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Junkers F13 Floatplane: Two Builds of the Same Aircraft


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junkers-f13w.jpg

I've got myself two of this kit, because I'm interested in building Construction Number 650 at two very different moments in its life.

This aircraft was part of the Junkers Spitsbergen Expedition of 1923, registered as D-260.

junkers-f13-D260-svalbard-1024x715.jpg

It spent the next decade knocking around Germany, Russia, Estonia and north Norway under various registrations, before ending up as the property of Nord-Norges Aero in 1932, registered as LN-ABH.

Junkers-F13-LN-ABH.jpg

 

Passengers were flown on sightseeing trips by Norway's famous aviatrix, Gidsken Jakobsen, until June 1934, when it "lost its engine" near Balestrand on the Sognefjord. Literally--the engine fell out of the aeroplane, landing in the fjord somewhere between Hella and Vangsnes. The pilot retrimmed the aircraft by inviting the front-seat passenger to climb out on to the cowling, after which a safe landing was made, but the aircraft never flew again.

 

I'm starting with the trickier option, LN-ABH. It's well documented, photographically, but many images are copyright of the Norsk Luftfartsmuseum (the one above is a rare public domain photograph). I'll post links to reference photos, as well as a few small detailed sections of the original images as "fair use quotations".

I'm aiming to reproduce the appearance in this copyright photograph, which I believe was taken later than the one above--but only because it seems more likely that someone painted a pale rudder black, rather than the other way around.

 

LN-ABH was considerably changed from its original configuration. It was fitted with that unusual home-grown rudder, for a start. But it had also been fitted with wider ailerons (visible in my linked picture), and at some point had lost the aerodynamic fairings on its float struts (see image above). It may also have been fitted with a new engine--it certainly lost its original rhino-horn exhaust, and was fitted with a new cowling with a row of rather improvised-looking exhausts on the starboard side.

exhaust-prop.jpg

(Original)

cowling.jpg

(Original)

I got myself a set of resin extended ailerons from Lumir at Master-X (I won't give a link at present, because his website is currently setting off a trojan warning in my browser), and some decals from Lima November decals (who also provide some very nice documentation for LN-ABH, too).

 

Then I carved a replacement rudder, put together some exhaust pipes, and created a slot in the kit cowling to receive the pipes in due course.

junkers-rudder-and-exhausts-1024x768.jpg

 

Filling the hole in the cowling was never going to come out perfectly.

junkers-cowling-1024x769.jpg

I'll distract attention by adding the tie-down lines visible in the photograph of the original aircraft, above.

 

Then I thinned the moulded shrouds on the float struts--originals above, adapted below:

junkers-struts-1024x769.jpg

Here they are in place:

junkers-floats-1024x768.jpg

And because this will be a flying model, I designed and printed myself a prop disc. The bands of yellow and brown are intended to reproduce the appearance of a rotating Heine propeller, laminated in alternating dark and light layers.

junkers-prop-1024x769.jpg

The boss is the original kit part, shorn of its blades and split in half with a razor saw.

 

And at some point I'm going to need to adapt Lima November's otherwise lovely decals. The typography on the real aircraft included a quite distinctive letter "N", which isn't reproduced by the decals (at right).

lettering.jpg

(Original)

 

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Hi, I sit down and watch with interest.

Do you know what it is? The D-260 had this thing mounted on the right side of the fuselage.

YPEu28am.jpg

Edited by KayFranz
image as miniature
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I'll be watching this build. 

 

I have this kit, with some Rising Decals resin and some JBot decals:

 

49901917053_d280b26992_b.jpg

 

 

This is what I would build:

 

50835758051_8537cb2dca_b.jpg

 

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50835836642_e4309979f1_b.jpg

 

50835836697_9773b97cc7_b.jpg

 

 

 

 

 

Chris

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8 hours ago, KayFranz said:

Hi, I sit down and watch with interest.

Do you know what it is? The D-260 had this thing mounted on the right side of the fuselage.
 

