B-Model Features Added to Xenos Motorglider

Sonex Aircraft announced the new Xenos B-Model aircraft kit. The Xenos-B combines all of the enhancements of the Sonex and Waiex B-Models with the outstanding motorglider performance and value of the Xenos. The Xenos-B is available to order now, with a Complete Airframe Kit base price of USD $27,495. Kit shipments are estimated to begin in March, 2017.

Continue reading "B-Model Features Added to Xenos Motorglider"

Power up!


Boy, I am enjoying building "simple" for a change. Most of my airplane projects are fairly complex machines with multiple EFIS screens, IFR capability, and all the bells and whistles. The Xenos, on the other hand, is a straightforward motor glider--just the stuff we need, and none of the complexity of the bigger craft.

I pulled out the panel blank the other day, along with the Avionics that we’ve put aside for the project, and within a couple of hours, the holes were cut and the units test fit. Essentially, we have a single screen EFIS to give us flight and engine data, a single Comm radio, and an electronic Variometer for soaring (the MGL EFIS has a software-derived Vario, so we thought it would be fun to install a dedicated unit and see how they compare). Switches are minimal – a Master, to ignition toggles, a start switch and an avionics master. Four circuit breakers handle the loads, and heck, I had this little corner for a couple of warning lights, so I installed two from my stock drawer – one for the EFIS warning, and another for oil pressure.

After everything was fit, I took it apart, scotchbrited, and shot some primer and paint. While that was curing in the sun, I pulled out the manuals and figured out how the CAN Bus connections work for MGL. The answer? Quite simple and easily!. The MGL units al came with pre-made harnesses from Approach/Fast Stack, so when the paint was hard and the units re-installed, it was a matter of minutes to connect up the data lines and another half hour to mock up the power feeds so that we could throw the switch and - voila! We have a panel!

Now, of course, I have to tidy things up, figure out where to mount he RDAC (engine data unit) and Magnetometer, choose places for the headset jacks, and do some installation in the fuselage. But its nice to know that everything works,, and we can start to play with the MGL software environment..

Pretty cool for an afternoon’s work.

Spars – The Heart of the Wing

Xenos spar
Xenos spar

I haven't reported much recently on our Xenos Motor glider project, mostly because the past half year the push has been to get our Tundra flying, and now to get the Phase 1 complete. But the Xenos moves slowly on because it is in our home hangar, and anytime I have ten or fifteen minutes, I can go out and drill a few holes. We finished up all the work we could do on the fuselage maybe six months ago, and have put that of to the side. Before we can build wings, we have to build the spars – and that is no small undertaking!

For those that don’t know – the wing span of the Xenos is 46 feet, so the spars are about 24’ long…each!  Sonex (maker of the kit) offer a set of prebuilt spars for about $4,000, and while that seemed a lot a lot when we bought the kit (and I wanted to build spars), I now realize that the labor involved is extensive. These things are LONG – and that means the rivet count is high….and that means that the hole count is high.

The spar webs are pre-punched, and this allows them to be clecoed together to lay things out. The spar caps are NOT pre-drilled however, so they have to be match drilled to the webs. The webs are, of course, a stack up – providing a very thick web at the root, and a very thin (single layer) web at the tip. The caps also have some very unique shapes and tapers to them, and it took me a couple of months of clamping things together just to make sure I knew where al the pieces went. The out came the #40 drill to match drill and cleco everything together.


Today I finished the months-long task of upsizing al of the holes to their final size – mostly 5/32” for-5 rivets. 5/32” is a #21 drill, and I bought several 6” long bits because you end up getting too close to the spar caps with the drill chuck if you use short ones. The big decision I had to make was regarding clecos. Dash 5 clecos are black, and out near the tip, with only a single layer of spar web, standard spring-type clecos worked well - but I need a couple of hundred. I solved that at the Fly Market at SnF – got a few hundred of them. But nearer the root, the web get thick- like 3/4” thick, and the only clecos that will work there are the wing-nut draw-type - and they cost a pretty penny! Well, like 350 pennies each.

After some consultation with old-timers who have built many a spar, we decided that all things considered, it couldn’t be that much slower to simply use bolts and nuts – 4 mm being the appropriate size -  to hold things together, Yes, it is slower, but it’s a small percentage of the total spar build time.  So there you have it – the left spar of our future bird! Well, the drilled version – now we have to disassemble it (lots of pieces), deburr everything (lots of pieces), and then re-assemble it before getting out the rivet guns and having at it. Oh yes, according to the plans, we’ve also got some countersinking and dimpling to do – there are flush rivets at the inboard end.

Now that I’ve use the left spar as a learning exercise, we plan to fully document the right wing build – look for a future article (or two) in Kitplanes on spar construction!

Xenos Motorglider Quick Build Kits Available


Sonex Aircraft is now offering Quick Build kits for the Xenos Motorglider. The Quick Build upgrade price for the complete Xenos airframe kit is $16,000, and it includes all the same features as Sonex, Waiex, and Onex Quick Build kits: completed fuselage with canopy installed, completed wing panels, and the wings are rigged and match-drilled to the fuselage. These Sonex Quick Build upgrade options drastically reduce build time and the level of skill required to complete the aircraft. They offer the fastest build possible within the bounds of Experimental/Amateur-Built homebuilding regulations. Continue reading "Xenos Motorglider Quick Build Kits Available"

Airplane Noises

Airplane Noises

There comes a time in every fuselage build where you just have to get in and see how the cockpit feels! We reached that point on our Xenos Motorglider project yesterday, and my pilot wife Louise tried it out first. The Xenos is basically a Sonex with a longer tail and MUCH longer wings. So the cockpit is comfy for two and a few extra things thrown in back. As far as anyone knows, we’re both too mature to make airplane noises of course, but we did imagine what the view will be like when we get some cushions and the controls installed. Continue reading "Airplane Noises"