Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auThe Germans actually flew the first swept wing aircraft in the world.
This comes back to swept wing definitions since some early aircraft had
swept wings but of course they did not have the speed to benefit from
the advantages. Then came the WWII designs.
Post by e***@yahoo.com.auIt was the Junkers Ju 287 and it had swept forward wings.
First flight of the Ju287 was on 15 August 1944.
Curtiss XP55 Ascender, canard design with swept wings, first flight
19 July 1943, over a year before the Ju287, 2 other prototypes had
flown by the end of April 1944.
The swept wing of the Curtiss XP55 Ascender was not built to take
advantage of mach reducing effects of swept wings: no one in The USA or
UK had even an inkling nor did the 1920s designers of the British
tailless "pteradactyle".
Ah right we now have the usual retreat of definitions.
Actually we now have the usual incendiary mass scattering of creatively
improvised factoids.
You know "Eunometric" you describe yourself so well, keep the
above definition.
Post by e***@yahoo.com.auIt is in a complete variance from common usage of the collective term
"swept wing" or "swept wing technology" to maintain the
illusion that the XP-55 or B-36 had this "swept wing" technology
prior to its actual historic discovery thereby pre-empting researchers
such as Bussman, Kuechmann & Mullhope.
Yes here we go again, swept wing is not wings being swept back or
forward, they have to be swept for the "right reasons", ones that just
so happen to make the WWII Germans the first, even when they are
second, third or whatever when it comes to flying aircraft that had
swept wings.
Post by e***@yahoo.com.auWhen referring to "swept wing technology" the accepted context is of
referring to the shock wave formation delaying effects of highly swept
wings and also the various ADDITIONAL techniques and technologies
needed to take advantage of the swept wing technique at high mach
the form of certain kinds of wing sections while simultaneously using
certain techniques to counter the particularly serious negative effects
of high sweep angles at lower speeds.
Yes folks, you have to do the design for the right reasons, which just
so happen to make the Germans first.
Note by the way it is not enough to have a wing sweep, you need
the additional techniques and technologies, which by the way the
WWII Germans did not have, they had some theoretical ideas on
some of them.
Plenty more have been discovered after WWII, so I guess the
Germans were not the first. I mean given there are still discoveries
that might be made you can say no one is the first yet.
Post by e***@yahoo.com.auThe term "swept wing technology" is most pointedly NOT referring to
modest amounts of sweep occasionally implemented to create TAILESS
aircraft designs or to improve the pitch stability of subsonic canards.
Such TAILESS designs dated back to the early days of aviation.
Ah yes, modest amounts of sweep. Checked out the ascender's sweep
angle recently?
But hey, when cornered, do not give the real numbers, switch to
descriptions, so the inconvenient designs are written off with words
like "modest".
Simple really, the Ju287 was not the first swept wing aircraft to fly.
This is an unacceptable fact to some, so, rather than pointing out
things like it was the first to fly using the results of research into
high speed effects, or that it had swept forward wings, a lot of
effort has to go into disqualifying every swept wing design that
flew before the Ju287.
Sad isn't it?
Post by e***@yahoo.com.auThese are referred to as 'tailless' designs and the issues and
technology are quite different.
A swept wing is apparently not a swept wing if the aircraft is
classified as tailless. Very good. The technology is different,
for some reason.
Post by e***@yahoo.com.auIn fact Geoffery DeHavilland Jnr was
to pay with his life in another Comet like debacle in his death dive in
the DeHaviland Swallow for failing to appreciate the fact that a
tailless design with shallow swept back wings doesn't have sufficient
pitch control to correct for mach tuck.
One thing for sure, when Eunometric chooses a bad example it will
be from the allies, not the Germans. If possible it will cast aspersions
on multiple allied designs.
By the way the Comet airframe lasted a long time, after the metal
fatigue issues were sorted out. Of course in the Eunometric world,
any fault in an allied aircraft is important, faults in German aircraft
are ignored, or easy to overcome.
Post by e***@yahoo.com.auMach tuck is caused by
shockwaves creating their own lift further back on the wing of an
aircraft.. DeHaviland died from Mach Tuck. (in fact the series of 3
swallow prototypes killed three British test pilots). Even more
bizzare the phenomena was made known to the allies in the form of
German research and the direct esperience of the Me 163 which suffered
from this phenomena.(though not as badly as the Swallow).
You know it is really cute to simply note yet again how the Germans
are supposed to be telling the allies about high speed aerodynamics
when the allies did things like install dive flaps on some WWII
production fighters and did all those high speed dives to investigate
what was going on.
The Spitfire, with its thin wing, was very useful in this research.
Meantime the Germans stuck labels on their aircraft saying do not
exceed this speed, and did wind tunnel research.
Oh yes, the allies did not fly the Me163 as a powered type very much,
it was considered too dangerous.
Post by e***@yahoo.com.auYes, tailless designs may employ angled back wings but this would
incorrectly create the impression of the aircraft having transonic
technology, which is not the case.
