Myrsky's wing root walkway

Lauantai 26.9.2020 - Tuesday Club member

At the wing root of VL Myrsky II, on both sides of the fuselage, on the wing’s plywood covering there is a strengthening strip of plywood. This makes it possible to walk on the wing when doing maintenance work. Very often these strengthened strips, which allow stepping on the wing, are clearly visible from the wing surface or painted black at least. However, this is not the case in the Myrsky, where these plywood strips have the same black and green paint scheme as the upper side of the wing.

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Upper photo: The photo archive of the Finnish Air Force Museum.

On the Myrsky drawings these strengthening plywood strips are called “step plates”. They are fastened on the wing’s plywood covering with glue and screws. The aluminium wing root fairings, which protect the connection of the fuselage and the wing, are fastened onto the fuselage side edge of the step plates with flange nuts and screws.

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The step plates for the Myrsky’s wings are being made at the Tuesday Club. The semi-finished plates were cut from 2 mm thick plywood according to the original drawing. The actual plywood covering of the wing is 4 mm thick at the wing root. The step plates for the port and starboard wing are mirror images. The position of the fastening screws and wing root fairing flange nuts were marked on one of the step plates, following the original drawing. The pencil marks were highlighted with a metal punch. The punch markings will make it easier to drill the holes into their exact positions.

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After this the mirror image step plates were placed accurately on top of each other and fastened with pieces of double-sided tape. In this way the holes for the screws can be drilled simultaneously on both plates and exactly in the same position on the plates. The holes for the fastening screws were drilled with a 3 mm drill bit.

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For the flange nuts on the wing root fairings, holes for the nuts had to be made on the edge of the step plate. These holes must match the shape and size of the flange nut and be slightly oval-shaped because the nut is sunk through the step plate, all the way to the level of the wing surface.

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First three holes were drilled into the plywood with a 3 mm drill bit, these holes help when the oval hole is made into the step plate. The small holes were used when making the holes larger with a column-type drill, using drill bits of two different sizes. The work continued by shaping the holes into their correct size and shape with a chisel and a file.

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The following phase will be to fit the step plates into their places on the top surface of the port and starboard wing and to fasten them with glue and screws. The step plate has already been preliminarily fitted to the root of the starboard wing.

Photos: Except separately otherwise mentioned, Lassi Karivalo.

Translation: Erja Reinikainen.

Kommentoi kirjoitusta. Avainsanat: aviation history, restoration, VL Myrsky, MY-14

Myrsky MY-5's fuselage frame was taken to sandblasting and painting

Keskiviikko 16.9.2020 - Tuesday Club member

The earlier blogs describe how  the Myrsky MY-5’s rusted fuselage frame will be straightened, sandblasted and painted before it can be used for the wing test assembly of Myrsky MY-14.

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The text in the box: Original paint under the bracket.

The MY-5 fuselage frame has been fastened on a sturdy metal frame, the assembly jig, outside the restoration space at the Finnish Aviation Museum. It has been straightened on the jig and the remaining parts and equipment have been dismantled. Most of these are different band-shaped fastening brackets. The fuselage frame was cut behind the cockpit, so that it became easier to handle and it can be brought into the museum’s restoration space for the test assembly of the MY-14 wing. Later the fuselage frame parts will be welded together so that it will be the whole Myrsky MY-5 fuselage frame.

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The fastening brackets, which were still attached on the MY-5 fuselage frame, are important when the original paint and its tint are being investigated. When the brackets were unfastened, some well-preserved original paint of the fuselage frame was revealed. The painted surface has been protected from rusting, hidden under the brackets.

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The original paint surface was cleaned by grinding it lightly, so that the tint of the paint became even more intensified. On both sides of the cleaned painted area a paint test was made, using two different shades of grey Isotrol paint (linseed oil alkyd paint). This was necessary so that the team could choose the appropriate tint of the undercoat paint for the fuselage frame. The tints of the tested grey paint were RAL 7005 ja RAL 7042.

