Fairey Rotodyne

I had never heard that before, Gilbert, was it related to some defense project?




!

Juergen,

if you do a google search on Prins Bernhard of the Netherlands you'll discover that he was "involved" in more than one "obscure" deal.
Very intruiging character and one of the founders of the Bilderberg Group....
 
What an interesting aircraft, Dave. Another concept that might warrant further exploration, like the title aircraft of this thread. Would it be possible, with given engine power, to lift about the same gross weight and useful load with a CL-84 type craft as does the Osprey? (Unfortunately we will perhaps not be able to answer that question ....;-)

Yes the configuration of an aircraft has a lot to do with the intended application.

There have been strong comparative discussions on PPRuNe about Bell's V-22 vs. Sikorsky's CH-53E Super Stallion. The V-22 wins on speed and the Super Stallion wins on payload efficiency.
Who is the overall winner. :noidea:


Dave
 
Prins Bernhard is indeed an interesting character, Gilbert! It is quite astounding that he became a high ranking member of the RAF staff although he was German (his relationship with the Nazis and the SA seems to have been unknown at that time). Nevertheless in another thread it has been argued that the internment of even second generation US citizens of Japanese descent was inevitable (http://www.rotaryforum.com/forum/showthread.php?t=39430). The different approach which the British took, with making a German member of the RAF and promote him to important bodies of decision making, is all the more remarkable.

Who is the overall winner?
In terms of speed the CL-84 should outperform the Osprey (and of course the Super Stallion) hands down. Payload would likely be lower. It has been argued in the combatreform forum that the OV-10 Bronco was not the best aircraft for the job (http://www.combatreform.org/killerbees2.htm) And of course you are right, Dave, an aircraft is designed for a mission! The CL-84 might have been the aircraft that comes closest to the ideal of a Close Air Support weapon that lives basically a few miles behind the front line and offers the tightest liaison with combat troops. Perhaps we will see UAVs of similar design fulfill that mission in the future. Any support for the troops fighting our war against terrorism would certainly be welcome.

Nice film featuring the CL-84:
F-0628 Tiltwing Versatility - YouTube

Some pictures here:
http://flickrhivemind.net/Tags/shorttakeoffandlanding/Recent

And a brief article from Flight Global:
http://www.flightglobal.com/FlightPDFArchive/1963/1963%20-%202119.PDF
 
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Prins Bernhard is indeed an interesting character, Gilbert! It is quite astounding that he became a high ranking member of the RAF staff although he was German (his relationship with the Nazis and the SA seems to have been unknown at that time). Nevertheless in another thread it has been argued that the internment of even second generation US citizens of Japanese descent was inevitable (http://www.rotaryforum.com/forum/showthread.php?t=39430). The different approach which the British took, with making a German member of the RAF and promote him to important bodies of decision making, is all the more remarkable.


QUOTE]

Yes Juergen,
Bernhard was a sneaky guy and he not only fooled the British......
His son in law, Claus von Amsberg was a member of the NSDAP jungvolk and the Hitler jugend but that didn't seem to be an obstacle for o'll Bernhard to allow Claus to marry his daughter,the later queen of the Netherlands, Beatrix. !!
By the way, the Belgian royals also have German roots, Von Sachsen-Coburg.
Oh well....you need a few of every kind to create history LOL !
 
The biggest surprise is the VTOL lift capacity: the CL-84 lifts 49.7% the A-609 52.47% of its empty weight and the 84 is based on 50ies technology and was designed using slide rules(!) (and some marvelous engineering ...;-). The top speed of course is much greater. This seems to be another example of superior technology that was somehow killed; what a pity!
 
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some marvelous engineering
Your article from Flight Global says "250,000 engineering man-hours and some 2,500 hours of model testing" That's a lot of engineering down the drain.
Cry.gif



Dave
 
What a steady pass....going backwards "we" have achieved over the past 50 years LOL !!

"40 years ago the CL-84 was lighter, flew faster could carry more passengers and used less power than the computer era designed Augusta and this all with pen and paper, anybody care to explain this ?".....could have been the words one of the board members of Augusta asked when the design team came up with the AW-609,..... assuming the board member new his history...

What is going on ? Re-invent the wheel, make it square and let everybody believe that a major leap forward is being made....
 
