A Quiz (for the fun of it)
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A quiz. (for the fun of it)
The following craft have been proposed by three different helicopter manufacturing companies, for the role of vertical flight aircraft in a future air transportation system.
Anyone want to try to guess at which manufacture is proposing each craft?
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Anyone want to try to guess at which manufacture is proposing each craft?
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...going with the trend below....
I'm with baranfin, though I'd have said number 2's nose looks more like the classic MD airline cockpit window layout ala DC-9/MD83 etc.
Actually, better change my number 2 to Boeing too: I'd forgotten they bought MD (it's still an MD nose though, not Boeing)
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And the winner is ----
The first proposal is from Bell. A V-22, but bigger and better. 
The second is from Boeing. It is encouraging to see a large innovative company propose the side-by-side configuration. Laterally located twin rotors were used on the world's first two production helicopters; the side-by-side Focke Achgelis Fa 223, and the intermeshing Flettner FL 282
The third is from Sikorsky, which seems unable to wean itself from Igor's single rotor and mandatory torque compensator.
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There are many with the correct answer, therefore the book will be auctioned on eBay, with a reserve price of $0.26. The proceeds will be divided up amongst the winners and mailed.
Of course, this assumes that the successful bid is enough to cover the postages.
The second is from Boeing. It is encouraging to see a large innovative company propose the side-by-side configuration. Laterally located twin rotors were used on the world's first two production helicopters; the side-by-side Focke Achgelis Fa 223, and the intermeshing Flettner FL 282
The third is from Sikorsky, which seems unable to wean itself from Igor's single rotor and mandatory torque compensator.
________________________
There are many with the correct answer, therefore the book will be auctioned on eBay, with a reserve price of $0.26. The proceeds will be divided up amongst the winners and mailed.
Of course, this assumes that the successful bid is enough to cover the postages.
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Here's a slide presentation on #3, the Sikorsky one with the reverse velocity concept. High Speed Rotorcraft Concept by Sikorsky. It takes a while to download.
Pictures of the craft did not display on my monitor but they did on the printouts. Weird. Here's another view, just in case. Picture
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It's an interesting, but problematic, concept. In fast forward flight, the forward speed of the craft will be greater then the rotational tip speed of the rotors. This means that the entire span of the retreating blades will be in reverse airflow.
One concern is that of maintain lift on the retreating side during transition, when the blades on this side are subjected a varying reverse velocity. Active blade twist would probably allow this transition, but they do not seem to be considering it. Apparently, the "2-P control for transition" means that the lift is provided solely by the forward and the rear quadrants during transition.
Edited to clarify remarks.
Pictures of the craft did not display on my monitor but they did on the printouts. Weird. Here's another view, just in case. Picture
_______________________
It's an interesting, but problematic, concept. In fast forward flight, the forward speed of the craft will be greater then the rotational tip speed of the rotors. This means that the entire span of the retreating blades will be in reverse airflow.
One concern is that of maintain lift on the retreating side during transition, when the blades on this side are subjected a varying reverse velocity. Active blade twist would probably allow this transition, but they do not seem to be considering it. Apparently, the "2-P control for transition" means that the lift is provided solely by the forward and the rear quadrants during transition.
Edited to clarify remarks.
Last edited by Dave_Jackson; 27th Oct 2003 at 01:58.
