Ask the DAR

SLSA max empty weight, sailplane condition inspections, licensing a RANS S-7LS as an ELSA.


Question:Is there a maximum empty weight for an SLSA? I read on a forum about an 890-pound max empty weight, but that’s the first I’ve heard about that.

Answer: Yes, there is an empty weight limit for SLSA, but it is not a definitive number. Basically, it’s a formula that says: Add 190 pounds per seat plus a number equal to 1/2 the rated horsepower. Subtract that number from the gross weight. That will give you your maximum empty weight.

Here’s an example for a two-seat, 100-hp SLSA on wheels: 190 x 2 + 50 = 430. 1320 – 430 = 890 pounds. Obviously a single-seat aircraft, a different horsepower engine, or the addition of floats will provide a different empty weight limit.

Experimental Light Sport Aircraft (ELSA) do not have this limitation. This is the reason SLSA manufacturers using a 180-hp engine typically go with ELSA.

Question: There are a number of different subcategories of experimental aircraft: amateur-built, R&D, racing, etc. Many foreign factory-built sailplanes imported into the U.S. are licensed as Experimental/Racing or R&D because the foreign manufacturer never got a U.S. type certificate. When it’s time for the annual condition inspection, does the inspector need to be an IA, or is an A&P certificate adequate, no matter the subcategory?

Answer: The inspector requirements should be listed in the operating limitations for each particular aircraft. To the best of my knowledge, an IA should never be required on these aircraft. The primary purpose of an IA is to confirm compliance with the type certificate. Since these aircraft do not have a U.S. type certificate an IA should not be required.

Question: I’m helping a friend sell his RANS S-7LS, which was factory built and has an SLSA certificate, as well as helping the new buyer get situated with the airplane. It’s my understanding that the new buyer can convert it to ELSA pretty easily, which is a huge personal property tax benefit here in Kansas and Missouri (about $50 per year instead of $1,000 to $2,000 per year), in addition to being able to take the training courses to do the annual condition inspections. However, I’ve also read that you have to be very careful not to do anything that violates the ELSA certificate. What kind of things are allowed? Can you update the avionics, for example?

Answer: Yes, the current owner can convert an SLSA to ELSA. The local FSDO or a DAR with the proper function code can perform this conversion. The only physical changes to the aircraft are changing the Light-Sport placard to an Experimental placard, and changing the passenger warning placard to the appropriate Experimental passenger warning placard.

After this conversion, the owner may take the 16-hour LSA repairman/inspection course and obtain the repairman certificate. This will allow him/her to perform the annual condition inspection on an ELSA that he/she owns.

Under ELSA, the aircraft may be modified without approval from the manufacturer, as long as the modification does not take the aircraft outside of Light-Sport parameters as described in FAR Part 1.1, General Definitions.

Please send your questions for DAR Asberry to [email protected] with “Ask the DAR” in the subject line.

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Mel Asberry
Mel Asberry is an experienced Designated Airworthiness Representative specializing in Experimental/Amateur-Built aircraft. He and his wife, Ann, have built seven amateur-built airplanes including two ultralight types, a Moni Motorglider, a Dragonfly Mk2, two RV-6s and a Zenair CH 601HDS. They are currently building a scratch-built biplane.


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