Ryan "Rogallo wing" concepts

[RanulfC]

I had never seen the air-mobile container in the first post in this thread, but I had something very similar in mind. I was searching SPF for information on flexible wings to flesh out a concept for a rugged, low-speed utility aircraft small enough to fit in an ISO 20' shipping container. Does anyone know of any good resources on the design of flexible wings? I am particularly interested in the combination of the flexible wing with more more conventional aerodynamic control surfaces rather than weight-shift control of hang gliders and microlight trikes. Thanks!

Let me do some checking around but I seem to recall a series of patents on ISO container delivery by air that had several "flexible" wing designs. One thing to note though is that Rogallo himself studied dozens of "other" methods to control his wings in flight OTHER than the mass-shift or wing-angle ones.

Randy

 

[circle-5]

A rare photo, showing Neil Armstrong was the NASA test pilot for this classified project.

 

[robunos]

............ ;D

cheers,
Robin.

 

[ChuckAnderson]

Hi Everyone!

This is a little off topic, but I have a para-wing kite built and autographed Francis Rogallo.
(It flies great too!)

Chuck

 

[Grey Havoc]

http://www.dtic.mil/dtic/tr/fulltext/u2/461202.pdf

 

[robunos]

Thanks.......... ;D

cheers,
Robin.

 

[robunos]

Posted on OBB's blog here :-

http://up-ship.com/blog/?p=24373

A Ryan concept for a Flex-Wing Equipped flying boat. Further discussion at the above link.

Cheers,
Robin.

 

[Grey Havoc]

I'd wager a guess it was primarily intended as a general Liaison and Communications type for what was then U.S. Army Alaska (USARAL). A runabout for keeping in contact with isolated outposts and the like, in other words.

 

[Grey Havoc]

I'm now also wondering if it was possibly additionally linked to some Project Washtub follow-on (but under the Army this time).

 

[circle-5]

Ryan encouraged everybody to put flex-wings on everything...
(from the San Diego Air & Space Museum archive)

 

[Jemiba]

Looks, as if it was meant for improving take-off performance. There's no tail hook visible.
Otherwise it reminds me on this old cartoon by the German cartoonist Gerd Bauer :

 

[steelpillow]

It does not seem widely known that the British pioneer J. W. Dunne patented the Rogallo wing in 1909 - See UK Patent No. 8118 of 1909 (GB190908118A), Fig. 5.

Maintenance page: http://worldwide.espacenet.com/publicationDetails/biblio?FT=D&date=19100331&DB=worldwide.espacenet.com&locale=en_EP&CC=GB&NR=190908118A&KC=A&ND=5

PDF download: http://worldwide.espacenet.com/espacenetDocument.pdf?ND=5&flavour=trueFull&locale=en_EP&FT=D&date=19100331&CC=GB&NR=190908118A&KC=A&popup=true

The text of the patent shows a full understanding of how its conical surface provides inherent stability. Indeed, such stable cones were the core of the patent. The Rogallo design is merely one variant of the Dunne wing.

 

[The Artist]

Here are some pictures of a Ryan PDG display model that came into the Greater St Louis Air & Space Museum this past weekend.

 

[steelpillow]

It does not seem widely known that the British pioneer J. W. Dunne patented the Rogallo wing in 1909 - See UK Patent No. 8118 of 1909 (GB190908118A), Fig. 5.

Maintenance page: http://worldwide.espacenet.com/publicationDetails/biblio?FT=D&date=19100331&DB=worldwide.espacenet.com&locale=en_EP&CC=GB&NR=190908118A&KC=A&ND=5

PDF download: http://worldwide.espacenet.com/espacenetDocument.pdf?ND=5&flavour=trueFull&locale=en_EP&FT=D&date=19100331&CC=GB&NR=190908118A&KC=A&popup=true

The text of the patent shows a full understanding of how its conical surface provides inherent stability. Indeed, such stable cones were the core of the patent. The Rogallo design is merely one variant of the Dunne wing.