If one desires to communicate unambivalantly then such aircraft are
unambigiously referred to as "tailless." I expect you may
appreciate that.
What I appreciate is yet another attempt to over state the German
contribution to aerodynamics.
(snip) a multi page attempt to announce swept wings are what
Eunometric says they are and how the good Germans fit the definition
and the bad allies do not.
Post by e***@yahoo.com.auPost by Geoffrey SinclairThe new one no longer swept wing, but swept wing to take advantage of
mach reducing effects. How nice, presumably in a little while the
definition will have "with jet engines" added as well.
?????
Simple really, I have no doubt that the only way to keep the Ju287
as "the first" is to keep defining things until only it fits.
Post by e***@yahoo.com.auPost by Geoffrey SinclairWhy not just admit the original
claim was wrong, instead of trying to change the definition and adding a
whole lot more "The Germans did it first".
Context is decisive in determining meaning.
Or pre determined conclusions need special rules to support them.
Post by e***@yahoo.com.auThe original poster wanted
to know why the Convair B-36 was not regarded as being "swept
wing". A number of intelligent posters have eruditely answered that.
Like the actual wing sweep angle? Technically it had swept wings.
Post by e***@yahoo.com.auPerhaps you would like to argue that the designers of the B-36 were
attempting to increase mach limit rather than support their engines?
Simple really, swept wings are wings that are swept. If you want to
claim more add the extra definitions.
Post by e***@yahoo.com.auPost by Geoffrey SinclairYou see the Ascender, when fitted with the intended engine was expected
to have a top speed of around 507 mph. Well able to enter the high mach
area of flight.
"Was Expected" to have a speed of 507mph. There is no advantage to
sweepback at this speed.
You know it is amazing for someone to be talking about the Ar234 as
being mach limited in the low to mid 500 mph range, therefore needing
a swept wing, but then to announce it does not matter for another
design in the same speed zone.
Really good. Of course the fact a level speed of 500 mph would
translate into a diving speed even higher is going to be ignored
for a start.
(snip) of yet another list of how bad the competitors would have
been. As if this matters when discussing first flights, and in any
case needs to be put against the known Ju287 problems.
(snip)
Post by e***@yahoo.com.auPost by Geoffrey SinclairSuggestions about swept wing aircraft had been around for quite a while
pre WWII as a way of coping with high speed drag, but of course at a
This is simply not correct and I challenge you to provide a citation to
this seemingly arbitrary claim.
Eunometric missed a German talking about good aerodynamics, there
is a first.
http://en.wikipedia.org/wiki/Swept_wing
See also Professor A Busemann.
(snip)
Post by e***@yahoo.com.auPost by Geoffrey Sinclaircost in low speed handling.
As far as the poor handling: The Me 163 had wing sweep as a way of
achieving a tailless design and short larger diameter fuselage suitable
for rocket fuel tankage. (note how I use the term sweep only after
having established the context of tailless)
In other words having come up with your definition to make the Ju287
the first you are going to keep using it. Thrilling.
Not only that but we have the Me163 as the new wonder aircraft.
Post by e***@yahoo.com.auIt had superb handling: it could NOT be stalled and simply mushed
forward. It could not be spun even if the pilot tried. Tailless
designs with modes sweep actually have excellent handling.
Of course minor things like a landing speed of 115 mph indicate the
problems at low speed. For a machine that was 10% lighter when
empty than the Bf109E.
You could not bale out over 250 mph thanks to the cockpit canopy.
And to quote Eric Brown, "The stall was an abrupt and severe one,
except with the CG in the forward position when it could not be
stalled owing to lack of elevon power. In any other loading configuration
there was no advance warning of a stall other than a sudden silence
accompanied by sloppiness of control. The port wing dropped rapidly,
followed by the nose, and the subsequent spiral dive was steep, but
recovery was straightforward."
"Luftwaffe pilots having all told me that the Komet buffeted badly and
then dropped its nose violently in a "graveyard dive" at Mach 0.84."
Brown does have compliments for the aircraft, I include two bad points
to show the gap between Eunometric and reality.
Post by e***@yahoo.com.auThis contrasts with the Northrop XP-56 and the Curtiss XP-55 where a
lack of groundwork fundamental theoretical and experimental research
produced premature aircraft with severe handling deficiencies.
That's because Dr Alexander Lippisch knew what he was doing BEFORE he
started on the Me 163. This is called 'having technology' and it
is built by a combination of insight, theory and experimentation until
the point is reached that an aircraft can be built with high
confidence.
Once again the list is of claimed allied failures and claimed German
successes.
I have no problems the Germans did more research earlier. I also note
Eunometric is overclaiming what was done.
Post by e***@yahoo.com.auPost by Geoffrey SinclairAs for the allies "not having an inkling" this also ignores the fact the
allies
were the only ones doing high mach trials with real aircraft. The Germans
were doing more experiments in wind tunnels.
Yes there were super pilots doing dive recovery research.
So now we have the allied pilots are super, and now we have a lot of
junk about how it did not matter for the Germans.
