Building of the missing Link Trainer aileron

Suomeksi

The restoration of the Lappeenranta based Karelian Aviation Museum’s Link Trainer wings is underway at the Aviation Museum Society’s Tuesday Club. Our main work is to refurbish the wings and cover them again. Furthermore the missing aileron from the left-hand wing had to be built. As a model we used the right-hand wing aileron, which was stripped of its covering.

Photo by Kimmo Marttinen.

Photo by Lassi Karivalo.

Photo by Lassi Karivalo.

We started to build the aileron from strips of wood according to the original. However, we noticed after a few days that the finished parts of the aileron didn’t keep their form, but there were distortions. The material we used wasn’t good enough. We ended up with a solution different from the original by building the left-hand aileron mainly from plywood, which keeps its form well. The decision facilitated our work also so that the curved trailing edge tip had originally got its form from strips of wood soaked in water. Making the curved part of the aileron from plywood will be easier.

Photo by Lassi Karivalo.

We started making the aileron from the curved tip of the trailing edge. In order to get thick enough plywood to build the trailing edge tip, we glued two sheets of plywood together. After the glue had dried, a picture of the right-hand aileron’s curved trailing edge was drawn on the plywood. The plywood was sawn along the drawing line, to give us a blank for the left-hand aileron trailing edge. The blank was shaped tentatively to its form.

Next we made from plywood the left-hand aileron’s leading edge, which could be called the spar of the aileron. We sawed it from 6 mm thick plywood according to the model given by the right-hand aileron. The leading edge is not at right angles to the wing base. The correct angle (98,3 degrees) was defined from right-hand aileron’s leading edge. The left-hand aileron’s leading edge base was ground to that angle. The leading edge batten was now ready.

The necessary three triangular ribs were made of plywood according to the right-hand wing aileron ribs and angles. In the same way some thin 3 mm strip of pine was found, from which the straight stem of the trailing edge was made. The trailing edge stem will be joined according to the original model with a 5 cm long glue joint to the curved tip of the trailing edge batten.

When all the components of the aileron had been made, the construction of the aileron was started. The compilation was commenced with the leading edge and the ribs that were glued to it. As a gluing platform sturdy plywood was used, onto which a guiding piece with an angle of 93,8 was fastened. The leading edge batten was fastened with clamps to the guide piece and its sturdy platform.

First the aileron’s root rib was glued into place and after that the two other ribs. The gluing was secured with two screws. The aileron had already got its basic form.

The trailing edge of the aileron was still missing. First the straight thin stem of the trailing edge, which was shaped from a batten of wood, was glued to the ribs. Last to go to place was the curved tip of the trailing edge. At the same time the tip and stem were joined at the rib with a glue joint. The rib also strengthens the glue joint.  Because the curved tip of the trailing edge had only been tentatively ground, the tip was ground to final form after the glue had dried.

The missing aileron of the Link Trainer was structurally finished. The aileron will be covered and painted in accordance with the covering of the Link Trainer wings.

Photos by Pauli Jokimies except if otherwise mentioned.

Translation by Matti Liuskallio.