Empennage Construction -Alexander Sportair Workshop


Empennage - Alexander Technical Center  (6/21/2004-6/26/2004)

Notes on the Program

I traveled to the Alexander Technical Center in Georgia to build my empennage.  This was a 5 day long class/workshop.  The goal was to both construct the empennage, but more importantly to teach the appropriate quality techniques to allow for a very high caliber job to be performed by the user on the rest of the aircraft assembly job.

From what I can tell this course is no longer offered, which is too bad,  as it was excellent.  I learned a lot and have great confidence in the material that was assembled there.  My old web pages used to detail the course specifics.  I will forego that now since there is no longer a course to critique.


Home for a week

You can't beat having your hotel room 50ft. away from your work.   This worked out great.   The only issue was that we got infested with tiny little biting Georgia ants.   They took a shine to my mother's oatmeal cookies she had packed in a tin before we left.   There were thousands on-board at one point. 

The 'before' picture.   This was to be our center of operations for the week. 

After inventory and a review of basics, you start, as anyone with a horizontal does, shaping the 603's and assembling and drilling the HS spar. 

Smoothing and shaping the front spar angles prior to bending them.   I had to get myself in a couple of photos for official records.   When I did the HS previously, I remembering agonizing over the 6 degree bends for the better part of a day.   It took about 5 minutes here.   Mark them, clamp them in a metalworking vise (really neat vise with wide, smooth jaws), and bend them a bit each time until 6 degrees is hit (about 4 or 5 iterations). 

My father ready for action.   I offered him many occasions to bail out if things were getting to be too much, but he stuck with it the whole time, working as hard as anyone else there.   I must admit to some trepidation about who would be running the show, since it's my dad and all, but he established that he was slave labor and at my beck and call. 

The parts start to pile up.   At this point we finished preparing the HS and look to be done with most parts for the VS.   Unfortunately we were working fast enough, that I ended up not taking as many pictures as I should have along the way. 

The only 'problem' we encountered was fitting the E705 root rib on the right elevator.   There's a pretty tight reverse bend as this rib has to match up with the spar, the skin, and the weldment.   The radius on my rib was substantially larger radius than the other elevator's, and also versus the other participant's parts.   Here was a shining benefit of this course.   I immediately had parts with which to compare my own rib and quickly come to the conclusion that there was a parts problem, not an assembly problem.   We futzed around for a while trying to tighten up the bend (all the instructors swarming to the problem, or course), and concluded that we would be better off just ordering a new one, than trying to mangle the old one into shape. 

I called Van's, explained the situation, and got them to overnight a new part out.   I explained where I was, and the resulting time pressure, convincing them to overnight the part.   Usually they mail it.   I was surprised to get the invoice for $0.   I was at least expecting to pay the difference between regular mail and overnight shipping.   Nice job Van's! I missed the priming session for that part and had to prime it separately with a rattle can of zinc chromate primer.   The rest was done with a 2-part Sherwin Williams epoxy primer.   All-in-all a very good customer satisfaction experience that did not hold me up at all in completion of the project. 

Here is my father fashioning himself a new index finger out of some clecoes and scraps of old aluminum.

Everything has been primed and we're ready to start riveting the VS together.   One of the clear advantages with the modern kits is that BOTH the skins and the ribs are pre-punched.   This allows everything to be assembled with NO jigs.   It greatly speeds up the initial assembly and allows riveting to occur on flat surfaces as opposed to jockeying around in the jig. 

The first truly completed piece to come together.   By the way, don't wear any white shirts to the course if you want to keep them that way. 

The HS frame starts to take shape.   We mounted this in the jig to rivet one side, then removed the rear spar and riveted the opposite side flat on the carpeted bench.   Minimal contortions needed with this approach.   This is only possible with the new style of parts where both ribs and skins are prepunched.   Otherwise you have to do it all in the jig with the frame 100% riveted up.   The new method allows for the spar to be riveted on last.   The inner ribs are pull riveted to the rear spar.   All other rivets are accessible from the edges. 

Here I am imperiling my father.   A little awkward, but we got into a rhythm quickly and it went fast. 

The rudder followed.   I did not get any photos of the back riveting plate they have there but it looks to be a flat piece of steel about 2' x 3' and 3/8"  thick.   It really reduces the amount of labor as you can quickly move from stiffener to stiffener without moving the work piece.   At home my chunk of steel is just not even long enough to do the longest stiffener on the rudder. 

The last major assemblies were the elevators.   Once you've worked through the rudder, the elevators are pretty straightforward.   We left the trim hinge mounting for the last day.   The process involves a lot of sighting and fiddling to make sure it's exactly in line.   When you start to rivet, start in the middle and work outward, giving each rivet only a half squeeze at first until they're all set and tight, then go back for a full squeeze.   All 3 trim tabs in the course were bind-free and straight.   Very cool. 

Very last is the rolling of the control surface leading edges.   This task was probably 90% Jacob and 10% me.   It's clear that after having done 120 tail kits, he had the technique 100% down.   There's a lot of finesse to this task.   I as just as happy to let him do it as his results were far better than what I would have likely achieved. 

The photo is probably more critical than the naked eye.   When sighting down the bends, there are no visible flaws.   It looks a little flat-fronted here, but that's very hard to see in the flesh. 

The obligatory 'after' picture.   The parts are in the motor home and it's time to roll. 

S. Metzger © 2011