I spent all day looking for this after comparing the Sling 2 to the RV-12 and finally found it in the Title 14 1.1 General Definitions, I did not see anything else anywhere covering this in the FARS. "Light-sport aircraft means an aircraft, other than a helicopter or powered-lift that, since its original certification, has continued to meet the following: (1) A maximum takeoff weight of not more than—(i) 1,320 pounds (600 kilograms) for aircraft not intended for operation on water; or(ii) 1,430 pounds (650 kilograms) for an aircraft intended for operation on water." My understanding is a sports pilot can fly anything that meets the performance definitions of weight, airspeed, seating, etc. Here it specifically says maximum takeoff weight with no mention of gross. So if the weight and balance was based on 1320 lbs., but the gross much higher was something else could the sport pilot fly it? The reason I started thinking about this was primarily the Sling. As a certified LSA its Gross is 1320, but as a EAB it is 1540. Generally it is accepted that a sport pilot can fly an EAB if it meets all the requirements, which the sling would be excluded if this was gross and not takeoff weight. So if you tests your EAB at 1320 and have a weight and balance done for 1320 a sling can be flown by a sport pilot, but what if you had down everything for 1320 and 1540 could a sport pilot fly it using the 1320 weight and balance and the private pilot fly it using the 1540 weight and balance since the only thing changing between the two is how much fuel you are putting in the aircraft? The quoted bit from the FARS sure makes it look like you could, AOPA and the EAA pages on goggle searches word it as "Gross Takeoff Weight", which does not match the FAR and would make a Sling EAB not a LSA unless you specifically made it as ELSA reducing its gross to 1320. Thoughts?