New 3300 Weight

[rbarber]

If memory serves me correctly, it is not the FWF weight that is 200 lbs or less, but the engine package must less than 200 lbs or less. I assume this means Engine (with exhaust, alternator, vacuum pump, etc.) is what must be included, and does not include the engine mount. Can someone verify-reference?

Rob.

[Rynoth]

Per https://www.sonexaircraft.com/engines/engines.html

"Sonex Aircraft engine installations must not exceed 200 lbs total weight forward of the firewall. Any builder considering use of a heavier installation should take notice of the important information contained in our Gross Weight Advisory (LSA Compliance and Safety) Letter."

One thing to keep in mind from an engineering standpoint (even though I'm no engineer) is the tail-down force required to lift a forward CG. By loading a heavier engine, you are also increasing the necessary tail-down force, and both downward forces together must be carried by the wing. Also, just how much weight can the engine mount/attach points handle at +6 G's? I don't plan on finding out, personally!

However, it does seem that the hard-line of 200lbs has more to do, specifically, with LSA rules. The following quote is in reference to max gross weight:

"Any Sonex Aircraft licensed above those limits is not Light Sport (LSA) compliant as the
wing loading exceeds the allowable wing loading for a Light Sport aircraft."

[rbarber]

Interesting. I also found the following:
SONEX is a basic and economical all metal two place monoplane. Designed to meet the needs of the European and Domestic sport aircraft markets, it can incorporate various light weight contemporary engines of 80 to 120 hp (engine package weight of less than 200 lbs.)

http://www.sonexaircraft.com/aircraft/sonex.html

I would also note that, due to the 30 degree angle of the firewall, that one could also include the landing gear in that "firewall forward" definition. This is not a huge deal in the tricycle gear version, but the conventional gear are integral to the engine mount. So where is the actual line drawn?

Rob.
N157SX, "Sexy Hexy"

[vigilant104]

"Any Sonex Aircraft licensed above those limits is not Light Sport (LSA) compliant as the
wing loading exceeds the allowable wing loading for a Light Sport aircraft."

I'm away from my sources, but I'm virtually positive there's nothing in FAA regulations on LSAs which set out a maximum allowable wing loading for an LSA.