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Van’s Aircraft Comments on MOSAIC NPRM FAA-2023-1377

The following comments were submitted to the FAA regarding their Notice of Proposed Rulemaking on MOSAIC. The letter was prepared by Rian Johnson, Chief Engineer at Van’s Aircraft and Chairman of the ASTM F37 committee, which governs light-sport aircraft standards.

January 22, 2024
Docket Operations, M–30;
U.S. Department of Transportation (DOT),
1200 New Jersey Avenue SE, Room W12–140,
West Building Ground Floor,
Washington, DC 20590–0001

FAA-2023-1377; Modernization of Special Airworthiness Certification, Notice of Proposed Rulemaking

This document includes comments and feedback to the Federal Aviation Administration’s (FAA) Modernization of Special Airworthiness Certification (MOSAIC) Notice of Proposed Rulemaking (NPRM).  We would like to thank the FAA for taking on this project to expand the light-sport aircraft category. MOSAIC is a revolutionary change for general aviation. We recognize the FAA has expended a considerable amount of energy and thought into this rule change, which touches many areas of the organization as well as other aviation authorities around the world. Considering the magnitude of this project, the FAA came close to the mark for a first proposal. While this document includes constructive feedback, overall the NPRM is a success.

We must realize the importance of general aviation as a foundation for our aviation infrastructure. The experience pilots and mechanics obtain while participating in general aviation is the basis for the levels of safety throughout our aviation industry. We have a common interest in safety in aviation. Affordable, safe aircraft will attract new pilots. We believe MOSAIC, when properly implemented, will strengthen this foundation upon which we depend.

We look forward to working with the FAA through the consensus process. Light-Sport aircraft have had a safety record equivalent to or better than that of general aviation. Leveraging the flexibility of the consensus process we can implement cost-effective safety enhancements, which we believe will result in levels of safety that will match or even be better than that of type certificated aircraft. The consensus process not only represents regulators and manufacturers but also the end-user pilot community and flight schools that must balance their needs for new aircraft with the reality of running a business. We believe that this collaboration will result in aircraft that reflect the needs of the customer, which will help provide marketable aircraft.

As the world’s leader in the kit industry, we see an opportunity to offer the benefits of safety and reduced build times provided by ELSA and SLSA aircraft. We look forward to providing private owners and flight schools with aircraft that are safe and exciting to fly, while being easy to operate and maintain. We are encouraged that this category will expand the privileges of sport pilots, attracting more pilots to aviation and allowing others to continue flying. This rule also has the potential to address the growing need for maintenance technicians.

Stall Speed

The FAA has proposed under 22.100 a “clean” stall speed of 54 Vs1 for both light-sport aircraft and light sport pilots. This limit also defines which legacy aircraft will meet the definition of light-sport.  This is the single most important parameter that will determine the success or failure of this category.

As of the morning of January 22, 2024, there were 394 comments mentioning the word stall. This demonstrates the overwhelming compelling public interest in this issue. Almost universally, these comments asked that the stall speed be increased.

Within the supporting documents supplied to the docket, Safety Continuum View of MOSAIC Rulemaking Attachment 2 under the section for Max stall speed, the FAA also expresses the same concern.

“A stall speed in the mid-fifties is
not enough and would leave out
airplanes appropriate for 21.190
and for operation by sport

A lower stall speed would also
jeopardize international

Consider the option of higher
stall speeds with a
crashworthiness requirement;
e.g., simple crash survivable seat
designs. However, industry
does not want a new dynamic
test requirement.”

We agree with the points raised by the FAA and we will discuss those points within this section. We would like to point out for those who may only have an interest in the stall speed section of this document that other comments related to a change in stall speed are included throughout the document. See also: Critical Angle of Attach Indicators, Primary Category, Increase for Vh, Maneuvering Speed Va, and Maximum Seating Capacity.

While the FAA has expressed that the given stall speed will be used to limit the gross weight and top speed of these aircraft, very little safety justification is made in the NPRM for the current limitation of 54 KCAS Vs1.  We find the 54 KCAS Vs1 parameter to be arbitrary and too restrictive.  We have given much thought to this issue and realize the challenges faced by the FAA. We find the current limitation overly restrictive and ask the FAA to consider the alternative methods and as discussed below. Of greater concern is that this limitation would limit the FAA’s ability to adapt part 22 to future technology.

The FAA is silent in the connection of 54 KCAS Vs1 to the limitation of what a sport pilot may fly. In this regard, we would like to see an increase in the stall for aircraft that may be flown by a sport pilot to at least a minimum of 58 KCAS as proposed by other organizations. This would allow more legacy aircraft (including many Piper training models) to be included within the legacy fleet that meet the definition of light sport. We believe that while this speed may set a useful minimum for what a sport pilot can fly it should not limit the stall speed of a light sport aircraft. The NPRM allows expansions of a light sport aircraft that would only be available to a sport pilot, or private pilot for that matter, through endorsements.

Therefore, we have separated the scope of what a sport pilot can fly from the definition of a light sport aircraft. We feel strongly that two stall speeds should be established, one as a limitation for sport pilot privileges, and a second limitation for a light sport aircraft. 

Proposed changes to 22.100

Increase the maximum stall speed to 61 Vso

Van’s Aircraft believes that changing the stall speed to 54 Vso with the use of conventional flap systems would be acceptable. A better solution would be 61 Vso (which was already deemed safe in the preamble for Primary category decades ago). 61 Vso is in active use by foreign countries with MOSAIC standards in place and should be considered for consistency and harmonization between governing bodies and markets. Further explanation is provided below.

Increase the stall speed through the use of consensus standards

We have considered the FAA’s concerns over a Vs1 versus Vso stall speed as well as concerns about how higher stall speeds would fit within the safety continuum. We agree with FAA concerns that prescriptive language will limit the future applicability of standards and limit innovation. To help ensure the future applicability of Part 22 to the aircraft of tomorrow and to promote investment in and inclusion of safety enhancements, we propose the following changes in red below:

Add part (c) to § 22.165

22.165 Emergency evacuation.
(a) The aircraft must be designed and
(1) So that all occupants have the
ability to rapidly conduct an emergency
evacuation; and
(2) Except as provided in paragraph
(b) of this section, to account for all
conditions likely to occur following an
emergency landing.
(b) Aircraft not intended for operation
on water are not required to account for
ditching in an emergency landing.
(c) Aircraft meeting the requirements of
22.100(a)(4) must meet additional crashworthiness
requirements addressing such issues as
crashworthiness, safety enhancing features.

Add language to § 22.100  Eligibility (a)(3)

22.100 Eligibility
 (a)(3) Except as provided in paragraph (a)(4)
have a maximum stalling speed or
minimum steady flight speed, without
the use of lift-enhancing devices (VS1) at
the aircraft’s maximum certificated
takeoff weight and most critical center
of gravity of 58 knots CAS for an
airplane, or 45 knots CAS for a glider or
weight-shift-control aircraft., unless
(4) the aircraft has distinctive features that
provides sufficient margin to prevent a tendency to
inadvertently depart controlled flight.

An aircraft would need to meet additional requirements to use a stall speed above the minimum. A means of compliance would be provided through consensus standards governing these additional requirements.  The work of determining what additional requirements would be necessary to increase the stall speed would be addressed in the collaborative environment of the consensus process. The FAA would participate in the development of those standards and control its acceptance as a means of compliance. This would provide and maintain a checkpoint to ensure the standards fit within the expected safety continuum.

