Nick_Karatzides

CHAPTER I - Building process planning This helicopter has a special significance for me - it is one of my favourites. To be honest, I always wanted to build it under scale, since I was a kid and had seen it for the first time during an elementary school visit to Hellenic Army Aviation AB. As far as I know, it is available as a scale model kit by Special Hobby into 1/72 scale and Profiline into 1/48 scale, but didn’t manage to find a large (eg 1/32) scale kit sold in the hobby shops. That means scratchbuild party time, using styrene plastic sheet, epoxy putty, basswood and my best of luck. Building from scratch, is actually (from my POV) the essence of scale modeling, because it offers the satisfaction to build a unique, one-of-a-kind model. Unfortunately, scratchbuilding may also bring up unpleasant surprises if the scale modeler does not previously provide efficient references and have planned a comprehensive working methodology by which to proceed all construction stages. For this reason and to ensure that I will successfully manage to handle any difficulties that might arise, I preplanned every construction stage, scheduled a time period to achive my goals and determine in advance which parts will be built earlier and which later to finally set assembled as a realistic looking scale model. Bubble shaped cabin & clear canopy construction, Instrument panel & cockpit components construction, Undercarriage skids & shock absorbers construction, Main internal framework & components construction, Engine & pwr transmission components construction, Tail boom airframe and tail rotor blades construction, Fuel tank canister and supporting plate construction, Main rotor blades & transmission shaft construction, Clear canopy installation on the bubble shaped cabin, Individual built parts primer coat and paint applying, Decals, wash and weather effects applying on paint, Individual built and paint parts final test & assemble, Airfield tarmac diorama display base construction.

