We have been making steady progress on the RV-12 prototype. At this point, that means we’ve been making lots of parts for the fuselage, and just started putting them together. The wings and tail are finished.

As a step toward fool-proofing (I use the term with all due humility) the airplane, I was put to work assembling the cabin section of the fuselage while the rest of the crew was at SunNFun. Although there are, as yet, no actual construction plans for the airplane, I found the pieces easy to understand and assemble from rough sketches and the occasional helpful word from drafter Amber Peterson or engineer Ken Krueger (example: "NO! Not that way, you idiot…").

As ever, I’m amazed at how matched-hole punching has reduced assembly time. I learned a few things about blind rivets, too. I hadn’t thought about it before, but one of the advantages of blind rivets is that you no longer have to consider bucking access when you design the structure. Rib flanges can turn either way and there’s no need to worry about how to reach inside a closing structure. Just cleco the skins on, stick blind rivets in all the remaining holes and go to work with the pneumatic rivet puller. No dimpling -- since the airplane’s top speed is limited by rule, there’s no particular need for flush rivets. Low profile blind rivets ain’t cheap (at least, compared to solid rivets) but they are quick. Another lesson – seaming pliers will be an important tool on this project. Flanges must be adjusted carefully to make the full-sized pre-punched holes align exactly — and they need to be aligned if the blind rivet is to go in easily.

All through the airplane, you can see the lessons we learned on earlier kits, especially the RV-10. There are some really clever combinations of forming and punching techniques that make several parts at once. After about eight days in the shop, I’m convinced that this airplane will go together very quickly indeed.

When the cabin section from baggage bulkhead to firewall was virtually complete, The wings were trial fitted. We found a few minor "erks" during this, which is why we do trial fits!

Current work includes making parts for the tail cone and prototyping the engine cowling with particular attention to the ducting necessary for the oil and coolant radiators.

    
    Above: Scott McDaniels and Amber Petersen have the basic cabin
    structure together and are fitting the roll-over structure. Something,
    incidentally, that many of the LSA airplanes we saw at Sun n' Fun
    didn't have.... 
    

Our last minute decision to take the RV-12 to Oshkosh meant that we couldn’t do any work on the actual airframe, but it didn’t mean that Amber Peterson, Rian Johnson and Phil Rivall stopped working on the drawings and design. At the moment, there really isn’t much to see in the airframe that wasn’t in the last issue, but progress is being steadily made on systems and wiring.

Like our customers, we’ve spent a lot of time thinking about what to put in the panel. Surprisingly — at least it’s surprising when you consider that our panels are traditionally pretty simple and this is an even simpler airplane — the RV-12 is slated for an all-glass panel. Illustrated below is one computer generated conception. It may not be the absolutely final iteration, but it should be pretty close.

 

                            Click here for a larger view of the image

On the left is a Dynon EFIS/engine monitor. In the middle is a Garmin 196, an SL-40 and a GTX-327 Garmin transponder. The big screen on the right is a  AF-3500 combined EFIS/engine monitor. The six small slots on the left side are plug-in fuses — cool little units that light up when they blow. The small rectangular cut out on the upper left is the ELT readout. Guarded switches for various duties, a couple of light switches and the ignition key round out the panel design.

This is far more avionic/instrument power than our other demonstrators have. In fact, the RV-12 will be our only airplane with an attitude instrument. Overkill for this little bird, perhaps, but the arrangement will give us a chance to compare two of the more popular systems in a side-by-side, real-world situation.

more on the 12 panel

                          Click here for a larger view of the image

Here’s some clarifications to the RV-12 panel set-up. We used the term "light switches" in the RVator, which is not quite correct, as the airplane has no lights and none are planned. The diagram above shows the switch/warning light layout on the lower left part of the panel.

The light-up fuses shown on the panel are only available in 5 amp and above. There are a couple of 1 and 2 amp fuses used in our panel that will not light up when they blow.

Once the RV-12 returned from Oshkosh, Scott McDaniels, Rian Johnson and Ed Chesney fell upon it with a vengeance. The Rotax 912S was installed, complete with radiator ducts and induction manifolds designed by Van. Rian tackled the panel wiring. That’s quite a task in this airplane, with two different EFIS displays, a radio, a transponder and an intercom. Lots of wires. Scott applied his skills to the canopy while Ed went to work on all the other odds and ends in the cabin and control system.

All of these systems are worth a little explanation. The canopy is a tip up design, but quite different than the ones used on the RV-6/7/9. It is hinged on the outer edges, just above longerons, which frees up the space behind the instrument panel. The frame is welded steel, and the plexiglas is mounted in two left/right halves. For this one prototype we adapted halves of the old Nigerian AirBeetle canopy – simply because we had a couple and they were close enough to make work and save some time. The result is not as sleek as we envisioned, but we were willing to live with that to expedite the building process and get the airplane into the air. For production airplanes, we will make a mold and provide canopies that fit the RV-12 exactly.

   

The instrument panel, as noted above, is actually higher-powered than any we currently have in our demonstrators. Both Dynon and Advanced Flight System EFIS displays are planned, with a Garmin radio/transponder/GPS stack in the middle. We are experimenting with automotive fuses mounted in the face of the panel – an idea that has worked well so far in the KK-1. At the moment, AFS units are so popular that AFS hasn’t had time to complete the unit they are designing for the RV-12. Rather than hold short, we’ve chosen to start flying without it, but with all the necessary wiring in place. When the unit is ready, we will install it and let you know how it works.

The control system in the RV-12 is quite different from any other RV. We are using cables for the elevator and rudder, but pushrods for the flaperons. A clevis arrangement on the fuselage pushrod plugs into a fitting on the wing in a manner that makes it impossible to put the wing pins in the removable wings if the controls are not engaged.

On October 18, we assembled the airplane and weighed it. There was lots of interest in this, because we had a pool going in the office. Unfair advantage to the engineers and their spreadsheets, I said, but plugged in 742 lbs as my best guess. I was delighted to find I was much too pessimistic when it came in at 714 lbs. (Who won the pool? Silly you for asking! Van was within one pound.) This is very good news, because the design gross weight is the Light Sport Category mandated 1320 lbs. A 606 lb useful load with a 19 gallon (115 lb) fuel load gives the airplane 491 lbs for people and baggage. Quite a useful number and about as good as any of our other 2-seat airplanes.

On October 20, we rolled the airplane outside and started the engine.

   
                    Click on the photo above for a larger image
                   
   
                     Click on the photo above for a larger image

After a brief bout of troubleshooting, both ignition systems were working and the Dynon was displaying. Balancing the carburetors has been the biggest challenge. When they are right, the little Rotax runs smoothly and promises to be a pleasant engine to fly behind.

    

On October 24, FAA inspector (and multiple RV builder) Mike Robertson squeezed us into his schedule – caught us by surprise, because initially he thought he couldn’t get to us for two weeks. Scott and Ed had about 30 minutes warning of Mike’s arrival, but they were ready and the airplane was signed off in the Experimental (not Light Sport) category.

We eagerly anticipate the first flight.