And in the National Aerospace Library archives at Farnborough I recently found correspondence between Dunne and Lord Rayleigh which unequivocally pushes back his date of discovery to 1905, when he sent Rayleigh a model (though in one letter he claimed he had actually discovered it in 1904 but not told Rayleigh until the next year). Rayleigh commented that "it behaves very well". No copies or photos allowed, so if you doubt it you'll have to go visit too,

Five years later Dunne sought confirmation from Rayleigh that the model had indeed been of this form - including an unmistakable sketch of the wing - and Rayleigh duly obliged. There had evidently been some little tiff at the Aeronautical Society and Dunne was anxious to establish his primacy. One has to wonder, who else had just discovered it too and thought they were first? Mr. & Mrs. Rogallo, get on that third pedestal down and like it!

 

[Stargazer]

One has to wonder, who else had just discovered it too and thought they were first? Mr. & Mrs. Rogallo, get on that third pedestal down and like it!

Oh wow... Cool find. Another case of someone unjustly getting the merits and his name all over something they didn't quite invent... Thanks for the info!

 

[steelpillow]

One has to wonder, who else had just discovered it too and thought they were first? Mr. & Mrs. Rogallo, get on that third pedestal down and like it!

Oh wow... Cool find. Another case of someone unjustly getting the merits and his name all over something they didn't quite invent... Thanks for the info!

They probably did re-invent it -- unless they took a sneaky look at Figs. 3, 4 and 5 of Dunne's US Patent 1,003,721 filed in 1910, found that it had lapsed and kept quiet about it. And they can be given credit for realising it could be made flexible and shaped by wind pressure. I guess they deserve their bronze medal for that.

 

[joncarrfarrelly]

One has to wonder, who else had just discovered it too and thought they were first? Mr. & Mrs. Rogallo, get on that third pedestal down and like it!

Oh wow... Cool find. Another case of someone unjustly getting the merits and his name all over something they didn't quite invent... Thanks for the info!

Ummm, no. Read the Rogallo's original kite patents and you'll get that it was the 'flexible' nature they originally invented/patented in 1948. The first was diamond-shaped, the second bird-shaped. They didn't patent or make
cliams to have invented a half-conical wing.

The similarity of the triangular version to the Dunne half-conical wing is coincidental.

http://www.google.com/patents/US2546078

http://www.google.com/patents/US2751172

https://www.google.com/patents/US3185412

 

[steelpillow]

Ummm, no.

So, if the "Rogallo" type is not even a double-cone, then why does everybody call such wings "Rogallo" wings? Why is this thread not titled "Ryan 'Dunne wing' concepts"? Who does deserve knocking off even the bottom pedestal for starting the misnomer?

 

[joncarrfarrelly]

Why does anybody need to be knocked off anything?

As to naming, may as well ask why Brits call all vacuum cleaners Hoovers. :

Seems though that you're still confusing any conical wing form with Rogallo's flexible wing,
which is correctly called a Rogallo wing and is the form used by Ryan in a number of designs,
which BTW, is the actual subject of this thread. Go figure.

Having just read the Dunne patent I have to wonder if folks are misreading the patent and misinterpreting the
drawings, the figures quoted in previous posts are not drawings of a half-cone wing, they are of a triangular
wing, that has the shape of a cone in plan as seen in Fig. 3. Figures 4 and 5 are rear and side elevations
that make it clear that the wing cross-section is not the exaggerated half-cone of the Rogallo, indeed it is
almost flat. Dunne's patent does indeed cover the use of sections of cones (and cylinders) in the creation of a
wing surface, however the wings are not themselves conical.

No Rogallo like half-conical wing shows up in the Dunne patent, but I suppose one could argue that the wing shown
in Figs. 3, 4, and 5 is a form of delta wing. Maybe something to take up with the Lippisch fans.

 

[steelpillow]

let's stay objective here and try to avoid ad hominem tactics. The pedestal bit was just a fun way of saying that some people's assertions don't stack up. But if it upsets people, then I'll apologise for any affront that I may have caused and drop the metaphor.