1/18 scale Schweizer S-300C / Breda Nardi Hughes NH-300C scratchbuild model The Hughes TH-55 Osage was a piston powered light training helicopter produced for the United States Army. It was also produced as the Model 269 family of light utility helicopters, some of which were marketed as the Model 300. The Model 300C was produced and further developed by Schweizer Aircraft Corporation as S-300 after 1983. The Hughes 300 has been also built under license by: Kawasaki Jukogyo KK in Japan, for delivery to the Nihon Rikujyo Jieitai (Japanese Ground Self Defence Force) and given the Japanese military serials 61301 to 61338 at Akeno, Kasumigaura, and Iwanuma. Breda Nardi in Italy, for delivery to the Aeroporia Stratou (Hellenic Army Aviation) and given the Greek military serials ES-111 to ES-130 In both countries, the parts were initially imported from the United States with full scale production following later. Now, manufactured by Schweizer Aircraft Corporation, a recent subsidiary of Sikorsky Aircraft, the basic design has been in production for almost 50 years. The three bladed main rotor and piston powered Schweizer S-300 is mostly used as a cost effective platform for training and agriculture. The helicopter was created with a fully articulated clockwise rotating (as seen from the cockpit), three bladed main rotor and a two bladed tail rotor that would remain as distinctive characteristics of all its variants. It also has shock absorber dampened, skid type landing gear. The flight controls are directly linked to the control surfaces of the helicopter so there are no hydraulic systems. There are generally two sets of controls, although this was optional on the civil version. Frakie steps out of his private helicopter. The glass with Scotch in hand doesn’t surprise me. What really strikes me is that he does not hold a lit Cuban in his other hand. The Schweizer S-300C / Breda Nardi Hughes NH-300C helicopter has flown under Greek flag markings, with two users: Schweizer S-300C with Olympic Aviation - subsidiary of Olympic Airlines Olympic Airlines (now Olympic Air) was the flag carrier airline of Greece, operated services to domestic & world-wide destinations. It was formed by invested by Greek shipping-magnate Aristotle Onassis, back in 1957 as Olympic Airways and the company developed rapidly. Under Aristotle Onassis' leadership, the airline gained a reputation for lavish style. The cabin crews were attired in Pierre Cardin designed uniforms and passengers ate with golden cutlery and listened to the stylings of a pianist in the first class cabin. On 22 January 1973, an incident occurred that dramatically changed the future of OA. The death of Aristotle Onassis' son, Alexander, in a plane crash came as a shock to the Greek people and a new phase began for Olympic Airways. A few months later, Aristotle Onassis sold all of the OA shares to the Greek State and died shortly after in 1975. By December 2003, the Olympic Airways Group of Companies owned Olympic Airways, Olympic Aviation, Macedonian Airlines, Galileo Hellas, Olympic Fuel Company, Olympic Into Plane Company and Olympic Catering restructured by the Greek State and renamed as Olympic Airlines SA. On March 2009, the Greek State announced they had reached an agreement to sell the flight operations, ground handling operations and technical base of the group to MIG - Marfin Investment Group, the largest Greek investment fund, thus ending a 35-year period of state ownership. On September 2009 Olympic Airlines ceased all operations and most flights and Olympic Air, the new airline formed from its privatization, commenced flights. Sketch diagrams by Nick Karatzides Schweizer S-300C registered as SX-HNB with Olympic Aviation markings as seen at Eleftherios Venizelos LGAV airport on February 6, 2008. This specific helicopter had an emergency landing on mount Parnitha on 22/4/2008. Photograph by Alex Filippopoulos. Breda Nardi Hughes NH-300C with Hellenic Army School of Aviation The Hellenic Army School of Aviation, based at Stefanovikio AB, Greece, operates 20 Breda Nardi Hughes NH-300C (actually Italian made S-300 built by Breda Nardi under Schweizer Aircraft Corporation licence) helicopters for the initial rotary aviation training, received in 1985, replacing in this role the old Bell OH-13/47G Sioux helicopters. The total flight training lasts 44 weeks and the training conducted by Breda Nardi Hughes NH-300C helicopter, lasts 15 weeks. Each student completes 30 flight hours behind the NH-300C controls before proceed to the next level. Each student pilot works with his own flight instructor. Every flight hour is conducted in the presence of the flight instructor seated as co-pilot while the helicopter is operated by the student pilot. Today, after almost 27 years in Greek service and about 35000 hours of training conducted in this type of helicopter, the ratio of accidents to personnel is zero, proving the reliability of the helicopter, despite the large strain susceptible because of nature of training. Sketch diagrams by Nick Karatzides Breda Nardi Hughes NH-300C registered as ES-111 with Hellenic Army Aviation markings as seen at Stefanovikio AB located at LGSV airport on September 16 2008. Photograph by Chris Lofting. According to Textron Lycoming engine manual legend: “AE” means “Aerobatic Engine”, “H” means “Helicopter”, “I” means “fuel Injected”, “L” means “Left hand rotation crankshaft”, “O” means “Opposed cylinders”, “T” means “Turbocharged”. The Hellenic Army’s Breda Nardi Hughes NH-300C helicopter is powered by a 190 shp / 142 kW Textron Lycoming HIO-360-D1A 4cylinder, horizontally opposed engine compared to HIO-360-B1A, 180 hp / 134 kW of the basic version and had a larger diameter main rotor 26 ft 10 in (8.178 m) compared to 25 ft 4 in (7.6 m) of the basic version. Larger rotor and engine gives a 45% performance increase over previous models. Flight operation under IFR - Instrument Flight Rules is prohibited. Flight operation is permitted at night only when landing, navigation, instrument and anticollision lights are operative. Flight operation at night is limited to VFR - Visual Flight Rules conditions. The technical data & general characteristics as described into official flight manual are: Type designation: Breda Nardi Hughes NH-300C, Usage: Basic training helicopter, Crew: 1 student pilot & 1 instructor pilot, Year of construction: 1985, Manufacturer: Breda Nardi Italy under Schweizer Aircraft Corporation licence, Country: Italy, Length: 30 ft 8 in (9.34 m), Height: 8 ft 9 in (2.75 m), Width: 6 ft (1.83 m.), Main rotor diameter: 26 ft 10 in (8.178 m), Main rotor blade area: 22.64 ft² (2.103 m²), Main rotor geometric disc area: 565.49 ft² (52.534 m²), Main rotor geometric solidity ratio: 0.04, Main rotor blade chord: 6.75 in (171.5 mm), Main rotor blade twist: -8° 39’, Main rotor number of blades: 3, Tail rotor blade area: 1.69 ft² (0.157 m²), Tail rotor geometric disc area: 14.19 ft² (1.318 m²), Tail rotor geometric effective solidity ratio: 0.116, Tail rotor blade collective pitch full left pedal: +25° to +27°, Tail rotor blade collective pitch full right pedal: -11° to -13°, Horizontial stabilizer area (to tail boom): 2.65 ft² (0.246 m²), Vertical stabilizer area (to tail boom): 1 ft² (0.093 m²), Empty weight: 1040 lb (470 kg), Loaded weight: 1000 lb (450 kg), Maximum takeoff weight: 2050 lb (930 kg), Powerplant: 1 x Textron Lycoming HIO-360-D1A 4cylinder, horizontally opposed engine rated at 142 kW, Horse power: 190 shp at 2700 rpm, RPM limits: 442 to 471 rpm (power on), 390 to 504 rpm (power off), Maximum hover altitude with ground effect: 5900 ft (1800 m), Maximum hover altitude without ground effect: 2750 ft (840 m), Maximum takeoff / landing operating altitude: 8000 ft, Maximum enroute operating altitude: 10200 ft (3110 m), Maximum speed at sea level with doors not installed: 91 kts (169 km/h), Maximum speed at sea level with doors installed: 115 kts (212 km/h), Maximum speed at 10000 ft with doors installed: 82.5 kts (153 km/h), Cruise speed: 75 kts (140 km/h), Rate of climb: 750 ft/min (229 m/min), Maximum autonomy range: 195 nm (360 km), Maximum flight duration: 3 hours 30 minutes depending on flight conditions & type of mission, Maximum range fuel consumption: 10.2 gallons, Fuel tank capacity: 29.6 US gallons, Collective stick (full down to full up): 10 in (254 mm), Cyclic control stick (full forward to full aft): 15 in (381 mm), Cyclic control stick (full left to full right): 16 in (406 mm), Directional control pedals (full forward to full aft): 8 in (203 mm), Throttle grip twist angle (full closed to full open): 130°. The truth is that until this moment, I have not decided yet if I’m about to build the civilian Olympic Aviation version or the military related Hellenic Army Aviation version, Although these two versions (Schweizer S-300C and Breda Nardi Hughes NH-300C) do not differ too much, there are some elements that set them aside - especially in the cockpit area. General speaking, I don’t really feel like a military model enthusiast or to be more precise, after all these dozens of F-16s, F-4s & Mirages I have built since I was a young boy, I need to deal with something less militarized. However, I must admit that the dirt, dust and rust suits best on military scale models. In short, I'm into a dilemma and do not know which version to proceed, since both Olympic Aviation & Hellenic Army Aviation, looks nice! Ideas & suggestions are very welcome.

