Tuesday Club's DO-5 work completed

The hard work of the Tuesday Club members was instrumental in getting the fuselage of the type C-47A DO-5, owned by Aviation Museum Society Finland, into sufficient shape for putting it ready for showing before the Turku Airshow. It was touch and go because the last tasks weren’t finished until two days before the fuselage of DO-5 was transported from the yard of the Finnish Aviation Museum to Turku Airport on June 15th, 2023.

The last significant project was to install new plexiglass panes for the cockpit. The Air Force DO-5 hasn’t had original panes in the cockpit for decades. Part of the windows lacked panes altogether, resulting rainwater and snowstorms ruining the cockpit badly, whilst the fuselage lay forgotten for decades in the Utti forests.

Because the original cockpit panes and the large sliding panes on both sides of the cockpit weren’t available, we ended up with acquiring plexiglass panes for the window openings. On top of that we decided to attach the plexiglass panes to their frames with a mixture of glue and sealant mass. In this way the windows become watertight, preventing water to seep into the fuselage. This also meant that the big sliding panes on both sides of the DO-5 cockpit couldn’t be slid open anymore.

To acquire new 5mm polycarbonate plexiglass panes we made a template out of thin plywood for each of the window openings. For the windscreens we had already in the autumn acquired from ETRA plexiglass panes ready cut to form. Cold weather and the oncoming winter, however, put paid to carrying on with the installing of the windowpanes. We fastened then the plexiglass panes and the temporary panes in the other windows with plastic tape from their edges to wait for the warmer temperatures of the spring, when we could continue with the cockpit windows.

Photos by Lauri Veijalainen

Other tasks to refurbish the DO-5 fuselage in the spring delayed attaching the new plexiglass panes, so that we didn’t get to it until May 2023. Then the plexiglass panes for the large sliding windows on the sides of the cockpit were acquired.

Photos by Lauri Veijalainen

Each plexiglass pane was squeezed into its frame and a thin rubber strip was installed under the lower edge of the pane in order to get the pane at the right elevation in its groove. After that the edges of the panes were taped either by masking tape or with plastic tape so that there remained a suitable zone for the glue and sealant mass. The tape is to protect the rest of the surface of the pane from the sealant mass to spread and that the seam of the sealant mass will be clean.

Photo by Lauri Veijalainen

After the taping, the glue and sealant mass was squeezed out along the seam of the pane and the frame. After that the mass was formed even with a plastic forming spatula. As mass we used black Soudaseal and Würth glue and sealant mass. When the seaming was ready, we extracted the protective tapes along the pane edges and the protective film on the panes. The seaming of each pane turned out to be very neat.

Photo by Lauri Veijalainen

There are also small sliding windows in the cockpit that can be opened. For them we received original framed panes from Airveteran Oy. Installing them proved to be a bit problematic. Both the sliding window frames lacked a locking screw from the bottom, with which the window was pressed with its rubber seal tightly against the frame to make it watertight. On top of that, both the frames of the sliding windows we received were both for the right-hand side. Luckily the right- and left-hand side pane differ from each other little enough, so we pushed the right-hand side pane deep and tightly enough into the grooves of the left-hand side frame. There it can remain for the time being, until we’ll find a suitable pane for it.

We noticed that along the windscreen and cockpit side window frames there were empty screw holes. What for, we wondered? To stop water from leaking into the fuselage, we blocked the holes by screwing groove-headed sheet metal aluminium screws into each of them.

Photos by Lauri Veijalainen

Photo by Janne Salonen

With the windows we had accomplished all the agreed tasks to refurbish the DO-5, so for our part the fuselage was ready to be transported to Turku Airport and to be on show there at the Airshow on June 17th -18th. The DO-5 fuselage left for Turku on Thursday June 15th.

Photos by Lassi Karivalo except if otherwise mentioned.

Translation by Matti Liuskallio.