Post by e***@yahoo.com.auProbably
because the lack of all moving tailplanes for trimming as in the (Me
109F+, FW 190 and Me 262)
Ah yes, the Germans had a wonder technology that eradicates the
problem, the "all flying tail" is a post WWII discovery, no more
elevators, however we have a new wrinkle "for trimming" which is
supposed to be significant.
Post by e***@yahoo.com.aumade dive recovery so much more difficult and
neccesitated dive recovery flaps,
You know the Spitfire pilots worked out diving when close to the
ground with a Bf109 on your tail stood a good chance of the Bf109
being unable to pull out in time.
Post by e***@yahoo.com.auprobably because the allies didn't
know anything about the possibility of swept wings so they persisted in
improving what they had while the Germans had recognised this direction
to be less likely to bear fruit and focused their visions elsewhere.
You see the allies are stupid, the Germans gifted. Ignore the dive
flaps were an idea fitted to P-38s in late 1943 for example. Or the
problems Bf109s had in pulling out of dives compared with Spitfires.
Ignore the implied idea the average fighter could be retrofitted with
swept wings. After all just how many JU287s did fly and how many
flights?
No, instead of admitting the allies came up with a practical solution
tell us all the Germans had a better one that they never used.
Post by e***@yahoo.com.auIncidently even then the P51D has a poor dive speed due to its bubble
canopy.
Another claimed allied failure, of course this had to do with the cutting
down of the rear fuselage and was largely fixed by a kit extending the
tail.
(snip)
Post by e***@yahoo.com.auPost by Geoffrey SinclairI note the failure to note the specification for the Ascender included low
drag.
That doesn't mean swept wing: it means clean fuselage,wings and
surfaces.
Yes folks, the Ascender is not allowed to have a swept wing for the
drag abilities, that causes the Ju287 to look bad again.
Post by e***@yahoo.com.auPost by Geoffrey SinclairSee folks, the idea is to try and pretend the fact it had a swept wing does
not matter, it was for the "wrong" reasons. Anything to have the Ju287
the first, it was German.
The derisorily named XP-55 (Ass Ender) or Ascender had few of the
techniques needed to actually make a swept wing feasible. The Ju 287
however did.
As I stated, it has to be for the "right reasons", and yes, the XP-55
needs a derogatory name put in as well, it is allied.
Post by e***@yahoo.com.auNor would the Ascenders angled back wings have reduced
The shockwave delaying effects of sweep are given by cos(angle of
sweep). Along with this comes a reduction of lift of cos(angle of
sweep). At subsonic speeds swept wings must therefor be enlarged to
maintain the same coefficient of lift and this increases drag. There
is no net gain unless speeds close to 600mph are involved and then only
because wave drag is delayed.
If there are no net gains until 600 mph what exactly does the Ar234
at 530 to 550 mph benefit from swept wings?
Ah yes, the Ar234 is German, it benefits, the Ascender is allied, it does
not. Simple rule.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auIt had appalling handling and spin stall stability even after
modification. (Perhaps these were related to the inability of the
NACA and Curtiss to recognise the poor characteristics of swept wings)
Ah yes, now the design was bad, and yes, with no evidence we will
have the assumption that the relevant Americans did not know the
characteristics. They are not Germans, so assume bad things.
Your rhetoric astounds me and is uncalled for.
No it is quite simple, Eunometric knows something about WWII aircraft,
but has lots of gaps and incorrect understandings, filled in with German
good allied bad.
When trying to hand the Trans Atlantic flight record to a German
aircraft, we had such gems as a flight to Bermuda being the German's
and when told about the B-29 Atlantic crossings (as part of the
deployments to India) the reply came,
"If a B-29 tried to cross the atlantic there would be an unacceptable
risk its engines catching fire due to issues eminating from lack of
fuel injection and burning through the main spar."
Simple really.
Post by e***@yahoo.com.auThe NACA did superb
work however it is simply a fact that they missed the boat on swept
wing technology though they made up with it with gusto after the war.
This rather ignores the research done during the war, missing the boat
is defined as being behind some of the German work.
Post by e***@yahoo.com.auLike it or not the Germans did not miss the boat in the case of swept
wing research.
Like it or not the Germans missed the boat on swept wing aircraft.
Post by e***@yahoo.com.auThe Germans missed the boat on the multi-cavity magnetron (for which
they had patents dating to 1935) until they reactivated work belatedly
in 1942/43.
The "patents" idea is of course an attempt to overclaim what the
Germans did and thought.
Post by e***@yahoo.com.auYou seem to have the assumption that no German can come up with a good
idea and then develop it in a coherent manner: there is apparently
always someone in the USA or UK that had the idea first only in a more
practicable though non existent form.
You seem to have the assumption that no non German can come up with
a good idea and then develop it in a coherent manner: there is apparently
always someone in Germany that had the idea first.
I can live with the fact the Germans did pioneering research in high
mach flight areas, I can live with the fact the Ju287 was built to take
advantage of some of the results. I can also live with the fact it was
not the first swept wing aircraft.