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On Tuesday, September 15th, the shortened MY-5 fuselage frame was loaded on a trailer, using a stacker. The frame will be taken to Auto- ja Teollisuusmaalaamo Oy, a paint workshop in Vantaa. The Tuesday Club team tried also to fit the rusted engine frame on the trailer, but it wasn’t possible. The engine frame will be transported to the paint workshop later.

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At Auto- ja Teollisuusmaalaamo Oy the fuselage frame will be sandblasted and painted with undercoat paint. When the sandblasting has been done, the clean metal surfaces will be covered with clear varnish, which protects the frame from rusting. The grey Isotrol undercoat paint will be applied on top of the varnish. The MY-5 fuselage frame, with its undercoat paint, will return to the Finnish Aviation Museum in a couple of weeks.

Photos: Lassi Karivalo.

Translation: Erja Reinikainen.

Kommentoi kirjoitusta. Avainsanat: aviation history, restoration, VL Myrsky, MY-14, MY-5

City of Vantaa politicians visit Finnish Aviation Museum and learn about aircraft restoration

Maanantai 7.9.2020 - Tuesday Club member

City of Vantaa politicians visited the Finnish Aviation Museum for “practical training” as a part of the Politician’s museum internship campaign, coordinated by the Finnish Museums Association. The politicians who visited the museum were city council member Minna Räsänen (sdp), member of parliament, city council chairman Sari Multala (kok) and member of parliament, city council member Jussi Saramo (vas). Räsänen and Multala were present at the museum, Saramo attended via remote access.

As a part of the “practical training”, the cooperation of the museum and Aviation Museum Society was introduced to the guests. The Tuesday Club volunteers’ work was illustrated in the museum’s restoration space, although the Tuesday Club has officially been terminated because of the corona virus pandemic.

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From left to right: Pia Illikainen, Minna Räsänen ja Matti Patteri.

In the restoration space museum Intendent Matias Laitinen told the guests about the volunteers’ role at the Aviation Museum. Tuesday Club project manager Lassi Karivalo introduced the aircraft restoration activities of the Tuesday Club. The leader of the VL Myrsky II (MY-14) restoration project Matti Patteri introduced the history of domestic aircraft industry and explained how museum aircraft, and more specifically the Myrsky, are restored in practice. The Myrsky project was launched in 2013 and up to now the restoration team has spent about 30 000 working hours. Most of the work has been done by volunteers. The Myrsky restoration also includes cooperation with vocational colleges, e.g. Vantaa Vocational College Varia and Tavastia Vocational College in Hämeenlinna, and naturally work contribution from the Aviation Museum staff. The visitors learned that the main motivating factors for the volunteers’ participation are the sense of community, the good team spirit and the interesting work items.

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From left to right: Sari Multala and Matti Patteri.

Due to the corona virus pandemic situation, the museum’s volunteer activity has been terminated since March. In the future the working procedures will have to be reorganized. A large volunteers’ gathering can’t be organized yet, and not for some time – and in the social aspect this is very unfortunate. During the corona virus time the Aviation Museum Society has arranged for its members, and to all who are interested, remote access to presentations about aviation history. The museum has produced videos and audio tours with its partners. However, by now everybody is very eager to get back to work and to meet the volunteer friends at the museum. The aim is to relaunch the Tuesday Club activities in October, at some extent. The corona virus situation in Finland will define whether this is possible or not.

Photos: Mia Kunnaskari.

Translation: Erja Reinikainen.

Kommentoi kirjoitusta. Avainsanat: aviation history, restoration, VL Myrsky, MY-14

Undercoat painting of MY-14?s horizontal stabilizer

Perjantai 28.8.2020 - Tuesday Club member

Before the painting work, the port and starboard halves of the VL Myrsky II’s (MY-14) horizontal stabilizer were fastened on an assembly jig, made of square steel tube. On the jig the stabilizer can be turned around as needed in the various phases of the surface treatment process.

