I mounted the instrument panel a while back. That task involved creating mounting tabs on each side of the fuselage and a mounting tab on the center keel. Then nutplates were riveted to the tabs. It worked fine but the problem is that it will be almost impossible to remove the panel once the engine controls (Throttle, prop and mixture) are installed. There are a couple of approaches to work around this issue. Malcolm’s is to create a sub panel that the engine controls are mounted to and that sub-panel is permanently attached to the fuselage.

First, the location of the engine controls is determined. There’s a bit of guesswork involved since I don’t know what the correct spacing between the controls should be until they’re drilled. So I checked with a couple other builders and came up with 2 – 2.25″ between each control. I went with 2.25″.

This picture shows the left side of the instrument panel with the location of the Throttle, Prop and Mixture controls. I’ve also created the line where EC (Engine Control) sub-panel will be cut away from the main panel.

Partial cuts are made in two places along the two lines. Then structural adhesive is applied to the back of the sub-panel and the whole panel is screwed and clamped into position.

Once the adhesive has cured, the cuts are completed and the main panel is removed leaving the sub panel attached to the inner skin of the fuselage.

Then tape is applied to the front and back of the main panel and a release agent is applied.

The main panel is reinstalled and reinforcing layups are applied to the back of the sub-panel and extended over the back of the main panel. This will create a flange that will be used to connect the main panel and the sub-panel.

View from the back of the panel.

Then holes are drilled through the main panel and flange on the sub-panel and nutplates are installed. After that, the holes for the engine controls are drilled into the EC sub-panel.

Next the EC sub-panel will be painted and the engine controls will be mounted.