm not aware of German use of anechoic tiles in WWII, could you
provide references?
SNIP
The one on-linen reference I was able to find listed its range with as
a 4000 kg bomd load as 9600 km (6400-6500 miles by my reckoning). A
round trip from Hannover to New York is about 7550 miles. It's extreme
range is listed as 12000 km (8000 miles)- load unknown. Based on this,
it sounds like it would need flight refuleing.
Could you go into German work on flight refueling or rpovide refrences?
Thanks!
renab...@aol.com
Eunometic wrote:
>
> The final Horten bomber of the wars was the Ho XVIII B-2 which had a
> huge keel fin.
>
> It was supposed to bomb the USA and was made of steel tube, plywood
> combosite scrap and fabric.
>
> This is the only image of it on the net, in Italian I believe:
> http://www.europa1939.com/luftwaffe/proyectos/xviii.html
>
> It was to be an impressive aircaft with in flight refueling capillity
> and in theory was up to the task of bombing the USA even without in
> flight refueling, apparently it was ordered into 'production in march
> 1045'
>
SNIP
March 25, 1945 - six weeks before the collapse - which shows the
fantasy land that the nazis were living in.
Keith W
<renab...@aol.com> wrote in message
news:1114108986.9...@o13g2000cwo.googlegroups.com...
Well to be fair he did acknowledge it was made of 'composite scrap'
What this really means of course is 'lets build a mockup with
whatever we can lay our hands on, with luck it'll keep us out
of the army until the end of the war'
Keith
machf
>
>This is the only image of it on the net, in Italian I believe:
>http://www.europa1939.com/luftwaffe/proyectos/xviii.html
>
It's Spanish, actually...
--
__________ ____---____ Marco Antonio Checa Funcke
\_________D /-/---_----' Santiago de Surco, Lima, Peru
_H__/_/ http://machf.tripod.com
'-_____|(
remove the "no_me_j." and ".sons.of" parts before replying
Eunometic
> Eunometic wrote:
> > The fuel tanks were supposed to be integral with the wooden wings
> using
> > a special fuel resistent glue but again not on the prototypes.
This
> > fuel resistent glue was used on the Heinkel He 162 wings and also
on
> > the Ta 152 H-1 (the Ta 152 H-0 didn't have the glue available yet)
> and
> > it abviously heled to reduce radar cross-section.
>
> SNIP
>
> I'm dumb, how would the glue reduce the RCS? By eliminating metal
> tanks (I presume rubber-based self-sealing tanks were out of the
> question by then due to the limited availability of rubber).
Yes, by eliminating metal linings. My speculation.
I believe the standard German self sealing fuel tank was made of rubber
expanding material (multiple sheets) about 1 inch thick with a leather
outer package and a metal interior. The tanks were suspended from
straps. The Germans had snthetic rubber but I don't know if it swelled
enough on contact with fuel.
Part of the radar absorbant material on the Go/Ho 229 was supposed to
be a glue/sawdust/graphite RAM filler between the double plywood skins
about one inch thick. It wasn't just a 'paint' or coating although
this existed as well.
On the Go/Ho 229 the special glue for the integral fuel tanks wasn't
ready on time so they had to accept a theoretical range reduction of
about 25%.
> IIRC, the
> Ta-152 had a wooden wing incorporating two steel spars, so even metal
> wing tanks should not have made much of a difference.
I thought it was an all wooden wing? It definetly was on the He 162.
Either way the special fuel resistent wood glue crops up in the
development histories of all three aircraft.
There was no deliberate attempt to reduce radar cross section on either
the Ta-152 or He 162 that I know of: they both had metal fueselages.
The Hortons in the 1950s mentioned that wood is a good material to use
becuase it can be used to help reduce radar returns and give the
element of suprise.
>
>
> > If you look at all of the work and the many photographs of RAM
> coatings
> > on snorkels and periscope in German subs it is clear that the
Germans
> > had evolved a fairly effective anti-radar 'stealth capabillity' and
> > knowledge using ferrites and graphite, though I wouldn't suggest it
> is
> > anywhere near as effective as the current technology and state of
> > knowledge.