The Dunne patent covers any swept wing form which uses a conical upper surface to achieve stability in the manner described, by imparting a reduced incidence or wash-out to the outer section. The text of the patent makes this abundantly clear. The double-cone taken up by a Rogallo delta is one such form. Dunne's patent shows a slightly different conical development of the delta (among other planforms). Both - and many others - are covered by the Dunne patent. To help clarify this, may I quote briefly from Dunne's letter to Rayleigh (I took a full transcript by hand): "The principle features of the surface were the acute backward slope of the leading edges on both sides of the centre, which gave the whole surface a dart or triangular shape when viewed in plan, and the rolling down of these edges in such a fashion that each wing formed part of the surface of a cone, the apex of which coincided with the forward apex of the triangular surface...." Note that this is the exact form which defines the "Rogallo" delta shape. That Dunne's subsequent patent drawing depicts a slightly broader application of the principle, as he had refined it over the intervening years, is quite irrelevant.

As you have pointed out, the flexible conical wing is covered by Rogallo's flexible kite patent. But as I have pointed out, it is also covered by Dunne's conical patent. So rightly it should be described as a Dunne-Rogallo (or Rogallo-Dunne?) wing. We can make this extra clear in a list:

• Biconical wing - Dunne conical patent.
• Flexible wing - Rogallo flexible kite patent.
• Flexible biconical wing - Both Dunne and Rogallo patents.

I trust this is clear enough.

Of course, technically the Dunne-Rogallo is a subtype of Rogallo just as it is a subtype of Dunne. I am not disputing that. But even where a biconical wing is stiffened to the point that it is not really flexible any more (maybe even rigidly attached to a fuselage as some ultra-light class of aircraft) people still refer to it as a "Rogallo" delta. But this appears to be incorrect if it is so stiffened and/or rigidly attached that it is no longer a Rogallo patent flexible kite. OTOH it is still a Dunne patent conical delta. This adds a fourth type to our list:

• Stiffened biconical wing - Dunne patent only.

I can still ask why folks still call this last a "Rogallo" when it isn't. OK, this is off-topic as Ryan did not appear to have significantly stiffened any of their biconical deltas, but it seemed silly to spawn a new thread just to ask for a quick clarification in passing. Is it just habit born of ignorance or is there some particular history behind it?

 

[Stargazer]

This thread is getting more and more interesting.

I, too, believed that the "Rogallo wing" denomination pertained to its shape/configuration, while in fact it's all about it being FLEXIBLE !?

Kind of makes sense. But now that I thought they were actually "Dunne wings", it appears it's not that simple after all...

Thanks a lot jcf and steelpillow for these most valuable contributions to the subject.

 

[steelpillow]

The plot thickens.

Had a hunt through some more of the Rogallos' patents and could find only stuff about collapsible fabric wings and their control. Deltas appear only occasionally - and incidentally - in their quest for the flexible and collapsible.

Yet by the 1960s everybody was talking about "Rogallo wings", drawing pictures of collapsible deltas and tumbling over each other in the doorway to the patent office.

Ryan patented an inherently stable delta type of Rogallo-winged airplane on 14 Jul 1964 17 March 1961 [struck date was date of publication - sp]: https://www.google.com/patents/US3140842
It is quite a long and busy document so I am not sure how much of it is novel. But it references an interesting antecedent:

On 15 Feb 1910, Ulysses Grant Lee and William Austin Darrah in the USA patented an inherently stable rigid biconical delta-winged airplane: https://www.google.com/patents/US989786

As already said, Dunne had sent a model to Lord Rayleigh in 1905. And he patented the wing in April 1909 - in the UK. But he didn't file his patent in the US until 1 April 1910, just two weeks after Lee and Darrah - oops! This may explain why Dunne wrote to Rayleigh again in December of 1910 to confirm his own prior art of 1905. And it may also explain why trawling through the web of US patent cross-citations does not reveal the whole story.

 

[Stargazer]

As some little girl once said: "Curiouser and curiouser..."

The plot does thicken indeed, and I love all this detective type investigation about it... Thanks for all this, steelpillow, and keep up the good work!

 

[steelpillow]

Here is a brief timeline of some key events, several new to this discussion:

1948: The Rogallos patent their collapsible diamond kite.