Post by e***@yahoo.com.auThe American 'swept wing' designs were abandoned for various
reasons but all related to the incompetent application of "sweep",
it did not seem that they could be fixed or that they offered any
advantage and they were therefore abandoned. That seems to have been
the end of so called US swept wing research (really tailless research)
until Robert Jones produced his brief 'technical note' from a
completely different direction 1 month before the end of the war.
Note also these American aircraft, XP-55, XP-56 were not research
aircraft but attempts at producing production aircraft.
So in other words the Ju87 was going nowhere?
Post by e***@yahoo.com.auYou have
criticised and derided the German research and development of theory
No, criticised and derided the person overclaiming what it did.
The Germans did discover some things first.
Post by e***@yahoo.com.aubut by contrast the Germans prudently studied the mach problem to
develop insight; they built gliders, large scale wind tunnel models,
did design studies and did extensive wind tunnel research that showed
them to problems of tailless designs or swept wing designs and the
folly of attempting them without proper understanding or proper
solutions.
And the reality is you need to do real world testing to see if the
designs really do work.
You need both.
You also have to cope with the fact others did work.
Post by e***@yahoo.com.auWhen attempting a pusher aircraft they built test vehicles first. Note
http://www.luft46.com/prototyp/go9.html
There were thus no handling issues in the Dornier Do 335.
I know this is really silly but pusher aircraft were around in WWI.
Pusher does not equal swept wing.
Post by e***@yahoo.com.auPost by Geoffrey SinclairMeantime simply ignore the problems the Ju287 had, like the wings
flexing and what that did.
Ignore the fact that the Ju 287 V1 was a RESEARCH aircraft built
specifically to explore those issues.
However the other types that had swept wings will be classified in a
less generous manner.
Post by e***@yahoo.com.auIgnore that this was not a
prototype but a TESTBED.
You know I wonder how many times I have to tell people it was the
first to take advantage of the high speed research.
Post by e***@yahoo.com.auIgnore the fact that the data gathered (such
as frequencies of vibration, points of flexture etc) would have been
analysed by the matrix methods that the Germans had developed to solve
differential equations and the appropriate adjustment of stiffness in
the appropriate areas would have been attempted.
Yes the Germans would have again solved all the problems, all by
themselves.
You know disasters like the Me210 simply did not happen to the Germans.
They keep solving the problems.
Post by e***@yahoo.com.auIgnore the fact that
the aircraft relied on an unbroken two spar wingbox to provide the
required torsional rigidity and that it damped flutter by suspending
its engines of pods somewhat as a pendulum with a mass would reduce
frequency of vibration, ignore the fact that several forward swept
aircraft have been built and ALL have been a technical success and that
they are aerodynamically superior at both low subsonic speed and up to
Mach 1.6.
In other words ignore any problems with the Ju287 by admiring the
wing structure and the success of other types with a similar layout.
You know the Me210 was a wonder aircraft, look at the Bf110.
Post by e***@yahoo.com.auIt is merely a matter of using a two spar wing with a wing box of
unbroken upper and lower skins: in the Ju 287 this was achieved by
having the engines suspended in pods from beams as is the modern
practice. The main restriction is that engines must be suspended from
pods, which is actually an aerodynamic and structural advantage and
that the undercarriage can not retract into the wing to avoid
If the Ju287 did something and it is still done today, highlight the
fact. Ignore the inevitable problems with fuselage mounted
undercarriage, the narrow track.
Minor things like the way the aircraft needed rocket boost for take off.
More important things like the elasticity of the wing. The way a yaw
started to turn into a roll, the way high speed turns tightened, the
effects of a gust of wind.
The Germans managed to get the aircraft to around 404 mph in a dive,
not bad given the undercarriage.
Post by e***@yahoo.com.auPost by Geoffrey SinclairNot to mention the fixed undercarriage which
rather limited high mach flight. There was only one Ju287 flown during
WWII, starting from August 1944, the flight trials were rather curtailed
by bomb damage to the aircraft and the general situation.
And it first flew well after the Ascender.
Irrelevant.
No, it is quite relevant when we are discussing the first swept
wing designs to fly.
Not the first jet propelled ones, not the ones that were built as
the result of studies on swept wings.
Post by e***@yahoo.com.auAscender was irrevocably a subsonic not transonic design
devoid of any hope of transonic performance or even good low speed
handling.
In other words the "competition" to the Ju287 have to have even
more conditions put on them.
Post by e***@yahoo.com.auThe Ju 287 had a He 177 fuselage, a Ju 188 tail and a B-24
Liberator undercarriage. It was built as a testbed. Those were the
materials that were available.
And this has what to do with which swept wing design flew when?
Also note the Ju287 had an adapted He177 fuselage, some Ju388
tail components, Ju352 mainwheels and B-24 nose wheels.
Note the big, speed killing, spats on the undercarriage.