> >
> > I believe a reduction in detection range of 30%-50% was achieved in
> the
> > first generation of RAM coating retro-fits to sub conning towers
and
> > persicopes and possibly better on the advanced type XXI subs.
>
> SNIP
>
> Do you have any references to read up on here? I was able to find one
> on-line reference that stated the periscope/snorkel coating worked
well
> but was easily washed off...
I've come across photographs from time to time. Igor Witowski, a
Polish Historian: "Truth about the Wunderwaffen" has photographs and
further references. He has a photograph of an sub snorkel with what
looks like a radar warning receiver in a small dome attached to the
side with a cable running down the outside of the snorkel; the dome is
probably a naxos radar warning device. The coating is very thick like
plaster of cement and has a grooved and checkquered pattern. It looks
exactly like the anti-magnetic mine cement coating applied to German
tanks. (zimmermat?). Even the cable is covered in it. It might be
cement or it might be a foam or plastic material.
Most of his references come from post war allied intelligence reports
(CIOS?)
I came across a reference to the 30%-50% reduction in detection range
in an very old magazine called "War Monthly" I collected in the 1970s
in reference to it being applied to conning towers.
To get a 50% reduction in range a factor of 16 of reflection is needed
however becuase of backround clutter reducing the S/N ratio perhaps
only 4-8 is needed?
The sonar opperator of the U-234 "Hirschfeld" has published his memoirs
and refers to them erecting radar screens around the conning tower when
they had to surface to conduct repairs on their sub.
>
> conning
> > towers were also coated and a rubber sonar absorbing material was
> also
> > used on some German subs that was effective over certain frequency
> > ranges.
>
> SNIP
>
> I'm not aware of German use of anechoic tiles in WWII, could you
> provide references?
Igor Witowski's book is a good reference becuase he does cross
reference and end note. I'll give you a specific reference from his
book tonight. However I've seen it several times casually in reading.
The Germans were interested from 1935 or so onwards. They were
actually quite succesfull early on but the coatings only worked at one
fairly narrow frequncy range and they had trouble with this factor.
It was a rubber like material about 1.5mm thick from the descriptions
I've read.
Doenitz pushed it along. Oddly when the Germans detected a conning
tower with one of their primitive radars around 1937 Doenitiz ignored
its implications.
> a 4000 kg bomd load as 9600 km (6400-6500 miles by my reckoning). A
> round trip from Hannover to New York is about 7550 miles. It's
extreme
> range is listed as 12000 km (8000 miles)- load unknown. Based on
this,
> it sounds like it would need flight refuleing.
I think the missiions were planed from "Brest" and the range is given
as 9000-12000km. the upper range of 12000km equates to about 7452
miles. The range either refers to variations in bomb load or aircraft
with various engines.
The cross sectional views sometimes show the aircraft with 6 engines in
two pairs of 3 closely coupled in rectangular intakes and sometimes
with 4 engines in two pairs of two less closely coupled.
I suspect the 6 engined versions are usually designated as having jumo
004 engines and must have been designed to use late model Junkers Jumo
004 (same as the Me 262) engines of about 1100kg thrust while the 4
engined models probably had the longer range and used engines like the
Jumo 004H or Jumo 012 or HeS 011 that were in the prototype stage at
that time and supposedly offering around 2000kg thrust.
With 6 engines it would have a thrust of about 6600kg but with 4 of the
larger engines probably 7600kg-8000kg and therefore MTW and range would
go up.
Just a guess.
However the Ho 18 B-2 was unique in supposedly having the range for a
round trip.
>
> Could you go into German work on flight refueling or provide
refrences?
Manfred Griehl has recently (1994) published a book called "The
Luftwaffe over America". He has a whole chapter dedicated to German in
flight refueling attempts but one is left with a desire for more
information.
They were a bit bipolar about it actually starting of trying to tow the
aircraft to save its fuel rather than refuel it. They also conducted
towed takeoffs with the hose and drogue connected like a sailplane
using the reel to both tow and refuel. It worked after some vibration
issues but this way the need to couple in flight was avoided.