CHAPTER XII - Epilogue Final details were added and I tried some close-up pictures. Although initially I plan to represent a brand new bright ‘n’ shiny Bölkow Bö-102 Helitrainer, I changed my mind during the building process and finally decide to present as found in an abandoned small airfield in Vlotho, where the Helitrainer used to rest for decades till found and finally donated to the Hubschraubermuseum helicopter museum in Bückeburg, Germany. The museum workshop team, managed to restore it and display it as on of these experimental helicopter training devices. That is why I preferred to add much wear, dust and stains from oil and scorched medals at several points and some rust as example in the exhaust. I tried black paper background (instead of white) & different light conditions. Thank you for following this thread and I hope you enjoyed reading this article.

CHAPTER XI - Instructor’s bicycle type seat construction I almost forgot to build the instructor’s bicycle type seat in which he sits, next to the student pilot. Using plasticine, I made an image cast of how I would like seat’s surface to look like. I only had to push the material gently with fingers and got the desired shape - in fact, the process took less than 5 seconds. Using a small amount of Milliput putty, I made a small ball, dust it with talcum powder and pressed it against the working bench with a roller until it becomes as thin as could get. The use of talcum powder is necessary to avoid Milliput sticking on roller or fingers and get easier to handle without tearing to pieces. When the Milliput was pretty thin, I lifted it and place it on the plasticine image cast I made earlier, to let it follow the shape and curves of the seat. Using an old wet brush, I let few drops of water on the Milliput sheet, to make it softer and easier to follow the seat shape and left it overnight to get harden. Of course, the same technique can be also used to build blankets, truck covers, etc. I left the Milliput overnight to get polymerized. As soon as it was got harden, I removed the plasticine image cast and cut the seat, as shown into the following pictures. Using airbrush, basic blue colour and shades of sand & rusty brown tones sprayed at low pressure to represent the weathering and dusting on the seat and the lower part of the landing pad with supporting base. After a satisfactory weathering result, the scale model was sprayed with mat enamel coat and left 24 hours to dry.

After placing the clear canopy on cabin and adding few tiny drops of CA super glue just on few spots to secure the installation, small amounts of Squadron MMD green putty filled tiny gaps. Later, the green putty overages sanded lightly and the cabin prepared for airbrushing. The cabin was painted using the Life Color UA025 Light Gull Grey FS36440 acrylic paint and later the lower part was dusted by airbrushing a very light layer of Life Color LC37 Matt Burnt Umber FS3004 acrylic paint.