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The seams of the plywood covering on the horizontal stabilizer had been spackled and ground smooth before starting the undercoat painting work. The plywood surfaces were washed, using a water-Sinol-solution, containing 50% of water and 50% of Sinol. This is a normal procedure for removing grease from the surfaces before painting. After the wash, the surfaces were dried with a heat blower and sanded three times, with 240 abrasive paper.

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Photo: Jouni Ripatti.

The MY-14’s horizontal stabilizer will be painted in several phases. First an undercoat paint is spread on the plywood surface, and the actual paint is applied after this. There will be several layers of both paints. The undercoat paint and the actual surface paint are both alkyd paints, as were the original paints when the Myrsky fighters were being built in the 1940’s at the State Aircraft Factory (VL) in Tampere.

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Right photo: Jouni Ripatti.

The undercoat paint, which is used for the plywood surfaces of the MY-14 under restoration, is TEMALAC AB 70 alkyd paint which contains aluminium flakes. The shade of the paint is RAL 90006, white aluminium. The aluminium flakes will fill the grain structure on the plywood surface, which will make the plywood surface smooth and sealed when it is ground and honed.

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Photo: Heikki Kaakinen.

Now the upper and lower surfaces of the horizontal stabilizer have been painted once with the undercoat paint containing aluminium flakes. For the first layer the paint was made thinner, using Ruiskuohenne 1032, and the paintwork was done with a polyester roller (mini paint roller). The roller produced a very even layer. When the paint had dried, the surfaces were ground smooth for the second layer. The next undercoat paint layer will be done using paint, which is not thinned, and which is slightly darker in colour than the first layer. The darker shade will show clearly which areas have been painted for the second time and which haven’t. If a third layer of undercoat paint is needed, it will be darker than the second one.

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An unexpected break in the painting work appeared, when the darker shade of TEMALAC AB 70 undercoat paint wasn’t available due to holidays. The Tuesday Club team will have to wait for the mixing and delivery of the darker paint before continuing the undercoat painting work on the horizontal stabilizer.

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The MY-14’s horizontal stabilizer will eventually be painted according to the standard paint scheme of the Finnish Air Force in the 1940s: the upper surface will have a green and black pattern and the lower surface will be painted light blue.

Photos (expect otherwise separately mentioned): Lassi Karivalo

Translation: Erja Reinikainen

Kommentoi kirjoitusta. Avainsanat: aviation history, restoration, VL Myrsky, MY-14

About Myrsky MY-14 oil cooler, wing root fairings, landing gear doors and MY-5 fuselage frame

Maanantai 24.8.2020 - Tuesday Club member

When the VL Myrsky II (MY-14) port wing half covering was being finished in the restoration space of the Finnish Aviation Museum, also other Myrsky-project items were under work.

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Before the Corona virus pandemic interrupted the work, the Tuesday Club team had completed most of the engine’s oil cooler supply and exhaust air duct parts. They have been made from 1 mm thick aluminium plate. Now it was time to start building, according to the original drawing, the airflow control device into the supply air duct. The control device consists of a circular frame, inside which there are three flaps, which move on their axles. The air flow into the oil cooler can be controlled continuously with these flaps. The air flow control is done from the cockpit.

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The parts needed for the air flow control device were cut from 1 mm thick aluminium plate, using a laser cutter, at ProLaser Oy. Holes for the rivets, which are needed in the assembly work, were drilled on the semi-finished control flaps. The parts of the air flow control device were also chromated to prevent corrosion.

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The assembly work of the oil cooler control device was started at the circular frame. When the round frame had reached its final shape, the ends of the axles of the three control flaps were riveted on the frame. There is a slot on the end of the axle, into which the edge of the aluminium flap fits. The three flap plates fitted perfectly on the axle slots. The following phase will be to rivet an aluminium profile on the flaps, which locks the flaps on the axles.