In flight mating and refueling started as a sort of probe and drogue
afair with the probe actually being on a large L shapped mast or beam
above the cabin to get extra clearence from the props. The ball on
the hose was latter suplemented with a cone to help stabalise it. This
system was tested and Griehl has photos of it in his book.
However at some point they seemed to favour using a Y shaped fork
attached to the L shaped beam in the same position above the cockpit
cabin which would grab a ball (instead of the cone shaped drogue) and
then use a pilot line to actually physically reel the fuel line in and
connect mannualy to the refueling receptical presumably above the
cockpit or to the side. It was a good system becuase it needed a
relatively slim beam that didn;t need to support full forces but had
safety issues with a fuel leak potentially flooding the cabin if a leak
occured.
I'm not sure what the Ho 18 B-2 was supposed to get but it was probably
the probe and droque.
There were several experiments and all were positive to varying
degrees. Erhardt Milch got cynical (its clear he regarded the boffins
as impractical) and lost in the issue of rendevous in bad weather
problems and the technology wasn't pursued vigorously.
The rendezvous issues seemed to make it a show stopper in his mind as
he imagined the aircraft getting seperated in bad weather.
Much time was wasted becuase the reel had to be re-engineered to make
it smaller at one point since big aicraft like He 111 were not
allocated to the experiments due to insufficient priority. (they had
to use smaller czech aircraft and engineers).
Its clear that this technolgy if applied to the Ju 290 could have given
the Luftwaffe an abillity to bomb the USA as early as 1943; not
withstanding the issues of rendezvous.
The Ju 290 was a good aircraft used as a maritime reconaisence machine.
I think only 50 were built but the range was about 4500 miles with a
top speed of 278mph. Range was not enough for a return mission. It
evolved from the Ju 89 4 engined bomber that the Germans abandoned with
their whole 4 engine progeram in the 30's. Junkers turned it into the
Ju 90 airliner and then the Ju 290 transport which became a maritime
patrol aircraft. Equiped with a Hohtenweil radar it could detect a
periscope at 6 miles. It had a tail gun and about 1 ton of armour but
was considered as lacking the armour and strength needed for use as a
bomber. A Ju 290 once circled an allied convoy for 6 hours and was
left alone as they thought it was allied (that's how long it has been
since they saw a German aircraft)
The Ju 290 was modified as a Ju 390 by adding a plug in the inboard
wing sections to make it a 4 engined machine. This added about
1000-2000 miles of range but it was still not enough for a return
mission to the US without refueling. I think the idea was abandoned
when it was realised an aircraft with a speed of 280mph would be
destroyed to easily. A Ju 290 however did fly non stop from Germany to
the US breaking the transatlantic speed record in late 1945 as a war
prize.
I beleive the Ju 290/390 would have been used to refuel the Ho 18 B-2.
>
> Thanks!
>
>
>
>
> apparently it was ordered into 'production in march
> > 1945'
Cub Driver
>> dangerous practice to include a clue in code names.
>
>SNIP
>
>One the Gremans were rather prone to. Operation Sea Lion is the classic
As opposed to the deep dark secret of Overlord?
-- all the best, Dan Ford
email war...@mailblocks.com (put Cubdriver in subject line)
Warbird's Forum: www.warbirdforum.com
Piper Cub Forum: www.pipercubforum.com
the blog: www.danford.net
In Search of Lost Time: www.readingproust.com
Cub Driver
>in its construction to make it anti-radar.
Reimar Horten said that the stealth properties of the Ho/Go-229 were
not discovered until the plane was flying, and were no part of its
design. At that, I think it was invisible only to airborne radar.
The same was true of the Norton YB-49 Flying Wing bomber, which was
stealthy to the ground-based radars of the time.
The Enlightenment
the Go 229) was modified by coating on the inside with a glue based
paint of charcoal and sawdust to shield the underlying metalic
structure as part of a trial. He doesn't know the results but there
was an attempt to take advantage of the alreadt stealty shape. I've
come across repeated reports of a sandwitch construction that used a
filler material.
While the discovery of the low radar cross section was an accident they
did recognise it and do some work extending it in part presumably
because they had a radar absorbing materal development program in
place.
