Light Sport’s Next Steps

Editor's log.


At AirVenture this year—just before it, actually—the FAA released the Notice of Proposed Rulemaking encompassing MOSAIC, short for Modernization of Special Airworthiness Certificates. The program, many years in gestation, embodies a package of rule changes that aims to change the face of Light Sport Aircraft and expand the options for Sport Pilots. Buried in the more than 300 pages of the NPRM can be found many useful nuggets, but the gist is this: MOSAIC should allow series production of aircraft through an ASTM consensus standard that could—repeat: could—reduce costs compared to FAR Part 23 certification. It also opens the door for greatly expanded E-LSA aircraft in the same way that a current design can be factory built as an S-LSA or constructed in a conforming, very-fast-build kit as an E-LSA.

Van’s RV-14/14A would not be eligible as a MOSAIC LSA under the current rules because of the “clean” stall-speed requirement. But the RV-9/9A would be. Something’s not right here.

You’ll be looking back more than two decades to find the origin of LSA, which promised less expensive, lightweight airplanes to counter the ever-increasing cost of new certified designs. The rule favored airplanes that were growth versions of simple, two-seat examples with modest performance. To keep peace with the existing manufacturers of certified aircraft, the speed was limited to 120 knots and weight to 1320 pounds (1430 for seaplanes), engines were defined as piston powerplants only and there were a host of other restrictions intended to keep them simple and from competing too heavily with production designs.

More than anything, the 1320-pound weight limit had unintended consequences for the category. Keeping empty weight down meant making the airplanes very light. Experience has shown that they were often too fragile for flight training, even though that was one of the explicit market goals.

The Proposed Rule

With MOSAIC, the FAA, working with a broad industry coalition, has knocked down some of those potential problems. New MOSAIC airplanes (that we can really call LSA once the rule is passed) don’t have an explicit maximum weight. Instead, there’s a 54-knot VS1 (clean) stall-speed limit and no explicit weight limit, though the stall speed acts to keep the practical limit near 3000 pounds. The proposed rules also allow four seats (more on that in a minute), unlimited powerplant types (not just a single reciprocating engine), any type of propeller (not just fixed-pitch), retractable landing gear and a max level speed of 250 knots.

Let’s look closer at the stall-speed issue. There’s language in the NPRM that says “flight controls intended to improve aircraft performance characteristics or relieve excessive control loading, such as high lift devices, slats, flaps, flight spoilers, and aircraft trim systems, would not be considered primary flight controls.” As such, they’re not available to meet the stall-speed requirement. My understanding is that this was a compromise to ensure that manufacturers wouldn’t game the system and get faster-landing airplanes into the LSA category. As a result, though, there are some very odd consequences. For example, some models of the Piper Archer are eligible but an earlier Cherokee 180 isn’t. Many popular homebuilts could be flown by Sport Pilots (and could, potentially, be built as S-LSAs) but the 54-knot-clean rule takes many RV models off the list. It is a boon, however, for many of the kit manufacturers who are close to the LSA limits and offer kits in two forms: one you complete to meet the old LSA restrictions and one that would be licensed at a higher max-gross weight.

About the Pilot

Under MOSAIC, Sport Pilots could fly these new LSAs, although the four-seaters can only have two aboard. There are requirements for endorsements into airplanes with controllable props and retractable gear. And there’s a limitation on day VFR unless the Sport Pilot has a medical or is on BasicMed, then night flying is allowed. Sport Pilots are also limited to flying no higher than 10,000 feet msl.

For the most part, these are important and useful updates to Light Sport Aircraft and for Sport Pilots. A few things have caused considerable public comment so far and will continue to do so. First is the stall-speed limit being based on VS1, or clean configuration. Pretty much every airplane you or I learned to fly in was certified with a maximum stall speed of 61 knots, but that’s in landing configuration (VS0). I fail to see how adding flaps to the equation somehow makes the LSA so much harder to fly. It feels to me like an artifact of the original LSA idea, and something that need not be carried forward. If the FAA is worried about other work-arounds that might get airplanes considered too fast into the new category, simply state that conventional flaps are allowed. If you’re worried about powered, distributed-lift devices, make them ineligible.

I would also like to see the 10,000-foot (or 2000-foot agl) limit reconsidered. There’s real value to having a higher limit in the West. And I’m not just talking about those based at Leadville, Colorado. In many places out here, allowing flight up to, say, the oxygen altitudes would help ensure terrain avoidance and provide many more useful landing sites than forcing the pilot to stop at 10,000 feet. (And when you think about it, we’re really talking 9500 feet msl if you’re VFR.) The new LSA rules provide for more useful airplanes. Give the pilots the benefit of that utility.

We’re still at the beginning of the comment period for the NPRM, which runs through Oct. 23, 2023. You can comment directly or via your favorite alphabet group. It’s vitally important that your voices be heard. And for that matter, we’ll continue to talk about MOSAIC as the manufacturers consider the new rules package and lobby for their alterations to it (because you know they are), all with an eye toward anticipating how this program will open doors for a new generation of Experimentals and the Sport Pilots who want to fly them.

A New Home for Us

If you paid attention to some of the news out of AirVenture, you might have noted that KITPLANES®, along with all the other aviation titles in the Belvoir family, have become part of FLYING Media Group, which also includes FLYING and Plane & Pilot. CEO Craig Fuller is dedicated to keeping print publishing viable and feels that our offerings, working together, can provide an unmatched set of choices for aviation enthusiasts. “KITPLANES® is a very important title for FLYING Media going forward,” Fuller says. “Not only is the builder audience among the most passionate about aviation, they also represent a large part of the future. With the upcoming FAA MOSAIC overhaul promising to democratize aviation, the builder community will offer plenty of growth, content and excitement for years to come.” Couldn’t agree more.

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Marc Cook
Marc Cook is a veteran special-interest journalist who started as a staffer at AOPA Pilot in the late 1980s. Marc has built two airplanes, an Aero Designs Pulsar XP and a Glasair Aviation Sportsman, and now owns a 180-hp, steam-gauge-adjacent GlaStar based in western Oregon. Marc has 5000 hours spread over 200-plus types and four decades of flying.


  1. Maybe VANS will move away from the inefficient (all the ribs are the same!) constant chord wings and give us tapered or semi tapered wings; lower stall speed, faster cruise if done properly.
    Thus, bring more RV’s into the new category.

  2. Not practical for Vans to change the wing design. It would greatly increase the kit cost. Using VSO as Mark suggested would
    change the equation and make more of the RV’s light sport.

  3. The RV-9 always was a tamed and de-tuned RV-7.
    Bigger wings, slower stall speeds, an IO/O320 rather than an IO/0360 and an aircraft not rated for “Gentleman’s Acrobatics.”
    It was designed and is marketed as the least “hairy-chested” option in the RV range.
    It’s not so odd it might quality under MOSAIC whereas the RV-7, RV-8 and RV14 do not.
    The objective of MOSAIC is to take a holistic approach to identifying aircraft that are capable of being flown on a light sport license after all.

  4. A gyro copter I’m interested in has 3 seats so I’d be
    legal as light sportwith only two of us onboard.
    Like a 172 with two empty seats .Seems preposterous.If anything,pilot and 3 passengers should be allowed for light sport rules.With increases in power, stall speed etc, increase training
    if necessary and allow lots more aircraft into light sport market.


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