Another Sonex Canopy installation mod

This Sonex canopy installation is in no way a Sonex Aircraft Inc. recommended design. It is presented for Sonex builder's consideration only. Builders using this information do so at their own risk and the ASA assumes no responsibility for the either the design or installation. If you see any improvements in the design or have further questions please contact the ASA Webmaster

This method of installation has proven successful and is a mixture of several other builders' methods. The Sonex standard canopy installation has a very minimal edge margin that exists at the lower canopy sides where it attaches to the 1/2" square canopy frame. This seems to be a common source of canopy cracks among builders. The newer canopy material, now used by Sonex, seems to be significantly more resistant to cracking but there is still a very minimal edge margin that is easily a source of trouble. This method anchors the sides of the canopy material without drilling holes in the near vicinity of the canopy material edge. While adding only a minimal amount of weight, the design also helps mitigate torsional stress that would otherwise have to be absorbed by the fragile canopy material caused by stressful handling or conditions. In this design the sides of the canopy are held in place by a pair of aluminum strips that serve as clamps to hold the canopy material with out having to drill holes near the edge. The aluminum strips used were .032" 6061 but they can be built with thicker strips if you desire. The thicker strips are harder to joggle and do not want to conform to the canopy as well as .032" seems to. Be sure to check that the left side joggle strip does not inhibit the canopy locking slide bars' movement. The interior strips need to have a 1/8" or so joggle to match the thickness of your canopy material. The joggle and trim strips were made 2" wide. The joggle is made 1/2" above the lower edge of the interior strips. You may wish to vary the width of the strips but the wider the strips are more difficult to conform the canopy's curvature and provide little if any additional canopy grip. The sandwich of joggle strip, trim strip, and canopy may need to be shimmed out to match the lines of your windscreen depending on how you installed the windscreen bows. This design used CCP-44 rivets to attach the sandwich to the frame, but you may need a different length rivet based upon your particular sandwich thickness. Alternatively you could drill and tap the 1/2" square tube and use 6-32 AN526C machine screws to attach the sandwich. Although the rivet are the preferred fasteners, the limited availability of longer grip rivets make machine screws your only choice if you have to shim the canopy outward very far.

Using the same technique used else where on the canopy bows, install MS24693 machine screws and washers through the exterior trim strip and canopy material and anchor them into the canopy bows as depicted. Verify the proper machine screw length as different lengths may be required based on your individual installation. Alternatively you could use soft aluminim rivets here but be careful not to crack the canopy material by setting the rivet too tight. Note also that the interior joggle strip is trimmed to fit between the canopy bows so that it does not distort the canopy fit to the canopy bows. The exterior trim strip is cut to shape and length to match the shape of the canopy material. On the hinge side of the canopy be sure to carefully locate the holes through the hinge half and sandwich to insure you do not violate the minimum edge margin for the rivets attaching the sandwich to the canopy frame square tube. Consider using a wider hinge half on the exterior hinge to afford you more room to insure a good rivet edge margin on the canopy frame square tube.