Work on German stealth materials is available under
BIOS 'British Intelligence Objectives Subcommitte' Report nos 869
Ferromagnetic Materials for Radar Absortbtion'
and also:
BIOS 'Work of Professor Huttig on Ferromagnetic Substances for Use in
Radar Camouflage'
Much of the German Stealth work is lost but those involved include"
The BHS The Plenipotentiary for High Frequecy work (Bevollmachtiger
for Hufrequeze Forschung) set up to catch up in the microwave field,
IG Farben and Hoechst.
Institute of Inorganic Chemisty (Proff Klemm) in Danzig (now Gdansk in
Poland)
Osram (Dr Friedrich)
Degussa (Proffesor Fuchs)
Tecnische Hocheschule Stuggart
Ceramic Lab of Lutz and Co (Inventor of the coating used on u-boat
snorkels) eg Type XXI u-boat.
Technische Hocheshule Praha.
The radar absorbing material program must have been quite extensive to
involved so many people.
Eunometic
renab...@aol.com wrote:
> Eunometic wrote:
The anti-sonic coating was called "Alberich" and was developed by
Proffesor Meyer of the Heinrich Hertz Institute.
It probably consisted of two thin 2mm rubber coatings glued to a metal
plate with a smooth exterior coating. The inner plate was drilled with
two different sized holes 2mm and 5mm with damping occuring inversely
proportionally to the diameter and frequency.
It damped 95% of sound at a peak frequency but would fall away at
others. It worked best if matched approximetly to the frequecy of the
enemies sonar. Below 70m depth compression also caused it to reduce in
effectiveness.
It was used on 9 u-bats two of which saw service. One of these was
sunk but that was becuase it didn't have a snorkel. The Type XXI had
it as standard.
The anti-radar coating was invented by the Lutz and Co by Dr Franz
Lothar. It entered service on many standard submarines and was to
applied as standard on the Type XXI but other submarines.
Peter Kemp
1st April? How appropriate considering the state of the Reich at that
point. What use was something that could hit the US when everything
needed to finish off the Reich was already in theatre?
--
Peter Kemp
"Life is short...drink faster"
Errol Cavit
"Cub Driver" <war...@mailblocks.com> wrote in message
news:vshh61173vtfl288e...@4ax.com...
> On 21 Apr 2005 10:50:48 -0700, renab...@aol.com wrote:
>
> >> dangerous practice to include a clue in code names.
> >
> >SNIP
> >
> >One the Gremans were rather prone to. Operation Sea Lion is the classic
>
> As opposed to the deep dark secret of Overlord?
>
Fairly minor in comparison to Neptune.
--
Errol Cavit | errol...@hotmail.com
The great pain we feel / Is for you who were our future
Comeback return home, / We have waited for you
Through the long years / You were away
Sorrow / Aches within me
Tomb of the Unknown Warrior, NZ
renab...@aol.com
Eunometic wrote:
> > IIRC, the
> > Ta-152 had a wooden wing incorporating two steel spars, so even
metal
> > wing tanks should not have made much of a difference.
>
> I thought it was an all wooden wing? It definetly was on the He 162.
> Either way the special fuel resistent wood glue crops up in the
> development histories of all three aircraft.
SNIP
Please see the NASM page on their Ta-152
"Because of aluminum shortages, Focke-Wulf made the wing spars from
steel and built the rear fuselage and empennage. The wing contained two
steel spars. The front spar extended slightly beyond the landing gear
attachment points but the rear spar spanned the entire wing."
http://www.nasm.si.edu/research/aero/aircraft/focke_ta152.htm
renab...@aol.com
Eunometic wrote:
> >
> > The one on-linen reference I was able to find listed its range with
a
> > a 4000 kg bomd load as 9600 km (6400-6500 miles by my reckoning). A
> > round trip from Hannover to New York is about 7550 miles. It's
> extreme
> > range is listed as 12000 km (8000 miles)- load unknown. Based on
> this,
> > it sounds like it would need flight refuleing.
>
> I think the missiions were planed from "Brest" and the range is given
> as 9000-12000km. the upper range of 12000km equates to about 7452
> miles. The range either refers to variations in bomb load or
aircraft
> with various engines.
