MOSAIC (Modernization of Special Airworthiness Certification) is a regulation that affects all aircraft with special airworthiness certificates. Aircraft built by Cessna, Piper, Cirrus, Diamond, and others instead have standard certificates, and their new models remain untouched by this proposed regulation.
In contrast, all light sport aircraft (LSA), experimental amateur-built airplanes, and warbirds are issued special certificates. In my view, the rule can be divided into two main parts: airplane descriptions and capabilities, and pilot certificates, technician privileges, and operating limitations. In short, airplanes or people.
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For airplanes, the NPRM (Notice of Proposed Rulemaking) felt like Christmas in July, granting many capabilities industry and pilot member organizations had sought over some years of negotiation. The people part describes who gets to fly and maintain these MOSAIC LSAs and under what rules. This latter section inspired greater concern.
Airplanes: What We Gained
Here’s the list of what FAA offered and how each changed:
Gross weight: LSAs have been limited to 1,320 pounds (land) or 1,430 pounds (water). Under MOSAIC, the weight limit is removed and clean stall constrains size so the aircraft remains what FAA sought: those “easy to fly, operate, and maintain.” It is expected that weight can rise to 3,000 pounds depending on the design.
Stall speed: Presently, LSAs cannot stall faster than 45 knots. This will be raised 20 percent to 54 knots, but this is clean stall, the purpose of which is to limit aircraft size and difficulty. It has no relation to landing speed or slow-flight qualities. This more than doubled the potential size, hence a new term, “MOSAIC LSA.”
Four seats: LSAs are presently limited by definition to two seats. This rises to four in a MOSAIC LSA, but if operated by someone using sport pilot certificate privileges, then only one passenger can be carried. A private certificate with medical may fill all four seats, assuming weight and balance allows.
Retractable gear: Light sport aircraft have been fixed gear only, except for amphibious models. Now any MOSAIC LSA can be retractable. Several imported LSAs already offer retractable options in other countries.
Adjustable prop: LSAs were allowed only ground-adjustable props. Now a MOSAIC LSA can have an in-flight adjustable prop. Such equipment on similar aircraft is common in other countries.
250 knot max speed: An LSA was limited by definition to 120 knots at full power. Now the speed limit matches all other aircraft below 10,000 feet: 250 knots. No one expected such a large expansion, but now retractable and adjustable props make more sense.
Rotary expansion: After 20 years of waiting, fully built gyroplanes will be allowed. That followed years of advocacy effort, but when the opposition finally yielded, the FAA also granted helicopters.
Electric or hybrid: Because the FAA did not want turbine LSAs in 2004, it specified reciprocating engines, unintentionally knocking out electric motors that few were considering at the time. In fixing the definition to allow electric, the agency will also permit hybrids. Examples are already flying in Europe.
Turbine: Perhaps turbine engines were harder to operate 20 years ago when LSA were defined, but today they are seen as simpler, and the FAA will allow them. Turbine-powered MOSAIC LSA candidates are already flying in Europe.
Multiple engines/motors: The LSA has been limited to a single engine by definition. That constraint is removed, although no language was given to address how the pilot qualifies.
Aerial work: The Light Aircraft Manufacturers Association (LAMA) lobbied for MOSAIC LSAs to be permitted to do forms of aerial work, although not passenger or cargo hauling. The FAA has granted this opportunity to the manufacturers, which can specify what operations they will permit. A commercial pilot certificate will be required.
One downside to all these goodies? Each will increase the price. The good news? Present-day LSAs offer lower prices and have proven enjoyable and dependable. Many LSAs are fine as they are and have no need to change.
A lot of LSA producers already meet higher weights in other countries where permitted. They are merely reduced on paper to meet U.S. standards. It should be straightforward for them to redeclare meeting all MOSAIC-level ASTM standards to qualify for higher weights.
The only question is how far backward compatible they can go for aircraft in the field over which they have had no control for some time. It’s an industry question to resolve, and it will swiftly be handled to aid sales.
People and Areas of Concern
Medicals: Lots of questions surround one of the principal benefits of LSA operation: the lack of requirement for an aviation medical if operating as a sport pilot. More specifically, pilots want to fly larger aircraft using these privileges, meaning no medical certificate, or BasicMed, instead using the driver’s license as evidence of their medical fitness.
To keep within their budget, many pilots wish to buy (or keep flying) legacy GA aircraft such as the Cessna 150, 172, 177, and some 182s, plus certain Pipers, Diamonds, Champions, or other brands. Many of the latter aircraft are too heavy to allow such privilege today. MOSAIC appears to change that, but without presenting compelling evidence that possession of a medical assures a flight proceeds safely, the FAA nonetheless clings to this premise. Many assert the occurrence of medical problems sufficient to upset a flight or cause an accident are incredibly small in number.
