Moving Myrsky's test wing from Museum Hall I to the Aviation Museum Society's sea container

Suomeksi

The test wing built as part of the Myrsky project has been on display in Hall I of the Finnish Aviation Museum. The two-and-a-half-metre root section of the right wing half was built at the beginning of the Myrsky project. Later, a one-metre-long counterpart representing the root of the left wing half was built. We have referred to this wing entity as the test wing. Building the test wing helped us clarify contradictions in the original Myrsky drawings before we began constructing the actual Myrsky wing, to be assembled on the restored aircraft.

The test wing will become part of the Demo Myrsky currently under construction, which is intended to showcase the internal structures of the mixed-construction VL Myrsky II fighter. The Demo Myrsky will consist of the fuselage frame of Myrsky MY-5, including its tail section, and the test wing. Like the test wing, the fuselage of the Demo Myrsky will be partly covered with plexiglas so that its internal structures remain visible.

The test wing on display in Museum Hall I had to be moved out of the hall. This is related to the Finnish Aviation Museum’s forthcoming relocation, for which preparations concerning the exhibition halls are already under way. Aircraft that will not be included in the exhibition of the new museum, which is already under construction, will be moved into storage from the old museum’s halls. As a result, the test wing standing in front of the hall’s overhead door had to be moved out of the way so that it no longer blocked the passageway.

The test wing was destined to be stored in the Aviation Museum Society’s sea container in the museum yard. This sea container is well suited for the purpose because its entire side can be opened to move the test wing into the container. To make room for the test wing, a sufficient 4,5-metre space was cleared in the container. Some of the items in the container, such as the pilot’s seat and canopy of a MiG-21BIS, could be moved temporarily to the museum’s adjacent fabric-covered storage hall.

To move the test wing, which weighs about just under 200 kilograms, a transport cradle had to be built. The maximum dimensions of the cradle were determined by the 220 cm height of the container opening and the 200 cm maximum width of the test wing. The starting point for building the cradle was that the wing would be moved into the container by forklift and that no modifications would be made to the wing structures. Among other things, this meant that the cradle would be attached to the wing only at the wing’s existing attachment lugs, or brackets. The transport cradle was designed by adapting drawings made by the Finnish State Aircraft Factory for a Myrsky wing transport cradle, which used a similar attachment method.

Photo: Reijo Siirtola

The transport cradle is made of wood with metal supports. Its key component is the vertical post attached to the attachment lugs of the right wing, which will carry the full weight of the test wing. The vertical post is supported by three strong angle-iron braces running down to the base frame of the cradle. The structure of the transport cradle allows a forklift to lift it, together with the wing, onto its forks and carry it.

Photo: Reijo Siirtola

Sturdy 50 x 100, 50 x 125 and 50 x 150 mm timber was used to build the transport cradle. The metal support structures of the cradle were made from 30 x 30 x 3 mm angle iron, and the attachment lugs from 6 mm flat bar. Strong angle plates and standard 12 mm bolts were used to fasten the parts together. At the two critical attachment points between the wing and the cradle, where the lugs were joined, we used the best possible 12 mm extra-high-strength bolts and nuts of strength class 12,9 / DIN 918.

Construction proceeded according to the drawing. During construction, however, certain considerations emerged that led to minor changes in the plan. Once the transport cradle was complete, it was moved by forklift from the museum’s restoration area to Museum Hall I and attached to the two attachment lugs of the right wing of the test wing with two 12 mm extra-high-strength bolts. Temporary raising blocks had also been placed under the cradle so that the forklift forks could fit underneath it. Before the test wing was moved, the flap was removed from it. This shortened the test wing by just under half a metre.

Photos: Reijo Siirtola

Photo: Juha Veijalainen

When everything was ready, the test wing was lifted manually from the display stand and turned on the floor into an upright position on the cradle. The forklift could then be driven up to the transport cradle and secured with straps. The test wing and its transport cradle rose smoothly onto the forklift forks, and the journey began from Museum Hall I to the Aviation Museum Society’s sea container, waiting in the museum yard.

Photo: Juha Veijalainen

Photo: Reijo Siirtola

Everything went well, and on arrival the test wing, together with the transport cradle, was pushed on the forklift forks to the rear wall of the container. The test wing moving operation had been completed. Finally, the upper end of the vertical post of the transport cradle was secured with cargo straps to the brackets near the ceiling of the container.

Photo: Kari Lehtola

Photo Jouni Ripatti

The wing’s display stand was also moved from the hall into the container together with the test wing. Because the stand takes up a great deal of space when assembled, it was dismantled and its parts were stored in the container. The parts were also numbered in case the stand is ever reassembled. Once the test wing was in the container and the display stand had been dismantled, the MiG-21BIS pilot’s seat and canopy that had been temporarily stored in the fabric-covered hall, could be moved back into the Aviation Museum Society’s sea container. Thus the entire test wing moving operation, with all its stages, was brought to completion.

Photos: Lassi karivalo, unless otherwise mentioned

Translation to English: Erja Reinikainen