>
SNIP
OK, basing around Brest gives a distance of about 6700 miles, so maybe
you cut the load to 2000 kg and/or ionstall bomb bay tanks and you have
enough range to make the round trip with some fuel reserves.
By the way, found this neat-oh site that allows you to calculate the
distance between just about any two cities listed by the ICAO
http://www.findlocalweather.com/how_far_is_it/ny/new+york.html
renab...@aol.com
SNIP
Thanks! I did a Google using "Alberich + U-boat" as my key words and
found a lot of information. "Alberich" was the key, I'd originally
tried "Anechoic + U-Boat" and got nothing...
renab...@aol.com
Eunometic wrote:
> The sonar opperator of the U-234 "Hirschfeld" has published his
memoirs
> and refers to them erecting radar screens around the conning tower
when
> they had to surface to conduct repairs on their sub.
SNIP
Could you go a little deeper into that? I found one (German) web site
which claimed the "Alberich" anechoic coating was designed as an
anti-radar device - something I think is incorrect. I would tend to
doubt the hydrophone operator thinking this, given his training and
position.
On the other hand, the Metox radar warning receiver's antenna ("The
Biscay Cross") had to be carried up through the conning tower hatch and
mounted on the conning tower with its cable going through the hatch.
Never understood why a properly waterproofed mounting couldn't have
been developed. So perhaps we have a bit of trouble in the translation
of the memoirs with "screens" being used instead of "antennas"....
Eunometic
carved out of rock and ornated with gems and precious metal. He guarded
the Nibelung hoard and was also a very powerful magician. He gave
Siegfried the sword Balmung and a cloak which granted INVISIBILITY.
Freya received the necklace Brisingamen along with Draupnir, Odin's
ring, and the magical sword Tyrfing."
The Type XXI was apparently tested by the US navy in 1946 (According
to Witowski's book page 127) and couldn't be detected by the sonars of
the day and by any means at 200 meters! (he doesn't say what depth)
The Type XXI u-boats would have been quite deadly. They had anti-sonic
coatings, anti-radar coatings on the periscope and snorkel and I expect
other parts, a PPI radar that could be extended by mast and opperated
underwater, the quick firing guns could be slaved to a fire control
system using a radar and had a high probabillity of defeating a single
patrol aircraft, they could submerge completely in less than 18 seconds
and they had an effective passive array sonar which worked with the
"Balkon Garaet" which was a passive sonar '3 dimensional' rangefinder
good enough to aim torpedoes and handy in avoiding escorts. At 6
knots using their V-belt creeper drives they were essentially
undetectable while at 17.2 knots they were 5.3 knots faster than the 12
knots at which allied sonar was effectively blind. They had a very
rapid automatic torpedo reload that on its own made them deadly. I
think a salvo of 6 was possible every 10 minutes.
The Type XXI formed the basis of the French and German post war navies
and was reproduced as the type 633 romeo class in the USSR (they took
over the Germania Shipyards) and are still at sea in the form of the
Ming Class to probably 2010.
They entered service but famously didn't fire on 3 British cruisers
they had interdicted themselves into as they surrender was only days
away.
Eunometic
for example and put the designe through some kind of computerised
aerodynamic analysis or even wing tunnel modelling?
It would be interesting to see what understanding of some of the issues
such as high speed snaking on the Me 262 came from. Apparently this
could be cured via individual adjustments to the airframes but was
quite time consuming. It was a problem I believe early Meteors and
P-80's had as well.
Cub Driver
<peter_...@hotmail.com> wrote:
>1st April? How appropriate considering the state of the Reich at that
>point. What use was something that could hit the US when everything
>needed to finish off the Reich was already in theatre?
When you read the radio traffic at the end of both wars (European and
Pacific), you get the impression that the war was on autopilot by that
Peter Stickney
"Eunometic" <euno...@yahoo.com.au> writes:
> Do you guys have the abillity to take the designes, eg Me 262 or Ho 229
> for example and put the designe through some kind of computerised
> aerodynamic analysis or even wing tunnel modelling?
Yes, indeed.