As discussed by the ASTM F37 committee, multiple safety enhancing features  – many of which are discussed within the Small Airplane Crashworthiness Design Guide – would be included in the standard. Some of these features may be mandated to allow a higher stall speed. A list of other features would be included from which a minimum required scope must be incorporated for compliance. A points-based system could also be used.

In the Safety Continuum View of MOSAIC Rulemaking Attachment 2 comment made above, the FAA mentions a “simple crash survivable seat” but also mentions the industry does not want a dynamic test requirement. We would propose to the consensus committee a simplified standard for a crash survivable seat. This would provide a means of designing a seat that meets the expectations of the FAA.

Many safety features are already included in modern avionics that are used within the light sport community. Leveraging this would reduce the cost of an aircraft meeting these additional requirements. Some of these features already included by Garmin, Dynon and Advanced Flight Systems include Angle of attack (which ANAC has voiced their intent to mandate), an overspeed warning (mandated by the F3619 flutter standard) and a warning to notify a pilot via an audible voice warning when a door or canopy is unlatched and the rpm raises above runup rpm (this unique warning was developed in the light-sport community). With simple, cost-effective changes we believe that a substantial, measurable impact can be made on safety.

Overall, this approach would “future proof” the standard, allowing flexibility for future technological change. This would address the FAA’s concerns about prescriptive language.

Next, let’s look at reasons to raise the stall speed.

Raising the stall speed will encourage the incorporation of safety devices into aircraft designed for Part 22

“Safety enhancing” is mentioned on pages 47654, 47657, and 47659. It is clear from discussions during the MOSAIC process that both the FAA and the industry wish to increase safety of aircraft in Part 22. Yet there is no incentive within the rule to encourage manufacturers to make the investment in technology that would increase safety. Aircraft cost is shared almost equally across three main factors: avionics, engine and airframe. Recent years have shown an increase in both avionics and engine costs. The airframe manufacture is therefore burdened with making a profit from a fraction of the aircraft. There is little incentive to expend engineering resources to add safety equipment to airframes. Allowing higher stall speeds with the addition of safety enhancing features provides incentive not only to add technologies available today, but also to develop creative new technologies that will further enhance safety in the future.

Allowing a higher stall speed while employing safety enhancing features bridges the gap in the safety continuum between the current proposal and 61kts Vso of primary category. Part 22 fills the gap left by primary category and allows for a proper overlap in the safety continuum with Part 23.

Currently there is no requirement for a critical angle of attack warning device where applicable. This is a requirement of Part 23. It would be preferred that all aircraft be required to use an AoA system. See the Critical Angle of Attack section, below. If this requirement is not implemented for all LSA’s, requiring AoA within consensus standards for aircraft having a stall speed greater than 54kts would provide incentive to install this safety equipment, which will have a dramatic positive effect on reducing LOC accidents.

Safety Devices: AOA versus Vs1 Stall Speed for base-to-final turn

Of concern is the base final turn, where high lift devices may or may not be deployed. LOC accidents on the base-to-final turn happen regardless of stall speed. Examples of this are accidents (some public facing) in the STOL community involving aircraft with very low stall speeds. The answer here is leveraging available technology, such as mandating AOA as standard equipment and/or requiring the use of an envelope protection system if a higher stall speed is desired.

If safety devices are used, 54 KCAS Vso (using conventional flaps) or the higher 61 KCAS Vso should be allowed. A lit of specific safety devices and how they should be implemented does not need to be defined now. The proposal stated above, allowing an alternate speed through the consensus process, would allow this problem to be thoughtfully solved in the future and therefore would not slow down the release of the NPRM.

It should be noted that 54 KCAS Vso does not account for future technology such as autonomous or semi-autonomous vehicles. These aircraft, which augment or replace pilot skill requirements, may be safe at speeds well above 54 KCAS and may be equipped with safety devices that will limit kinetic energy concerns. Why embed a prescriptive number in the standard, leaving no room for innovation?

Flaps Versus Other High Lift Devices

During discussions early on with the FAA, when stall speeds for LSA and LPA were proposed Vs1 versus Vso was discussed. At that time Van’s voiced concerns over using Vso as a stall speed for LSA. The concern was not the use of conventional flaps, but rather the use of novel high lift devices or numerous high lift devices to reduce the wing area. Our concern is that if these high lift devices fail, the aircraft would be difficult to control and exhibit stall speeds well above conventional FAR 23 designs. It should be noted that even if these novel aircraft were introduced, they would represent a small portion of the population.

Many high lift devices achieve lift at an increased deck angle. This decreases visibility, and therefore decreases safety. Watch the Valdez STOL competition and note that aircraft using high lift devices on average are not as successful/consistent in spot landing as aircraft with more wing area and well-designed flaps. The current 54 KCAS Vs1 limitation will encourage manufacturers to add fixed high lift devices to make their aircraft fit within the category. This will reduce safety.

One measure of a good standard is when designers look for ways to design an aircraft within the limits of that standard. This has been the case for Part 23. Yet, in this case manufacturers are already looking for loopholes around the limitations of Part 22.

Raising the stall speed will encourage a transition from EAB to LSA

The FAA states in multiple locations their desire that owners would transition from EAB to LSA aircraft.

From Page 47651

“The FAA intends for these
expansions to increase safety by
encouraging aircraft owners, who may
be deciding between an experimental
aircraft or a light-sport category aircraft,
to choose aircraft higher on the safety
continuum and, therefore, meet higher
aircraft certification requirements.”

Van’s Aircraft has over 11,000 flying aircraft (more than Cirrus as well as many other certified manufacturers) and is representative of the majority of owners and pilots within the experimental amateur built aircraft community. At AirVenture, well over half of all EAB aircraft flown in are RV’s. RVs are seen at many airports around the country on a daily basis, reflecting the fact that these aircraft are not only owned but flown. RVs are enjoyable to fly, affordable, and require a skill level no higher than many aircraft in general aviation. RV aircraft models have an equivalent safety record to that of the GA fleet. All of these reasons are reflected in their low insurance rates. The aircraft are affordable with a balance of safety and performance. The RV-10 four-place and RV-14 two-place aircraft are the most popular models. In August 2023 the RV-10 received approval from Brazil’s ANAC as an Expanded LSA aircraft. The RV-14, although not yet approved, was tested to both ASTM F37 and FAR Part 23 standards during its development. The proposed rule with a clean stall speed of 54 KCAS Vs1 will eliminate both of these aircraft as well as many others from participating in MOSAIC. The Sling Tsi another popular homebuilt that has a stall speed above 54 kts. If Vs1 was changed to Vso, these aircraft would be able to participate. If the intent of the rule as stated is to move the public from EAB to LSA, we have missed the mark. There is no greater vote of compelling public interest than a consumer’s pocketbook, and the public has clearly chosen aircraft with greater performance that the current proposed rule allows.

