MiniArt Junkers F13 Mid Production (48005) 1:48

[Mike]

Junkers F13 Mid Production (48005)

German, Polish & Swiss Service

1:48 MiniArt via Creative Models Ltd

 

 

The design process that led to the Junkers F13 was begun while WWI was still raging, and it was an unconventional and advanced design for the time, when most aircraft were still wood and canvas biplanes that were strengthened by copious rigging wires that created excess drag, making them slow and delicate.  The J13 as it was initially called first flew in 1919, and reached maturity during a time that Germany was prevented from having an Air Force, and the market was flooded with military surplus aircraft that could be quickly and cheaply converted into rudimentary airliners or transports.  It had a few cards up its sleeve however, such as its all-metal monoplane construction that was far easier to protect from the deleterious effects of weather, especially in humid or damp climates.  Through careful design and extensive testing, it had a clean aerodynamic profile that meant a lower power output engine could be utilised to achieve desired speeds, meaning that it could be fitted with different engines from many manufacturers, rather than being saddled with a single high-output and potentially temperamental power-plant.  It was crewed by one pilot with a spare seat to his side twin control columns, and a further four passenger seats in the rear compartment, utilising the cockpit seat for an extra passenger should the need arise.  Its stressed, corrugated duralumin skin and internal bracing made it both light and strong, with the fuselage attached to the top of the wing, which gave the crew and passengers an extra layer of protection in the event of a rough landing that compromised the gear legs.  It also had an unusual trimming system that utilised fuel that was pumped between header tanks in the fore and aft of the fuselage to adjust for centre of gravity changes of the aircraft, and its fixed gear was simple to replace with skis or floats if the need arose.

 

Germany was prevented from building any aircraft until 1921, which resulted in initial sales going overseas, even selling to England and America, Germany’s former enemies.  It became so popular thanks to its many appealing qualities that within a few years it constituted around 40% of the world’s civilian air-traffic, and was a familiar sight in the skies of many countries around the world.  Production continued until 1932, and included license-built examples that were manufactured in Russia and America, with airframes around the world continuing commercial service until the early 50s, whilst civilian operators were less inclined to give up flying them.  The type’s development was mostly centred on the engine type that was mounted in the nose, having several options during its life-time, but there was also a stretched-fuselage variant that could carry more load, and the afore-mentioned float or ski options.  More unusual variants were created by users, including a light bomber in China, a bizarre ground-attack aircraft in the US that mounted thirty downward-firing machine guns to pepper enemy troops below, and Soviet forces pressed some of their aircraft into military service with the Red Army.  The aircraft remained popular despite its age, and in the new millennium, a Swiss-German company decided to create a series of replica airframes in the noughties, utilising as much of the original design as possible, but substituting a more modern Pratt & Whitney engine and precision instruments where the improvement would be worth the change.  The design was based upon original blueprints and a laser-scan of an original airframe to confirm their accuracy, but at $2.5m per example, there won’t be too many gracing the skies any time soon.

 

 

The Kit

This is a new boxing of a recent tooling from MiniArt of this grandfather of the Ju.52 that utilised many of the same technologies and engineering techniques that were pioneered in this small aircraft.  The kit arrives in a standard MiniArt top-opening box with a painting of the subject-matter on the top that is parked on a grass field on a sunny day, and has the decal option profiles on one of the sides.  Inside the box are twelve sprues of various sizes in grey styrene, a clear sprue, a fret of Photo-Etch (PE) brass, a large decal sheet, and the instruction booklet that has a cover printed in colour, with a full set of profiles on the front and rear pages, also in colour.  Detail is up to MiniArt’s current standards, and examining the sprues reveals a huge quantity of detail that extends across the entire exterior, covering the model with finely rendered corrugations, and where appropriate, these corrugations also extend to the interior.  The cockpit is well-rendered, and sits behind a replica of the BMW IIIa six-cylinder engine, with a radiator at the front, while the passenger compartment has a humped floor just like the real thing to accommodate the wing spars under the floor.  This edition also sports extended span wings, and the changes to the airframe commensurate with this mid production airframe.

 

 

 

 

 

 

 

 

 

 

 

 

Construction begins with the starboard rear fuselage, which has a window and two bulkheads fitted, setting it aside whilst building the cockpit on its contoured floor.  The two control columns are detailed with a lamination of two PE layers that represent the control cables, fitting a bow-tie wheel at the top of each one, and setting them in place through rectangular holes in the floor, mounting rudder pedals in front, and making up two barrel seats from two styrene parts and PE lap-belts, setting those aside while the unusually-shaped instrument panel is further detailed with levers and controls, plus a few PE parts, adding another PE lever between the columns along with a styrene part.  The panel is decaled extensively after painting, and is fitted to a bulkhead via a C-shaped stand-off bracket that locates on two recesses.  This too is put aside, mounting the starboard fuselage half to the short cruciform fuselage floor after drilling out a few holes, and fitting two optional boxes in place in the wing roots if you plan on building your model with the wings mounted for flight.  The forward section of the fuselage has three window panes added and is fixed to the rear, using raised guides in the floor to ensure the assembly is straight and true.  The cockpit is fitted next, and will be useful to help align the fuselage sides, fixing the two seats in place, then adding the instrument panel on its bulkhead.  Another bulkhead is made to separate the cockpit from the passengers, adding a window and two tied-back curtains, plus a pair of wedge-shaped strengtheners into slots at the sides.  Two more individual two-part seats with PE lap-belts are made and inserted in the floor as the front row, building a four-part bench seat/sofa that also has PE seatbelts added, gluing it to a stepped bulkhead, and fitting that into the rear of the passenger compartment, using the guides to ensure it is correctly aligned.  A handle is inserted into a hole in the side door, fixing another to the opening door on the opposite side later.

