Thorp Air Command - T18.net

It appears the requirement for an aircraft to be LSA under the new MOSAIC requires a landing configuration stall speed of 61 knots CAS. Does the T18/S18 fit under this new category?

If yes, it is my understanding you can take the 16 hours LSA repairman class and be authorized to conduct the condition inspection on any EAB you own (whether you built it or not).

What are your thoughts? Am I correct?

Kitplanes answered it. While existing EAB's can't be moved into the LSA category, you can now do your own condition inspection on your EAB after attending the 16 LSA repairman certification course.

https://www.kitplanes.com/mosaic-is-her ... omebuilts/

Excerpt from link:
A Game-Changer for Condition Inspections

Perhaps the most significant change for EAB owners is a massive new privilege for repairmen. The final rule expands the privileges of a holder of a repairman certificate (light-sport) to perform the annual condition inspection on an Experimental/Amateur-Built aircraft.

This is huge. Previously, unless you were the original builder of your EAB and held the specific repairman certificate for that airframe, you had to find an A&P mechanic to perform your annual condition inspection. Now, any EAB owner can take a 16-hour LSA repairman—inspection course and, once certificated, legally perform the condition inspection on their own amateur-built aircraft, provided it is in the same category (e.g., airplane) as their training. For those who want to do more, completing a longer LSA repairman—maintenance course allows a person to perform the condition inspection on any EAB of the same category, not just one they own.

To answer the posters original question. Since most if not all Thorp T/S-18 have a clean (flaps up) stall speed of 59 CAS or less, a SPORT PILOT, or a person with higher pilot certification exercising the privileges of sport pilot can fly the T/S-18 without a medical or even basic med as I understand the new rule (which is not final until 90 days after federal register publication or about 80 days from now give or take).

It is important to note there is a critical differentiation between what qualifies an AIRCRAFT to be CERTIFIED as a Light Sport Aircraft (LSA) based on performance and what performance a SPORT PILOT, or a pilot exercising the privileges of a sport pilot can legally fly.

Sport AIRCRAFT: The new serial factory manufactured aircraft can have Vso (stall speed in landing configuration i.e. gear and flaps down) of 61 knots CAS

HOWEVER

A sport PILOT: or a pilot acting as PIC exercising sport pilot privileges (no medical) can only fly an aircraft with a clean (Vs1) stall speed of 59 knots CAS. Note that clean stall speed (Vs1) is almost if not ALWAYS higher than stall in landing configuration (Vso)

Therefore it is entirely possible for a sport PILOT to be ILLGAL to fly a certified light sport AIRCRAFT! To fly any LSA AIRCRAFT with a clean stall speed higher than 59 knots will require a higher pilot certificate (recreational possibly) or private pilot or higher to fly these light sport AIRCRAFT with a dirty stall speed of 61 knots, AND the pilot must must have basic med, or class III or higher AME medical certificate.

It is also my understanding that a homebuilt aircraft can NEVER be certified as a light sport aircraft as light sport aircraft certifcation is for under consensus rules for factory serial manufacture. It is my understanding that ALL homebuilt built aircraft are certified as "Experimental Amateur Built Aircraft or EAB. The performance of some EAB's (T/S18 included) will happen to have the performance limits and seating capacity's that will allow a sport PILOT to fly the aircraft (or higher rated pilot exercising the privileges of sport pilot). With appropriate or necessary endorsement(s) if the plane has retractable gear or constant speed prop. (further detail the rule may actually state "manually adjustable" propeller. Which begs the question what is defined as "manually". Is a constant speed prop manual? Is a ground adjustable manually adjustable? would an "automatically adjustable propeller need an endorsement?)

I am also making the assumption that all the stall speeds listed will be based upon the aircraft at max GROSS WEIGHT.

This brings a further complication. As a certified light sport AIRCRAFT can have 4 seats, and thus a gross weight appropriate for 4 seats. But the sport PILOT can only fly an aircraft with only the sport pilot and up to one passenger (2 occupants max). Since stall speed is based on weight. It is possible that the performance of a LSA certified AIRCRAFT could have a clean (Vs1) stall speed that is less than 59 knots at some weight LESS than max Gross weight of the 4 seat light sport AIRCRAFT. In other words, below a certain weight with only a pilot and up to one passenger COULD meet the performance requirements to allow a sport PILOT to fly. However they MAY still be illegal to fly it if the published stall speeds are based ONLY upon gross weight. Perhaps in this situation the new certified light sport aircraft may identify this limitation within the approved aircraft operating manual. Somewhat similar to a C-172 which can be operated under normal or utility category based upon weight. Perhaps the flight manual will be written to state that the certified 4 seat LSA AIRCRAFT can be operated legally by a sport pilot privileges under a certain max take off weight less than max gross for the aircraft.

Lots of things to learn and find out as time goes on.