It's a puzzle to me. It looks like it has a little handle, about four o'clock, to revolve the circular component on the rectangular base plate, but to what end I cannot guess. Having looked through Andersson et al's book, I can't find it on any other aircraft, so it's some sort of custom fitting, which had been removed by the time it ended up with Gidsken Jakobsen.

I may end up having to scratch build it without understanding its function, but the appearance will be easy enough to reproduce.

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24 minutes ago, KayFranz said:

Additional fuel tank behind the cabin? And this is fuel filler?

I like that idea. If I read this site correctly the "mission" for D260 was to fly to the edge of the polar icecap to pick up Amundsen and Omdal if they got into difficulties and landed on the ice. Green Harbour (now Barentsburg) is at 78 degrees north, and the edge of the pack was at 82 degrees in the summer when I visited it. So we're talking a round trip of about 1000km (and the D260 did make a flight of that distance while in Svalbard). According to the ever-reliable Wikipedia, that would be well within the quoted range  for the standard F13 of 1400km--but I assume the floatplane dealt with a lot more drag and would have a shorter range. And they would probably need some loiter time, too.

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> And at some point I'm going to need to adapt Lima November's otherwise lovely decals.

>The typography on the real aircraft included a quite distinctive letter "N", which isn't reproduced by the decals (at right).

 

When I made these decals for Lima November twelve years ago those photos at Norsk Luftfartsmuseum were not available then. I have now made the corrections based on this newer material. Just contact me via email (arcticdecalsATgmail.com) and I'll send you corrected decals.

regards,

Mika

Arctic Decals

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14 hours ago, Mika Jernfors said:

> And at some point I'm going to need to adapt Lima November's otherwise lovely decals.

>The typography on the real aircraft included a quite distinctive letter "N", which isn't reproduced by the decals (at right).

 

When I made these decals for Lima November twelve years ago those photos at Norsk Luftfartsmuseum were not available then. I have now made the corrections based on this newer material. Just contact me via email (arcticdecalsATgmail.com) and I'll send you corrected decals.

regards,

Mika

Arctic Decals

Wow. Many thanks. I've sent you an email.

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Dear Hamiltonian

I built one of these last year and managed to put the floats on backwards, have you done the same thing? Turning them around was done with difficulty and I found the top ends of the struts did not match the holes under the wings.

 

Regards Toby

 

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The morning mail continues.

 

D260 from the left

 

uPc20Gem.jpg

 

Here is a float from my catalog called "Junkers F13". Is it exactly as you need - I am not sure, something was constantly changed during production and it does not have to be the same as your planes had. In my opinion, it should have four fittings for fixing the supports connecting the float to the hull, here you can only see three clearly, the fourth is almost invisible, but if you look carefully - it's there. The photo shows a view from the back side, the structure should be common to both floats - symmetrical.

 

I788zBIm.jpg

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Evocative period subject(s). Looking forward muchly to seeing your progress on these.

Best of luck!

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9 hours ago, Planebuilder62 said:

Dear Hamiltonian

I built one of these last year and managed to put the floats on backwards, have you done the same thing? Turning them around was done with difficulty and I found the top ends of the struts did not match the holes under the wings.

 

Regards Toby

 

Oops. Thanks for pointing that out. Fortunately, the strut assembly was just posed in place using the floats as a jig to get everything level and square. I should have put a bit of thought into it before I took the photograph--pointy end first looks intuitive, but the underside step would produce rather significant drag!

 

On dry fitting, I don't seem to have too much of a problem with the holes under the centre section--we'll see how it goes.

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10 hours ago, KayFranz said:

And morning mail ...
G-ACDP on the shore of a mountain lake.

