Sunday, November 1, 2015

The RV-12 Receives Another EAA Tech Counselor Inspection

Knowing an EAA tech counselor visit was scheduled for Saturday, Friday was spent playing with the tail cone fairing and connecting the stabilator control cables. The previous post showed the tail cone fairing sitting roughly in position … so Friday the positioning of the tail cone fairing was tweaked a little then the fairing was drilled and Clecoed to the tail cone. The plans call for a minimum of 1/8" of clearance between the tail cone fairing and the skin of the horizontal stabilator … there was no position that achieved that without the need to do some filing so I picked a position that offered a good compromise.  After all the holes were drilled, the fairing was removed. The holes need to be final drilled to #27 and nutplates need to be installed … but placed that on hold due to the upcoming EAA tech counselor visit.

I wanted to have the upper and lower horizontal stabilator cables attached to the two horns on the stabilator so the horizontal stabilator would be totally functional for the inspection. This required connecting the aft end of the upper and lower stabilator cables onto the horns on the horizontal stabilator. Nothing special here, just a little grease, one bolt, three washers, a castle nut and a cotter pin per each cable attachment.

The upper and lower stabilator cables in the tail cone make up the aft half of the stabilator cables. Because each upper and lower stabilator cable is comprised of two sections … a forward and aft cable, the aft cables need to be joined together to the forward cables using a special threaded barrel. One end of the barrel has a ring grove machined into the metal which denotes that end of the barrel has reverse threads … this end needs to point aft. Following the directions in the plans, the forward and aft stabilator cables were connected together by getting on a creeper and rolling under the fuselage to reach in through an inspection access hole and threading the barrel onto the threaded ends of the cables. Following a sequence in the plans, each barrel is turned until the slack was taken out of the cables. I stopped at this point because the DOG Aviation procurement department still needs to purchase a cable tensiometer to finalize the tensioning on the cables. However, at this point I had a working horizontal stabilator which completed the instillation of the flight controls for the EAA tech councilor visit on Saturday.

The grove on the aft end of the adjustment barrels for the stabilator cables can be seen if looking closely. This grove denotes reverse threads and needs to face aft. Also: The cables in this photo are not fully adjusted yet … so they do not have the proper amount of threads showing, nor are the locking clips installed.

Saturday, the EAA tech counselor visit went quite well and no work corrections were pointed out. Jim the EAA tech councilor and his friend Don a fellow EAA chapter member came down from the Cleveland area to give the RV-12 a good looking over and gave it a clean bill of health. For being a small plane, both Jim and Don were impressed with the level of sophistication and complexity of Van’s RV-12 design.
Jim the EAA tech counselor in the foreground and his friend Don in the background looking over the DOG Aviation RV-12 project.

While there was extra muscle in the hangar, decided the time was right to lift the Rotax engine box out of the crate and unbolt the engine from the box so the engine could be set on the workbench. Prior to installing the engine on the firewall there are a few tasks that are required to be performed.  These tasks can be completed much easier if the engine is setting on a workbench.
The right side of the Rotax 912ULS engine. The mechanical fuel pump (two orange hoses attached to it) is just aft of the prop flange and the starter can be seen on the bottom left of this photo with the red label on it.
Front view of the Rotax engine … behind the flange for the propeller attachment is the gear reduction unit, the black oil filter is on the bottom left.
Left side of the Rotax engine. Just above and to the left of the Bing carburetor (center far right) one can se what looks like a silver radiator cap … which it is. This is the cap for the small black coolant reservoir.