1950s: The Rogallos made and sold their FlexiKites in diamond and maybe hexagonal forms, but not it seems triangular: http://image.slidesharecdn.com/francisrogallosflexikite-140609120022-phpapp01/95/francis-rogallos-flexikite-insights-and-results-15-638.jpg

ca. 1958 Rogallo's work moves to Langley.

17 Mar 1961: Ryan apply for a patent on their "Rogallo" collapsible delta-winged airplane. The name "Rogallo" appears to reference the collapsible kite patent.

29 October 1961: The journal Flight first mentions Rogallo (page 651), in connection with an unspecified parglider wing for spacecraft reentry.
http://www.flightglobal.com/pdfarchive/view/1961/1961 - 1547.html

19 April 1962: Flight's first identification of a delta type as a Rogallo appears on p600, with a photo of a test model of a reentry design. http://www.flightglobal.com/pdfarchive/view/1962/1962%20-%200600.html

29 Apr 29 1963: Rogallo, still at Langley, applied for a patent on collapsible wings for reentry vehicles. It describes several forms, one of which happens to be a delta and is basically the design seen being tested in the Flight photograph.

David Pelham's "Penguin Book of Kites", 1976, page 81 shows a photo of Rogallo at Langley, surrounded by collapsible deltas and similar, but the photo is undated. It might have been taken before or after the Ryan work.

None of which yet justifies the common claim along the lines of; "The paraglider, or "Rogallo Wing", invented by Francis M. Rogallo in the late 1940s, used flexible fabric airfoils arranged in a V-shape." http://www.globalsecurity.org/military/systems/aircraft/rogallo-wing.htm

The collapsible delta appears in a Ryan patent two years before Rogallo's. But is that the last word?

 

[Mark Nankivil]

Good Day All -

Two bits of Ryan artwork I found in the Parks Air College Collection at the St. Louis University library.

Enjoy the Day ! Mark

 

[Stargazer]

Nice pics, thanks.

The sheer amount of work and energy that Teledyne Ryan deployed into all the Flex Wing programs is phenomenal: ACG, PDG, TUG, Flex Bee, Tow Bee, Fleep... you name it. They even planned to retrieve the Saturn boosters with Rogallo-type Flex Wings... And then, the whole thing was no more, as some kind of summer dance fad that suddenly goes out of fashion as suddenly as it came. It seems to me that it was a cheap and flexible (no pun intended) way of doing things. Was there a hidden vice to them?

 

[steelpillow]

And then, the whole thing was no more, as some kind of summer dance fad that suddenly goes out of fashion as suddenly as it came. It seems to me that it was a cheap and flexible (no pun intended) way of doing things. Was there a hidden vice to them?

It was because it was flexible and collapsible. The whole program simply folded up and collapsed. ;D

Seriously, the flexibility is a problem in extreme flight conditions such as might be expected in a war zone. For example a negative angle of attack would cause the double-cone to collapse and lose the controllability necessary for recovery, while too high an angle could stall it with similar effect. I live near the Malvern Hills and several Rogallo hang glider deaths have been caused by unexpected wind conditions there.

Another inherent problem is aerodynamic inefficiency. Although it flies and glides OK, it has a poor lift coefficient and therefore respectively either high fuel consumption or a steep gliding angle. For applications requiring endurance it is a non-starter.

At the other end of the scale, the paraglider is even more collapsible as it has no rigid sticks in its construction. It ate up some of the low-end applications that the Flexwing might have hoped for.

A problem with unmanned gliders and drones is the need for remote guidance to steer them on course. Without such guidance, a simple parachute drop is both more accurate and allows the launch aircraft to get out of the front line sooner. The pilots of lumbering glider tugs are especially unhappy people as they approach the battle zone, and the military glider pretty much died out during WWII.

Space recovery would work, but the Flexwing would not be deployable until the craft had slowed down a great deal. At high altitudes and hypersonic speeds, that was a key job of the ablative heat shield. At intermediate heights and speeds, a drogue chute was about the only workable solution of the day. So once you have a parachute system going, why not extend it to the landing regime as well? It's not as if a seaborne splashdown needs precision targeting.

So really, I think the Flexwing was a solution looking for a problem and, once the basic research was done, it had not found one.

It was left to recreational pilots to develop as their plaything.

