380 hours on the hobbs - riveting stiffeners

Well, got all the stiffeners riveted, except one. Started at the trailing edge, working solo. Using my arms and hands to force the opposite skin back far enought to clear the rivet gun and retaining spring. Thought this would be the same process as before - back rivet the stiffeners and move on. Well, guess again. The rivet on this particular siffener ended being severely folded over. So I drilled it out and inspected the skin and the stiffener. The flange of the dimple had been severely deformed on one side. I tried to reset it with the dimple dies but I don't think I did any good. The hole ended up just a bit enlarged so I decided to use slightly longer rivet to fill the hole. The rivet folded over again. I drilled it out and basically stopped all work on the elevator out of total frickin disgust. How could such a simple stupid process end up screwing things up so bad? I couldn't believe it.

Net step was to decide to use what is affectionately known as an "OOPS" rivet.All that means is that there are a set of 1097 odd-sized rivets that have the same head size as a standard AN426AD rivet that fits the same dimple, but contains a wider shaft. SO instead of a 3/32 inch diameter these rivets have a 1/8 inch diameter. All you are supposed to have to do is drill out the oblong hole to 1/8 inch, insert the rivet, and reset it - no problem. Except of course in my case, where the rivet head is not sitting very flush in the dimple any longer. Now I have a bad dimple with an oversized hole drilled in it, and no easy means of trying to reset the dimpleto make it fit the 1097 oops rivet properly. Worse case scenario, I need a new left elevator skin and a new stiffener. Best case is that I will figure out a way to reset this dimple in the skin so that the oops rivet will fit correctly, order a new angle so I can form a new stiffener, and try to reset it again.

THIS REALLY SUCKS! What a way to end a vacation.

I needed to regroup and think this thing through a bit so I did nothing on the elevator today. Instead I spent most of the day revewing Avionics info from the Grand Rapids, SafeAir, Garmin, Dynon, and SteinAir companies. The thing that forced me to start going down this road is that once I build the left wing, I need to determine what Pitot solution I need, and I will need to order the parts for the installation of the correct Pitot mast as a result. The type of Pitot tube I use may be dictated by the type of EFIS, or electronic flight information system, I employ in the aircraft.

Right now I am favoring the Grand Rapids over the Dynon, for reasons I will not get into right now. The only thing I will say is that both of these units work on slightly different principals, and one requires use of the pitot static system where the other does not seem to rely very much on this. This difference in design will determine what pitot/static system I need to employ. For right now I think I am siding with the GRT Horizon HX EFIS with a dual AHRS unit. AHRS is short for attitude/heading reference system. The EFIS and AHRS combine to provide basic and advanced flight instrumentation of the airplane, or the "glass cockpit" components that replace the standard "steam gauges" of the past, including the airspeed, attitude, altimeter, Heading Indicator, Turn Coordinator, and VSI. I will then use the Dynon heated pitot tube, which contains two separate air lines to provide airspeed and Angle of Attack reference, and will most likely cap the AOA on the pitot tube and not use that, since the GRT Horizon apparently has a different method for calculating AOA which does NOT rely on the pitot static system.

For those not familiar with advanced aircraft avionics, I know this is a mouthful. Don't worry, I will go into more detail on this subject when the time is right. There are lots of acronyms, terms, and concepts to understand about all this. Basically you can just think of it as replacing all those traditional gauges with a video game that has all sorts of bells and whistles and really colrful displays all crammed into one screen.

Next steps for me - order a new angle for a new stiffener from Vans tomorrow. Then try to reform this stupid dimple in the skin. Then I can continue with preparing the skeleton and trim tab. Just another day at the factory..........