RV-12’s Rear Wing Spars Completed

Today work continued on the RV-12’s rear spars after taking a three day hiatus to fully recuperate from the marathon work sessions of last week along with preparing for possible storm related power outages. Fortunately, the worst of storm Sandy’s havoc in our area passed to the north of us, so there were no power interruptions or damage here at DOG Aviation ... just a few days of seemingly endless rain and cold stiff winds thus far, with a couple of more days of rain in the forecast.

There are a few components that need to be attached to the left and right W-1207A rear spars before the spars are ready to become part of the wing skeleton. Work began with riveting the previously assembled left & right W-1212 hinge assemblies onto the W-1207B doubler plates. There are two rows of holes on the hinge assemblies and only the inboard row of holes are riveted at this time … the outboard row of holes will be riveted later when a rib is attached onto the rear spar assembly. There are also two other rows of holes on the spar/doubler assembly which need to be left open as well for ribs which will be attached later during assembly of the wing 's skeleton.

Attaching blue tape to identify the three rows of holes on each W-1207A rear spar assembly that will be riveted later.

                                              W-1212 hinge assemblies and W-1207B doubler plates clecoed
                                              onto the left & right W-1207A rear spars and ready for riveting.

The plans call for riveting the inboard row of rivets on the hinge bracket using AN470AD4-6 solid rivets but call for using LP4-3 pop rivets for all the doubler to rear spar rivets. All those rivets were easy to assess with the pneumatic squeezer so I elected to use AN470AD4-6 rivets on the entire assembly … stronger, lighter.

Using a pneumatic squeezer to set the last rivet attaching the doubler/hinge assembly onto the right W-1207A rear spar.

                                   Front and back views of the RV-12’s W-1207A rear wing spars with the hinge
                                   assemblies and doubler plates riveted in place with AN470AD4-6 rivets.

The finishing touches to both rear wing spars come in the form of riveting the W-1207C tip attach angles onto the outboard end of both spars. Once again the plans called for using LP4-3 pop rivets to rivet the W-1207C tip attach angles onto the rear spars … but there was good access for a pneumatic squeezer, so AN470AD4-4 solid rivets were used in place of the LP4-3 pop rivets.

                             The W-1207C left tip attach angle clecoed onto the left rear spar and ready for riveting.

                                    Riveting the left W-1207C tip attach angle onto the left W-1207A rear spar.

                   Front and back views of the outboard end of both completed W-1207A rear spar assemblies.

The W-1207A spar assemblies are now both completed and ready to become part of the RV-12’s wing skeleton when the wing assembly begins in the near future.