By the way, nice set of pages, thanks.

 

[Stargazer]

Thanks a lot for your answer, steelpillow, and the way you summed it all up in a nutshell: "A solution looking for a problem"! ;D

 

[Grey Havoc]

Apollo Design Concepts From 1961 - Original Drawings Revealed

Thanks to Ben for sharing these drawings he found in his Grandfather's files. These are drawings from the original proposal by North American Aviation for the Apollo Command Module. These were made in September 1961 before the Apollo program had decided to use Lunar Orbit Rendezvous to reduce mass requirements. As such the designs are built around landing the command module on the moon using a big lander.

Ben has shared the high resolution scans of the designs at https://apollopreliminarydrawings.com/

Source:

Link; https://apollopreliminarydrawings.com/
Feel free to post this link in a much more suitable topic.

 

[riggerrob]

Another aside is the development of Rogallo wings as sport parachutes.

During the 1970s sport skydivers were looking for faster (horizontal speed) parachute canopies that out-performed “cheapo” military surplus canopies or (purpose built Lemoigne (e.g. Para-Commander) parachutes.
Inventors experimented with a variety of gliding canopies: Barrish, Jalbert, etc. based on Rogallo’s concept.
I made four jumps with a Delta II canopy (sewn under license by Irvin Industries of Canada). It opened HARD- even with the Opening Shock Inhibitor strap.
Mind you, most sport parachute manufacturers struggled to soften openings during the 1970s.

By the mid 1970s, Southern California rigger Jim Handbury married Rogallo’s concept with a ”slider” to reduce opening shock. I made one jump on a copy of a Handbury, single-keel Para-Dactyl and rather enjoyed it! It flew almost as well as 1980 vintage ram-air (Jalbert) canopies, but packed significantly smaller, than say. 200 square foot Para-Flite Cruisair, 7 cell.
Handbury also built a 240-ish square foot Double-Keel Paradactyl which saw limited service as a student canopy during the early 1980s. The Double-Keel Dactyl had triangular outer cells with a rectangular center cell.

Later communist countries copied Handbury’s Para-Dactyl to make the Russian Telka and Czech PZ-81 Rogallo sport canopies that remained in production until the Iron Curtain fell circa 1990.
Eventually Rogallos were replaced by double skin canopies based upon Dominic Jalbert’s ram-air kites. The primary advantage of double-skinned canopies is that they shrug off most turbulence.

Like I said earlier: I have made 5 jumps on Rogallo parachutes, 1 1/2 on Lemoignes, 70-ish on round canopies and more than 6,000 on Jalbert’s square parachutes.
Guess which I prefer?

 

[carvalho2008]

Another found interesting video

 

[Maveric]

Ryan XV-8A Fleep in colours

 

[Maveric]

Ryan FlexWing

 

[RAP]

...

 

[kocovgoce]

I had read in a Russian book that the Soviets in 1985 wanted to experiment with such a wing but armed with strela -2 or igla for air defense

 

[publiusr]

Not all such parawing-equipped designs were meant to fly slow.

Perhaps memory metal designs for military Starship payloads?

 

[hesham]

...

Source please.

 

[RAP]

Hesham- Ryan photo w/info printed on the back. Unfortunately no date.

 

[kocovgoce]

and how the plane rotates left or right using the rear stabilizer or by tilting the whole wing?

 

[riggerrob]

I had never seen the air-mobile container in the first post in this thread, but I had something very similar in mind. I was searching SPF for information on flexible wings to flesh out a concept for a rugged, low-speed utility aircraft small enough to fit in an ISO 20' shipping container. Does anyone know of any good resources on the design of flexible wings? I am particularly interested in the combination of the flexible wing with more more conventional aerodynamic control surfaces rather than weight-shift control of hang gliders and microlight trikes. Thanks!

Let me do some checking around but I seem to recall a series of patents on ISO container delivery by air that had several "flexible" wing designs. One thing to note though is that Rogallo himself studied dozens of "other" methods to control his wings in flight OTHER than the mass-shift or wing-angle ones.

Randy

Go read Theo Knacke's book on aerodynamic decellerators.