Post by e***@yahoo.com.auThe Ju 287 didn't spontaneously flip over and go into a spin as the
ascender did, at least it warned of an impending stall. Its forward
sweep was designed to eliminate tip stall rather than aggravate it.
All this in an attempt to have the Ju287 the first swept wing
aircraft.
Post by e***@yahoo.com.auThe Ju 287 V3 would have had a completely different Ju 388 based
fueselage and of course retractable undercarriage.
Note the V1 was the only one to have flown during WWII.
Yet again the Germans were going to and yet again something that
never flew is being used as the proof.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auIn January 1945, Robert T. Jones, a NACA aeronautical scientist,
formulated a swept-back-wing concept to overcome shockwave effects at
critical Mach numbers. He verified it in wind-tunnel experiments in
March and issued a technical note in June. ( I believe he was
performing radio telemetry drops from bombers perhaps as early as
1944.)
In other words independent of any German wartime research.
Only 6 years behind the Germans though and 5 years ahead of the US.
Jones's data was insufficient to design a trouble free aircraft. It
was a preliminary call to further research.
Yes folks, never admit non Germans actually came up with good ideas
independently, the Germans did it all first and better. Oh yes, if Jones
is 6 years behind the Germans then the ideas of swept wings were
around pre WWII. If the Germans were doing wind tunnel tests the
equivalent of Jones in early 1939, based on various ideas, the ideas
were pre WWII.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auBy that time the Germans had thousands of hours of data from high speed
wind tunnel research giving lift coefficients, drag coefficients,
moments and pitch changes at various mach and various sweep.
Try more theoretical research than the allies but less practical
Research. And try and produce a reference about the amount
of research done.
The US and UK had neither practical nor theoretical research at the
time.
You know it seems all those high speed dives by allied fighters and
the associated work that produced things like dive flaps are going
to be ignored.
You know, practical research, using the various allied fighter types
to see what was going on.
Post by e***@yahoo.com.auAs for ME producing a reference: try and put you actions where you
mouth is and produce one that there was anyone in the UK or US
contemplating using wing sweep to reduce mach problems or drag.
Robert Jones?
Post by e***@yahoo.com.auI at
least provide names that anyone competent in using a search engine can
check up on.
Actually Eunometric gives various names and spellings of what are
probably supposed to be the same name.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auTheodore von Karmen estimated that there was research that would take
two years for the US to accumulate.
Sigh, as usual we end up with estimates.
Theodore von Karmen was one of the worlds foremost aerodynamicists of
the century; He headed US aeronautical research at the time. He would
know.
Assuming he has been quoited correctly for example.
Post by e***@yahoo.com.auI'll take his expert estimates as authoritative over your assertions
and rhetorics.
This is known. The key here is to note Eunometric changes my
facts into assertions and questions into rhetorics.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auThe Germans were well aware of issues such as spanwise flow (which
produced nasty low speed characteristics) and hence proposed the
following solutions: aircraft with forward swept wings, or W wings
(only 1/3 wing tips swept forward the rest rearward),
See the Vultee XP-55 for a tentative start at W wings, first flight
in January 1943.
It's actually the Consolidate Vultee XP-54 swoose goose you refer to
and it has NO discernable sweep at all!
Check out the inner wings, between the engine and fuselage.
And it was the XP-54, a typo on my part. It was also a Vultee
design, the company was taken over in 1943.
Post by e***@yahoo.com.auIt has corsair/stuka like gull
wings and radiators that extend forward in a slight sweep on the inner
quarter of the wing at the roots that create the illusion of some
degree of sweep from some angles: in any case the cosine law shows that
a tiny sweep has no advantage.
Yes folks, when caught with another allied design that was playing
around with various wing forms, announce it does not matter when
the allies did it.
Post by e***@yahoo.com.auPost by Geoffrey SinclairBy the way seen the Boulton and Paul P100 design, for a low altitude
fighter from 1942, canard configuration with a swept wing? With the
vertical surfaces at the wing tips?
Mild wing sweep solely for C of G or stability reasons simply doesn't
count as swept wing technology'.
Eunometric definition applies, otherwise the Ju287 is not the first
swept wing aircraft.
Post by e***@yahoo.com.auThe knowledge of 3 dimensional
swept wing flows means that any of these aircraft would have likely
been failures if they had high angles of sweep.
In other words folks without seeing the designs Eunometric will
write them off. Meantime German designs that never flew are
assumed to work well.
Post by e***@yahoo.com.auPlacing the vertical surfaces at the wing tips would also have been
inefficacious: placing them half way along might have made them act as
fences against spanwise flow.
Of course you see the allies would always be unable to learn from
test flights and maybe reconfigure things.
Basically find a reason why the allies would be wrong, find a reason
why the Germans would be right.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auin flight swing
wings as in the F-111 and Tornado (Messerschmitt P1101/101 and
P1101/103 and some Blohm and Voss designs.). High lift devices such
as the leading edge slat (the standard device used today)
You mean the ones by Handley Page?
