The MY-14 sliding canopy

Suomeksi

The original sliding canopy of VL Myrsky II MY-14 has disappeared. However, we had at our disposal two original but badly corroded sliding canopies with all their parts remaining. The plexiglass parts were, however, destroyed.

The sliding canopy which had been chosen to be restored was taken apart and we noticed that total corrosion hadn’t taken place. So the canopy frames were sandblasted and painted grey. The bearings of the sliding mechanism were replaced with bearings of original quality. For some reason the sliding mechanism didn’t work with the new bearings before the outer rim of the bearings was honed slightly narrower.

The locking peg, which moved inside the canopy frame, was rusted solid and the wire moving the peg was cut off. The old locking peg was removed and replaced with a new one, lathed according to the blueprint. A reinforced peg was made, according to modification amendment C 301, because the original peg in the frame was of that model and the locking slots in the runner were measured for the reinforced peg.

The wire inlet/guide piece was in a poor shape and was replaced with a new one, made of parkesine according to the blueprint. A new wire was soldered to the locking peg and an end piece was made to the wire according to the blueprint, and a piece of rubber hose, which worked as the handle was attached with brass string. The original lever for the opening mechanism, cast in brass and the aluminium press button at the end of the lever were cleaned, and the lever was painted grey, the press button black. The “PRESS”-text engraved at the end of the press button was nearly vanished. The engravement was repaired where needed and the text was painted white.

The new bent canopy plexiglass panes were sawn into measure and the necessary rabbets were milled and ground, so that the panes settled flush with the canopy frame strips. The original inner plexiglass aluminium holder strips were cleaned with oxalic acid and painted grey. The plexiglass panes were fastened with new 3 mm screws and nyloc nuts. A suitable hole was made into the canopy’s top plexiglass pane to give access the opening press-button.

The original aluminium strip at the rearmost end of the canopy was badly corroded and broken, so a new strip of 0,7 mm aluminium plate was made according to the blueprint. According to the blueprint there should be a seal made of felt at the front end of the canopy, but according to photographs it seems that it has never been fitted there, so we left it out, too.

The blog has been edited from the report by the Finnish Air Force Museum’s restoration group. Photos by the Finnish Air Force Museum.

Translation by Matti Liuskallio.