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Some metal work has been needed when making the aluminium fairings, which cover the connecting point of the Myrsky’s fuselage and wing. The work was started on the fairing which covers the wing’s leading edge and the fuselage. The complicated fairing shape consists of three pieces of aluminium plate, which are welded together. The preliminary fairing parts were cut from 1 mm thick aluminium plate. A wooden last was made for shaping the aluminium sheets into the desired shape. Two lasts are needed, one for the starboard wing and the other for the port wing. The preliminary fairing parts were shaped into their final shape at Flanco Oy, using the last. The shaped fairing parts were welded together at GA Telesis Engine Services Oy.

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The work on the landing gear enclosure doors of the test wing has also continued, including the door fastened on the wheel hub and the oleo strut door. The doors had been nearly finished already in March. The remaining aluminium profile stiffeners were riveted on the inner surface of the doors. The doors were now ready to be installed. The bulging parts or the “bumps” on the outside of the oleo strut door have also been welded into place. These bumps are needed for the landing gear retraction fork which is fastened on the oleo. These bumps have also been welded on the preliminary oleo door plates of the actual Myrsky wing’s landing gear. However, the actual wing doors have not been chromated yet and their stiffeners have not been fastened.

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The Myrsky MY-5 fuselage frame, which was brought from Tikkakoski, has also been under work. The parts, which were still fastened to the frame, have been unfastened and now the frame is “clean” for sandblasting. The fuselage frame will be sandblasted at Auto- ja Teollisuusmaalaamo Oy, where it will also be painted grey.

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A pile of different kinds of brackets and parts was dismantled from the MY-5 fuselage frame. Some of the parts had to be unfastened with some violence, using an angle grinder for the work, because the badly rusted fastening bolts couldn’t be opened. The rust will be removed, and the parts will be painted. All the parts will be needed when the MY-5 fuselage frame is restored to be the exhibition fuselage, which illustrates the structure of the Myrsky fighter. The 2,5-meter test wing, built during the Myrsky project for testing the wing construction procedure, will eventually be fastened to the MY-5 fuselage.

Before that, the MY-5 fuselage frame will be used for test assembling and fitting the Myrsky MY-14 wings. In the fitting phase the MY-5 fuselage frame will be lowered on the MY-14 wing, built by the Tuesday Club team. The wing will be locked onto the fuselage with the four wing attachment brackets or bolsters. The wing parts will be fastened with steel plates and the whole wing can be test fitted in about a month’s time.

Photos: Lassi Karivalo.

Translation: Erja Reinikainen.

Kommentoi kirjoitusta. Avainsanat: aviation history, restoration, VL Myrsky, MY-14, MY-5

MY-14´s port wing half is covered with plywood

Sunnuntai 9.8.2020 - Tuesday Club member

The work on VL Myrsky II (MY-14) is continuing at the Tuesday Club, but not at full speed yet, though. Work is being done e.g. on the plywood covering of the starboard wing leading edge and trailing edge, and the sides of the flap cavity. The engine area is also under construction: the air supply duct is being fitted into the opening in the NACA-ring, the cowling under the engine is being built and the gills controlling the air flow through the air duct on the oil cooler are being installed. However, the main emphasis is in getting the port wing plywood covering to the same situation with the starboard wing. The work is almost ready.

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The leading edge of the port wing is now almost covered with plywood. The strips of plywood covering the leading edge were first soaked in water so that they could be bent around the tapering leading edge. When the plywood had dried into shape, it was glued on the leading edge. The seams of the plywood were spackled and honed smooth. Only small areas around the pitot-tube and at the wing tips have not been covered.

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Right photo: Heikki Kaakinen.