> It would be interesting to see what understanding of some of the issues
> such as high speed snaking on the Me 262 came from. Apparently this
> could be cured via individual adjustments to the airframes but was
> quite time consuming. It was a problem I believe early Meteors and
> P-80's had as well.
The root cause of the snaking in the early jets, most notably the Me
262 and the Meteor was uneven flow separation off the fairly thick
vertical stabilizers. as teh flow over teh fins & rudders went
trandonic, it would separate off one side or teh other. The resulting
yaw would cause teh other side to separate, & so it would swing back &
forth. This was aggravated on the Me 262 by the rather primitive
rudder hinging and balancing (Which was also a major source of drag),
and the poor quality of late-war German construction. Adjustments to
the rigging of the rudder, and closing up teh gaps as much as
possible, could slightly delay the onset of snaking and reduce the
feedback that increased its ablitude, but it couldn't address the root
cause. The solution for the Meteor was, eventially, to fit a new
tail. The F-80, designed with Lockheed's experience in transonic
behavior, gleaned from having had to sort out the P-38, was less
prone to snake, but there was still some at speeds above Mach 0.78 or
so.
The Go 229 - that's an interesting question, since it only flew twice,
and didn't exceed 400 mph. Given that it didn't have a tail, or
enough shord (like a delta) to balance out the moment shift as it wnnt
transonic, snaking would be the least of its problems. Pitch
stability would have been seriously deficient. Flying Wings don't so
so well in the high transonic range. There are time when a tail is a
good thing to have.
--
Pete Stickney
p-sti...@nospam.adelphia.net
Without data, all you have are opinions
Cub Driver
Stickney) wrote:
>tail. The F-80, designed with Lockheed's experience in transonic
>behavior, gleaned from having had to sort out the P-38, was less
>prone to snake, but there was still some at speeds above Mach 0.78 or
>so.
What about the Bell P-59A? Among its other deficiencies, it was deemed
too unstable as a gun platform. Was that "snaking" also?
Seems to me that the problem with the early jets was that they lacked
propellers. Surely the prop was a great stabilizing factor, whether as
a gyro or merely by blowing all that air across the tailfins. So that
design elements that would have passed unnoticed in prop planes gave
trouble when applied to jets. (Doesn't explain Lockheed's comparative
success, of course.)
Interesting post. Thanks.
Eunometic
It was 9000 km range and with supplementary fuel tanks it was 12,000km.
(7452) I don't know what nature the supplementary fuel tanks took or
if they compromised bombload.
The engine was the Jumo 004H also known as 109-004H. This was a
significant modification of the Jumo 004B used on the Me 262.
Differences were:
1 11 stage instead of 8 stage compressor. Note Germans focused on
axial compressors specifically because they could stack stages to
increase pressure ratio and mass flow. Pressure flow went up to 5:1
from about 3.2:1.
2 8 combustion chamber cans instead of 6. They were probably the same
combustion chamber.
3 A new two stage turbine.
The sfc specific fuel consumtion went down from 1.38:1 to 1.2:1 and
thrust was at least 1800kg.
The entry to service was expected to take 2 years. Thus by March 1947
the Nazis were expecting to have an ultra long range bomber able to
reach the USA and probably penetrate beyond the coast with the aid of
in flight refueling.
Speed was 560mph and service ceiling 16,0000 meters.
Only a little work was done on the engine, the 109-104H but a larger
more powefull engine the junkers jumo 109-012 which was a much larger
more powerfull engine did precede much further. The parts for this
engine had been fabricated but was waiting final assembly when the war
ended. Illustrations show that it is likely the 6 x 109-104Hs would
have been replaced with 4 x 109-012.
This unit was the same layout but larger and replaced the casting with
sheet metal and I believe would have been the engine that the Ho XVIII
B-2 would have used since no other German aircraft was to use the
109-004H.
My rough calculations show it was feasible: assuming a mass fraction of
fuel of around 45% and a typical lift to drag ratio for a wing.
Up untill this point the Nazis had little time for an "Amerika Bomber".
The Me 264 was Willy Messerscmitts personel pet project and was given
little support. It was barely up to the task but the streched more
heavily armed 6 engine version known as the Me 264/6m (6 motor) or Me
364 was up to the task.