CHAPTER X - Clear canopy installation on bubble cabin The Bö-102’s cabin and one-piece glass bubble canopy, offers wide visibility for the student pilot. The absence of side doors is a benefit in a hot climate and also provides better vocal communication with trainer who sits nest to student pilot. Of course, canopy modifications can be done, as seen Bö-102s with total absence of glass canopy. As written and described into previous “CHAPTER” I, the basic shape of the thin-skinned, right-to-scale bubble typed canopy, was made by vacuum forming 1mm clear polycarbonate sheet, on a solid rock one-piece image cast made of modeling clay and additional layers of epoxy putty & polyester filler with fiberglass grains. To do so, the clear sheet were pined on a wooden frame, preheated into electric oven and as soon as I noticed that it started drooping down, I vacuum formed it. The clear sheet nicely formed around the canopy cast following the curves & details as planed. Using an X-acto knife, I removed the formed canopy bubble from the transparent sheet and start adding details, such as canopy's frame. The clear canopy frame was made by 1mm masking tape. Few drops of CA super glue applied on the right spots with great caution. Remember that CA super glue does fog the transparent parts and this canopy would not be an exception - that's why I placed some very tiny drops of it, just on few spots to secure the installation.

CHAPTER IX - Attempting the final assembly As soon as the individual scale model’s parts were already painted & weathered, I had to conclude the most difficult part. To assembly everything in one piece, without damaging the construction, the paint, the weather effect and of course ,my patience. That’s why I had to constantly monitor and try dry fit tests for each part during each step of this project, to ensure that I will not face any nasty surprises. The landing pad & the wheeled supporting base construction, would be the first to be placed on the tarmac display base. Everything secured in place with hidden pins encased in plaster & glued with CA super glue.

CHAPTER VIII - Tarmac & grass display base construction I found nice idea to place the Bö-102 Helitrainer on a display base, simulating a concrete ground area. The idea was to establish the picture of an abandoned small airfield in Vlotho, where the Helitrainer used to rest for decades till found and finally donated to the Hubschraubermuseum helicopter museum in Bückeburg, Germany. The museum workshop team, managed to restore it and display it as on of these experimental helicopter training devices. From my local store, I bought a 20x30cm polished wooden picture frame. I add some grams of plaster powder and few drops of water with a syringe into a soft rubber cup to make the right mixture. Materials like plaster, start as a dry powder that is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after drying and this characteristic make plaster suitable for the job. Keep in mind that adding salt into wet plaster mixture, reduce the plaster's hardening time and adding vinegar into wet plaster mixture, extend the plaster's hardening time. When the first layer of thinned plaster applied on the picture frame, a glass were pushed against the plaster to form a flat basic strong cast. The basic idea, is to produce a totally flat cast and later add some detail or apply extra stuff where is needed. I left it few hours to get harden in order to be sure that the cast wouldn't break when I would try to cut it into desired shape. Meanwhile, I took the soft rubber cup which I used to make the plaster mixture, squized it to break the last hardened plaster left inside, so it would be easier for me to clean it afterwards and prepare it for any future mix. That's the reason this soft rubber cup were used for. As soon as the plaster cast got harden, cut into shape and the concrete plaques were lined with a scriber, I used my airbrush to paint it. After the polished wooden frame was covered with masking tape, three different acrylic paint layers were applied on the plaster surface. First, mat black colour covered the area and then a light grey applied with airbrush, spraying in almost zero degrees angle, to let the darker areas between the concrete plaques remain naturally dark. The corner was paint with earth tones and as soon as the acrylic colours dried, I tried some drybrushing on selected spots using sand tones. As for he grass & plants, I used different colors of static grass from my local hobby shop, empty them into a plastic box and make a mixture. Water based white glue for wood, which becomes transparent when it dries, is just the right for the job. So, I opened a 500gr canister bought for 2€ only, pick a small quantity, add just few drops of water with a syringe into a small metal container to make the right mixture and finally I applied on the desired areas to be filled with grass & plants, using a wet brush. Because the mixture is enriched with water based glue, it is easy to correct possible mistakes. As soon as the result was OK, I sprayed over with Humbrol enamel mat coat, to seal the paint and grass, so far. I left it overnight and as soon as the enamel mat coat dried, I add very few light & dust effects with chalk dust and pigments.

Dark brownish pigments & chalk powder shades, dissolved in water and spread in selected engine block spots gave a better look. When satisfied with the result, I began the tail boom painting process. To do so, I used the Life Color UA140 Yellow RLM 04 FS33538 colour which is actually the colour found into the official Bölkow’s technical order manual. Paint applied over 2-3 very diluted (almost pure water) thin layers, one after another, using a fine brush, keeping in mind that leaving paint marks should be avoided.