The NPRM currently proposes a clean stall speed of 54 KCAS Vs1. This would allow a sport pilot to fly an older, previously built, two-place RV. However, these RV aircraft (and some legacy aircraft certified to CAR standards), do not meet the current design requirements for LSA aircraft. So, as currently written, Van’s Aircraft would not be able to produce any of its legacy two-place aircraft under MOSAIC. In addition, the clean stall speed of the RV-14 and RV-10 aircraft are 61 KCAS and 65 KCAS respectively. So, as things stand, no Van’s RV aircraft would be able to be produced under this proposal. One of the stated hopes of the NPRM is that: “The increased utility of light-sport category airplanes may also improve safety by providing aircraft owners with an attractive alternative to experimental amateur-built aircraft.” Simply put, without a change in the currently proposed stall speed, the most popular amateur-built aircraft from several manufacturers will not be included in this expansion of light sport. Unless the rule is changed to include aircraft with performance that is marketable, Van’s Aircraft from a business perspective would need to carefully consider further investment in Part 22.

Raising the stall speed will encourage a transition from ELSA to EAB

Within MOSAIC, ELSA is a safe alternative to under-the-radar EAB contract builds that honestly allows assistance while building. Van’s Aircraft would much rather a customer build ESLA than EAB. If the FAA desires the added level of safety provided by ELSA and wishes to provide an attractive alternative to the  51% limitation when building amateur built aircraft, we must use a stall speed that includes popular homebuilt aircraft. A simple change of Vs1 to Vs0 54 KCAS would include most of the EAB community without including high performance homebuilts that have known safety issues.

Insurance companies in recent years have refused to cover high performance homebuilt aircraft with poor safety records. Market forces will help eliminate unsafe aircraft.

As a side note, some have commented that EAB aircraft with the builder listed as the manufacturer would better protect Van’s from lawsuits. The reality is that the risk of a lawsuit is the same if the aircraft is an EAB, ELSA or EAB. What does change the probability of a lawsuit is not having an accident in the first place. ELSA and SLSA aircraft with higher levels of safety will reduce the number of lawsuits.

The RV-14 instruction manual is a comprehensive, step-by step-process. Almost all aircraft are built as specified. The only major differences are paint schemes and position of the instruments in the panel. We believe that most customers would build these aircraft as ELSA aircraft if the option were available in exchange for not being limited by the 51% rule. This would also have the safety benefit of each aircraft having full documentation (Maintenance Manual, POH, FTS and PAP) as well as a defined fuel system and engine group. All of these factors would add significantly to safety, maintenance and continued operational safety of these aircraft. Much of the Van’s community would transition to LSA, one of the stated intents of the NPRM. Beyond Van’s Aircraft, this could move the bar on safety within the entire homebuilding community.

Raising the stall speed will encourage more sport pilots to participate in aviation

Pilots invest both time and money to become a pilot and maintain that rating. Pilots learn using training aircraft, but they learn to fly because they want to transition to an aircraft that has a mission or utility that justifies their investment.

A 54kt stall speed may allow training aircraft of the past to fall under the umbrella of LSA, but it does not provide a pilot with aircraft that will provide sufficient utility and performance. There are a few pilots who can afford the type-certified aircraft offerings, but the reality is that many pilots will be left with the choice of buying a used aircraft from the general aviation fleet, which has an average age over 50 years old, or turn to EAB.

Pilots may also want to advance and achieve further ratings. From the business perspective of a flight school, an aircraft with more utility than a basic day VFR trainer makes economic sense. Increasing the stall speed of affordable training aircraft will allow flight schools to purchase training aircraft to fulfill the next steps in a pilots training path.

Raising the stall speed to include the SR20

One of the stated goals of MOSAIC is to promote flight training. The SR20 is regarded as an aircraft designed for flight training. This aircraft has a clean stall speed Vs1 of 65 kts and a Vso of 57 kts. In earlier discussions of MOSAIC, the SR20 was included within the corner of the envelope for LPA. Are we now saying that the SR20 is unsafe? Consider that a student pilot with less privileges than a Sport Pilot could be flying solo overpopulated areas in an aircraft that is defined as less safe than a light sport aircraft. Where is this training aircraft positioned on the safety continuum? Why would we not include one of the most popular modern training aircraft on the market?

Raising the stall speed: Environmental and Cost Concerns

To meet the lower stall speed, aircraft will need to do one of two things: add wing area or reduce weight.

There are many examples in Europe of LSA aircraft that are built from carbon fiber. These composite aircraft meet the stall requirements but have pricing for even a fully-equipped two-seat aircraft above $300K. These aircraft prices are often subsidized by the low labor rates found in eastern Europe or South Africa. If produced within the United States, these prices would be higher. Making affordable composite aircraft requires a significant investment in tooling and automated manufacturing equipment (Consider the Cessna Columbia versus Cirrus SR series).  If MOSIAC is meant to promote affordability, we will not achieve that goal. When the ASTM F37 committee invited insurance underwriters to attend a MOSAIC task group we asked, what would keep the insurance cost down? The answer was sheet metal construction, which is much lower cost to repair and has a more known useful life. We cannot release a rule that demands manufacturers use the lightest advanced materials to achieve a low stall speed while maintaining a marketable top speed.

The other means of lowering the stall speed is to add wing area. The RV-10 would need 40% more wing area to meet the Vs1 stall speed requirement. The aircraft becomes heavier, reducing its performance parameters, many of which are related to safety. This area translates into drag. The Cessna 172 for instance easily fits within the Vs1 54 KCAS requirement but its top speed is only 120 KTS. The Cessna 182 using the same wing area solved marketability problem by increasing the horsepower from 180 hp to 230 hp, which increased the cruise to 145 KTS. But this came at a cost by increasing the fuel burn to 13.8 gph (or 10.5 miles per gallon or slightly less than a 1988 Ford F250 V8 truck 11 mpg city 13 mpg hwy).  The Vs1 stall speed will require larger wing areas, which in turn will require more horsepower, which will burn more fuel.

Raising the stall speed will support harmonization with other CAA’s

A goal that has been expressed by the FAA, ANAC, EASA, TCCAA and even smaller countries is that MOSAIC aircraft should be transferable between countries. 54 KCAS Vs1 does not match ANAC Expanded Light Sport Aircraft or EASA Part 21 Light standards.

Aircraft designed to the US standard would not be marketable in foreign markets that allow Vs0 stall speeds greater than 54 KCAS Vs1. Developing an aircraft is an expensive business venture. Manufacturers will design aircraft with higher stall speeds for foreign markets, then find ways to modify performance parameters for import into the US. The “game” will be the same as it is now for European LSA’s imported into the US.

Currently, many European aircraft will meet the proposed 54 KCAS Vs1 US requirements. They were designed for a market that uses smaller aircraft. U.S. manufacturers have designed larger aircraft for our market. The current proposed stall speed will create a disadvantage for U.S. manufacturers. Due to the low cost of using the US self-declarative LSA system, foreign manufacturers will have few expenses beyond the cost of shipping their aircraft to the U.S. On the other hand, U.S. manufacturers face very high approval fees, which can add up to hundreds of thousands of dollars when importing into EASA governed countries. This creates an uneven playing field. 54 KCAS Vs1 does not support job growth or promote the success of companies owned and operated in the United States.

Raising the stall speed will be relieving to the overall FAA workload

Only few level-one and -two aircraft have been developed under the exiting Part 23 over the past few decades. This is a result of the high entry bar set by certified requirements as well as ongoing costs incurred over the lifetime of a product. If aircraft were being developed by the LSA and EAB markets at the pace set over the last 20 years in the certified world, it is doubtful that the FAA would have the bandwidth to meet its compliance obligations. The safety record of LSA is equivalent to that of general aviation. Raising the stall speed would include more personal use and training aircraft within light sport, allowing the FAA to focus their attention on the many other areas within the rapidly changing landscape of aviation.

