Osprey Madness

[scooter]

The book on the 'dyne by David Gibbings, pu8blished by the History Press.

It's called 'Fairey Rotodyne', catchy title, eh? 

But what's it about? (/snark  )

[zenrat]

Kit - what's your source for that?  I don't have any personal knowledge of this bird, only what I can find on the internet.  I'm not saying you are wrong - please don't think that.  I'd just like to know your source ... I hate being wrong, myself.

Wikipedia - dubious source at at best, I know - says each Eland fed only two rotors
https://en.wikipedia.org/wiki/Fairey_Rotodyne

and so does Aviastar
https://www.aviastar.org/helicopters_eng/fairey_rotodyne.php

History.net also says this.
https://www.historynet.com/fairey-rotodyne-an-ingenious-blend-of-airplane-and-helicopter/

I suspect all three sources have used the same, wrong, source of information.  One of them may actually be that source of course.
Rotodyne is going to be complicated enough without adding extra things to go wrong by segregating the air flow to the rotors.

I wonder how leak free the rotor head would have been after being in service for a while?  A fuel leak up there would be potentially disastrous.

[PR19_Kit]

The rotor head manifold would have been complicated enough as it was built, being a 'common feed' system, but how they could have segregated the compressed air feeds into two, separate inputs and outputs just BOGGLES the mind! 

[McColm]

The Rotodyne is essentially an autogiro, the main rotor is unpowered in forward flight. The tipjets are only used for takeoff and landing, the rest of the time the rotor functions solely as a free rotary wing.
A coaxial rotor setup wouldn't work.

However if you make it into a "compound"
helicopter, that's a different kettle of fish.
There was an actual Kamov concept many decades back that added a coaxial rotor system; engine, transmission and rotors,
to an Li-2 to produce a compound helicopter.

 


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Thanks that's a future project, I added a pair of turbofans to the Osprey and did think of a kitbash although the two kits that I used aren't compatible so a straight forward switch isn't possible without some PSR. A second kit as a donor either Osprey or Rotodyne will be required so two of the same kits would be a better option.

[Scotaidh]

The rotor head manifold would have been complicated enough as it was built, being a 'common feed' system, but how they could have segregated the compressed air feeds into two, separate inputs and outputs just BOGGLES the mind! 

Thanks, Kit!    Since I've no idea how they did any of it, so I'll accept any half-decent explanation.  How does one deliver a fluid - air or fuel -  through a rotating hub? 

I think, that if it'd been left up to me to invent it, I'd have had replaceable solid fuel pellets in the tip-jets, ignited from the cockpit but once they're lit, they just burn to exhaustion.  The pilots wouldn't have liked it, but I suspect they'd have gotten used to it in time. 

[PR19_Kit]

Imagine two 6" deep pudding plates, one one top of the other, the bottom one with a port on each side, and the top one with four ports at 90 deg. to each other.

The bottom plate stands still, and the top one rotates and they're sealed on their edges with all sorts of temperature and pressure proof seals. There's a ruddy great shaft runs right through the middle of both plates and it's sealed to the max as well and it's attached to the upper plate.

Attach the rotor blades to the upper plate's four ports and the Eland's compressed air outlet to the lower plates two ports and Bob's your uncle.   

[jcf]

Kit - what's your source for that?  I don't have any personal knowledge of this bird, only what I can find on the internet.  I'm not saying you are wrong - please don't think that.  I'd just like to know your source ... I hate being wrong, myself.

Wikipedia - dubious source at at best, I know - says each Eland fed only two rotors
https://en.wikipedia.org/wiki/Fairey_Rotodyne

and so does Aviastar
https://www.aviastar.org/helicopters_eng/fairey_rotodyne.php

History.net also says this.
https://www.historynet.com/fairey-rotodyne-an-ingenious-blend-of-airplane-and-helicopter/

I suspect all three sources have used the same, wrong, source of information.  One of them may actually be that source of course.
Rotodyne is going to be complicated enough without adding extra things to go wrong by segregating the air flow to the rotors.

I wonder how leak free the rotor head would have been after being in service for a while?  A fuel leak up there would be potentially disastrous.

The source is Flight 9 August 1957, and it's correct.
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[jcf]

9 August 1957 Flight article on Rotodyne.

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[PR19_Kit]

IIRC, and I'm a long way from my copy of the book now, they modified that system numerous times during the lengthy flight programme.....................

[zenrat]

I can't get to my copy either.
Thanks for the article Jon.  I've not seen that before.  Some usefull stuff which is going to help me finish the rotorhead on my Tinydyne.
 

[jcf]

I have the e-book version of the Rotodyne book and the description of the air-ducting is the same as in the Flight article, and the diagram from it is reproduced in the book.

[PR19_Kit]

In that case I must have read it elsewhere!

[kerick]

I've been thinking about Osprey wings and engines on a Lockheed Cheyenne fuselage for a tilt rotor attack chopper. There is an upcoming kitbash GB on BTS.