Usually, there are two available options for a scale modeler, to apply paint on a model: Paint the individual parts first and assemble the scale model later and Assemble the scale model parts first and paint the overall built model later. While building this Bölkow Bö-102 Helitrainer scale model project, the first option seemed as more appropriate and would make my job easy. Unfortunately, I had to follow the second option – and that was not the only bad news. Building first and painting later, would be more difficult and would take much longer, but the reason I chose first to assemble most of parts and paint later, is because most of the Bölkow Bö-102 Helitrainer scale model’s airframe consists of a tail boom structure, in which contained the Hirth 3-cylinder / 2-stroke 40hp ILO L3X375 piston engine, the transmission components, the cable wiring etc that could not be masked without causing any damage. It could be very difficult – maybe impossible - to airbrush for example the tail boom and manage to leave the interior details remain unaffected by the painting same time. Here comes the bad news: Tail boom structure would be painted by using fine brush and lot of patience to avoid leaving any brushing marks that would be clearly visible on such a big scale as the 1/18 is. After preparing the engine’s basic elements, connecting electric cables and oil or fuel lines, I airbrushed the engine block with Life Color LC24 Matt Aluminium FS37178 acrylic paint as a base coat and apply darker enamel mixtures using the Humbrol #27001, #27002, #27003 metal cote paint and finally add some Mr Metal Color #212 Iron on the engine and let about 24hrs to dry before trying dark brown and black washes. As I personally believe that following simple techniques and sometimes unconventional methods, result in superior effects, I usually do not use enamel or acrylic paint to wash, because I feel risky when applying the paint mixture and let it run. I prefer an easier technique that can be undone if the results are poor - that makes it the perfect technique. I use hard chalk pastels to wash (NOT oil pastels). The hard chalk pastels, looks like a teacher would use on the blackboard in school. Do not use the soft oil pastels that artist use to draw on paper. The hard chalk pastels are easy to find in a variety of colours into your local art store or maybe Wal-Mart if in US or ASDA if in UK. To do the wash, I use an blade, a small metal or plastic container, an old toothbrush, dish washing soap and a bit of water. Begin by scraping some chalk powder from the side of the chalk pastel stick, carefully put this chalk powder into the small container and add a tiny amount of water and stir. It is important to add a tiny amount of water in order to make the mixture look like mud - not like soup! For this reason, I use a syringe to add just few drops on the hard chalk pastel powder and I stir using the old brush. Because the chalk powder doesn't mix well with the water, a drop of dish washing soap is needed to break the surface tension of the water and also acts as a “glue” to help the chalk powder stick to the model. Once the chalk is fully dissolved into the water/soap mixture it is time to “paint” this mixture onto the model's engine. “Painting” the mixture is simple - just apply it anywhere it is needed to darken recessed detail. The mixture can be applied carelessly, because any mistakes can be completely removed and redone. Once the chalk wash dried, I rubbed off the high spots with a slightly damp dry (not wet) Q-Tip cotton swab (Kleenex papers can be also used) and I wiped the dark colour from the areas should be light & shinny. The high spots were cleaned to the bare metal finish and the low spots were left black. I did the chalk wash on the engine in under 30 minutes which makes it a very quick and effective technique. You can also read about this into Steve Bamford's article, by clicking HERE. Some of the wash mixture is re-applied and the wash being wiped completely out of the narrow points. If you follow this method, it is adviced to not rinse out the wash container till you are finished this job. You will probably be touching up certain spots a few times, so it helps if you're not mixing up a new chalk mixture each time because you kept cleaning out your container of the chalk wash mixture. As soon as I paint the electric cables, the oil or fuel lines etc, I repeated the wash process with lighter colours where needed. Using micro cotton batons found into cosmetic shop for less than 1£, I applied some brown chalk pastel powder on the engine's chrome exhaust, to make it look overheated. I repeated the weathering process until it satisfied me and finally I sprayed a Humbrol clear coat to seal the chalk powder on the engine.

CHAPTER VII - Applying paint, wash & weather effects Model parts were washed with liquid soap and warm water to disappear leaving oil traces, fingertips etc and then sprayed with Humbrol light grey primer.

CHAPTER VI - Main rotor blade & transmission components construction The rotor blade is made of styrene sheet softened in boiling water to stretch 'n' turn in a way to look realistic. I also tried soft and careful sanding on the blade's leading edge to be shaped as realistic as it should be. The transmission shaft components and minor details also made of styrene, sprue and metal wire bond together with CA super glue. Everything was sprayed with Humbrol light grey primer when ready to paint.