 

 

The six-cylinder in-line BMW engine is based upon a two-part block, into which the individual cylinders are dropped, adding a prop-axle and generator, then completing the tops of the cylinder heads, cooling tubing, wiring loom, air-intake and exhaust manifold to the sides, ending the manifold with a vertical horn if you plan on leaving the cowling open.  Engine mounts are installed on both sides of the bay, lowering the completed engine into position between them, fitting the radiator after gluing the rear and a PE cross-brace to it, and a fixed aft cowling panel.  The opposite side of the fuselage is made from two almost identical (but handed) parts, although a separate door is included, fitting the windows, a door handle and rail, and drilling two small holes in the rear section close to the wing root.  The completed parts are then brought in and glued to the floor, creating a cowling for the engine bay from top and side parts, with a further option of a PE strap around it if you wish.  The cowling open option isn’t discussed any further in the instructions, which is unusual.  A folded PE part is available to replace a styrene grab-handle part if you prefer, mounting it on the forward section of the cowling, fitting the roof on the fuselage after adding a circular light to the inside and drilling a small hole nearby.  Another styrene or PE grab-handle is fixed to the side cowling on both sides, and a pair of clear windscreens are installed in front of the cockpit, as this variant also didn’t have an enclosed cockpit, which is tough luck for the crew.  At the rear, the elevator is made from upper and lower halves, the upper half having the entire flying surfaces moulded-in to achieve a slim trailing edge, mounting it on the open rear of the fuselage behind the roof panel.  The new straight tapered tail fin is slotted into the top of the elevator, with the rudder moulded-in.

 

There are two short C-beams provided for the inner wing upper panels, which are only utilised if the wings are to be built ready for flight, fitting into a recess under the short inner wing panels, then gluing them into place either side of the fuselage.  At this stage the decision must be made whether to mount the wings, or leave them off for transport, using either three parts to create the joint for the mounted option, or an open rib with a socket glued behind it that will be seen in the wingless option, depending on your choice.  Your preferred insert is glued into the ends of the inner panels, adding a pair of intakes under the belly, fitting a PE crew step under the port trailing-edge, the tail-skid under the rear, and a PE actuator tab in a recess on the rudder.  More PE or styrene grab-handles are fitted to the rear fuselage for ground-handling, and around the square back windows to ease access to the door over the wing.

 

The extended outer wing panels are stiffened by adding two ribs to the grooves moulded into the inner surfaces, and slotting a three-quarter span spar lengthways into the grooves in the ribs, cutting the inner ends off as indicated if you are leaving the wings off the airframe.  The wing underside is glued to the uppers over the spar, and once the glue is cured, the ailerons can be fitted into the cut-outs in the trailing edges along with grab-handles in drilled-out holes under the wingtips.  They are put to the side for a while so that the landing gear can be made, which is based upon a K-shaped axle, which has a pair of V-shaped supports glued near the ends, finishing the assembly with a pair of two-part wheels, or using two-part tyres with PE spokes spaced apart by a hollow bearing in the centre, and mounting the completed gear in the recesses under the belly between the wings.  The supports are handed, so be careful when putting them together to ensure the correct parts are used.  The wings are completed by fitting PE actuators at the inner ends of the ailerons, after which the completed assemblies can either be slipped into their slots in the inner wing panels and glued, or depicted stowed nearby in whatever fashion you choose.  An aerial mast is slotted into the roof behind the cockpit, and a choice of two propellers with or without spinner is supplied for you to complete the build.

 

 

Markings

There are three decal options on the large sheet, all wearing the same basic scheme of silver over black, with a black engine cowling and landing gear, differentiated mainly by the large individual markings and black or red wing bands.  From the box you can build one of the following:

 

• CH-91 Ad Astra Aero, Switzerland, Early 1920s
• P-PALD ‘Daniel’ PLL Aerolot, Poland, Early 1920s
• D-230 ‘Wieldehopf’ Deutsche Luft Hansa AG, 1920s

 

 

 

Decals are screen printed by Cartograf, which is a guarantee of good registration, sharpness and colour density, with a thin matt carrier film cut close to the printed areas.

 

 

Conclusion

This popular aircraft went through design changes through its career like many other successful designs, extending the wingspan, changing the underside of the fuselage from flatter to tapered, and amending the shape of the tail fin, all of which are depicted here.  Detail is excellent, and the kit should build into a creditable replica of this corrugated monoplane.

 

Highly recommended.

 

 

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