The trailing edge area on the upper surface of the wing, between the rear spar and the trailing edge, has also been covered with plywood. First the plywood sheets of the trailing edge area were cut into the accurate size, then covered with protective varnish on the inside and then fitted into place. When the plywood sheets had settled into their places and their bevelled edges met correctly, the sheets were glued into place. Before the inner parts of the wing were permanently covered from sight, the Tuesday Club members who were involved in the work, wrote their names on the inside of the wing as a greeting for the future generations.

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Left photo: Heikki Kaakinen.

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The gluing of the plywood sheets on the upper surface of the trailing edge was secured by fastening pieces of plywood on the wing ribs and the connecting battens with a staple gun. The permanent gluing of the plywood on the trailing edge batten was ensured by fastening a long row of clamps on the edge. When the glue had dried, the clamps and the stapled pieces of plywood were removed. The marks of the staples that were left on the plywood surface and the seams of the plywood sheets were spackled and honed smooth.

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It was a difficult task to fasten a 10-centimeter strip of plywood onto the upper edge of the flap cavity on the port wing. A similar, but narrower strip, has already been fastened on the lower edge of the flap cavity. These strips will form an aerodynamic compartment to the front of the flap space. The leading edge of the flap will sink into this space.

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Photos: Heikki Kaakinen.

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The port wing covering work had now reached the phase where the starboard wing already was. The surface work, i.e. smoothing and honing which are needed before the painting of the plywood surfaces, can now be started. Some painting has already been done: the open inner areas on the top surfaces of the wing roots on both wings have been painted with grey alkyd paint. These open areas at the wing root will not be covered with plywood, because the areas will be left under the Myrsky fuselage when it is lowered on the wings.

Photos (expect if separately otherwise mentioned): Lassi Karivalo

Translation: Erja Reinikainen

Kommentoi kirjoitusta. Avainsanat: aviation history, restoration, VL Myrsky, MY-14

About the fuselage frame of VL Myrsky MY-5

Tiistai 4.8.2020 - Tuesday Club member

When the restoration project of VL Myrsky was launched, three damaged Myrsky fuselage frames were available at the Finnish Air Force Museum in Tikkakoski. The rear section has been violently cut away from all three fuselage frames. The least damaged fuselage frame of MY-14 was chosen for the restoration project. This is how the project became the restoration project of the VL Myrsky MY-14 fighter. The MY-14 fuselage rear section, which has been cut off, has disappeared and therefore the rear section of MY-9 was chosen to be connected to the MY-14 fuselage frame. Also a fourth Myrsky fuselage frame (MY-10) exists, in a private collection, and there have been negotiations about purchasing it for the Myrsky project.

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The MY-14 fuselage with its engine and control equipment is mainly restored at the Finnish Air Force Museum in Tikkakoski. The main task of the Aviation Museum Society’s Tuesday Club is to build in Vantaa in co-operation with the Finnish Aviation Museum the other parts of the fighter, such as the wings with all their equipment, the parts of the tail and to build the parts for the nose, e.g. the front engine cowling, NACA-ring and the engine cowlings on the sides.

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Photo: Jorma Laakkonen.

The restoration project started in 2013 and the development of the project has been followed all the time on homepages of the Aviation Museum Society and Myrsky Project, and also in yearly journals. In Tikkakoski the restoration of MY-14 fuselage is already quite far. In Vantaa the Tuesday Club has prepared the tail parts and the wings to the point where their surfaces can be honed smooth and painted. The aim is that the restored – but static – MY-14 can be placed on display during the year 2021.

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The second best Myrsky fuselage from Tikkakoski, i.e. MY-5, was also taken into the restoration project with its separate rear fuselage and engine mounting. The MY-5 fuselage frame has its own important role in the Myrsky restoration project. Some useful parts have been dismantled from the fuselage frame and repaired in Tikkakoski for the needs of the MY-14 fuselage frame restoration. On the other hand, the fuselage frame of the MY-5 will be used by the Tuesday Club for the fitting of Myrsky’s wings. The wing positioning and fastening will be tested on the fuselage frame by the Tuesday Club before the wings are sent to Tikkakoski to be installed on the fuselage of MY-14.

