View Full Version : Personal Vtol Concept
08-16-2008, 11:20 AM
Something a little different. (http://www.rotaryeng.net/VTOL.html)
08-16-2008, 12:19 PM
The author sure spent a substantial amount of time in research for his paper.
However I doubt that any aircraft with a configuration like the Osprey has much future.
It has no dynamic stability, and I am unconvinced of a reliable autorotation capability.
Any lift imbalance between the 2 rotors quickly goes to hell in a handbasket.
Asymetric mechanical incident, weather turbulences like micro bursts, settling with power on one side are just a few of the risks involved.
I've seen Mr. Larmar's web site before.
As for that Osprey machine, then as now I never had much faith in that particular rendition of a VTOL design. As viewed and as understood here, only Pentagon Funding is keeping, what I view to be a pehnominal waste of tax payer funds, in the air.
That Pogo aircraft, I bought and built a model of that when I was a child and it was from that plastic model that I learned one way of how to make counter-rotating props, counter-rotate. The model did not have an electic motor in it to make the props spin but when oiled and held into the wind generated by a relatively strong house fan or when held out a car window when cruising along at thirty or so miles an hour, those blades would spin very nicely.
While I wish Mr. Lamar only the best of luck with his proposed project, I frankly don't have much faith in the future of such a VTOL tool any more than I do for the Moller car project (but as I know and understand these things, Lamar and Moller are right with regard to choice of power plants, air cushion safety devices and the like) but one "ancient" project, which almost demands another visit due to the promise it holds seems to be the Hiller's VZ-1 project. The stunning brilliance of Zimmerman, Delackner and those at Hiller who were involved with the VZ-1 and it's deriitives is something which even in this day and age is something to be held in awe.
08-20-2008, 05:04 AM
Well, as far as I know from a docu on Discovery the Osprey is in service on aircraft-carriers of the US-navy and was meant to go on in development as a mid-range-commuter.
As could be seen in the documentary the Osprey handles quite well in diff weather sits and has a good safety record.
The trouble with all these developments is: if a construction is a (commercial) success and/or gets reknown is a matter of lobbying and politics and not of craftmanship.
A lotta protos nicely working vanished by lack of funding. Just remember the gyro ! La Ciervas plans were bought by Sikorsky and were kept away not to interfere with his heli-development .......
08-20-2008, 09:16 AM
La Ciervas plans were bought by Sikorsky and were kept away not to interfere with his heli-development .......
Is this, fiction, folklore or fact?
Interesting! Is this, fiction, folklore or fact?
Could be true. Ski may have bought those rights/plans just to see if there was anything he could learn from them but Kellet Aircraft here in Pennsylvania bought production rights as well and as I understand it did produce autogyros for several years.
08-21-2008, 08:20 AM
Thanks for the information.
It appears that Kellett also had the best solution for helicopters when started incorporate 3-bladed rotors to Flettner's intermeshing configuration.
09-02-2008, 05:03 AM
Is this, fiction, folklore or fact?
For an educational textbook on gyroplanes I did some research in internet-libraries and historical documents.
This was stated several times but nobody can rely on personal knowledge. Almost ALL history is hearsay as long as one does not know it by beeing PART of this history.
I can only say: it is plausible, ´cause why was the development of the gyro stopped so suddenly ? And Sikorsky bought the patents from LaCierva as a fact.
The only gyros in use after 1929 were gyro-gliders on German submarines (to extend the sight over the horizon to dedect enemy-ships) and the American Pitcairn used by the US-Post for mail-transportation.
The gyro-"boom" once again started with Bensen in the 60s.
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