Stall speed: Most NPRM readers agree that it was a worthy solution to use 54 knots clean stall as a means to limit the size of the airplane and to keep it within the FAA’s mantra of LSAs being “easy to fly, operate, and maintain.”
However, many respondents note that adding just a couple knots to that limit will allow several more airplanes that some wish to buy and fly under MOSAIC rules. Note that the 54-knot reference is not related to landing speeds or slow flight, where lift-enhancing devices like flaps would normally be used.
Some pilots asked if adding vortex generators could reduce stall speed enough to qualify. The problem lies in proving a slower stall speed was achieved. Stall (VS1) printed in the POH will be the standard about compliance.
Several pilots have complained about use of calibrated versus indicated airspeed for the stall limit, but this is another matter that might be clarified after the comment period.
Endorsements: One of the significant lessons learned in 20 years of pilots operating LSAs is the so-called magic of endorsements. Instead of asking pilots to receive training, take a knowledge test and possibly an oral exam, followed by a practical flight test, they can just go get trained for added skills from an instructor who then endorses their logbook accordingly, and they’re good to go. This puts a significant burden on flight instructors to do their jobs well, but that’s already the situation.
The NPRM already refers to the use of endorsements for retractable gear training or adjustable prop training, and many believe that expanding endorsements to all privileges described in the MOSAIC proposal has merit.
Noise: For the first time, the NPRM introduced noise requirements that encompass several pages. Coincidentally, the LSA sector is already one of the quietest in the airborne fleet.
This is partly because of European noise regulations that have been in place for a long time, motivating quieter engine and exhaust system development. However, LSAs are also quieter because the powerplants are modern, thanks to the faster approval process implied by industry consensus standards.
The industry was not pleased about the noise proposal, as these requirements add burden without identifiable benefit. Nonetheless, the situation might be handled through the ASTM process more quickly and still satisfy political demands.
Night: MOSAIC’s language invigorated many readers when the NPRM expressed support for a sport pilot to fly at night—with proper training and a logbook endorsement. Then the proposal refers to other FAA regulations that require BasicMed or a medical. If you must have a medical, you are not exercising the central privilege of a sport pilot. Why suggest that a sport pilot can do things that are blocked by other regulations? This conflict should be resolved.
This is one of several aspects of the NPRM that many describe as “inconsistencies,” where one part of MOSAIC appears to restrict another part, often for unclear reasons. Such observations lead many to declare the NPRM looks “rushed to market.” Hopefully, most problems can be addressed in the post-comment period.
When surveyed about why night privileges are valued, most pilots wanted to be able to complete a cross-country flight with a landing after dark.
IFR/IMC: Contrary to what many think, the FAA has never prohibited LSAs from IFR/IMC operation. It is the lack of an ASTM standard to which manufacturers can declare compliance that prevents such sales. (Some special LSA owners elect a change to experimental LSA status and can then file IFR, assuming they have a rating, are current, and the airplane is properly equipped.)
However, as with night operations, many LSA owners report higher-level pilot certificates often including instrument ratings, and they would like to be able to use their LSAs to get through a thin cloud layer.
Maintenance and TBOs: The maintenance community has found several objections within the NPRM. It appears that changes could cause a loss of privilege for LSA owners who have taken training to perform basic maintenance on their own LSAs.
In addition to altering the privileges of light sport repairman mechanic (LSRM) certificate holders, MOSAIC adds capabilities such as electric propulsion, hybrid, turbine, and powered-lift devices, which leaves the mechanic-training industry guessing where to start. Some organizations wonder if it’s worth the investment to create appropriate courses with uncertain privilege at the end.
Indeed, eight training organizations suggested they would petition for an extension to the comment period. It was successful, so the extension will delay the expected arrival of the finished MOSAIC regulation. Absent any extension, the FAA has repeatedly said 16 months were needed, equating to the end of 2024 or early 2025.
One group creatively suggested using add-on training modules to solve the problem in much the same way that endorsements can be used to solve pilot training enhancements.
Lack of sector expertise: The FAA knows a great deal about conventional, three-axis airplanes but far less about so-called “alternative LSAs.” For machines that use different control systems or operate substantially differently than airplanes—weight shift and powered parachutes come to mind—some industry experts believe a better system is to authorize an industry organization to manage these sectors. This has been common throughout Europe for many years and could work well in the U.S.
In a document of its size, some errors will arise and some clarifications will be needed. It is only a proposal after all. Pilots can comment on certain aspects but will have little idea how the FAA can or will solve various points, even if they offer solutions.
This frustrates some readers and can cause uncertainty about a pending or planned airplane purchase. In turn, purchase-decision delays frustrate airplane manufacturers. That’s the precarious terrain surrounding new regulations. Such comments on regulation are part of the American way, where the citizens can be part of the process. Here’s your chance to speak and be heard.
This column first appeared in the November 2023/Issue 943 of FLYING’s print edition.