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Additionally, an even bigger role has been planned for the MY-5 fuselage frame. It will be used to build a demo-fuselage of the Myrsky-fighter to illustrate the metal and wood structure of the aircraft. The 2.5-meter piece of the starboard test wing and the 1-meter piece of the port test wing will be fastened on the fuselage frame. Before building the actual wings, the test wings have been built to test the methods how to build the complicated root of the wing with the landing gear and how to lock the wing halves to each other with steel plates.

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The rear fuselage of MY-5, brought from Tikkakoski to Vantaa to the Finnish Aviation Museum, has already been used in the Myrsky-project. The badly rusted rear fuselage frame was straightened in a jig, specially made for the purpose, and sandblasted and painted, using grey alkyd paint. After this the rear fuselage has been used by the Tuesday Club to fit and support the horizontal and vertical stabilizers when they are being built.

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The fuselage frame and engine mounting of MY-5 were brought from Tikkakoski to the Finnish Aviation Museum in Vantaa on July 21st, 2020. The MY-5 fuselage was transported by the Myrsky-project’s PR-man, on his holiday trip to Ostrobothnia. On Friday 10.7 on his way there he took the trailer and “some Myrsky items” to Tikkakoski. On Tuesday 14.7 a group of Tuesday Club members travelled to Tikkakoski and moved, with some assistance from the Air Force Museum, the MY-5 fuselage frame and engine mounting on the trailer to wait for the transportation. The unusual load travelled successfully to the Finnish Aviation Museum on 21.7. Fortunately, the traffic was rather quiet and it wasn’t raining.

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When the fuselage frame was outside the museum, the cargo straps were unfastened. Then the MY-5 fuselage was lifted from the trailer with a forklift and placed on the ground to wait for cleaning and repair. The badly rusted and partly bent and damaged fuselage frame will be straightened and cleaned by sandblasting, straightened and repaired, and then painted grey. Behind the cockpit some frame pipes have been bent and some are even missing.

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Left photo: Heikki Kaakinen.

The assembly jig, which was made from square steel pipe for the straightening of MY-14’s fuselage frame, was re-assembled and modified for the MY-5 work. The jig was fastened on the four brackets by the cockpit on the MY-5 fuselage. These brackets are used for fastening the wings with four fastening bolsters on the wings.

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Photo: Heikki Kaakinen.

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The MY-5 fuselage frame, now fastened on the assembly jig, will be measured carefully and straightened. The places of some parts or their fastening brackets will be defined and photographed before they are dismantled for cleaning. Also the rusty engine mounting, brought from Tikkakoski, will be cleaned by sandblasting and painted.

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When the fuselage frame has been cleaned and painted, the rear fuselage frame (which has already been restored earlier) will be welded to it. Then the MY-5 fuselage frame will be ready to serve as the fitting frame or assembly jig for the MY-14 wings, and later as the basis of the Myrsky demo fuselage. The MY-5 demo fuselage will be restored so that the structures remain visible in the way they were left visible when building the short test wings. The restoration of this demo fuselage is not the main priority at the moment, the work will be started when the restoration of the MY-14 has been completed.

Photos (except if separately otherwise mentioned): Lassi Karivalo

Translation: Erja Reinikainen.

Kommentoi kirjoitusta. Avainsanat: aviation history, restoration, VL Myrsky, MY-14, MY-5

Cockpit canopy for Gnat model

Torstai 19.4.2018 - Member of Tuesday Club

Suomeksi

The Finnish Aviation Museum has donated the models of BEA Hawk, Folland Gnat, Saab Draken and MiG-21BIS to the Aviation Museum Society’s Hawk Experience Center. The large wooden models were found in the storage room of the museum. The models need some repairs which will be completed in the Tuesday Club before the Hawk Experience Center season 2018 begins in May. The repairs of the BAE Systems Hawk Mk.51 model have already been described in an earlier blog.

