MOD: making the passenger windows removable Part 1

Because our plane will hold hydrogen components and a firewall between the pilot and these hydrogen components will make it difficult to access these components, we have decided it would be nice to have the passenger windows removable.

After having discussed this with Sling and other builders, the solution we came up with was using an aluminium strip which we would glue to the canopy (where originally the windows would be glued). Anchor nuts can then be placed onto this strip and buttonhead screws can screw into these anchor nuts holding the window into place.

The aluminium strip was made to size with the window as a reference guide, then it was held into place and holes were drilled around the outside of the strip through the strip and the canopy. This allows us to not only glue this strip but also hold it into place with 16x 2.4mm stainless steel countersunk rivets (this also helps with the Sika Flex since it is very hard to clamp the strip with regular clamps).

Now the holes in the aluminium were dimpled and the ones in the canopy countersunk, The canopy round the outside of the window is quite thick so this actually turned out quite nice for countersinking these small rivets.

Unfortunately the aluminium strip did have to be cut in half because when actually clecoing it into position it kept buckling, apparently a 2d sheet cannot be bend in this more complex 3d shape. But by using some extra rivets no significant structural integrity to the window was lost.

Now the 2 strips can be bonded onto the canopy and the countersunk rivets were set to give the hold the strips firmly.

Lastly 9x4mm holes were drilled for the m4 anchor nuts to fit behind, next to these 2x 2.4mm holes were drilled and dimpled for the anchor nuts to sit against. The anchor nuts that we plan to use are quite thick and the 2 small holes can therefore be countersunk.

Builders of the removable windows:

Pepijn

Francesco