Monday, August 17, 2015

RV-12 Canopy – One Half Step Backward

Over the weekend work continued on the RV-12 canopy instillation. On Saturday I was able to enlist the help of Jan to help with screwing the C-1201 canopy to the C-1202 canopy skirts and C-1203 attach angles using #6 hardware. Once again climbed inside the cockpit and closed the canopy so the nuts and washers could easily be installed from inside while Jan stood outside and prevented the screws from turning with a Philips screwdriver.

Jan holding the #6 pan head screws with the Philips screwdriver while I tightened the nuts from inside the cockpit.

While inside the cockpit, thought this would be a good time to match drill the C-1206 guide plates into the WD-1219 canopy frame ... so they were drilled and secured with Clecos. The plan is to rivet the right guide plate onto the canopy frame … but for the time being, leave the left one secured with Clecos. The reason for this is to keep the options open for a canopy lock. Aircraft Specialty is working on a canopy lock that will use the canopy latch handle … however, if that project does not come to fruition before it is time to fly, the plan is to extend the length of the left C-1206 guide plate and cut a slot in it for a key lock (see second photo below).
Right C-1206 guide plate match drilled and Clecoed onto the WD-1219 canopy frame.
Parts for the canopy locking mechanism Rob (a builder in Australia) designed.
Photo of the locking system Rob came up with. The C-1206 guide plate is made longer and fabricated to capture the arm on a key lock.

Yesterday, while about to begin riveting the C-1202 canopy skirts onto the WD-1219 canopy frame, it occurred to me that in my exuberance to get the canopy finished I forgot to dimple the canopy skirts for the flush rivets (the first five are already dimpled) that are being used on the DOG Aviation RV-12. However, in order to dimple the canopy skirts, all the screws Jan helped me place through the canopy skirts will need to be removed. Not wanting to take a step backwards I tried to rationalize that there are screw heads sticking up so there will be a row of rivets showing below the screws … so no big deal. But then there is the row of flush rivets along the upper edge of the side skins …. It wouldn’t look right and I know it would bother me forever if I did not take the C-1202 skirts off to dimple and countersink for flush rivets. So, all the screws were removed and the canopy skirts were removed for dimpling and machine countersinking of the WD-1219 canopy frame. Gee !!! Don’t tell Jan her excursion to the airport to help me was all for not.
Machine countersinking the remaining holes in the WD-1219 canopy frame aft of the first five that were previously countersunk.

After dimpling the C-1202 canopy skirt and machine countersinking the WD-1219 canopy frame a little primer was placed on the countersinks and the canopy skirt was Clecoed back onto the canopy frame for riveting. Prior to riveting the screws were slipped back into the holes and the canopy was swung up so the #6 canopy screws could be made snug … but not tight.
Riveting the C-1202 canopy skirt in place with flush rivets in the place of LP4-3 rivets.
Finished right side of the canopy … this looks far better that if I had not taken the time to install the flush rivets.

Work moved over to the left side … the canopy screws were removed along with the canopy skirt. The canopy skirt was then dimpled and the WD-1219 canopy frame was machine countersunk. As on the right side, the countersinks in the canopy frame were primed … hind sight being 20/20 should have used a Q-Tip or small paint brush for the primer, it would have been much neater than the foam brush I had available … but it will be our hidden secret.
Dimpling the left C-1204 canopy skirt for the flush rivets being used on the DOG Aviation RV-12.
Machine countersinking the canopy frame using a #30-120 degree countersink bit.
The builder did a sloppy job of placing Chromated primer in the countersinks on the WD-1219 canopy frame.

Ran out of time so did not get the left side completed. Something to do during the next work session as the saga of the canopy instillation drags on.