SonexBuilders.net

Greetings,

I was chatting with several other homebuilders today, and I was asked what my empty and gross weights are. Obviously I don't know my empty weight yet but I'm hoping to keep my plane at or (hopefully) under 650 lbs, and after setting 1150 as a gross I'll have a full 500 lb useful load.

It got me thinking though what other Sonexes or Waiexes have. So, if anyone is willing, please post your empty and gross weights along with what engine and configuration you have. Perhaps something like:

Aircraft: ( Sonex or Waiex)
Engine: ( Aerovee, Jab 2200, Jab 3300)
Gear setup: ( tri or tail)
Avionics: ( MGL, Dynon, COMM, Transponder...)
Empty weight:
Gross weight:
Notes: (polished or painted, full interior, interior primed, etc.)



Thanks!

There's an extensive list on the Yahoo Sonex Builders forum in the files section.
Here's the link if it works
http://f1.grp.yahoofs.com/v1/QHKkTjILJa ... an2011.pdf

Looks like a bad link but yes, the spreadsheet is a great list of weights. Basically the weights are all over the place, rarely as light as factory models, and the Waiex's are all a bit heavier...

fastj22 wrote:There's an extensive list on the Yahoo Sonex Builders forum in the files section.
Here's the link if it works
http://f1.grp.yahoofs.com/v1/QHKkTjILJa ... an2011.pdf

Well,
go to Sonextalk on yahoo groups, go to files, its listed there.

BTW... I did some napkin scratching a while back to figure out good weights for the Sonex/Waiex. The airplane is still in utility category limits at 1200lb, and within normal category limits at 1250lb, and I know both of those gross weights are currently being flown by a good number of pilots. When it comes time to fill in the MGW box for the FAA, you might want to consider making it 1200 or 1250. Even if you never plan to fly above 1150lb, you'll have the flexibility to do so if you need to at some point. You need to flight test to that weight during phase I, of course. My current plan is to set my limit at 1250lb, but after flight tests I don't plan to fly above 1200lb.

There are several factors to consider when setting gross weight. First is the load factor when pulling Gs as you already noted. Certainly a Sonex is strong enough. Next, you must consider the rate of climb. What RoC can you realistically get at a GW of 1250 (on a hot summer day) with the 3300? Finally, consider stall speed. What is the stall speed at 1250 compared to 1150? Also, if you intend to fly as a Sport Pilot, does the plane stall at 45 knots clean at 1250?

radfordc wrote:There are several factors to consider when setting gross weight. First is the load factor when pulling Gs as you already noted. Certainly a Sonex is strong enough. Next, you must consider the rate of climb. What RoC can you realistically get at a GW of 1250 (on a hot summer day) with the 3300? Finally, consider stall speed. What is the stall speed at 1250 compared to 1150? Also, if you intend to fly as a Sport Pilot, does the plane stall at 45 knots clean at 1250?

Good points. The people I have talked to flying at 1250 have said over 500fpm at 1250, not sure about the stall. As a sport pilot I need to find that out. It's within all SP limits at 1200lb for sure.

IIRC, the change in stall speed with an increase in weight is:
new stall speed =(previous stall speed) x (sqrt (new weight/old weight))

From the factory numbers, an 1150 lb Sonex has a clean stall speed of 46 MPH, so, stall speed (clean) for a SONEX at the 1320 lb LSA limit (and I'm NOT saying it's a good idea to fly that way, given ROC and G-limits): 46 x sqrt (1320/1150) = 49.3 MPH = 43 KCAS.

I'm sure there are lots of good reasons not to fly a Sonex at 1320 lbs, but the airplane should still stall slower than the 45 KCAS LSA requirement.
(If my math is right!)

Mark W.

fastj22 wrote:Well,
go to Sonextalk on yahoo groups, go to files, its listed there.

It seems the whole Sonextalk Yahoo Group disappeared when Sonex discontinued the administration years ago. Anyhow, I am not successfull finding anything from those days.

Right now I am intensely looking for some info on tri gear Sonexes with Aerovee engines. How they were finished, what instrumentation was installed, and of course the resultant empty weight.

Thanks
Kai

Kai wrote:

fastj22 wrote:Well,
go to Sonextalk on yahoo groups, go to files, its listed there.

It seems the whole Sonextalk Yahoo Group disappeared when Sonex discontinued the administration years ago. Anyhow, I am not successfull finding anything from those days.

Right now I am intensely looking for some info on tri gear Sonexes with Aerovee engines. How they were finished, what instrumentation was installed, and of course the resultant empty weight.

Thanks
Kai

They are still there:
https://groups.yahoo.com/neo/groups/son ... s/messages
https://groups.yahoo.com/neo/groups/son ... s/messages

You just can't post to them anymore as they are locked.
You can still look at the files and photos as well though.