Another piece that fits into the picture of "21st Century Progress" is the DeHavilland Twin Otter. First flight of this aircraft was in 1965. Viking Air (http://www.vikingair.com/content2.aspx?id=276) has acquired the type certificate for this aircraft and in 2009 opened production. The only modifications, as far as I know, are that instruments have been converted from "steam" to a glass cockpit and more powerful engines are used. Viking air has so far sold more than 30 according to this source (http://www.timescolonist.com/victoria-s-viking-air-inks-70m-twin-otter-deal-1.324640)
 
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Since this thread has turned to the greatest ideas that never were competition, and the Fairey Rotordyne is my personal favorite for the "ahead of its time" award, I'll posit the next runner up should be the Lockheed Cheyenne!

https://en.wikipedia.org/wiki/AH-56_Cheyenne
 
I would also tend to think that there is a market for an aircraft like this. Some projects at that time seem to have been killed by American companies trying to get rid of competition. They bribed European (and perhaps Canadian?) politicians. The British fighter development using rocket booster engines seems to have fallen victim to that campaign. In Germany Lockheed won the contract for the Starfighter which led to a political upheaval as the newspaper "Der Spiegel" accused Franz Josef Strauss (then secretary of defense) of corruption.

PS: Thanks for the "Thumbs up" Wasp!

There's no need for a sinister conspiracy to explain the failure of the Rotodyne program. The British aircraft industry was totally dependent on government contracts and government support. Support for Rotodyne development was contingent on getting orders. The orders didn't come, and the government support evaporated. It's not a vote of no confidence in the concept - the specification that started the development of the machine was inadequate when first formulated, and totally obsolete by the time it flew. Fairey knew requirements were changing, and designed ab initio a machine that was faster and had a higher passenger capacity than specified, but customers needed still more passenger capacity and would have liked a little more speed. Westland, which in the meantime had taken over the project, had a larger machine on the drawing board when government support ended. As for American interference, it was favorable - Kaman wanted to produce the larger machine under license, and a major Canadian helicopter operator placed an order contingent on delivery of the larger machine. If development had continued, the larger machine would have found a ready market in North America, but - and this is typical of government making business decisions - there was no flex in the terms of Ministry support.
It would have been a very good thing to have American firms involved in further development, because it seems to me almost certain that a rigid rotor system would have been applied to the next-generation Rotodyne, giving a considerable jump in speed.
 
McDonnell's take on the Rotodyne concept

McDonnell's take on the Rotodyne concept

I found the attached concept drawing in a McDonnell light VTOL transport study dated February 1960. It is hardly necessary to point out the obvious Rotodyne influence; the only relics of the McDonnell XV-1 compound and Model 120 helicopter are the McDonnell rotor system and the vestigial tail rotor, which isn't actually needed for yaw control in a rotodyne! Imitation really IS the sincerest compliment.
The link to the full document is www.dtic.mil/dtic/tr/fulltext/u2/232716.pdf.
To me, this is the perfect solution:
- a rigid rotor system which allows a low pylon while retaining adequate vertical tail clearance and has very high speed potential compared with the conventional, articulated rotor of the original Rotodyne
- the rigid rotor also makes it possible to unload the rotor almost completely in cruise; this proved impossible in the Rotodyne - its wing incidence had to be reduced to keep the rotor loaded, or excessive flapping would occur
- a pressure-jet system for helicopter operation with the lowest possible weight penalty and life-cycle cost
The problem that the Rotodyne was designed to solve - basically, intermodal transfer delays - is worse today than back then. There is also a new problem - that of increasing centralization, with carriers operating out of central "hubs" and forcing travelers to travel hundreds, sometimes thousands of miles out of their way by traveling from their point of origin to a hub, and from there possibly to another hub, and from there to destination, instead of making the trip directly. Making the trip directly goes a long way toward reducing not only delays but fuel consumption, even factoring in the cost of operating the pressure jet system at takeoff and landing.

ADDENDUM: The rotor system of the XV-1 is not rigid. It is semi-rigid, since there is no lead-lag hinge, but there are still flapping hinges. What makes it so much more stable at speed than a conventional articulated rotor is not the mere removal of one degree of freedom, but the rotor head system designed by Hohenemser which couples flapping and feathering, and has independent delta-three angles for collective and for cyclic flapping/feathering. Brilliant! Though it does have problems at low rotors speeds and when starting in a high wind, which a later patent by Hohenemser, taken out while he was at McDonnell, attempts to fix.
 