Errors in Historical Stall Speeds

Near the beginning of the MOSAIC program the FAA shared a spreadsheet “MOSAIC Aircraft Power Index Examples.” This sheet had a column for stall speed. Many of the stall speeds listed were artificially low. One reason for this may be that stall speeds were taken from old data. Many aircraft designed in the 1960’s were much lighter when designed. Checking websites now, most aircraft have gained weight and as a result their stall speeds have increased. Speeds reported by manufacturers also may not be at the most unfavorable c.g. position. The main concern here is that the FAA could believe they have included aircraft within MOSAIC which in reality will be excluded under Part 22 requirements.

Critical Angle of Attack Indication

There is no current requirement for a critical angle of attack warning device proposed under the NPRM for MOSAIC. This silence on AoA may be an attempt to avoid stifling innovations such as other warning devices yet to be envisioned, semi- or fully-autonomous aircraft, stall-resistant aircraft, or the use of advanced envelope protection. For fixed-wing aircraft controlled by a pilot, at minimum Part 22 should require a warning with an equivalent or greater level of safety than AoA. This would only be applicable to an aircraft that can achieve a critical angle of attack. This would need to be written such that a stall vane would not meet the requirement. The statement below is an attempt that still needs crafting.

22.100 (x)(Y) Have an indication of reserve energy remaining when operating near stall or minimum safe speed if loss of control is possible.

Van’s Aircraft would prefer AoA be a requirement not only within Part 22 aircraft, but all general aviation aircraft in a manner similar to ADS-B. The cost of minimal standalone devices is similar to the cost of ADS-B systems. This would provide a monumental leap in safety and a reduction in LOC accidents. If this requirement was mandated across all light aviation in a manner similar to ADS-B, we would see implementation on older aircraft as well as experimental amateur built aircraft. AoA would need to be incorporated into pilot flight reviews as well as basic training.

Van’s Aircraft would like to see, at minimum, an AoA requirement for aircraft with a stall speed above the current Vs1 limit identified within 22.100. This would be one – but not the only – safety enhancing device that would be linked to the allowance of a higher stall speed.

ANAC currently intends to require AoA on all fixed-wing aircraft. From their comment to the NPRM:

“2.2 Has the FAA considered the possibility of mandating stall warning or Angle of
Attack (AoA) indicator for LSA with stall speeds exceeding 45 knots?”

As a result, ASTM has balloted a standard for the functional requirements of AoA (see WK 87199). ASTM may include the requirement of an AoA indicator within the integration standards for fixed-wing aircraft. Discussions have also covered the need for an AoA design requirement to provide quality systems to the market. This possibly could be addressed by an update of the F3011 AoA standard maintained by F39.

We ask the FAA to please provide comments on the absence of a warning system for critical angle of attack for those aircraft to which it would be applicable.

Primary Category, Type Certificates, Common Carriage

The primary category along with recreational pilots did not result in the change within aviation that was intended. In some ways the same could be said for light sport as well, which was too restrictive on weight and speed (which is one reason we are revising the category). A vast gap in the safety continuum still exists between LSA and Part 23 level 1 and level 2 aircraft. For reference, see the safety continuum chart within AC 21.17-3. Amateur built aircraft continue to fill this void in the safety continuum until a new category is created which will fill this space. A place will always exist for experimental aircraft for those who wish to learn and push the boundaries found within the term “experimentation.” This aviation freedom should not be infringed. Yet for those who want the added safety benefits of LSA with the performance allowed by their private pilot certificate, nothing exists to fill that gap at a cost point available to middle-class Americans.

For MOSAIC to truly be effective, we must separate the aircraft from the limitations of a sport pilot. Safety records show that within LSA private pilots are involved in more accidents than sport pilots. This is shown in the annual presentation by the FAA at AirVenture every year. Sport pilots are therefore not inherently limited in their ability. The reason a sport pilot certificate is attractive may be related to the lower cost of entry into aviation, not a pilot’s ability.

As the requirements to become a pilot increased in the early 1960’s we saw a corresponding decrease in the number of pilots. With high-cost-per-hour aircraft rental rates and the price of a private pilot certificate ranging up to $20K according to AOPA, it is apparent that Sport Pilots may be motivated (as student pilots were in the 1950’s) by the lower cost. Again, this choice has nothing to do with pilot ability. This further supports public statements by EAA and AOPA that sport pilots through endorsement should be able to fly any aircraft that may be flown by a private pilot. A Sport Pilot would then be at the same crossroads mentioned in the paragraph above when contemplating which aircraft, they want to invest in for their personal use.

Primary Category has already failed to fill this safety gap. If acceptance for any aircraft in this “gap” in the safety continuum is connected to type certification and the standards used for certified aircraft the gap will continue to exist. Requiring certified Primary Category or Part 23 level 1 and 2 for aircraft above the stated Part 22.100 stall speed of 54 Vs1 or limiting the number of seats to 2 or 3 instead of 4 will not fill the safety continuum. We will have allowed sport pilots to fly legacy aircraft that meet the definition of 54 KCAS Vs1 but the market for new aircraft will remain unchanged.

By imposing type certificates innovation will be stifled, designs will stagnate, and costs will escalate. As general aviation shrinks the number of shipped units decreases. This affects the economics of scale further driving costs upward. Why do type certificates stifle innovation? There are several reasons, but we can give one example that happened recently. In the past few years, several popular EFIS manufacturers certified their lower cost EFIS systems that they originally designed for the experimental market. This allowed a low-cost alternative for older aircraft. Note that this low-cost product was developed in the non-certified world. We recently found a parameter within EFIS software that inhibited a trim motor from functioning. We went back to the EFIS manufacturer and asked that a single variable be changed. Before these units were certified, such a change would take only a few weeks at most. The EFIS manufacture indicated that now that the unit is certified, this becomes a much more complicated and slower issue because of the testing procedures mandated for each application on certified aircraft. With no solution forthcoming, a modification or replacement of the trim motor is the only path forward. This is one simple example of the unintended consequences of type certification.

The cost of a type certificate should not be placed on aircraft having a higher seat count or higher allowed stall speed. This would only increase the price of aircraft within the United States, thus weakening our own aviation infrastructure. Under the intent of the NRPM a type certificate is only needed for sale of an aircraft overseas or for common carriage (types of commercial activity above and beyond the expansion of aerial work that is proposed in the NPRM). A company in development will not necessarily have the financial means to type certify an aircraft. They may choose instead to first sell the aircraft within the United States and overseas markets not requiring a type certificate, and then gain a type certificate as a second step in their business plan. Asking a company to absorb the full cost, complexity and overhead of type certification will only reduce the number of companies that enter aviation. This will limit competition, which in turn will reduce the need of the remaining companies to innovate. This reflects the current state of aviation over the past few decades.  The use of a type certificate should be reserved for overseas sales or commercial activities that are not currently proposed in the NPRM.

The Primary Category failed to bring about what it was intended to accomplish. As we have already shown, applying type certificates to any part of the gap in the safety continuum between the current LSA standards and a Part 23 (or Part 27 for rotorcraft) will result in yet another failure to help and boost general aviation. AC 21-37 for Primary Category lists “Other available small aircraft certification procedures,” one of which is AC 21.17-3 Type Certificates for Very Light Airplanes.

