Avro Atlantic Variants

[kitnut617]

Some of you know I'm building an Avro Atlantic on the 'other forum', but the main gist of the project was to do a 'wide-body' variant 'cause someone else had already built a 'standard' Atlantic, (but in the end I decided to build one too).  I have just in the last few days picked up the kit I will be using as a donor to do this build, a 1/72 Boeing 767.

The backstory is that Avro, much along the lines of the their Tudor, went a bit conservative with the size of the original fuselage diameter, and realized later that it should have been much bigger.  So after having Avro Canada build all the aircraft for the RAF needed (because they were booked solid with Vulcan orders at the time) a new design was proposed and accepted. It would use the fully developed wing of the Vulcan B.2 but with new inner wing to house more powerful engines, and turbofans to boot.

Here's a couple of pics of the 'standard' Atlantic as far as I've got with the build, although I have done a bit more to the rear fuselage than what these photos show. Bottom pic shows how I'm converting the Vulcan B.2 wing back to Vulcan B.1a wing, I'm using this wing because I had been in contact with a guy who was involved with the RW project and he told me had the Atlantic gone into production, it would have had this wing.

The model is in 1/72 scale.

[kitnut617]

Now here's a comparison between the standard Atlantc fuselage and the wide body variant I will start sometime in the near future.  I will modify the 767 tail to look more like the Vulcan tail only it will be bigger and I'll do some subtle changes to the profile to take out some of the Boeing look.

[GTX_Admin]

Now here's a comparison between the standard Atlantc fuselage and the wide body variant I will start sometime in the near future.  I will modify the 767 tail to look more like the Vulcan tail only it will be bigger and I'll do some subtle changes to the profile to take out some of the Boeing look.

Watching intently.

[kitnut617]

I was doing some 'matching-up-of-parts' over the weekend and found one of those strange coincidenses I find all the time while building my models.  It looks like I won't have to do too my surgery to the fuselage to get the Vulcan wing to fit, it just seems to fall into place -----  there's a large flat surface on the fuselage side which the 767 wing mates up to and the Vulcan wing just lays right there over it, all I have to do is to extend this flat surface further to the rear.

[ChrisF]

Love it !

[apophenia]

This is going to be very cool  :)

[elmayerle]

Where's the avatar for tongue lodged firmly in cheek?  I was going to ask if the wide-bodied Atlantic was going to be called the Pacific?  I'll leave now...

[kitnut617]

Where's the avatar for tongue lodged firmly in cheek?  I was going to ask if the wide-bodied Atlantic was going to be called the Pacific?  I'll leave now...

He! He!

Actually Evan, that's not a bad idea for it's name.     I think that's what I'll call it from now on.   :)

[Buzzbomb]

Really neato idea

[kitnut617]

Now that I've got the 767 I can now really plan what I want to do.  What I've seen so far makes it a fairly easy project, with the tricky bit being the new inner wing on each side to make from scratch.  This though has been made easier by understanding how the Vulcan wing works, or I should say, how the Vulcan structure works.

Studying a cutaway picture of a Vulcan (which appeared in Flight magazine) revealed to me that the very main part of the structure is really quite simple.  It's basically just six pieces, front spar, rear spar and four chord shaped ribs joining the two. The two spars are also the front and rear of the bomb bay, the two inner ribs are the walls of the bomb bay on the inside and the inner wall of the engine bay on the outside and the two outer ribs are the other engine bay walls.  Like this below, but before anyone says anything this is just a very basic sketch of how I see the main structure and is not to scale.  The rear spar is also the rear of the engine bay but the front of the engine bay is about a third of the bomb bay back from the front spar.

As you can see I've split the engine bay into two with two sub-spars and sub-ribs in each, which is how it shows in the cutaway drawing.  Everything else from what I can determine, hangs off this frame.

[kitnut617]

From what I've read, the Avro engineers had to be very creative when they installed the Olympus 301's, it was a very tight fit and not a lot of room left.  Measuring the Airfix Vulcan's fan fronts, they measure out to just a tad bigger than 13.5mm in diameter, the fan fronts I want to use in my 'Pacific', will be about 19mm in diameter so obviously the engine bays that are there are not big enough. So my plan is to do something like this below, I'll have to make the inner wing about 9/16" wider to accommodate the bigger diameter fan fronts.

[kitnut617]

Now this below is a rough comparison between the two inner wing frames, the section that goes through the fuselage would have a difference of 7'-0" in RW size, or 1 3/16" in 1/72 scale

[Rafael]

Kitnut, this is kit engineering at its best. I liked very much the plank and frame work in the rear of the original, and your craftsmanship skills show in the subsequent variations. This is a "little" jewel.
BTW, I didn't know this Avro bird, and your thread made me do a quick googling and found an interesting (Avro?) vintage model. Funny, all the seating is facing rearwards.
http://s35.photobucket.com/albums/d165/hws5mp/Avro%20Atlantic/

[kitnut617]

Not sure why the seats face backwards Rafael, it's a Brit thing I think because my wife tells me that when she and her family were flown overseas to Singapore and Hong Kong (her Dad was in the Brit Army), all the seats in the VC-10 were like that too.

