Bell AV-22A Mamba

[kitnut617]

Here's a little titbit that maybe you don't know, all the 1/72 V-22 kits except the Hasegawa one, are based on the first six V-22's to be built. There was a bad accident with one of them and one of the results of the investigation was that the engine nacelle was redesigned. You can see that I've revised the nacelle air scoops at the rear which corresponds with the real thing. BTW, I'm using an Italeri 1/72 V-22 kit as a donor for this project.

Pic of a real V-22 nacelle

[kitnut617]

Impressive engineering 

Thanks Chris

[Gondor]

Impressive engineering 

Seconded 

Gondor

[nighthunter]

Looks awesome!

[strobez]

Why do I get the feeling this thing is going to take off and fly around the room when it's done.   

[Old Wombat]

 

[zenrat]

This is just so much fun.  I can't wait for more.

Other solutions to arming an Osprey include synchronised guns on the nacelles firing through the rotors (synch by wire these days rather than the old fashioned mechanical way), gun barrels through the rotor hubs and a pusher version putting the blades behind the CoG (but also much closer to the ground on take off and landing).

[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

I forgot one:

CF-100

[kitnut617]

Thanks everyone ----- 

[kitnut617]

So my initial comment in my opening post about commiserating with Kit after reading about his trials and tribulations with his RotorCrane build, was because it sort of mirrors my efforts with this build. The rotors being one ---

While the idea sounds fairly simple, execution of what I wanted to do has been problematic. All the way down to getting the BERP ends to glue on to revising the twist to the blades because they're shorter.

I've been running my ideas past Evan, our resident aeronautical engineer, and while some of the ideas he liked, some he would suggest doing something else. One of the things he suggested was increasing the blade chord but then after initially shortening the blades as they were, there wasn't a lot to change. I then said 'what about BERP blade tips and he said he couldn't think of why not and that it would look kinda cool. So I decided on BERP blade tips.

I decided to copy the shape from one of the Merlin/Cormorant kits I had, and was surprised to find that the chord length of the blades were almost the same length, so it was just a case of duplicating the EH-101 BERP tips.

In this pic you can see how I've shortened the V-22 blade and added a BERP end. I have since shortened the blade a bit more than what is shown here.



Initially, I had made a BERP using 1.5mm styrene card but it proved to be to thin, so I remade it using 2mm card. After making up six blanks to shape it was the tedious job of sanding them into an airfoil shape. In this pic below, you can see the first effort which I've used as a template for all the others, and behind it is the second stack of 2mm blanks for the starboard nacelle all ready for the next sanding session.

[nighthunter]

Wow

[kitnut617]

So this is what I used for the revised nacelle shape, a C-130 'buddy' pod.



Also from a C-130 was what I'm using for my sponsons. But the end appearance won't be quite like it. They started off as the underwing tanks and in this pic I've added a stub wing which is from a V-22 wing.



I've then converted the tank by installing an u/c bay and a weapons bays and changed the tail end into a 'chisel' shape (I wanted it to look different).  I worked out a development for it to use some 1mm styrene card but after the first attempt to form it, it all split apart. So I had to redevelop it for some much thinner card which I had to do twice because there's not enough thickness for a lot of sanding.

The idea is to have the cross section look like this pod.



It will have similar doors, both for the u/c bay and the weapons bay. The u/c bay will have one door and the weapons bay will have two.

[kitnut617]

I was going to shorten the tanks, but the plan to have a weapons bay and a wheel bay nullified that idea.

That's because of what I've planned for the load-out. On the inside of each weapon bay door will be mounted a pair of Hellfires (I think I can get three to each door and I'm working on how the launch rail can be made). The doors will also mount ten 2.75" (70mm) RP's.

This pic I did a trial run to see how that would work out, I heat formed some 1.5mm card and then carefully recessed the leading edge and then using a drill bit that is the same diameter as what some RP pods have as rocket tubes, did a practice run.



Re-posting this pic below, you can see that the weapons bay length is dictated by the length of the Hellfire. Which just happens to be what is needed for the RP's used in a LAU-3/61 pod, the longer variant. I used the u/c bay from the V-22, but then shortened it some (not sure why the bay is so long, photos of V-22's with the gear down don't really reveal why). I shortened it so it was the same length as the shorter LAU-3/61 pod. That's because the u/c bay doors will also have RP tubes in them, only I've worked it out that I can get 15 in them.

[kitnut617]

These pics show I've added an APU and I have since added a flare dispenser to the rear of the sponson (pic of that later).

For the intake I used a Meteor air brake, the exhaust pipe is a bit of a curved sprue corner which I've hollowed out.

[kitnut617]

For the wing and fuselage top, I used the V-22 (obviously -- right).  I did that by cutting the whole top off each fuselage side, which then had the width reduced to suit the new fuselage. In this pic you can see I also cut out the u/c bay.



The wing parts were also reduced in width where it goes across the fuselage, these were all glued together and when dried, I filed out the center part to fit over the new fuselage I'm using.



Re-posting this pic because you can see the wing/top of fuselage.





The actual wing length is unchanged although the overall span is smaller.