Yes Handley Page invented the automatic leading edge slat and traded
the patent with Messerschmitt for his method of constructing wings in
the 1920s.
So far so good.
Post by e***@yahoo.com.auHandely Page did not invent the fixed leading edge slat or
slot (eg Me163) or the slat that is deployed by hydraulic forces.
Let me understand this the idea is Handley Page invented the moving
slat, but the fixed slat, effectively a subset of the moving one is
supposed to have been invented by others.
Post by e***@yahoo.com.auNo
one bar the Germans put much emphasis on slats during WW2 and the
complicated mechanisms needed to make them work.
About this time comes the idea no one bar the allies put much
emphasis on high speed flight and the complicated mechanisms
to make it work post WWII.
I know but yet again with an "allied" invention the Germans are
given lots of contributions to the idea. Meantime the allies
are assumed to simply take ready to go German ideas.
Post by e***@yahoo.com.auInterest in leading
edge devices increased due to the need to provide high lift for the
swept wings reduced efficiency and to compensate for the pitch changes
of high lift trailing edge devices on low aspect ratio wings.
Anyone able to decode the above sentence?
(snip)
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auThey proposed crescent wings and biconvex wings. (Double delta style)
to deal with spanwise flow at low speed. Alexander Lippisch had found
that a delta could deal with spanwise flow due to its short span and
the generation of vertices at the roots that re-energised the flow of
the whole wing.
You see the trouble is the various theoretical ideas had to be tried
and fixed in the real world, and the "Germans did it first claims" are
the usual exaggerations. Rather like saying the US flew the first
powered aircraft therefore everyone else were followers. And ignoring
others had the same ideas at different times.
The DM-1, a delta wing glider built to research handling showed
stability from low speed to mach 2.6.
A glider doing mach 2.6?
Post by e***@yahoo.com.auPost by Geoffrey SinclairBy the way note the Ju287 has gone missing for the moment.
Where did you put it?
I presume it had to be removed in order to keep the Eunometric
claims from seeing the truth.
Post by e***@yahoo.com.auThat's nothing but rhetoric.
No it is just the observation the Ju287 had to go missing in order
to make the latest "Germans first" claim.
Post by e***@yahoo.com.auIt's simply a fact that the Germans had understood the advantages of
swept wings and also developed an understanding of their flaws and
methods that might be used to overcome these flaws.
The Germans had done more theoretical research and were moving in
1944/45 into trying out designs.
Post by e***@yahoo.com.auUntil jet engines
were available that could push aircraft to over 560mph there was no
reason to built them but every reason to avoid them due to their
difficulties?
Alternatively the new wing shapes came with multiple problems which
took time to solve, and there are plenty of examples where the theory
has been shown to be wrong. Given the multiple problems that did
interact with each other it took time to figure things out.
No one knew how fast the jets could go until the trials mid war.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auDietmar Kuechmann had developed an area rule like effect with his 'flow
matching' methods' and theories to reduce transonic drag and reduce
spanwise flow by 'waiting' a fuselage
So far the only reference to this claim is the eunometric making it once
before. With a different first name for the man.
The Kuechmann coke bottle and Kuechmann Carrots are well known in
aeronautics. They can be seen on the Handley Page Victor. Try those
terms in a search engine. I've had several hits. You might use the
term "whitcombe" as a filter or note that Kuechmann might be
spelled as Küchemann.
Try Wikipedia under area rule and follow the link to Küchemann.
http://www.answers.com/topic/whitcomb-area-rule
http://www.aerospaceweb.org/question/aerodynamics/q0240.shtml.
http://www.luft46.com/fw/fw1000a.html
His names also comes up for his contributions to Concorde.
Thanks for a better reference.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auAt Heinkel it had been noticed
that staggering the engines of the Heinkel P.1073 which involved a
ventral and dorsal jet engine reduced drag and were aware of what would
later become formulated as the "Whitecomb Area Rule"
The Heinkel P.1073 never flew of course as a twin engined design, it
did become the He162.
P.1073 was wind tunnel tested and it was noted that the relative
positioning of the ventral and dorsal engines effected wave drag. If
staggered there was a significant reduction in wave drag. The effect
became properly formulated latter as the Whitecombe area rule.
This is what is significant about P.1073.
Kuechmann also came across the effect. It was a fact well
distributed in German aeronautical fields and any late war aircraft
proposal that ignored it could expect criticism from the evaluating
committee.
I will wait for other references before accepting the above claims.
Post by e***@yahoo.com.auPost by Geoffrey SinclairThe Germans did it first, well sort of, well they thought of it first, well
sort of and so on.
The Germans were definitely the first in the case of swept wing
technology.
All you need to do is add for high speed flight.
Post by e***@yahoo.com.auIt might be tragically upsetting but it is unfortunately the provable
reality.
It might be tragically upsetting but unfortunately swept wing aircraft
were around before the German types.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auPost by Geoffrey SinclairSee also the lightweight proof of concept model Curtiss built which
first flew in December 1941. There were various other designs with
swept wings as well.