There's a very large model of the Avro Atlantic at the Woodford Museum which is near Manchester in the UK, here's a pic of it.
 It looks like it's the same model as in your selection.

[taiidantomcat]

That is a helluva project! 

[Modelling_Mushi]

Not sure why the seats face backwards Rafael, it's a Brit thing I think because my wife tells me that when she and her family were flown overseas to Singapore and Hong Kong (her Dad was in the Brit Army), all the seats in the VC-10 were like that too.

Guys, I once looked into the backwards facing seat thing and I found out that the reason why it was adopted by the RAF VC-10 and some other a/c was that in a crash a person would suffer less injury facing backwards than forwards (I think that 2 of the things specifically mentioned was less cranial injury and neck injury form whiplash and also less chance of broken ankles [when facing forward and severe decelleration, your legs involuntarily fly forwards and upwards and the ankles get broken on the seat cross brace in front - then you cant move to get out and die in the smoke / fire]) . Seems the body was thought to cope with severe decelleration and impact better in that way. I also found out that the reason it is not in many (if any at all) commercial aircraft is that passengers did not like to face backwards and market testing showed the aircraft would be unpopular.

Ciao

[kitnut617]

I liked very much the plank and frame work in the rear of the original,

I think if I were to do it again, I would put in twice as many bulkheads to support the planks better. 

I can't say I came up with this idea because the flying model crowd would laugh me out of town, when I used to build my flying gliders and such, this was basically how I built them, only in balsa wood and tissue paper

[Daryl J.]

 :)

[Rafael]

Nice!
I've run up against that plastic problem in the past. Nowadays, when I build my masters I use the standard framing and fill the intervening spaces with EPS foam which is sandable and easy to shape. A little white glue as a surface protection and youcan make the external surface from resin, bondo paste, plaster or any other material you like, even plastic.

[kitnut617]

Over the last couple of days I've had a good look at the 767 fuselage, and come across some pleasant surprises. It looks more and more like this conversion will be fairly easy to do just by the way the 767 has been moulded.

I'd been pondering just where the new wing should actually go and decided that I should line up the main u/c legs in the same place --- well pleasant surprise #1;
If I fit the forward point of the Vulcan wing root where the 767 wing root starts, the u/c leg hinges line up almost exactly in the same place.
Pleasant surprise #2;, the chord profile of the Vulcan wing isn't far off the chord profile of the 767, except it's longer at the rear.
Pleasant surprise #3; I can make the Vulcan wing have the same incidence angle as how it is on the Vulcan without encroaching above the cabin floor.  The wing incidence of the 767 seems to be about the same as a Vulcans, at least they do on the model.

Although this below doesn't look it, the Vulcan wing has more area than the 767's.  Doing a fairly accurate comparison, the Vulcan wing works out to be about 440 square feet bigger (that's each side). Adding the extra I intend for the new inner wing section (basically the engine bays) I get an increase of area of 644 square feet.  Now whether that actually translates to better lift in the real world I wouldn't know.

[kitnut617]

I then got to think just what u/c I would put on this.  I'm going with Vulcan u/c on the Atlantic because the mainleg track would only be about 3'-3" wider than on a Vulcan (Vulcan's fuselage is 9'-3" dia' and the Atlantic is 12'-6" dia'), but on the Pacific with a fuselage diameter of 16'-6", the track will be a whopping 14 feet wider than the Vulcans by the time I've added the extra into the inner wings.  I started looking at various other undercarriages, specifically the 707's, and go with a centerline u/c leg too.  But fitting larger wheels the size of a 707's in the Vulcan wheelbay is marginal to say the least.  I then got an idea of using 'four' Vulcan legs, one either side of each engine bay, I'd go with the 8 wheels for the two inside u/c legs but just four wheels on the outer legs.  I think that would look quite neat.

[kitnut617]

Going back to the standard Atlantic, my idea is that it would be what is now called a Multi Roll Tanker Transport aircraft, the variant I'm building will be tanker capable.  I've decided to use the refueling pods from a Victor so I found the Victor kit I'm using to convert into a B.1 and swiped the pods out of it.  Then I had a look at the two wing tanks the Victor has and thought those would look about right on the Atlantic too, so after a bit of part matching, discovered a couple of things.

It seems the leading edge sweep of the Victor's wing at the point where the tanks are fitted, has the same sweep as the Vulcan inner wing section, because the tank pylons leading edge sweep practically matches it. Especially if I'm matching up the wings I'm using for the Atlantic which I'm converting into a Vulcan B.1a wing style.  Then I found that the chord profiles of the tank attaching face and the Vulcan wing are just about spot-on too, there only some very minor sanding to do to get it to fit exactly right.  This of course, could just be the quirks of the two kits I'm using.

So my Atlantic will have the two wing tanks and refueling pods and a 'swing-tail' and the Pacific will have a set of refueling pods and a Boeing Flying Refueling Boom (I've got a spare KC-10 conversion for that).

[kitnut617]

A couple of pics how I envision the Victor tanks will fit on --

[tc2324]

 

Come on, we need more updates.

[kitnut617]

I'll be getting back to this seriously, when I get my AV-19 finished.  Which I'm hoping won't be too long down the road.