Bell AV-22A Mamba

[kitnut617]

I have to commiserate with Kit after seeing his Rotorcrane project, I've been building this over the last few months since I posted my MB6 and Bronco projects here.  I've been working out the issues on one side first and then I'll do the other side.  It's a slow build though, I do a little bit each time I have some days off.

[kitnut617]

One of the things that's taking some time is the flaps, I'm going to try to make them work so that the model looks right when it's posed with the nacelles in various positions. Here I'm working out what needs to be done on another V-22 wing, once I've done that I'll do the AV-22.

The flap is in two parts (actually three), there's the main flap/aileron and then there's a strip which you can see along the leading edge of the flap here.



The idea I'm working on is to make the strip work independently to the flap, but to turn down by itself when I turn the flap down. Here I've done a test run to see if I can get a hinge to work for the strip.







It seems to work, so now it's onto the hinge for the flap and a mechanism to operate the strip part.

[NARSES2]

That's some prop' 

Looks good mate 

[PR19_Kit]

WHAAAAATTTT?! 

[kitnut617]

Thanks guys ---- he, he, he ----

[Scotaidh]

 

[nighthunter]

List of kits used, please?

[Dizzyfugu]

That's looking quite epic! 

[zenrat]

Fabulous.
I was just going to put Osprey wings onto a Hind.  This goes so much further.

[kitnut617]

Thanks everyone. The idea came about because of what I've been reading on the problems of arming a V-22. If you want to put anything that has to be fired (guns, missiles etc) they have to be mounted forward of the prop-rotor when it's in forward flight. This is because the tips of the blades run very close to the fuselage sides and practically blocks anything being mounted further back where the cg is. Other than bombs that is.

So I had two main criteria  --- first one was it had to be able to do head-on attacks, and the other was it had to out-perform the V-22. I don't see the use of an escort if what is being escorted is faster.

So my solution was to shorten the blades for mainly two reasons. One reason is the blade tip speed would be slower so would mean the aircraft can go faster, so my prop-rotor is 30 feet diameter, not 38 feet the V-22 has. I then decided that to compensate for the reduce blade area, I would add some more blades. I originally planned on having five per rotor but some conversations/consultations with someone who knows  ,
I settled on six because I was told that if I used five I would have to still use the counter balance bob-weights you see on the V-22 spinner, and that six would balance out naturally without having to use them.

Another reason is that I could place a lot of forward firing ordnance closer to the cg and have them firing between the blade tips and the fuselage.

The idea then progressed as to how the fuselage would be, I decided it had to be like a AH-1 Cobra and do what the Cobra does for the Huey, only do it for the V-22. So it's a dedicated attack tilt-rotor.

Then it was down to deciding how to go about it --- 

[kitnut617]

List of kits used, please?

Hmm! let's see if I can remember ---   

Kits used are all 1/72 except the spinners which are 1/48.

The main items come from these:
V-22
A-10
C-130
F-14
P-61
Minor items come from these:
F-15 (eventually)
A-26
Harrier
Spitfire (1/48)
Spitfire (1/72)
Meteor
AH-1W (Hellfires only)
And a lot of scratch building

[kitnut617]

In this pic you can see what I mean about how close the original blade tips are to the fuselage, and it's the same on the V-22

[kitnut617]

There's a precedent for going the six blade route, there was this Westland project from a few years ago.  I think though this is a tilt-wing not a tilt rotor as we know it today.

[kitnut617]

I had worked out in my AutoCad, that five blades would just about fit around the V-22 spinner but not with the counter balance bob-weights in place. Six blades do not fit the original spinner though, so I had to source a bigger spinner. After a lot of rummaging through the stash I realized that a spinner from a 1/48 Griffon Spitfire worked quite well and as you can get nice aftermarket replacement ones, I snaffled two of them from the 1/48 kits I have.

Now that created another problem, the bigger diameter spinner doesn't fit the nacelles. So I've had to revise the nacelle body, just around the gearbox though as I was told by he who knows, the lower engine housing shape was adequate for an upgraded engine. So by making the gearbox housing bigger, I'm able to explain how the gearbox had to be upgraded too, to handle the extra power and the dynamics of the new rotor.

Again rummaging through the stash, I found something that looked like it would work, I have an AModel vacuform C-130 conversion set for various types, and the air refueling buddy pods looked like just the ticket.

These pics show how I went about it.

[NARSES2]

Impressive engineering