The Me 264/6m was horrifically expensive, virtually equal to a B-36 and
certainly beyond the sane capabillities of the Germans. The Ho XVIII
on the other hand seemed to make sense. It was made out of non
strategic materials and only required to gun turrets for its defense
and 6 crew to opperate it.
Eunometic
Peter Stickney wrote:
> In article <1114241811.3...@z14g2000cwz.googlegroups.com>,
> "Eunometic" <euno...@yahoo.com.au> writes:
> > Do you guys have the abillity to take the designes, eg Me 262 or Ho
229
> > for example and put the designe through some kind of computerised
> > aerodynamic analysis or even wing tunnel modelling?
>
> Yes, indeed.
There appear to be some radio-controlled modellers looking at this as
well.
Very illuminating, thankyou.
>
> The Go 229 - that's an interesting question, since it only flew
twice,
> and didn't exceed 400 mph. Given that it didn't have a tail, or
> enough shord (like a delta) to balance out the moment shift as it
wnnt
> transonic, snaking would be the least of its problems. Pitch
> stability would have been seriously deficient. Flying Wings don't so
> so well in the high transonic range. There are time when a tail is a
> good thing to have.
One thing of course is that the aircraft would tend to develop shock
waves near the thick inner section first and as these generate their
own lift the aircraft will have a tendency to pitch down, the so called
Mach Tuck, unless the bat tail helps eliminate this.
An usual feature of the Go/Ho 229 was its little bats tail which I've
only ever seen on the B-2 spirit. It is supposed to help with
stabillity though it clearly also gives a neat jet installation.
I suspect at this time the Hortens, after a nearly a dozen gliders and
powered aircraft had worked out the handling issues pretty well since a
piston engined aircaft known as the Ho VII apparently impressed those
that flew it and decided to OK the Go/Ho 229 on the strength of its
handling. It apparently conducted a number of single engine flights
flawlessly to demonstate the safety and utillity of the flying wing
concept to a cynical Luftwaffe.
It's my understanding that the theory of a flying wing is to replace
the pitch control and stabalising function of a conventional tailplane
with the tips of the swept wing.
It goes beyond this however. The mid section of the wing is designed
to stall well before the tips, in fact the tips are designed to never
stall. If this is done properly the aircaft not only does not spin
easily but it will not stall but simply mushes forward. The Me 163 was
tailess had apparently had excellent handling, was completely stall
resistent and simply mushed forward and I believe the Vought XF5U
Flying Pan Cake worked on similar principles.
So despite the delicacy of the designe of the flying wing it would
appear to have big advantages if done properly.
There is a man carrying glider of the Me 163 flying somewhere.
Ensuring that section of the wing stalled first was not just a matter
of slats, reduced wing washout or different wing sections at the tip
but was a matter of making sure that the point of breakaway of
aerodynamic flow and the ensuing changes of momment of pressure were
all conducive to stabillity.
Horten calculated a spanwise lift distribution that eliminates the
danger of spinning as long as the center of gravity is within
prescribed limits.
There is an article here by I think Reimer Horton where he discusses
this distribution. (I think he was writing for a sailplane ethusiasts
club). It is a bit slow to get moving as he dwells on fundementals and
arcane German aerodynamacists but he cuts to the chase at the end.
http://www.nurflugel.com/Nurflugel/Horten_Nurflugels/theory/theory.html
Eunometic
Rob Arndt wrote:
> Schornsteinfeger was anti-radar paint, completely seperate from the
> Go-229's construction materials. You really don't know much about
> German secret weapons, do you?
> It also was the idea that produced US "Ironball" paint for the U-2
> postwar.
Little is known of Schonsteinfeger. It is known that the Germans had
an extensive ceramic, ferrite and plastic based radar absorbing
material program becuase there are plenty of allied documents freely
available from the Brtish BIOS, Lusty and Paperclip programs and it is
known that the technology was applied to submarines. Little specific
is known of Schonsteinfeger. Was it ferrit or graphite based? Was it
a plastic, tar, ceramic based material?