Non were swept to specifically delay shockwave formation and non would
have I suspect any of the other characteristics of high speed swept
wings: relatively thin sections, a tendency towards symmetry.
Yes folks, the Germans were first, even when they were second, just keep
redefining the problem until the Germans are first.
There were dozens of German aircraft that had wing sweep in the 1920s
by Lippisch and the Hortons for instance.
Ah yes, and I am accused of being wrong when I point out the idea
was around in the 1930's.
Going to now mention the other nationalities who did similar work?
Post by e***@yahoo.com.auIf I were taking the same
bizarre posture I could claim that this Storch 4 glider was a swept
wing design
http://www.nurflugel.com/Nurflugel/Lippisch_Nurflugels/lippisch_nurflugels.html
Offcourse these were tailless designs or aircraft that had their wings
angled back for stability reasons.
Yes "Swept Wings for Right Reasons" all together now.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auA Russian, V Stroominsky had carried on with research into swept wings
in the early
1940s so even the Russians were ahead (but not enough to be caught out
on the MiG 15)
So the Germans were not first, the Russians were first when it comes to
the design research.
Their research was no where near as developed and again lagged by
several years.
You see folks, the idea in all this Germans first idea is to keep
defining the problem until only the Germans fit.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auPost by Geoffrey SinclairThe Ju287 was not the first swept wing aircraft by a long margin.
The Ju 287 was the first research aircraft specifically built to explore
not only the shockwave formation delaying effects of swept wing
aircraft but to explore the flutter and low speed characteristics of
swept wing technology.
In other words the Ju287 was not the first swept wing aircraft to fly.
And having a fixed undercarriage did not help high speed trials.
The Ju 287 was definetly the first swept wing technology aircraft.
So not the first swept wing aircraft.
Post by e***@yahoo.com.auThe first Ju 287 was naturally to explore primarily the low to medium
speed characteristics of the wings: this was where all of the problems
were to be expected. High speed data could be obtained in a dive.
Which of course was limited thanks to a fixed undercarriage. Unless
400 mph is considered high speed?
Post by e***@yahoo.com.auThe aircraft used a Liberator undercarriage as an interim measure. If
you knew more about aircraft engineering you would appreciate that
developing an undercarriage can take as much time as the rest of the
aircraft.
Apparently this is some sort of important point, rather than actually
admitting the Ju287 as flown, was a medium to low speed aircraft,
as can be seen by the fixed undercarriage. Why is this important?
Well the claim is the Germans were first to explore the high speed
effects of wing sweep, except the Ju287 was not high speed. Hence
the need to throw in what I may or may not know about undercarriages.
Post by e***@yahoo.com.auPost by Geoffrey SinclairNow change the definition so it was the first, somehow.
Can you in all seriousness claim that the B-36, XP-55 or even XP-56
utilised 'swept wing technology'.
Easily, look at the wing sweep on them and decide.
Now tell us all how the Ju287 was the first for the right reasons.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auAll other swept wing aircraft prior to this used the sweep only for
stability, C of G or control reasons.
In other words the Ju287 was not the first swept wing aircraft to fly.
Which was the original claim.
The claim may have been "swept wing" but this clearly refers to a
Why note give the name, Scott Kozel, and note the following is all a
copy of that text?
Post by e***@yahoo.com.auThe generally recognized definition of "swept wings" would include a
sharp enough sweep to solve the aerodynamic compressibility and drag
problems that occur in the transonic speed range.
Sorry, I disagree.
Post by e***@yahoo.com.au'Transonic' is an
aeronautics term referring to a range of velocities just below and above
the speed of sound (about Mach 0.8 - 1.3). Mach 0.8 is at about 580
mph. The degree of wing sweep needed for that aerodynamic regime would
be an average wing planform sweep of at least 30 degrees, and some
aircraft have a wing sweep of 40 degrees or more. The B-52 wings look
like they have about a 45 degree sweep (the exact design figures for
these aircraft exist but I am not going to dig them up now).
Want to measure the sweep of the Ju287's wings?
Post by e***@yahoo.com.auWikipedia has an accurate definition of "swept wings", and IMO it
excludes the B-36 and XB-35 designs and the sub-sonic aerodynamic
regimes that they were designed to operate in.
Wikipedia definition of "swept wings" --
"A swept-wing is a wing planform used on high-speed aircraft that spend
a considerable portion of their flight time in the transonic speed
range.
The above is as used today. And high speed in 1945 was the low
500 mph mark.
Post by e***@yahoo.com.auSimply put, a swept-wing is a wing that is bent back at some
angle, instead of sticking straight out from the fuselage.
Lots of these around starting from the early days of flight.
Post by e***@yahoo.com.auThey were
initially used only on fighter aircraft, but have since become almost
universal on all jets, including airliners and business jets. As an
aircraft approaches the speed of sound, an effect known as wave drag
starts to appear. This happens because the air which would normally
follow a streamline around the aircraft no longer has time to 'know'
about the approaching object and simply hits it directly. This results
in greatly increased drag".