AC 21.17-3 from 1992 states:

“The fact that only three new two place, single engine airplane designs have been type certificated in the U.S. under FAR Part 23 in the last 10 years (two designs were produced by non-U.S. manufacturers and type certificated in the U.S.) supports the contention that FAR Part 23, in a number of sections, has become inappropriate for the type certification of VLA. The FAA believes this, in turn, has contributed to the growing numbers of VLA designs being developed without attempting design certification.  Components for these designs are being manufactured and sold to private builders for assembly and airworthiness certification as amateur-built aircraft. Amateur-built aircraft are certified with a special airworthiness certificate, under the experimental category without applying any FAA approved standards for design, production, quality assurance, or maintenance.”

Now, over 30 years later the message is the same. Imposing the limitations of Primary Category or the certification methods referenced within its advisory circular have already replicated the failure they attempted to solve.

LSA has successfully worked within the space it was allocated on the safety continuum, with a safety record equal to certified aviation. LSA has earned a larger space in the safety continuum. With further requirements beyond the proposal of the NPRM (described throughout these comments) the Light-Sport category should be expanded to fill the entire gap between Experimental Armature Built and the region previously filled by primary category with a stall speed of 61 Vso. While another stall speed may be employed to limit the aircraft that may be flown by a sport pilot, a private pilot or potentially a sport pilot with appropriate endorsements should be able to fly an LSA aircraft that fits within the safety continuum filled by Primary Category.

Van’s Aircraft would like to see aerial work expanded in the future to include certain types of common carriage. We realize that this is not the current intent of MOSAIC. Part 22 standards would need further modification to make this possible. One approach or alternative would be a revamped, lighter approach Primary Category for the light transportation of people or cargo. An argument has been made that since Primary Category is recognized worldwide by most CAA’s this would provide a lower cost path for U.S. manufacturers to sell aircraft outside the United States. We are encouraged by the recent use of F37 standards for approval of the ICON aircraft in Primary Category. It should be noted that unless the requirements of Primary Category are changed significantly, Van’s Aircraft will continue to use other countries for type certification where the process, timeline, cost and ongoing requirements are less restrictive.

Increase for VH Maximum Cruise Speed

The FAA has proposed under 22.100 (4) an increase in VH to 250 KCAS.

Van’s Aircraft supports this expansion. ASTM F37 has passed a new flutter standard F3619 based on other flutter standards worldwide. The content of this consensus standard is based on methods that at minimum are sufficient for 250 KCAS. The EAB community already has decades of experience in this speed range, and we have not seen issues related to flutter or control and maneuverability. With testing required by the new flutter standard and properly designed controls as specified in the design standards these aircraft will be safe to operate. Safety statistics show little risk associated with speed.

Within the preamble of the NPRM it was estimated that aircraft will have an estimated maximum speed of 220 KCAS. A footnote points out that typically a speed ratio of 4 applies between the stall speed and the maximum speed which would naturally limit the maximum speed to 216 KCAS. It was also mentioned that the stall speed will limit the cruise speed.

While this historically may have been true, we are seeing the beginnings of change within the industry. The introduction of the Rotax 915iS and 916iS turbocharged engines has made the benefits of a turbocharger available to the light sport market. These engines are already seen on many European aircraft. The Risen aircraft using a Rotax 916iS engine stalls just under 54kts and has a Vh close to 245 KCAS, a speed ratio of 4.7 and approaching 5. Market pressures will push this technology into other sectors of the light aircraft engine market. Electric motors in the future will also allow greater speed ratios. This will change the classical expectations set by conventional normally aspirated engines of the past. Stall speed will no longer be a parameter that controls top speed as in the past, and therefore stall speed should not be used to control the top speed.

Maneuvering Speed Va, Cruise Speed Vc, Cross Winds and Stall Speed

The current ASTM F2245 design standard states in that Vc may not be less than an equation based on weight divided by wing area.  A mandated stall speed of 54 KCAS will result in a low Vc minimum for an aircraft that potentially has a much higher Vh. Therefore, pilots will potentially be able to cruise at speeds well above the design cruise speed. Similarly using 54 CAS Vs1 will result in very low maneuvering speeds of only 108 kts maximum.

While technically pilots should comply with speeds given in the POH, the reality is that actual cruise speeds or speeds commonly used for maneuvering may be cause for a safety concern. A stall speed of 54 KCAS may be useful for determining what a pilot with a sport pilot rating may fly, but a higher stall speed limit of 61 KCAS Vso would allow the development of aircraft more in line with traditional safety margins.

A known issue of current LSA aircraft is light wing loading. This makes these aircraft less desirable to operate in a flight school in turbulent afternoon conditions. Large wing areas associated with light wing loadings can also make cross wind landings and operation in gusting wind conditions challenging both in the air and on the ground. Allowing a higher stall speed of 61 Vso with the use of conventional high lift devices and safety enhancing devices as defined in consensus standards would result in aircraft with higher wing loadings. These aircraft would be easier to operate in windy or turbulent conditions or when conducting IFR operations.

Maximum Seating Capacity

Van’s Aircraft strongly supports the change from two to four seats. Aircraft will become more marketable for both private aviation and for use in a flight school. Many flight schools fly with one student flying while the other observes the lesson.

We do feel that four-seat aircraft with sufficient wing area to support four full sized adults and baggage in combination with a stall speed of only 54 KCAS Vs1 will result in an unmarketable aircraft. The current four-seat aircraft that have been discussed as being “included” within the category were designed in an era when the average passenger weight was 170 lb which is far less than the numbers that are being considered today. In the golden age of aviation, the expected weight of a passenger and their baggage combined was less than the modern weight of many pilots flying today. Flying these aircraft today we have the choice of full fuel, full seats and or maximum baggage but not all three. We accept that this is how four-place aircraft are designed … but should we? Some aircraft such as the Cessna 172 are known to be four-place aircraft according to the POH, but three-place aircraft in real-world operation. If we redesigned these aircraft to include four modern adults, full fuel, and full baggage (a true four=place airplane) the wing area would increase significantly. The additional wing area would require more structure, increasing the weight further. This increase in wing area would also reduce the top speed. Additionally, the NRPM promoted the addition of safety features, which will add additional weight.

As an example, let’s look at the Cessna 172 – the safest and most prolific training aircraft of all time, which has a maximum payload of 870 lb. Full fuel weighs 310 lb. The stated baggage capacity is 120 lb. In the real world, many pilots are 200 lb or greater but let’s assume 200 lb., the number used by the light sport consensus committee during early discussions on MOSAIC. Fully loaded, we are 360 lbs. over the gross weight limit. Now, assume we wish to add safety enhancing features. An airframe parachute installed will add at least 80 lb. This additional 440 lb would increase the stall speed 8.2% to 52 kts (the max climb rate would also decrease from 730 fpm as well as the maximum cruise speed of 124 kts). We have not yet accounted for the necessary additional wing spar structure, increase in strut size and reinforcement of the landing gear. The increased weight and significantly reduced performance will require a heavier engine and soon we will see the design process that led to the Cessna 182. The Cessna 182 with a cruise speed of only 145 kts will struggle to compete with certified and experimental amateur built aircraft, which cruise faster with lower fuel consumption. For this reason, a higher 54 Vso to 61 Vso stall speed is required to make a modern four-place aircraft. Note the SR-20 and RV-10 aircraft are well within the 61 Vso limit.