Junkers-F13-G-CADP-of-Imperial-Oil-Ltd-o       Junkers-JL-6-G-CADP-Imperial-Oil-Ld.jpg

 

 

Larger views:

 

50841424483_80098a510f_b.jpg

 

50841424518_3660c5989a_o.jpg

 

 

 

 

Chris

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I'm painting parts of this before assembly. I'm mixing the Duralumin (masochistically) from Humbrol Aluminium and Gloss White, 4:1. Masking for the black paintwork seemed like it was going to be a challenge. The kit provides a decal for the edge of the black paint on the nose, but it's the wrong shape for this aircraft. I ended up scanning the kit part and constructing the necessary curves in a graphics program, then transferring the shape to Bare-Metal Foil, pressed into the corrugations with a cocktail stick.

nose-masked.jpg

nose-paint.jpg

Emboldened by this success, I embarked on something more complicated--masking the underside of the wing for its registration letters. Given that I will soon have Mika's revised decals, this was really a proof-of-concept effort, in anticipation of producing the underwing letters for D-260. (While I can print my own decals, I can't print my own metallic decals.)

So I printed the letters in reverse on the back of a sheet of Bare-Metal foil and cut them out:

creating-lower-wing-masks.jpg

lower-wing-masks.jpg

lower-wing-masked.jpg

And here's the result after a coat of black:

lower-wing-painted.jpg

I'm not hugely thrilled with the "B", which will need a bit of patching up.

 

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The interior is finished and painted, along with a couple of heavily modified figures from PJ Productions, depicting pilot and passenger.

junkers-interior-2.jpg

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No need for the engine, given that the kit cowling is now completely closed.

 

(I did once consider modelling this aircraft after its "engine loss", with the prop stopped, the lower panel dangling and the passenger out on the cowling, but I decided it would a) require too much explanation and b) probably be beyond my skills.)

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The floats are now mounted on the lower part of the wings. I've also added the little boarding ladder on the port side, fashioned from brass rod.

struts1.jpg

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The ladder seems to have gone through two version in the orginal aircraft--one that sloped markedly and one near-vertical:

ladder-detail-1.jpg

(Original image)

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(Original image)

I've gone for the more vertical version simply because I think the sloping version would be vaguely visible as a diagonal shadow (behind the man in the boat) in the photograph I'm using for this build: https://digitaltmuseum.org/021015549062/ett-fly-junkers-f-13w-i-1932-omregistrert-ln-abh-og-solgt-til-nord-norges

 

I've deviated from the assembly order stipulated in the kit instructions, because I thought it would be easier to get the struts in position with the wing assembly open. I was able to place the upper end of each strut into its locating hole on the wing and apply a dollop of CA gel down the locating hole from the inside of the wing, working my way through all the struts progressively with a little nudge here and there being all that was required to get everything connected. I also wanted to keep the wing open while the floats went on so that I could place an interior neodymium magnet to attach the aircraft to an old Airfix stand I've butchered:

stand1.jpg

This fits fairly neatly between the floats and cross-struts, and the interior magnet will be easily accommodated within the thick central chord of the wing assembly:

spacer.png

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I'll choose a final position for the interior magnet once I have a better sense of the centre of gravity of the whole kit, after the fuselage and tail are assembled.

 

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It turns out that both the fuselage halves and the interior floor have either lost, or never had, the appropriate curvature to come together easily.

So getting the interior attached to the first fuselage half was a bit of a war of attrition, working along the interior length with a succession of CA-glue-and-clamp manoeuvres.

Here's the final result:

first-fuselage-half.jpg

The kit windows are horrible, with scant overlap around the edges in which to hid the flaws associated with the sprue attachments--you can see some examples, above.

I didn't spend a lot of time on the passenger compartment, which will be largely invisible behind the horrible windows. I'll need to up my game for D 260, which I'm planning to model with a door open, though it'll take a lot of work on the interior to make that worthwhile. It also seems I'll need to shorten the rear seating provided with the kit, which (as you'll see) ludicrously overlaps the very narrow bottom of the doors.

 

Once I got the interior properly attached, a bit of dry fitting suggested the roof will actually fit pretty well. And the second fuselage half went on neatly--starting with closing the tail section and letting the glue dry, then a very gentle tweak on to the locating studs for the interior, and then curving and closing the nose around the lower panel.

fuselage-halves-1.jpg

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So my impression (so far!) is that these are actually well-fitting parts that have acquired unfortunate curvature while sitting in the box.

