by Eric W » Mon Jul 31, 2023 7:40 pm
John,
I doubt that Sonex will change gross weights, especially for the designs currently in production. They might consider something for the Highwing, but even that one seems pretty far down the path of its design. For the ones that will / can change gross weight, look at designs like the Zenith CH-750 series or the Rans S21. These are "artificially" gross weighted at 1320 lbs, and are actually designed for quite a bit higher weights. So for these designs, yes, it's just a matter of paperwork.
The Sonex, designed at 1150 lbs gross (with the heavier engine, yours might be 1100#), is designed for just and only that. It's not held to 1150 lbs by paperwork and really capable of the desired load factors at 1200, 1250, or pick some bigger number. Though 1150 is quite a bit less than 1320, there may be someone out there who "gross weighted" their Sonex at 1320#, but you would have to decrease the allowable load factor (it's 6g at 1150, so equivalent to 5.2g at 1320#?), but you'd also have to ensure that the cg stayed in range.
On the S21, their spec sheet says there's an "LSA" version at 1320#, but non-LSA is 1800#, so you're just throwing away 480#! of payload to run it as a 1320# LSA. When the Mosaic rules become final, for the S21, there wouldn't appear to be any reason to hold its gross weight to 1320#.
Sonex 815, TD, dual stick (sold in 2013)
Jabiru 3300