54 KCAS Vs1 or slightly higher stall speed may make sense in limiting what a sport pilot may fly, but it does not provide margin for a safe four-place aircraft with remaining capacity to add safety devices. A separate limit for light sport aircraft (which could be flown by a private pilot or a sport pilot with endorsements) will be required. For this reason, we recommend raising the maximum stall speed for light sport aircraft to 61 Vso, which will fill the gap in the safety continuum and harmonize with foreign CAA’s.


The FAA has asked the following question within the NPRM:

“The FAA requests comment on whether any categories of aircraft should or should not be subject to part 36 noise requirements, including any technical or economic data that support the comment.”

First, we would like to make abundantly clear that it is not the intent of Van’s Aircraft, EAB manufacturers, or the light-sport industry to develop and manufacture an aircraft whose noise level is objectionable. The industry realized that increased noise levels not only create concern with the public but also contribute to the fatigue of pilots and aircraft occupants.

There are two main issues that will cause MOSAIC to follow the failed path of Primary Category and similar efforts to rescue general aviation. These issues are:

  1. A stall speed so low that the category is not attractive to aircraft designers or pilots.
  2. The addition of burdensome and unnecessary noise regulations that inhibit the timely certification of light sport aircraft, unnecessarily rob performance causing a safety risk and raise the cost.

We must work together (regulators, pilots, and designers) to find a workable compromise for these key issues.

Noise Standards for Experimental Aircraft

The FAA proposal applies part 36 noise requirements on all aircraft without type certificates. Although the rule makes clear that aircraft certified under 21.191(a) through (h) or (k) are exempt including experimental armature built we are concerned that noise specifications would be applied to any aircraft in the experimental category and the precedent it may set. The experimental category is intended to be a space of experimentation and innovation. Limiting aircraft with noise restrictions will not meet the intent of the category.

Note that many experimental amateur built aircraft in operation are RV’s. RV’s built in Europe must meet noise testing requirements. We have attached an example report in which the RV-14A corrected noise level was 73.9 dBA. Testing of similar aircraft in the United States have all yielded results in the mid 70’s dBA. We conducted an analysis of the EASA Certification Noise Levels database for Light Propeller Driven Aeroplanes. The average measured noise level for certified aircraft with a maximum takeoff weight below 1590 kg (3500 lbs) which is reflective of the MOSAIC category was 74.7 dBA. Although EAB aircraft can vary from aircraft to aircraft, the vast majority of experimental aircraft will not be a factor. Yes, there may be outliers, but these are so few in number as to be statistically insignificant.

The NPRM would impose noise restrictions on ELSA aircraft. Currently an ELSA built to the consensus standards and configuration of a manufacturers original SLSA representative aircraft will not need to conduct further testing to gain an airworthiness certificate. The NPRM indicates that if an ELSA aircraft made a change that would affect the noise signature, they would need to conduct noise testing and submit an amended statement of compliance. How significant would a change need to be to trigger noise testing? Would the addition of an antenna require new certification? With the recent requirement of ADS-B we can easily see the burden this would place on aircraft owners and the FAA. Would the FAA then require ELSA owners to conduct Part 36 testing to the levels of certitude required by the NPRM? How realistic would this expectation be? What level of Part 36 testing would be required? What level of FAA oversight would be required? As written, the rule would place a significant burden on the builder and FAA without a demonstrated benefit.

Noise Standards for Special Light Sport Aircraft

If noise testing is required for SLSA aircraft, the FAA’s methodology of using consensus standards should be used for demonstrating compliance. The NPRM as written would require FAA oversight. Currently certified manufacturers have difficulty scheduling noise tests with the FAA. Existing SLSA and ELSA designs being sold today would need to show compliance before airworthiness certificates are issued. The backlog with well over a hundred SLSA manufacturers scheduling tests with the FAA would “pause” the light sport industry for an unknown duration. This would not be economically viable for many LSA manufacturers. A system using consensus standards and simplified methods would reduce the cost and burden on the FAA.

Analysis of aircraft that would meet the requirements of MOSAIC within the EASA Certification Noise Levels database for Light Propeller Driven Aeroplanes (see also Appendix 1 from AC 36-1H) shows that aircraft within this category fall well below the maximum noise level limits. Imposing this standard on small aircraft places additional cost without a demonstrated benefit. The committee sees therefore no need for noise standards to be imposed.

Since light-sport aircraft in general fall well below the maximum noise levels, the only benefit of limiting noise would be to prevent the possibility of an outlier aircraft exceeding the maximum noise level limit. Since field experience shows that this would be an outlier case, we should not impose a burdensome standard on the majority of light-sport applicants that will most likely pass. For this reason, reasonable simplified methods should be available to manufacturers.

Since light sport aircraft will fall within the maximum noise limits, why not just “check the compliance box” and move on? There are two reasons: Depending on the level of testing required, there can be a substantial cost. This testing will also add time to any aircraft design program. A common complaint of type certificated manufacturers is that mandated FAA oversight is not available. Tests also require a delicate envelope of acceptable environmental conditions that will cause delays as manufacturers need to coordinate both weather and oversight.

Currently, ASTM F37 has balloted simplified noise testing requirements. The ballot justifies that the methods used meet the level of certitude required by the NPRM. Two methods of compliance by calculation are proposed for conventional fixed-wing aircraft. Flight test methods are provided for aircraft that do not meet the requirements of the calculated methods (which would include testing for rotorcraft, eVTOL etc.). We ask the FAA to consider this work (see WK89291) when considering the use of industry consensus standards for noise compliance. We also would request that the FAA work with the consensus standards committee in the development of an acceptable standard. A part 22 standard that points to consensus standards as a means of compliance should be considered instead of imposing part 36 regulation on light sport aircraft.

If a simplified method is approved the NPRM language of 21.190 (c)(2)(iv) will need to be reviewed. Specifically, there may be issue with the requirement to place the tested noise levels within the POH.

The real cause of noise complaints

The best way to explain the genesis of noise complaints is to use a real-world example. Over the last eight years, a local Oregon airport has received increasing noise complaints. The change over that period involved the addition of a privately-operated control tower (NFCT). Hangars for general aviation aircraft were torn down to make room for corporate jet hangers, and jet traffic increased. Multiple commercial utility helicopter companies moved to the field. General aviation aircraft including multiple flight schools had operated out of the airfield since WWII in harmony with the local community. The noise complaints started with the addition of larger aircraft. A common citizen does not care what aircraft nor what gross weight of aircraft is making noise. For this reason, Part 36 requirements that impose lower noise level limits on light aircraft have no basis. For this reason, the maximum noise limit for aircraft in this category should be imposed for all aircraft within the category.

Some noise complaints center around the occasional certified aircraft which were allowed to install large propellers and turn at rpms for up to 5 mins on departure. Typically, these aircraft when loaded would depart at shallower angles than aircraft conducting flight training. Many heavy aircraft operating at this airport fly use the approved approach paths which in turn place them much closer to the ground further away from the airport than typical general aviation aircraft.

Before the addition of the control tower general aviation aircraft avoided noise sensitive areas. The control tower directs aircraft over these sensitive areas on a daily basis. We feel that how traffic is directed is in many cases more important than the noise level produced by aircraft.

Aircraft that meet the MOSAIC definition again are not the source of the problem, yet we will potentially add burdensome requirements and cost if the NPRM proceeds forward as proposed.