The Ho IX V1 (an unpowered glider version of the Go 229) and Ho IX V2
(the Go 229 prototype with jet engines) didn't use it. The Ho IX V1
glider was apparently modified by coating of its insides with a
graphite (i.e. semiconducting) material as part of tests to determin
how effeective the material was. Results of the tests are not known to
me. Preumably the theory was that the semiconducting graphite would
tend to absorb the microwaves rays before they could reflect back of
the underlying metal space frame structure.
The flying wing had a low radar cross section by its nature anyway.
Cub Driver
wrote:
>The flying wing had a low radar cross section by its nature anyway.
Add to that the fact that the 229 was built largely of wood, and that
the engines were on top of the wing rather than at the trailing edge,
where the hot exhaust would be immediately apparent to radar. (Note
that the B-2 positions its engines in the same manner.)
According to Reimar Horten, these features (including the wing's
design) were serendipitous, and stealth was not on his mind when he
designed it. The same was true of Nothrop when he designed the
XB-35/YB-49, which was also stealthy by the standards of the day.
Eunometic
Cub Driver wrote:
> On 25 Apr 2005 05:06:43 -0700, "Eunometic" <euno...@yahoo.com.au>
> wrote:
>
> >The flying wing had a low radar cross section by its nature anyway.
>
> Add to that the fact that the 229 was built largely of wood, and that
> the engines were on top of the wing rather than at the trailing edge,
> where the hot exhaust would be immediately apparent to radar. (Note
> that the B-2 positions its engines in the same manner.)
>
> According to Reimar Horten, these features (including the wing's
> design) were serendipitous, and stealth was not on his mind when he
> designed it. The same was true of Nothrop when he designed the
> XB-35/YB-49, which was also stealthy by the standards of the day.
>
Thanks, I've read the wonderfull articles on flying wings on your web
site.
While I accept the Hortens serendipidy of the discovery of the low
radar cross section (of the Ho IX / Go 229) because it was a flying
wing there does seem to have subsequently been an effort to enhance
this effect.
There are plenty of articles wich talk of the graphite impregenation in
the glues used in construction. I've come across at least one article
that talks of the Ho IX glider being coated internally with a grahite
impreganted glue on the inside of the airframe and then used in radar
cross section measuremeants.
Carbon Black is a common material used as a bulking and stabalising
agent in plastics so this may just have been part of the normal glue
process.
When doped into plastics such as polyethelyene at levels of about 12%
the plastic becomes a 'semi conductor'. It is used on screens between
condutor and insulators in high voltage electrical cables and
equipement to equalise electrical stresses so that the arcing that
would occur across the inevitable plastic-metal microscopic gaps is
replaced by a semi-conducting material that 'mates' insulator and
conductor.
Presumably it might have some mild radar absorbing capabillity.
Normally ferrites are associated with this.
There is something called the 'skin depth' which gives the penetration
of a radio wave into a metals and semi conducting material such as salt
water.
There is a calculator of it here:
http://www.microwaves101.com/encyclopedia/calsdepth.cfm
and a derivative of it here:
http://scienceworld.wolfram.com/physics/SkinDepth.html
If you plug in the correct values of resistivity, around 100-1000 ohm
centimeters the material would seem to absorb the microwave. I
remember going into this calculation at uni in reference to radio waves
reaching submarines in salt water. Given that the Go 229 had about a 1
inch thick semiconducting plywood skin it may just have absorbed a high
proportion of radio energy. wheras pure wood could tend to transmit on
to the underlying metal structure and a pure metal to reflect it.
Cub Driver
wrote:
>There are plenty of articles wich talk of the graphite impregenation in
>the glues used in construction. I've come across at least one article
>that talks of the Ho IX glider being coated internally with a grahite
>impreganted glue on the inside of the airframe and then used in radar
>cross section measuremeants.
It could be that Reimar Horten was trying to play down the military
significance of the 229, when he said that the stealthy aspects
weren't designed into the plane. "Nobody here but us visionaries!"
I no longer have the books at hand, but I don't think that David Myhra
got into the stealth issue in either of his Schiffer books about the
229. Or did he?
Rob Arndt
carbon. When applied in thickness carefully calculated in relation to
the radar frequency the arriving signal would be trapped within the
dielectric material and its return energy damped out.
Rob