The CRDA Cant Z.506 Airone (Heron) made its maiden flight in 1935 intended as a medium range floatplane airliner. Setting several records as soon as entering into service, it was operated through the Ala Littoria network.

C.R.D.A. stands for "Cantieri Riuniti Dell'Adriatico" (United Works of Adriatic). The letter "Z" is used after its designer: the famous Filippo Zappatta. The Z.506 is also the most famous and the most produced of his aircraft.

A military variant was then decided to be produced : The Z.506B kitted in 1/72 scale by Supermodel with a narrower fuselage, a weapons bay and several turrets or observer windows.

The Z.506C is the final civilian variant which is fitted with the Alfa Romeo 126 engines and the reinforced tailplane of the Z.506B.

Some early civilian Z.506 have been converted to Z.506C. Only one landplane variant has also been produced with lovely spatted wheels, sometimes reffered as Z.506T (Terrestre).

These gracious and dependable aircraft flew intensively in peace time as well as during World War Two. Some got operated until 1959. 

About Reference: Historians usually don't seem to pay interest to aircraft which are not involved in famous battles or overall fitted with deadly weapons. Therefore, you may find reference and data about the military Z.506B everywhere, but the civilian variants are poorly represented. The must as reference material for the subject is the issue #5 of Ali d'Italia although not surprisingly the major part of this monography being dedicated to the military variant... I've been collecting as much document as I could for a couple of years before being committed into building a model, and fortunately received support from some fellow modelers. Thence I have to thank Jean-Claude Guell, Fabio Beato, and Alex Meneghini for their very significant help! Getting involved in a civilian Airone is anyway matter of investigation, guesswork, and interpretation especially in the colors domain. Here is my own "interpretation" of the Cant Z.506C.

The ingredients I collected prior to start construction were:

1. The Supermodel 1/72 injected kit for the Z.506B (or Z.506S rescue sub-variant). I purchased this kit in a poorly conditioned box on eBay for a very high price at a time it had become a true rarity, to see it reissued pretty soon afterwards and available in quantity for decent prices...
2. The  Broplan civilian conversion consisting of  vacformed fuselage, bulkhaeds, wing spar, tailplane, and clear parts. The tailplane is the one that should be used for an early Z.506. Unfortunately no decals were provided.
3. An RCR photoetched brass detailing set for the military version, however part of it is useful for the Z.506C.
4. A set of 1/72 DC-3 resin seats of unknown origin, which I had from a private retailer.
5. Tauro Model decal sheets #72529 ( S.73 and Ju 52) and #72558 (S.73 and DC-3) for italian airliners.

Broplan's plastic is very thin, which is easy to work, but implies strenghtening operations to be seen later. After removing fuselage parts from their vac sheets, I set pencil marks on canopy limits to remove the corresponding styrene, then roughly cut cabin windows and cockpit area. I elected not to use the clear vac provided for cabin windows after cutting them out. Instead I used thicker clear plastic of my own, which I dry inserted and coated with Future floor polish on the internal sides, to seal them from outside using thin superglue. Once dry they were sanded flush up to the thinnest grade I had. There are also small round windows behind the cockpit. These are made from clear sprue, superglue inserted, then sanded flush.

Then I inserted some additional styrene to strengthen the wing roots and to obtain a decent cabin wall, to cut appropriate holes for the wing spar.

Interior construction started inserting some bulkheads and decking according to what seemed the most logical to me in the total lack of reference at that time. Structural components from Evergreen rods were also added which improve stength as well. Full interior was built so from personal inspiration, to discover a picture of the cabin layout several weeks after having joined the fuselage halves...! And even more frustration  when discovering that the picture I had taken just prior to close the fuselage ...was blurred...! Since then I tried to improve the picture by Photoshop but the one here is the only available...The curtains are made from kitchen aluminium foil. Cockpit interior was made using part of the RCR etched fret.

Once the fuselage halves were joined and the tail section added, not without some fitting problems, components of what I believe to be part of the environmental system were scratchbuilt on top and bottom of the fuselage, as well as the ram air generator mast. The generator itself is made from an Aeroclub metal set as the one provided by Supermodel did not seem too realistic. The wing spar which had been thouroughly tested and dry fitted previously was finally glued in place, with every gap sealed to prevent from foreign objects and dust to penetrate inside the fuselage.

The Supermodel kit has raised panel lines, which I converted to recessed by using a scribing tool along the still raised lines to sand everything afterwards. This operation was carried out for the wings, floats, and cowls. Floats proper position depending on wing dihedral and sweep, fitting of wings was crucial and tricky. once glued in place, a quick dry fitting of floats was conducted before glue would completely dry to allow for last minute adjustments. To proceed so, I used the clear plastic display device provided by Supermodel as a jig, but had to widen it very slightly to compensate from the civilian fuselage wider than the military one.