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The British aircraft industry was totally dependent on government contracts and government support. Support for Rotodyne development was contingent on getting orders. The orders didn't come
The question still remains why the UK government choose to buy slow, underpowerd US helicopters with a very poor payload when they had - in 1954 - something at their hands that achieved two thirds of the performance of the V-22, the latest and greatest in 21st century rotary wing transport (or so some people say...)? The V-22 has about twice the power of the Rotodyne so with double the power Faireys great ship would have been very close to a year 2000 V-22. The decision to kill this great engineering achievement (and most of Britains thriving helicopter industry in one fell swoop) is so utterly foolish that one can only think of treason and plot. In this 1962 Flight Global article http://www.flightglobal.com/pdfarchive/view/1962/1962%20-%201390.html the author points out that the issues with the aircraft had been resolved and the main argument - noisy tip jets - is invalid in a military role anyway, or did they put mufflers on jet fighters back then?

Some more stuff here:
http://www.klassiker-der-luftfahrt.de/geschichte/flugzeuge/fairey-rotodyne-in-der-werbung/543866/fsuebersicht
http://photochronograph.ru/2014/01/22/vintokryl-fairey-rotodyne/
 
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The decision to kill this great engineering achievement (and most of Britains thriving helicopter industry in one fell swoop) is so utterly foolish that one can only think of treason and plot.

When I see foolishness, I think of fools. But be that as it may, and as long as we're asking rhetorical questions, why did the McDonnell proposal, which was studied and confirmed at taxpayer expense, not get funded?
 
When I see foolishness, I think of fools. But be that as it may, and as long as we're asking rhetorical questions, why did the McDonnell proposal, which was studied and confirmed at taxpayer expense, not get funded?

I now have a partial answer to my own question. McDonnell was not pushing hard, because they had "too much business" already, and the Army and Air Force were not pushing hard because they had specified a speed goal of 350 mph, and the XV-1 achieved "only" 200 - and never mind that nobody had ever gone that fast before in a helicopter and this was an underpowered prototype.
The competing tilt-rotor concept seemed to offer more hope of achieving such speeds...and it finally did, a half-century later. Of course, we will never know what a half-century of developing rotodynes might have accomplished, so the decision that tilt-rotors were more promising became essentially self-fulfilling, in the absence of a strong private-sector push to keep the rotodyne concept in development.
Today, the closest thing to the XV-1 is the Carter slowed-rotor project, though Carter uses shaft drive which limits him to jump takeoffs - something I don't believe will ever be accepted in commercial or military aircraft, though it might very well produce a fast and versatile cross-country personal ship.
I just finished looking over Kottapalli et al's suggested conversion of a C-130 into a side-by-side twin-rotor helicopter...which is utterly ridiculous when you see the performance and payload loss which they freely acknowledge. I want to use the same basic data and analysis method to do a conceptual design of a C-130 rotodyne conversion.
 
Since this thread has turned to the greatest ideas that never were competition, and the Fairey Rotordyne is my personal favorite for the "ahead of its time" award, I'll posit the next runner up should be the Lockheed Cheyenne!

https://en.wikipedia.org/wiki/AH-56_Cheyenne

Agreed. And its predecessor the XH-51A set a record (unfortunately not homologated with the FAI, allowing Eurocopter to claim a record for a speed several knots slower than that achieved by Lockheed in 1960) of over 300 statute miles per hour.
I have mixed feelings about the demise of the Cheyenne project. On the one hand, the decision to procure the Cobra made very good logistical sense due to parts commonality with the ubiquitous Huey, and its much lesser tactical capability was more than adequate for Vietnam. On the other, it would have made good sense to keep the Cheyenne alive as a developmental program for later procurement. As it is, features and capabilities present in the Cheyenne have had to be laboriously and expensively redeveloped.
 
I built the model

I built the model

I've always liked that Cheyenne... built the Revell model DECADES ago, as a young boy. One of these days, I have to get to Ft Rucker to see that museum.
Seems that history is going in circles on that technology.
Brian
 
I believe they also have a Cheyenne at the Fort Campbell, Ky museum.
 
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