SonexBuilders.net

I just weighed my Legacy Xenos, dry.

No paint, no fuel, wheel pants, tips, upholstery, and basic instruments. My Hummel 2180 VW weighed 175 with starter, carb and intake. The oil separator and disc brakes were the only adds. My weight was 839 lbs vice the 760 quoted on the plans. My scale might be off by 1 or 2 lbs, but not 70 - 80 lbs.
How can a standard Sonex kit built Xenos be that heavy? Have any others had similar results? This is really frustrating in that I cannot safely fly dual in this aircraft with full fuel. My total reason for purchasing a Xenos was to be able to fly dual with my wife and others. With 15 gal of fuel I am left with only 340 lbs of useful weight.

I understand your disappointment. I've heard the average weight of a Sonex is around 660 lbs - or 40 lbs heavier than advertised.

I've heard that the advertised weight is actually the kit's raw material, not counting any of the hardware. I've also heard that it is based on not having much avionics, and a handheld radio, but who knows.

Someone once asked why anyone would ever fly above the gross weight specified by the designer. It's tempting when you've invested so much time and effort in a plane you thought would have much more useful load.

The original Xenos prototype (AeroVee powered) and fully equipped, painted, etc. empty weight is 777lbs. We use certified scales!!

Good point about certified scales. Being 80 lbs over expected weight is suspicious, 30 - 40 lbs seems more likely.

If you work, or know someone that works in the automotive industry, maybe you can borrow some scales.

I borrowed scales from work that are calibrated every year by an independent metrology lab. It was pretty cool; they communicated wirelessly to a handheld readout.

Certified scales. Bare bones Xenos with Aerovee, no paint, standard wingtips, 799.

If you look at the Xenos plans front page, it shows a 10 lb difference between the long and short wing tips. Just put those kit supplied long wing tips on a scale and see what you get. Don't take my word that they are heavy. The delta is more than twice that.

I made my own lightweight long tips because of their excess weight. The prototype tips must have been closer to the weight I achieved in order to get a 10 lb difference.

The wheelpants were slightly over 1 lb each heavier than the Van's pressure recovery pants I am using.

There is no question that the kit supplied polyester gel coated fiberglass lay-ups are not built with weight savings in mind. They are built with durability, low cost and quick construction in mind. Pooled areas of hardened raw resin and drips can be seen.

I'm not trying to knock Sonex on trying to keep costs down by supplying fiberglass parts made as cheap and fast as can be done. Just saying that unnecessary extra weight is the consequence.

As a builder, those parts can be made lighter if willing to make the investment in time and money.

Rick Caldwell
Xenos 0057

The empty weight of my Xenos was 785 pounds. Used scales borrowed from the local A&P. Polished, with painted fiberglass parts.

Thanks for all the responses, I will definitely be checking out a set of AC scales before I fly, which now looks to be next Spring. Weather is turning bad up here in WA, 3/4 of the Airport is closed for renovations for another month, and my trailer is still in the works.

Had a set of certified scales lined up, but they got sold. Bought a new supposedly accurate scale and best weight looks to be 830 lbs with the heavy utility tips. Before paint I believe that those were 16 lbs each. If I recall correctly the wings weighed in at 104 minus the tips.

I am close to weighing my Xenos. I just need to rivet on the forward bottom skin after some final details to resolve with the @#$%*&^ cowling. I have a set of scales now in the hangar I borrowed which have been used to weigh several RV8's and been cross checked with other scales so they seem acceptable. I will weigh without the wings on and then with the wings and utility tips. Mine is fully epoxy primed and PPG Concept top coat without a clear coat on the exterior and alodined only on the interior except the cockpit interior is primed & painted.

I'll post the results.

Rick Caldwell
Xenos 0057