Bits of plastic were then inserted in the wing root gaps, as well as Karman fairings from the military fuselage which I cut accordingly to Broplan's instructions. To fill the remaining holes and gaps, I did not use any putty, but my favourite mix of Superglue gel and talcum powder, which has about the same consistency than plastic and makes a very strong cement when dry, an essential feature in such circumstances. When sanding of wing roots was completed, masking of windows and canopy was done prior to painting.

The painting process could now begin. As I elected for the very paint scheme suggested by Broplan's instructions, I realized that it contained some errors. Actually, about every source of reference on the subject contains errors, and it's up to you to identify accurate or wrong information. After quite a bit of research, I concluded that Cant Z.506 I-DOTE had red patterns on "bianco avorio" ("Ivory" - not "cream"), except that the top of wings had aluminium dope as background (these aircraft had a wooden wing structure covered by plywood and fabric). This is "Ala Littoria Nucleo Communicazioni" scheme as far as I understand, which was later implemented with a large tricolor fuselage stripe on the rear fuselage and Italian flags on every flying surface at the begining of World War Two in 1939, or may be earlier during Spain's civil war.

Therefore I believe that Broplan's instructions contain the following inaccuracies:

1. Upper wing patterns are missing one element each side (there should be 9 instead of 8 per wing)
2. Color pattern upper wings is suggested as Red on Ivory (should be Red on Silver)
3. Scalloping on upper wings starts too far on the aft part of the wing (it should start almost immediately aft of the leading edge)
4. Scalloping is missing between windshield and central engine
5. Scalloping is missing upper aft fuselage, in front of fin.

It has to be noted that various paint schemes have been worn by civilian Z.506s, the early red and silver livery being best known. However, some seem to have worn blue patterns or different wing schemes as suggested by several publications.

First of all the floats were prepared for final assembly, coated with TS-30 "Silver Leaf" Tamiya spraycan, then with TS-29 "Semi-gloss Black".

The rest of the model was sprayed TS-30  "Silver Leaf" overall. Once dry, began the masking process for the upper wings. The operation consisted in placing a large stripe of Tamiya masking tape on the upper wings, then in carefully drawing the required scalloping on it using a pencil. The tape has to be removed and symetrically applied each side of a thin plastic sheet (I use plastic dividers). Every section of scalloping has to be cut separately using a sharp cutter, in a way both sides of the plastic sheet are evenly cut, thus obtaining a good symetry when applying one by one each section of masking tape on the upper wings again. Needless to say that such process requires wife and kids away, cellphones OFF, and the relaxing music of your choice...

The next coat involved a Tamiya TS-7 "Racing White" spraycan, which is a perfect match with "Bianco Avorio".

Another full day of masking and a coat of TS-8 "Italian Red" (of course!) was applied. I handbrushed the Cockpit structure and window borders with Modelmasters "Chrome Silver" enamel.

The engines from the Supermodel kit were painted dark grey and flat black, then dry brushed with "Chrome Silver". The exhausts were drilled to become more realistic and sanded flush to their collector ring once glued in place. To paint the cowlings, I used TS-30 "Silver Leaf" then handbrushed a coat of "Future". This way, the "Bronze" shade of the exhaust collector ring could be handpainted without melting with the silver. The tricky part was to let a thin ring of silver appear at the very beginning of the cowl lip as for real on Bristol Pegasus engines and such foreign variant as Alfa Romeo 126. For that I cut a thin cicular strip of masking tape using a compass-cutter at its near-minimum range of diameters, then carefully applied it the most accurately I could on the cowl lip. The bronze shade was obtained in mixing roughly Copper, Aluminium, and Brown enamels on a paper sheet. I realized at the final stages of completion of this model that I had forgotten the small carburetor intakes, the reason why they cannot be seen on the picture.

Once the masks were removed, a full day decalling session could take place:

• The small "Ala Littoria S.A." white letters come from a "Decal Details" sheet printed by Beacon Publications, designed for aircraft and armor mini scales, which I found in a Californian swap meet.
• Fuselage registration was obtained from Tally Ho German letters which are very similar to the Italians.
• Wing registration are made from the above mentioned Tauro Models sheets and plain black decal by cutting and assembling various elements.
• The "Ala Littoria Nucleo Communicazioni" logos each side of the fuselage aft central engine come from one of the Tauro Models sheets
• The fascist emblems each side of the central engine cowling are from the Supermodel kit.

After receiving two hanbrushed coats of "Future", floats were superglued in place. Due to the extra width of the civilian fuselage, the fuselage-to-floats struts from the Supermodel kit were a bit too short so I replaced them with Contrail Aerofoil Sections.

The rigging of float mountings and tail were made from Plastruct 0.3mm rods, the aerial antenna are hairs provided by my devoted lady. The props are natural metal and black painted on the back sides, spinners should receive the very same blue which can be seen on the Ala Littoria logo.

Now I'm rather happy with the result and a nice eyecatching subject in my showcase. Despite some unknown zones, I've been highly rewarded in reaching completion of what I consider an ambitious project!

Cheers!