Noise restrictions will cause a safety risk

Limiting propeller size, tip speed and robbing power from an engine through inefficient muffler systems will limit the performance of aircraft. Of greatest concern is the STOL, float plane and amphibian markets where power is critical to safe take offs and obstacle clearance. Limiting aircraft in this category well below heavier aircraft will create a safety risk without addressing the real noise issue.

Noise Restrictions – Conclusion

The FAA mentions the unanticipated growth of aircraft which do not conform to type certificates. This growth is due to the lack of burdensome regulation that has economically placed type certificated aircraft out of reach for many pilots. Placing burdensome noise regulations on light aircraft (EAB, ELSA or SLSA) may endanger the overall intent of MOSAIC. The FAA provides no justification or data to support the addition of Part 36 noise requirements. If nose restrictions are imposed there will be little if any safety benefit and will not change the real issue causing noise complaints. We would ask that noise limitations not be imposed on this segment of aviation. If noise limitations are imposed the industry consensus process through a part 22 standard should be used in place of part 36 noise requirements.

Maximum Takeoff Weight

The FAA has removed the maximum takeoff weight. ANAC has approved 61 KCAS Vso and has combined this with a 3000 lb weight restriction. Van’s Aircraft agrees with the FAA position to remove the weight limit although if the only method of raising the stall speed to was to add a weight limit for stall speeds above 54 KCAS Vs1, we would agree to a weight limitation similar to what ANAC has proposed.

Market economics will regulate the size of these aircraft. Engine size increases dramatically as aircraft become larger. The cost of power plants is prohibitive, and this would also naturally limit the size of aircraft developed.

If the type of commercial use is limited there is no longer a reason to limit weight. Weight may have a connection to the stall speed corresponding to the ability of a sport pilot but for a light sport airplane we agree with removing weight restriction.

Removing weight will allow the development of electric aircraft until such a time that battery technology allows lighter batteries. Electric aircraft should not be allowed to operate at higher gross weights than conventional powerplants. The physics linked to safety is the same.

Revision of the Definition Consensus Standard

Federal Register page 47656

Alternatively, the FAA is considering removing the definition of consensus standard from § 1.1.
Consensus standard is a commonly accepted term used by industry and across the Federal
Government and may not require a definition in § 1.1 to be understood in the context of 14
CFR. Additionally, as stated previously, the current definition of consensus standard is limited
to the context of light sport aircraft and does not recognize the breadth of using consensus
standards in aviation today. The FAA requests comment on whether the FAA should remove
the definition of consensus standard from § 1.1 altogether or revise the definition as proposed.

We believe that the definition is not necessary and should be removed. This term is commonly understood worldwide. Therefore, defining a consensus standard will have little benefit while limiting future use of consensus standards in unforeseen ways. The FAA approves consensus standards, and therefore with this check gate in place we see little risk in removal of the definition.

Consensus standards are not limited to light-sport aircraft as mentioned within the current definition of a consensus standard.  Consensus standards are currently used for compliance with 14 CFR Part 23 Amendment 64 and UAS. At minimum, if the definition remains within Part 1, the term “light-sport” should be removed from the definition.

We would ask the FAA to please provide comments on the need for a definition of the term “consensus standard.”

Naming of Part 22

21.190 uses the term “airworthiness” but does not reference the words “Design” or “Production.” These wors also do not appear for other standards such as part 23, 25, or 27. We would recommend removing “Design, Production and” from the title of Part 22.

22.110 Life Cycle

This requirement mentions the aircraft’s intended life cycle. Life limit testing and fatigue testing require significant resources. This would drive the cost and complexity of aircraft in this category. This would also detour some companies from using this category. Aircraft certified under part 23 recently must determine the life limit of an aircraft while older aircraft produced previous standards do not have to consider this testing. This creates an unfair competitive advantage. If life limit testing were added as a means of compliance to this standard this same inequity would exist between older type certified aircraft and part 22 aircraft. When we look at older certified aircraft that do not have to comply with life limit requirements, we do not see issues related to fatigue. The standards used to design these aircraft were conservative enough that either issues did not occur, or these issues were able to be detected in high time aircraft. We recommend removing the reference to life cycle from this standard.

22.130 Use of the word environmental

We recommend removing the word “environmental” from this standard. The previous 21.125 standard already addresses the environment. This standard would still meet the correct intent without the word environmental conditions.

22.135 Equipment and possible systems assessment

Currently in ASTM F37 standards the term equipment is used for items within the weight and balance. We believe that this standard would still meet the correct intent if the word equipment was removed.

Part (b) of this standard mentioned that systems and components must be considered separately and in relation to one another. We feel that this may lead to system assessments similar to those required for certified aircraft. The preamble language indicates a more reasonable approach in line with the rigor required for this level of aircraft would be accepted in a consensus standard. We would ask for further commentary or clarification by the FAA to confirm that this would be a reasonable requirement for manufacturers participating in Part 22.

22.160 Use of the word vision

Part (b) of this standard uses the word “vision.” We feel the word “visibility” would improve the standard. 

22.165 Difficult to account for “all” conditions

We recommend removing the word “all” from (a)(2) of this standard. What is the scope of the current standard? As written, this would raise the level of rigor above that of part 22 or part 25.

Maximum Altitude for Sport Pilots

The FAA has chosen to retain the current altitude restriction of Sport Pilots to 10,000 MSL or 2,000 AGL, whichever is higher.

We see no reason from the standpoint of aircraft operation and design for this restriction. Current LSA Rotax powered aircraft have no difficulty operating up to Class A airspace. Use of an oxygen bottle is simple and well within the skill set of a Sport Pilot. Oximeters are inexpensive and now are included in our headsets and smart watches as well. The absolute ceiling in modern LSA’s is well above the current Sport-Pilot altitude restrictions. A major concern flying VFR is being forced to go underneath weather and deal with terrain in marginal conditions (in the western United States this is a major risk) versus being able to go on top. Last year I ferried an aircraft from Idaho back to western Oregon. The ADS-B was non-compliant. I tried filing for an exemption which was not granted by the time I took off. Weather over the Cascades was marginal. I probed the mountains for over a hundred miles trying to find a way across the mountains. I was flying with another RV who crossed on top and indicated clear conditions over the mountains. I went on top but soon I realized the 10K restriction was not going to let me cross legally. I climbed to13,000 briefly to cross over and keep the FAA mandated cloud clearance. Climbing over the weather was much safer than underneath, which may have not been possible. I filed a NASA report and notified the FAA. Like top speed I do not see any logical issue with higher altitudes up to Class A airspace. Conversely there is a safety benefit lowering the risk of flight into IMC and flight into terrain. Consider higher altitudes with endorsement or training.

One argument could be made that Sport Pilots are flying using a driver’s license for a medical. Is there a concern that these pilots at altitude may be at greater risk of a medical issue even if oxygen is being used? As previously mentioned, it should not be assumed that all Sport Pilots fit within the same demographic. Cost not medical could have been the driving factor becoming a Sport Pilot. If a Sport Pilot uses Basic Med or obtains a minimum Class 3 medical certificate, higher operating altitudes should be allowed. The altitude limitation should be connected to both pilot rating and the type of medical certification that is held. Note we feel that this methodology could be applied to other limitations for a Sport Pilot.

Approval of Controllable Pitch Propellers and Retractable Landing Gear

We approve of these additions for aircraft within MOSAIC and sport pilots with endorsement. We agree that these systems fall within the safety continuum of MOSAIC.

