DO-5 cockpit windscreens to winter proof condition

Sunnuntai 16.10.2022 - Tuesday Club member


Suomeksi

Work on the fuselage of the DC-3 (C-47) DO-5, owned by Aviation Museum Society Finland, have started promisingly at the Tuesday Club. At the moment we aim to concentrate on tasks that are possible to do regardless of the weather during the cold period and winter season. The fuselage is out in the open at the yard of the Finnish Aviation Museum. Furthermore, we have prepared the fuselage, which is out in the open, for the autumn rains and the blizzards of winter.

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One such measure was to get the cockpit windows sealed so that rainwater and snow wouldn’t get into the cockpit. We had already earlier in the autumn covered the cockpit windows of the DO-5 with rainproof plastic, because the plexiglass panes fixed to the frames of the windscreens were too small to keep water out of the cockpit. Both the original windscreen panes of the DO-5 have been broken at some stage and been replaced with transparent 3 mm thick plexiglass panes.

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To replace those undersized windscreen plexiglass panes before winter we had to get new plexiglass ones to fit properly to the windscreen frames. Although that wouldn’t be the procedure with a flying DC-3 aircraft, but to replace a broken or otherwise unusable windscreen pane, a completely new pane with frames would have been changed as a spare part. Such spares we don’t, alas, possess.

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So the undersized windscreen plexiglass panes were detached and the chutes of both windscreens were cleaned of rust and dirt with a brush disc, attached to a battery driven drilling machine. To acquire new plexiglass panes, a window shaped template was made of 1,2 mm plywood. This template was cut so, that the template of the windscreen pane could just be slid into the chute of the frame through the windscreen opening.

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The plan is to glue the new plexiglass pane to the chute with silicone. In the process of gluing the plexiglass pane will be supported so that it leans with each edge a few mm against the inner side of the frame chute. Thus the plexiglass pane would cover the whole windscreen opening and the silicone seam would become watertight.

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WE had ETRA cut us two windscreen panes according to the plywood templates, from 5 mm thick UV-protected polycarbonate plexiglass. When we fitted them into the DO-5 windscreen chutes, after a bit of filing, we got the panes to click into place inside the windscreen frame.

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Because the autumn temperatures had sunk to about 10 degrees centigrade, we decided to postpone the gluing of the plexiglass panes to warmer weather next spring. Instead, we taped the new plexiglass panes, covered with protective plastic, on the outside of the aircraft with orange tape to the frames of the windscreens in order to stop rainwater or snow from getting into the cockpit. The tape covered completely the seam between the fuselage and the frame of the windscreen.  We covered the seams of the cockpit’s side widows in the same manner, to prevent rain from penetrating into the cockpit through them.

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Another preparation for winter was to cover the tail section with a protective tarpaulin. The vertical and horizontal stabilizers have been dismantled. Thus rain and snow have free access into the fuselage through the openings. We got hold of a large tarpaulin, with which we covered the tail section completely.

Photos: Lassi Karivalo

Translation: Matti Liuskallio.

Avainsanat: aviation history, restoration, Tuesday Club, DO-5;DC-3, C-47, Dakota