It’s been a long time since the last update, isn’t it? Well, I will not try to justify myself with cheap excuses. I’ve been so lazy the past few weeks and neglected the Bölkow Bö-102 Helitrainer project. Otherwise, I could possibly put the blame on anything but me, put the blame on the Mediterranean sun makes the summer last longer, put the blame on the planets spinning around the universe causing horoscope zodiac turbulences, put the blame on the Willie Coyote for keep failing to catch the Roadrunner, etc. That would sound like a cheap excuse, wouldn’t it? Some additional details were added to the fuel tank canisters. The left side fuel tank, was placed on the receiver base and strapped with hoops & tensioners to keep in place, while the right side fuel tank is to be placed on the ground, with the filler cap opened, simulating maintenance procedure. Finally, the landing pad base supports, built using balsa wood slats.

Each fuel tank, is placed on metal plate / receiver base and secured in place by hoops and tensioners, as seen into the following picture. In order to reproduce, these metal plate / receiver bases, I tried vacuum forming. Because I was planning to use smaller wooden frame to secure the styrene (the pieces to be vacuum formed are small and there is no need to spend big styrene sheet), I had to close the outer holes on the hardboard high-density fibreboard plate. To do so, I cut a plastic bag in shape and covered as required the desired area. The twin fuel tanks, wedged halfway into plasticine and placed on the vacuum former plate to form the fuel tanks receivers. I pinned a styrene plastic sheet on the wooden frame, insert it into the preheated electric oven as described before and as soon as I noticed that the plastic got warm enough and started drooping down, I removed it from the oven and thrown the sheet on the vacuum former plate, while the vacuum cleaner was already plugged & switched on. This procedure may take some practice and sometimes a mould tips over or the plastic won’t form properly over the mould (folding around edges). This is also the part where I should warn you that you can burn your fingers - I highly recommend Nomex Aramid flame resistant MilSpec gloves, which I personally use for the job. I buy large plastic styrene 50x30cm sheets for 0.5€ to 1.5€ each (depending width), not the more expensive styrene by Evergreen. When an attempt fails, I usually throw the sheet back in the oven and start again. Once you have the machine, you can make all kinds of things. You can make a lot of aircraft wings, airframe, panels etc out of a sheet like that. You can make the master moulds from balsa wood, epoxy, polyester etc and the parts you make depend on how accurate the master moulds are. The moulds must be as accurate and detailed as necessary to achieve the results you are after. The plastic nicely formed around the fuel tanks moulds and here is how it looks like. Using a new Nr 11 stainless steel surgical blade, I removed the formed pieces from the styrene sheet. The yellow stuff appears in the picture, is plasticine surplus - the plasticine used to secure the twin epoxy tanks on the vacumm former plate and caged into vacuum formed plastic sheet. Later, these two receiver bases will be sanded as required and some details such as securing hoops and tensioners to keep the twin fuel tanks in place will be added. It’s mid July already! It’s time to enjoy a nice cool summer and recharge batteries while drinking icy mojitos by the beach. I’ll meet all of you right after my summer holidays on sunny Cyprus island and I promise all the latest WIP pictures & updates when I’ll be back. I wish you best summer and happy holidays.

The twin epoxy blocks got trimmed and sanded gradually to shape into the desired form and look realistic Helitrainer fuel tanks into scale. Later, few thin layers of liquid scale modelling filler applied over the epoxy to smooth out small imperfections and be seen as a comprehensive outcome.