This is an explanation of why they are used today.
To repeat myself,
"With that blasted to pieces the new claim is substituted, it was the
first swept wing for high mach performance.
It just had a fixed undercarriage to help it go fast I presume."
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auThe fastest jet of the war was the Ar 234C with 4 x BMW003 engines.
At 566mph it could excede its mach limit in level flight and clearly
needed a swept wing.
The Arado 234C-3 top speed was around 530 mph, the B-2 version top
speed was around 461 mph.
For the Ar 234A recon version it was 482mph. The Ar 234B dispensed
with the sled/skid undercarriage and therefore resorted to widening the
fuselage about 1.5 inches to recover fuel tankage.
Remarkable how 1.5 inches are supposed to clip so much speed off, add
the extra weight carried.
Study more aerodynamics and consider wave drag.
Eunometric often finds when quoting aerodynamics claims in the
aviation news groups that a correction is made by those who
actually do the work.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auA variety of speeds are given for the Ar 234 C-3 in various sources.
The aircraft was Mach limited not thrust limited and maximum speed was
extremely temperature, pressure sensitive.
The reality is the top speed of the early jets in particular depend on air
temperature, so it differs between winter and summer.
As for thrust limited this comes back to the airframe, since there is always
the speed built up in a dive. Many later WWII fighters were thrust limited,
check out what they did in a dive.
Post by e***@yahoo.com.auFlutter commenced as low as
528mph in some circumstances for the prototypes.
Which is a build quality and airframe issue.
Balancing issue.
Ah how nice, just balancing what?
To repeat myself,
Given the German aircraft industry quality in 1945 top speeds found in
lovingly cared for test aircraft are very much different to the average
speed in squadron service.
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auFor the Ar 234C-3
Eddie Creek and Richard Smith in their book on the Ar 234 give 542mph
as the speed for the Ar 234C-3 and 547 mph for the Ar 234C-4 ( a
cleaned up recon version apart from a ventral camera pack that did fly).
Rudiger Kosin, the designer, used 554 mph as the speed of a 'clean'
234C airframe from which speeds were subtracted as external equipment
was added.
In other words we have a theoretical top speed at an unknown
altitude assumed by the designer.
That is the clean airspeed in a configuration not used because it is
not fitted out to be of any military value.
In other words a prototype test run, with the top speed assumed to
be correct. And well above the service speed. see just about every
other aircraft in mass production performance in service versus
prototypes and test versions.
Post by e***@yahoo.com.auPost by Geoffrey SinclairIn that case the Ascender had a top speed of around 507 mph. Isn't
theory wonderful.
The XP-55 had no hope of ever getting within 27% of that wishfull top
speed.
Not the point. Depart from reality for one and you can depart from
reality for all.
Post by e***@yahoo.com.auThe Ar 234 on the other hand operated consistently within 3% of
its 554mph limit..
Ah so the new claim is a top speed of around 540 mph, for one of the
versions. Versus the lower speeds quoted by other references.
Post by e***@yahoo.com.auCan you see how individual Arado 234s in the right
conditions might actually get there? It would take a 1.27^3 = 95%
increase in power for the XP-55 Ascender to achieve that or an
substantial increase in altitude with the same power.
1.27 cubed comes to 2.05.
Post by e***@yahoo.com.auThe Ar 234C needed only a 1.03^2 = 6% increases in thrust, something
that could occur due to good atmospheric conditions or well tuned
engines.
1.03 cubed comes to 1.09.
Now to move 20 mph faster than 530 mph is an increase of around 3.8%
To move 43 mph faster than 507 mph is an extra 8.5%.
Want to explain the above calculations?
Post by e***@yahoo.com.auPost by Geoffrey SinclairPost by e***@yahoo.com.auA crescent wing and swept tail was being fitted to the Ar 234 V16 to
increase Mach limit.
As usual with the Germans did it first claims, again we have something that
never flew.
The data was taken to Farnborough and assessed. Rudiger Kosin and
colleagues had formulated the crescent wing in early 1944. The wing
was under construction, well photographed but destroyed by British
troops who had no idea of what they were destroying.
Godfrey Lee and Reginald Stafford of Handley Page studied the wings in
Germany under the UK Fedden mission and returned to Britian full of
praise for the wings.
So the idea is the wings were studied before they were destroyed I gather.
You mean the fact it never flew on the Ar234?
You mean the fact the Arado had a wing span of around 46 feet and the
early HP Victor 110 feet. You mean the proof of concept aircraft the
HP 88 first flown in 1951 which broke up in the air after 14 hours of
flying? It was a 40% scale model. The Victor first flew in 1956, 8 years
after being ordered.
Simple really, the Germans thought of the idea and that is enough, ignore
any later research or efforts.
Da Vinci invented flight if you believe those that built his design
recently. Everyone else is a follower sort of idea, or substitute the US
thanks to the Wright brothers.
Geoffrey Sinclair
Remove the nb for email.