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After the Hawk model the next target was the Folland Gnat F.1 model. This model wasn’t badly damaged but the cockpit canopy was missing. In addition to some minor repairs the canopy had to be made.

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To make the new canopy, first a wooden model of the canopy had to be made. The cockpit was emptied by removing the pilot’s seat and the instrument panel. This was necessary in order to be able to fit the wooden canopy model, made of balsa, in its place in the cockpit. At the same time the measurements were taken of the line where the canopy meets the edge of the cockpit: a metal frame will be fitted on the sides and at the rear end of the canopy.

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A piece of balsa was carved slowly to match the shape of the canopy and the correct size by fitting it into the cockpit every now and then. Photographs and 3d-drawings of the Gnat were used to define the shape of the canopy. The wooden model began to take shape when it was gradually and carefully carved and buffed out and regularly fitted into the cockpit. Now the model for the canopy was ready.

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Photos: Jorma Laakso.

Before making the actual canopy, the metal frame for the edge of the canopy was made. The wooden model was used to dimension the frame. The location of the frame was marked on the model in red lines. The image of the frame was drawn on a 0.3 mm thick brass sheet and cut off. The thin strips of brass sheet were honed to match the shape of the frame on the lower edge and the rear section of the cockpit and fitted on the balsa model. When the metal parts seemed to fit nicely into place they were soldered together. Now the metal frames were ready to be installed on the actual canopy.

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Photos: Jorma Laakso.

The windscreen arc in front of the canopy was made of 0.8 mm thick plywood, laminating four layers of plywood on top of each other. The laminated arc was milled and buffed out into shape. Then a windscreen made of transparent plastic sheet was attached, using a friction-type connection.

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Photo: Jorma Laakso.

The making of the actual canopy was started, using the balsa model and a mould. A heated plastic sheet is pressed against the opening in the mould, using the balsa model for pressing. The mould was made from 4 mm plywood with an opening matching the shape and dimensions of the outer edges of the cockpit.

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Photo: Jorma Laakso.

A piece of 10x10 cm was cut from a 0.5 mm thick GAG-PET sheet. The sheet of plastic was attached by its edges on top the opening in the plywood mould. The sheet of plastic was heated using a hot air blower. When the surface of the plastic was soft enough, the sheet was pressed evenly into the opening in the mould using the balsa model. The stoppers on the sides of the balsa model prevented the model from pressing the sheet of plastic too deep into the mould.

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Photo: Jorma Laakso.

It took about one minute for the plastic sheet to cool down, then the balsa model was removed. A bulge had formed under the mould, shaped like the balsa model. This was the rough form of the canopy. The GAG-PET sheet was removed from the mould and the bulge, i.e. the preformed canopy was cut off.

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Photos: Jorma Laakso & Lassi Karivalo.

Now the metal frames (at rear end and lower sides of the canopy) and the windscreen arc could be attached to the canopy. The canopy was placed on the balsa model where the red markings showed the exact place of the frame. When the metal strips had been placed exactly on the marked lines, they were glued in place using UHU POR contact glue. Now the extra plastic material below the frame could be cut off. When the canopy was placed on top of the cockpit to test how it fitted, the result looked good. UHU POR contact glue was used to glue the windscreen arc to the canopy. Then the canopy frame and the windscreen arc were painted dark green.

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The last phase of work was to attach the new canopy on the Gnat model. The canopy was placed on the edges of the cockpit and attached with Plastic Padding. When the seam had dried it was honed smooth and painted dark green. The Folland Gnat F.1 model had a new canopy and is now ready to be placed on display in the Hawk Experience Center.

Photos: Unless separately mentioned, Lassi Karivalo.

