Fairey Rotodyne

[PR19_Kit]

The small scale Revell rotor-head is beautifully detailed, miles better than the rather rudimentary Airfix version, but sadly it's too obviously underscale perched on top of an Airfix pylon. We could do with a proper 1/72 resin aftermarket version of it......

[Maverick]

Thought this was great for the thread:

http://www.airliners.net/photo/Fairey-Aviation/Fairey-Rotodyne/1167871/L/

Regards,

Mav

[rickshaw]

As is this:

http://cdn-www.airliners.net/aviation-photos/middle/4/8/4/1050484.jpg

[Hobbes]

I think the way things are going, I'm going to be building an "inspired by" Rotodyne Z, rather than a Z itself.  The Beavertail is I suspect more aerodynamic but not what I like in a transport aircraft/helicopter. 

Unlike clamshells, a beavertail can be opened in flight.

[rickshaw]

I think the way things are going, I'm going to be building an "inspired by" Rotodyne Z, rather than a Z itself.  The Beavertail is I suspect more aerodynamic but not what I like in a transport aircraft/helicopter. 

Unlike clamshells, a beavertail can be opened in flight.

So can a ramp, which I'd prefer.

[Hobbes]

What's the difference between a beaver tail and a ramp, then? A beaver tail doesn't reach the ground?

[PR19_Kit]

The beaver tail is pointed in side view, at around mid-height of the fuselage, like the military Argosy, and the top half opens up and the bottom half opens down. The ramp just opens downward, like a Herk, although most ramped aircraft have an inward and upward opening part as well, also like a Herk, but it's invisible in side view.

[Mossie]

I've been considering that path as well.  My problem is finding a set of rotors large enough.  The Type Z had a rotor diameter of ~33 metres.  Thats ~450mm(!).  I was thinking of using some 1/48 scale ones but haven't found any.  I might have to roll my own.  The rotorhead is another problem.  Again, I fear I'll have to roll my own.

I did some Rotodyne comparison pics several days ago but haven't got around to posting them.  I dry fitted some kits together to show the size of the Rotodyne & also scaled some plans of the Z.

Airfix Rotodyne (centre) with Trumpeter CH-47A Chinook (left) and Revell CH-53J (right)


Airfix Rotodyne Y over Rotodyne Z plans.  I've added in the rotor blades of the Rotodyne Y (left) & CH-53 (right).  Rick, this seems to suggest you could use Academy 1/45 CH-53 blades.


Rotodyne Z to Fokker F27 Friendship & RA-5C Vigilante.  Seems an odd one this, but the Rotodyne's planned market was one that was taken by the F27.  The Vigilante is there as the largest aircraft permenantly based on a carrier, to show the problems with carrier ops.

[kitnut617]

Well here's a pic of the Academy 1/48 CH-53E rotor blade next to a 1/72 scale

[PR19_Kit]

Some excellent basic research there gentlemen, I wonder if Westland got this far?  

Some of us were discussing this at MK today, and I pointed out the remarkable narrowness of the 'dyne's rotor chord compared with many of today's helicopters, Chinook, H-53 and Merlin being just three. Perhaps the 'dyne Z wouldn't have needed such a large rotor span if the blades had a wider chord and thus more area, giving a lower disc loading?

[rickshaw]

Thanks for all the photos!  Its starting to gell in my mind what I've been thinking about.

As to the rotors, I think the narrow chord was because of drag versus materials strength.  Nowadays there are various exotic materials available which are stronger than steel which obviously weren't available in the 1950s.  I also suspect that the wider the chord, the greater the drag - or have I got that wrong?

The 1/48 CH-53 look like they might work but I'm loath to shell out that amount of money just for a set of rotorblades.  I know I'm a tight arse.      So, I'm moving in the direction of making my own.  Perhaps composite, with metal spars covered by plasticard skinning.   It'd also allow me to make the advanced silencers.  Ditto for the rotor head.  Making that from metal would give it sufficient strength - something I've always found decidedly lacking in most helicopter kits (invariably in my experience the blades are the first thing to break ).

[rickshaw]

One thing that has interested me is the chord of the main wing in the Rotodyne - both the Y and the Z.   My limited understanding of aerodynamics is that fixed wings under rotors interfere with the rotor downwash and thereby reduce lift.  Both versions of the Rotodyne had very broad wings.   Surely this reduced the lift from the rotors more than a narrow chord wing would have?  Also, a broad chord wing creates greater drag in forward flight.  Again, the wings on the Rotodynes appears to be optimised to increase, rather than decrease drag.   As all aircraft are compromises, there must be some point where breadth versus downwash+drag is optimised.  Was this what happened in the Rotodyne design?

[rickshaw]

The 1/72 scale (almost)* semi-mythical Frog Rotodyne kit has surfaced at Ebay:

http://cgi.ebay.com.au/Frog-1-72-Fairey-Rotodyne-/370486366685?pt=LH_DefaultDomain_0&hash=item5642b551d

*fixed for Wooksta .

[The Wooksta!]

It isn't mythical.  I saw one on the Collecktakit stand at Telford some years back for a cool £250.

[Mossie]

I think £250 makes it mythical!