Fairey Rotodyne

[The Wooksta!]

The following John Baxter book has some fictional operational Rotodynes in it:

Woohoo!  One of my finest pieces of work gets another airing!  I remember John sending me the photos of his RAAF 'dyne and being very mpressed.

[rickshaw]

Mmm, overlaying the Y over the Z drawings (once both are rescaled to 1/72) shows the Z is a little wider and taller, from behind the pilot's cabin.  However, it would be doable I think.  Now, where can I get some better drawings/pictures of the Tyne engine nacelles?

[Mossie]

I would have to say all of that equipment would be used all the time

So is the equipment on the Rotordyne.

Not quite, the tip jets are only lit for take off, landing & the hover.  You could use a similar argument with the V-22, the mechanism for tilting the engines is only used during translatory flight.  I guess you could use the same argument for almost any VTOL/convertiplane aircraft, there's always something, even if it's relatively negligable that is redundant for some phase of flight.

Personally, I'd like to build a Rotordyne but the only available kit at the moment is the 1/78(?) scale Revell one.

Has anybody moulded a 1/72 one to replace the Airfix kit or made one of the Type Z?

There's no recent kit of the Rotodyne to replace the Revell & Airfix ones, except for a resin 1/200 kit from Shed Models.  The Revell is the better kit, but if scale is important than the Airfix kit is the one to go for.  It's a bit dated, rivets, working undercarriage & clamshell doors but looks right.

My understanding of the differences between the Type Y and the Type Z Rotodyne is that the fuselage was slightly stretched and the wing plan and span changed as was the tail unit.  Is that correct?  There is a relatively poor drawing of the Type Z here:

Are there any better available?

The Z has never been kitted to my knowledge & I doubt it will be, mores the pity.  Myself & Robert have talked before about building one, it's probably a complete scratchbuild as it's quite different to the standard Rotodyne, while having a similar appearance.  The whole dimensions of the fuselage are larger, the cockpit is different.  The three view you've got there is slightly earlier than the definitive version, which had a beaver tail rather than clamshell doors.  This had a loading ramp for military versions, which was option for civil versions.  Wings & engines are the more obvious changes.  The tip jet arrangement would probably have been very different on production models, rather than a single jet for each rotor, there would have been nine smaller ones in a flat arrangement, with silencers of a square section, all part of the noise reduction program.

If you're looking at building the Z, the Gibbings books will be very useful.  It's got a similar three view with the beaver tail, as well as several more detailed drawings, & plenty of pics of the mock up including cockpit & cabin detail.  There are internal arrangement drawings for civil & military versions.

[kitnut617]

I'm also thinking of doing a modern day Rotodyne like I mentioned above.  One scenario would be a converted C-130, four engines, wings cropped off just outboard the outer nacelles, six or eight blades for the main rotor. The other scenario is a converted C160 Transall, two engines, wings cropped a bit further out than the outside of the nacelles, six or eight blades.  The engines would be a pair of A400M engines     (I read on another forum Revell are releasing a 1/72 A400M but I can't find anything about it on the Revell websites).  But what about a converted A400M rotodyne  ----- hmm!!!! --- four engines, cropped wings just outboard the outer nacelles, co-axial rotor ------

[Mossie]

How about the new Italeri C-27J for a 'lite' version?

[kitnut617]

Now there's another thought ----

[GTX]

How about the new Italeri C-27J for a 'lite' version?

Great idea - go to it!

Regards,

Greg

[rickshaw]

Everyone seems determined to put a Rotodyne rotor on top of something else. So what to do with the left-overs?

Introducing the Fairey Vertidyne STOL transport ...

Interesting.  Wings look a little small though...

Of course, you could make it a tiltrotor...   

[kitnut617]

Everyone seems determined to put a Rotodyne rotor on top of something else. So what to do with the left-overs?

I'm not using the Rotodyne rotor, it's too small to start with but I'm building my own pylon and rotor for the C-130/C160 (whatever I decide to use).  It would much too small for an A400M rotodyne too.  I've got an idea which rotor blades I could use to, 1/35th Chinook ones should work ---

[Stargazer]

Everyone seems determined to put a Rotodyne rotor on top of something else. So what to do with the left-overs?

Introducing the Fairey Vertidyne STOL transport ...

This Vertidyne is brilliant in every way!!! 

[Mossie]

Going back to the Rotodyne proper: anyone know why the add-on, upper vertical tails canted outwards. Would that not increase drag from downwash? Was it just to facilitate tail folding? Or were those surfaces VG (ie: were movable surfaces part of flight control)?

It was to prevent the rotor striking the tail.  The rotor was quite droopy with the weight of the tip jets & the tail fell within the rotor disc.  The verticsl tails folded down during power up & downonly.  Later in the program, when it was determined there was no danger of a tail strike, the vertical tails were set at 90^O.

You can see the tail folding in the Fairey video:
http://www.youtube.com/watch?v=y9633v6U0wo

[rickshaw]

Cheers Stéphane!

Interesting.  Wings look a little small though...

My first thought was larger wings with outer panel diherdral for a fully conventional tactical transport. Flat-o-dyne just didn't have the right ring to it.    So, on went the wingtip lift pods (based on the Do-31 but à la the original V/STOL Fiat G.222 proposal).

Yeah, I picked up where the idea had come from.  The G.222 had liftfans both behind the engine nacelles and in flattened wingtip pods.  Always felt that was a more elegant solution than the bulky pods of the Do31.

Going back to the Rotodyne proper: anyone know why the add-on, upper vertical tails canted outwards. Would that not increase drag from downwash? Was it just to facilitate tail folding? Or were those surfaces VG (ie: were movable surfaces part of flight control)?

Originally they folded flat - outwards - during hovering operations.  The fear was that the rotor would catch on them during aerobraking with the rotor.  However, they found that the rotor didn't go that far backwards and by folding them, they were causing control problems with downwash so they fixed them in place, canted slightly outwards.

Of course, you could make it a tiltrotor...   

Hisssssss ... take that back, take that back now!

Obviously I've upset the applecart...  

[Mossie]

Found this (Flight Simulator?) vid on YouTube of an 'Avro RJ200 Rotodyne'.  Basically uses an RJ85 fuse with modified control surfaces & the pylon & tip jets from the Rotodyne.  Animated kitbash!  It's been alluded to in previous posts, but due to current rotor technology you probably wouldn't need the pylon, but it looks good.
http://www.youtube.com/watch?v=VFk5Y_F-dwg&feature=related

[rickshaw]

rickshaw: thanks for the details. For a fixed-wing version, it'd be tempting to bun the existing tail and replace with something else (Halibag might work?). I do like Mossie's RJ85's twin tails 

How about a tilt-wing, rotor-less Rotodyne 

Tiltwings have interesting control problems it seems.  You need also to make the tailplane tilt as well, to keep a flow over it for control purposes if the CL-84 is any example to go by (you also need those little rotors as well).  Not sure how they get around that with a tiltrotor but they do with the V-22.

[rickshaw]

If you look at CL-84s in the hover, you'll notice that the horizontal tail is tilted as well.  The little rotor apparently gives control once you're actually in the hover but the horizontal tail tilts to improve control as you're approaching the hover as the propwash flows over it, I suspect.