Kommentoi kirjoitusta. Avainsanat: aviation history, Tuesday Club, restoration, Folland Gnat, aircraft model

Hawk model to Hawk Experience Center

Keskiviikko 21.3.2018 - Member of Tuesday Club

Suomeksi

A wooden model of BAE Systems Hawk Mk 51 jet trainer was found in the storage room of the Finnish Aviation Museum. The partly damaged model is approximately 50 cm long and it represents HW-310 which was in use in the Finnish Air Force. HW-310 belongs to the series of Hawks which were assembled by the Valmet Aviation Industries between 1980 and 1985. The real HW-310 has been withdrawn from use and stored. The State of Finland will donate it to an aviation museum in Switzwerland (Clin d'Ailes - Musée de l'aviation militaire de Payerne) and where it will probably be transported already this spring.

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The museum has no information about the builder of the HW-310 model. Originally the model has been attached by its landing gear on a white plywood board which has been hanging on the wall. So the model has been a wall decoration.

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The model is very well made and its proportions match the original aircraft. The cockpit has seats and its main equipment – also made of wood. The instruments on the panel have been painted, decals haven’t been used. The model has been painted according to the old camouflage scheme (black/green/grey) used in the 1980s, which suggests that the model was probably made about twenty years ago. Today the planes are painted all grey with small national insignia.

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Photo: Jorma Laakso.

When the Hawk model was found, the idea of bringing it on display in the Hawk Experience Center of the Aviation Museum Society was brought up. The center has on display the cockpit section of HW-314, which belonged to the same Hawk production series as the real HW-310. The model of HW-310 could be used to illustrate what a whole Hawk looks like. There is an existing showcase where the HW-310 could be on display. An additional advantage is that the HW-310 has a similar black/green/grey camouflage scheme as the HW-314 in the Experience Center.

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The Finnish Aviation Museum decided to donate the HW-310 model to the Hawk Experience Center and the Tuesday Club set out to work. The model was moved from the storage to the club workshop. The model had some damages: the nose landing gear was broken, one of the horizontal elevators was loose, the seam of the vertical elevator and the fuselage was broken and the cockpit canopy was loose and slightly broken.

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Fortunately the damage wasn’t serious and repairing wasn’t difficult. The right side horizontal elevator was glued into place, the seam between the vertical stabilizer and fuselage was re-glued and painted. The split wheel on the nose landing gear was repaired. The canopy of the cockpit didn’t quite settle in its place and some modifications were needed on the canopy and the rear seat in order to have the canopy in the correct position.

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As the model had originally been hanging on the wall, it hadn’t been balanced to be standing on its landing gear. When placed on a horizontal surface the rear-weighted plane’s tail is pointed downward. Therefore an additional support has to be added under the rear fuselage when the model is in its showcase.

The Tuesday Club team discussed whether the HW-310 identification marking should be changed to match the identification of HW-314 in the Experience Center. The decision was negative. It would have been difficult to modify the last number of the identification marking from a four to a zero so that the change couldn’t be noticed on the original paint. So the original appearance of the model was respected and no changes were made.

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The HW-310 model is made of solid wood and is very robust but it still needs a good storage and transportation box. A new box was made from plywood and wooden battens. The box has a hinged lid and it was painted with clear varnish. The box and the lid have supporting pads which were cut to measure and support the weight of the model during storage and transport.

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The Hawk model and its box are ready. The model was placed in the existing showcase to see how it fits there. And it looks great!

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Fine, isn't it?

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Now HW-310 is waiting for the summer exhibition round of the Hawk Experience Center to begin. The first event is already in the horizon: The “Military Aviation as a Profession” –event will be arranged by Satakunta Air Command in Pirkkala, Tampere on May 15th.

Photos (unless otherwise individually mentioned): Lassi Karivalo.

Kommentoi kirjoitusta. Avainsanat: BAe Hawk, model, Hawk Experience Center, restoration, Tuesday Club