CHAPTER V - Fuel tank canisters construction Once sprayed with the Humbrol acrylic grey primer the model’s constructed pieces so far, I thought it would be a good idea to use the spray cap in a productive way to construct two identical fuel tank canisters. The reason I chose to use this, is that the cup is made of a quite flexible polyamide material and the Miliput epoxy putty could hardly stack onto it. Using styrene, I split the cap cylinder’s inner area into 4 quadrants. The space of two of these quadrants, would be used as molds, filled with Miliput standard epoxy putty. To ensure that the epoxy putty would be easily removed after the polymerization, a generous coat of baby oil was applied on the contact surfaces. Johnson's baby oil or similar, is well know to anybody who have children in house. If you are not a father yet, ask your sweet girlfriend - all girlfriends have a tiny baby oil bottle in their cosmetics drawer, especially the beautiful and those who pay particular attention to their beauty & appearance. If you don't have a girlfriend, close this web page at once, shut down your PC/laptop and get your feet out of house to meet one! Scale modeling is nice & productive hobby, but feeling a beautiful female next to you, is much better. Thin layers of vaseline based mixtures can be also used instead of baby oil to apply with a soft brush as a segregative material between the styrene side walls and epoxy putty. Aluminum foil was placed underneath to avoid spilling the cut surface and to prevent the epoxy material to stick to the green cutting surface. When the cap cylinder, was filled with epoxy putty and had enough time to polymerize and get solid rock, it was slightly pressed and the epoxy cast removed easily. That’s the reason why it would be nice for the cylinder to be made of flexible polyamide material. With this simple and easy way, two identical pieces with the exact same curvature and volumetric dimensions, were built in just a few minutes. These twin epoxy parts, can be now used as a base to shape into the Bo-102 fuel tanks. Having measured the desired dimensions, the two identical epoxy blocks were cut the same length. Few epoxy overcast remains that were left, were also removed during cutting process. Remember that epoxy materials are dangerous when breath or shallow and could result skin, eyes or lungs severe problems or even cancer when used for long period with no precaution measures. Always keep in mind, that a powerful vacuum system to suck away the epoxy dust should be used all time to keep the workbench area clean while sanding or milling epoxy or resin materials. Using an issued breathing mask and a pair of surgery latex gloves to prevent dust contact with lungs and fingers while sanding or milling epoxy, is also an important matter that you should seriously take care of! My recommendation is to also wear an overall working suit (as I do) to keep your clothes dust free while sanding epoxy. Some people might find it too much, but I wouldn't like to bring epoxy dust & grains from my workbench into living room and my beloved. …if you are still reading the WIP article so far, you are a proud father already or you have a beautiful girlfriend to spend your money faster than you earn it.

When it looked OK to me, it was sprayed over with Humbrol acrylic primer to spot any mistakes and be ready for final paint. Each part was fit tested to ensure that anything can be combined together as one piece.

For my 1/18 scale project, I chose to recreate the wheeled version, which seemed to me as more interesting than others. As you can see in the following pictures, the landing pad & supporting base was built by styrene plastic, sprue, metal wire and glued with CA glue and Humbrol liquid poly.

CHAPTER IV - Landing pad & supporting base construction Having obtained a number of information data & pictures about the structure and functioning details of the Bölkow Bo-102 Helitrainer, I have concluded, that this training aid could be found in various versions. In most photographs, a solid land-fixed construction is visible, consisting of a system based on 4 sliding legs, stretched around, ensuring secure support. Nevertheless, both diagrams & photographs show that this was not the only version, as there were some BO-102s which were based on inflatable rubber pads to float on water or wheeled bases which enabled transport of the device in different places, even into a hangar. Careful observation of the individual photographs and archive material showed that there are too many differences between these BO-102s. Therefore, taking under account that only 18 were produced, I do not think too much to assume that each one of them was completely different from each other.

It was about time to sit back and take a break! I asked “honey” to prepare a nice cold Nescafe Frappé coffee for me. I had time for a close inspection on the model so far, while she was preparing this refreshment for me. For all you who do no clearly understand what is the Nescafe Frappé coffee, please let me explain that it is a foam-covered iced coffee drink made from spray-dried instant coffee. It is very popular in Greece especially during summer, but has now spread on to other countries. In French, when describing a drink, the word frappé means shaken and / or chilled; however, in popular Greek culture, the word “frappe” is predominantly taken to refer to the shaking associated with the preparation of a café frappé. For more infos, click HERE or visit a Greek island during this summer and relax on the beach enjoying a frappe coffee to feel the Greek way difference. You might think that I throw away the plastic straw after drinking the coffee? Hell no! Just wash with water and I had the basic material to build the exhaust tube, right on scale. The tail rotor blade was build by styrene & sprue, airbrushed and dry fitted into place to give me an idea if it looks right. At last the battery pack was built of epoxy and some cables and flexible air intake hoses added too. Control cables and wiring made of 0.20mm fishing line. Tail boom fins are made of forded copper and styrene. The fuel tank canisters and the fuel lines will later described. Everything covered with a light grey acrylic and placed into box to wait the final painting.

As soon as the joints between the tail boom parts were securely glued with combination of CA glue and Humbrol liquid poly and later filled with MMD green putty on tiny gaps, it was carefully sanded with sand paper and nail files, found at the local supermarket and bought for less than 1 euro per 10 files. The following toll attached to my miniplex to reach difficult spots and areas, that sand paper and nail files could not safely operate.