Watch this space for the roof going on, though.

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Dear H

When I built one of these I found the fuselage walls needed spreading a little at the top to match the width of the fuselage top section. Hope yours fits better than my Revell kit.

 

regards Toby

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10 hours ago, Planebuilder62 said:

When I built one of these I found the fuselage walls needed spreading a little at the top to match the width of the fuselage top section. Hope yours fits better than my Revell kit.

Mine seems to be fine. The top section was slightly bowed, as with all the other big parts, but a nice neat fit. There was a slight overhang of a fraction of a millimetre either side at the tail, which I picked up before gluing. I just needed to pop the glue between the two fuselage halves at the tail, and let them sit very slightly ajar while I glued the top section tail neatly in place. Then I reclosed the underside of the tail, where the left and right sections meet, under slight tension. The tiny remaining gap in the midline at rear will be completely covered by the rudder.

Photographs will follow once I have the tailplanes and rudder on.

 

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I love builds with a story behind them, and this is certainly one! I admire your attention to the individual details.


Cutting curved stencils is always a nightmare. For your “B” have you considered a decal with a clear “B” and a thickish black outline? (I presume it’s a black underside). The black decal edge would give you a bit of leeway with some not-too-sticky masking medium when you are painting the black.

 

Regards,

Adrian

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23 hours ago, AdrianMF said:

I love builds with a story behind them, and this is certainly one! I admire your attention to the individual details.


Cutting curved stencils is always a nightmare. For your “B” have you considered a decal with a clear “B” and a thickish black outline? (I presume it’s a black underside). The black decal edge would give you a bit of leeway with some not-too-sticky masking medium when you are painting the black.

 

That's a very nice idea--an extension of the paint-demarcation decal provided with the kit. I've filed it away for future use, thanks!

 

It's certainly an aircraft with a story to tell. I first heard about Gidsken Jakobsen and her Junkers F13W one afternoon at the Norwegian Museum of Travel and Tourism in Balestrand, where they have a nice little cinema that shows a documentary film about her. I'd ordered the Revell kit within an hour of getting back to our hotel. Then discovering that the same aircraft had also been involved in the exploration of Svalbard, one of my favourite places in the world, made it obvious that I needed to build it twice!

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So the CoG of the fuselage is back around the wing trailing edge. I've done a bit of revision work on the exhausts, so photographs of that will follow. But with the weight of the wings and floats towards the leading edge, it means I won't be too far off the CoG of the entire aircraft if I plonk the internal magnet right in the middle of the wing assembly. Here it is, in a little puddle of epoxy:

magnet-in-place.jpg

Easily within the footprint of the stand, as you'll see. You'll also see I've slightly displaced my boarding ladder during handling, so I'll need to attend to that.

The wings came together easily--again, a neat fit but slightly bowed. I slipped a bit of 0.75mm-thick styrene strip into the gap where I've excised the kit ailerons, because otherwise the wing gaped at that point. Resin ailerons from Master-X will follow.

wings-assembled-2.jpgspacer.png

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Master-X replacement ailerons are now on.

ailerons.jpg

They're a nice fit. A little light sanding to get them snug along their length, and one had a very slight vertical bow to it, which came out easily with a little hot water and some slight pressure. I also completely redid the boarding ladder, which I'd managed to dislodge--I'm more satisfied with the finish and the rung spacing on this one.

 

Here's the fuselage, as complete as it will be before final assembly:

fuselage-1.jpg

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It includes my interpretation of the rather informal-looking exhausts (styrene strip and rod), and the tie-downs across the cowling (added using stretched sprue). Reference photos below.

cowling.jpg

(Original)

exhaust-prop.jpg

(Original)

 

I'm going to keep fuselage and wings separate, for ease of applying the large decals when they arrive.

 

Time to open the second box and start work on D 260.

 

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