CHAPTER III - Tail boom frame & engine construction Following the 1/18 scale printed diagrams and using just a sharp Nr 11 blade and superglue, it took about 2 hours to build the basic tail boom frame. The tiny gaps between the connections, were filled with a combination of MMD white & green putty, applied with an old brush. In order to make the putty liquid and let it spread naturally and fill the tiny gaps, I mixed it with laquer thinner. As I wrote before, because the laquer thinner is volatile, the liquid putty mixture took about 45 minutes to get fully dry and be safe to sand - carefully ofcourse. MMD putty and laquer thinner mixed into metal (glass is also OK) plate, because the most plastic materials cannot stand it and melt. Because the Hirth 3-cylinder / 2-stroke 40hp ILO L3X375 piston engine is attached just behind the cabin, placed under the two fuel tank canisters, is clearly visible. Unfortunately, although I tried to avoid it because I am a lazy guy, the engine had to be built from scratch - keep in mind that engine building is my personal scale modelling nightmare. For this reason, I prayed to God to kindly send me a sign or even an ready built engine to fit in my 1/18 scale project. I was expecting for a a miracle to happen, but waited in vain. That might means that God has a sense of humor and wanted to see me to spend inconvenience. So, after waiting some more time the miracle to happen and after I finally realized that it was impossible to rain free 1/18 scale engines on my bench, I decided to build one from scratch, using styrene, epoxy putty and a number of absolutely unidentified parts found into my spare box. After completing my attempt, placing the engine into place and airbrushing acrylic primer paint to look unified, I was happily surprised that the result did actually look like a Hirth ILO L3X375 piston engine!

Yes! As I wrote into the first paragraphs "...simple 21 foot one-bladed fiberglass rotor with a counterweight..."

The instrument panel is made of standard Milliput epoxy putty, which is popular among modelers and also useful in countless household & restoration applications. Switch board, tail rotor control pedals, cyclic control stick and collective lever are made of drilled & cut styrene plastic card. Wiring is made of 0.20mm diameter fishing line. Using styrene plastic card, I cut the basic lines to form into the student pilot’s seat. The dimensions and the shape are based on actual BO-102 pictures. Standard Milliput epoxy putty was used to simulate the pillow. Finally, the cabin sprayed with Humbrol light grey acrylic primer to show up any possible scratches that I did not spot so far.. Please keep in mind, that despite the fact that only 18 BO-102s were produced, the available pictures show that there were many and obvious differences between them in several places. Different seats (some of them were not even seat), different cockpit and cabin colour, different fuel tank canisters, different tail boom frame construction, different landing pad and some of the BO-102s, were not even equipped with landing skids. So, don’t be surprised if you witness differences.

CHAPTER II - Instrument panel & cockpit construction As written before, the Bölkow Bo-102 Helitrainer was a helicopter training aid that was developed and built to allow a student pilot controlled experience of helicopter systems. That's why the cockpit panel was so simple, that a 5 yo child could operate. Three gauges on the instruments panel, few shiches, a cyclic control stick and a collective. That's all! After all, it was not designed to fly, but only give a helicopter hover & flight feeling. I started by cutting the cockpit’s floor shape in styrene and shape it as required to fit into the cabin. Once I tried test fitting, I discovered that there was some tiny gaps between the cockpit's floor and the cabin. These gaps, should be filled. So, "mind the gap"! To do so, some quantities of liquid modeling putty, filled between the gaping surfaces. In order to make the putty liquid and let it spread naturally and fill the tiny gaps, I mixed Humbrol putty with laquer thinner. Because the laquer thinner is volatile, the liquid putty mixture took about 45 minutes to get fully dry and be safe to sand - carefully ofcourse. If you follow this method, be sure that you mix the laquer thinner and the modeling putty into a metal or glass plate / canister, because the most plastic materials cannot stand it and melt. For this reason, keep in mind to use just the essential laquer thinner quantity, in order to remain the mixture in liquid form, as it is presented at the following pictures. The last liquid putty layer was applied using the MMD green putty instead of the general purpose Humbrol, because I personally find it better for final smooth details. The MMD green putty, also used to create some minor details on the cabin’s back side, where the tail boom frame (tail boom construction will be explained later) joints will be later fitted. At last, I tried many test fit attempts with the tail boob, to ensure that I’ll not face any unpleasant surprises later. An additional green putty layer applied and the cockpit surfaces carefully sanded to look as smooth as possible, before sprayed with Mr. Surfacer 1200 as a final touch.