21.190 (d)(6) Transition to and requirement of Part 22 Consensus Standards

We understand and agree with the need to transition to new part 22 consensus standards. Depending on the timing of applicability this may have implications for existing LSA aircraft produced under the current consensus standards. We would ask that a transition be planned that would allow existing LSA aircraft to continue to be produced for a period of time. This would allow an overlap for companies to ensure normal business operations will continue and allow time for manufacturers to update their compliance documentation.

Use of Light-Sport Aircraft in Aerial Work and Standards Thereof

Van’s Aircraft supports the increase in aerial work allowed as proposed in the NPRM. This will address the inequity between the current LSA limitations and the types of aerial work that UAS aircraft are allowed to conduct. The types of aerial work proposed will make the aircraft more marketable without the addition of significant risk. This proposal fits well with the position of MOSAIC and Part 22 in the safety continuum. We hope that this multipurpose use of aircraft will support flight schools’ business model justification for the purchase of new light sport aircraft to replace the aging training fleet. We also hope that as commercial pilots build time towards an airline career, they can conduct useful aerial work.

Van’s Aircraft does have concerns about the use of language within the NPRM such as strength degradation and ensuring structural strength. Consensus design standards will be developed for the additional considerations related to aerial work. We would like to better understand the concern related to terms such as strength degradation and how the industry would best address these concerns in a standard. The types of aerial work proposed are limited in scope and we anticipate little effect on the life of an aircraft. The preamble to the NPRM states that. “The agency does not propose relaxation of any of the existing regulatory safeguards that relate to aerial work operations, such as the minimum safe altitude, minimum safe distance, and minimum safe speed restrictions in part 91 and restrictions surrounding dispensing of chemicals in part 137.” With these regulatory safeguards in place, we do not foresee a significant reduction in aircraft life. We would like to avoid terms in the rule which would result in burdensome and expensive studies related to aircraft life limits. Instead, we would prefer to include simplified requirements that ensure sufficient safety margin in design within a design consensus standard for aerial work.

Light-Sport Repairman Maintenance Rating Changes

The FAA has proposed changing the Light Sport Repairman (LSRM) rating from a course of 120 hours to a curriculum aligned with ACS standards for Aviation Mechanic General, Airframe and Powerplant (A&P).

The NRPM gives no justification or data supporting this change. The safety history of light-sport supports the continuation or expansion of the LSRM program.

There is a growing need for maintenance throughout the light aircraft industry. The airline-commercial segment of aviation is able to pay much higher rates than general aviation. It is becoming more difficult to find applicants to work as an A&P. Students coming from A&P schools lack the practical experience of working on small aircraft. It is common to hear in the certified world owners asking, “can I do most of the work and have you come by and sign off the inspection.” We have a need for qualified maintenance personnel, yet we feel the changes proposed within the NPRM will increase the time and cost of gaining a maintenance rating. We need to increase access to rated maintenance personnel for the general aviation community as a whole. Allowing aircraft owners to take a course for LSRM which has a 20-year proven history, is far better than the reality of the current trend in maintenance. As more aircraft enter the market under MOSIAC and flight schools start purchasing MOSIC aircraft in greater numbers the need for qualified personnel will only grow. Maintenance is a major factor in safely operating a flight school and has a significant effect on the cost of flight training. We have an opportunity to help aviation by taking a fresh look at the opportunity the LSRM program provides. We strongly encourage the FAA to work with industry to identify a path forward for acceptable levels of maintenance in general aviation.

Van’s Aircraft would like to also add support for ELSA aircraft in regard to the need of A&P and maintenance personnel. Worldwide there are over 100 RV-12 projects involving youth build programs. Most of these programs take place at the high school level in the formative years where youth are deciding on career paths. These programs are available to youth with differing economic opportunities. Although not all youth continue a career path in aviation all students come away with levels of confidence that will help them their entire lives. Several students do remain in aviation working within the production environment, as engineers, pilots and maintenance. We would ask that the FAA look at the opportunity to credit the hours within these programs towards A&P certification.

These programs are an example of how the experimental light sport segment of this category can give back to society. We ask the FAA to keep in mind that these programs are possible because aircraft are at a cost point that schools can afford. As changes are considered for MOSAIC any change that would increase the cost should be considered with care.

Minor Alterations to Light-Sport Aircraft

The FAA has proposed to allow minor repairs and alterations under a revised 91.327(b)(5). These repairs or alterations would need to meet the applicable consensus standards and would be able to be performed without contacting the FAA or the aircraft manufacturer.

What is unclear is the full definition of what is minor and what is major. Are there any conflicts with Part 43.1 that need to be resolved? The current requirement for manufacturers is that items included within the maintenance manual are minor and those not included in the maintenance manual are major. Van’s Aircraft would like further clarification on the definition of what is minor and what changes the FAA would propose within the ASTM standards to support this.

The preamble states that authorized certified light sport repairman or an appropriately rated mechanic or an appropriately rated part 145 certified repair station would be able to perform a minor repair or alteration. What training has been put in place to ensure that mechanics and repair stations understand the consensus standards. Will they be required to take ASTM training similar to the training required to sign an 8130-15 form? LOA’s are widely used in the industry even though the consensus standards use a Major Repair and Alterations form. The reason an MRA form is required is because the form addresses many issues that would affect the safety of a repair or alteration. LOA approval letters in some cases have changed entire avionics systems with two simple paragraphs of text (a practice used by manufacturers outside the U.S. who import aircraft with a simple panel then upgrade the panel after the aircraft enters the U.S). If an LOA is being used in error for a major alteration how will the FAA, ensure that mechanics and repair stations understand the consensus standards? We realize the intent here of the FAA and agree that this is a step in the right direction (see further comments under comments for Major Repairs and Alterations).

Major Repairs and Alterations to Light-Sport Aircraft

The light-sport industry has a major gap in the area of major repairs and alterations. The previous issues with ADS-B updates and the upcoming changes related to unleaded fuel underscore the need for change. As a manufacturer we are concerned about the liability issues that may be caused by providing an alternate path to manufacture approval. A greater concern is the marketability of light sport aircraft to flight schools. We need an alternative path for major repairs and alterations that allows aircraft in a flight school to remain viable indefinitely independent of the manufacture. We encourage the FAA to work with industry withing the consensus process to develop a solution. Recent participation of AFS-300 within ASTM meetings related to maintenance is appreciated.

This solution may involve use of the “person acceptable to the FAA” clause within 91.327. While this method works, the upcoming possibility that a unleaded fuel type would be accepted across all LSA aircraft without involving manufacturers does raise concern. We as a manufacturer would ask for a more collaborative approach and creative use of this clause.

The ASTM F37 committee is currently working on a 3rd party alterations standard. A concern of manufacturers is that there would be a check gate to ensure that 3rd parties acting independently would be held to the same level of rigor as a manufacturer who signs an 8130-15 form. A 3rd party would need the requisite training required similar to a manufacturer, should consider all the safety issues related to the current MRA process, should notify a manufacture, and maintain a COS program to maintain their alteration over time.

To facilitate this check gate, we propose that a 3rd party be required submit an amended statement of comp0liance form as proposed in 21.190(e) for aerial work. Note that 36.1581 (h) requires that noise be documented per 21.190(e) yet 21.190(e) only relates to aerial work. We propose that at the same time this oversight is rectified additional information similar to what is defined for aerial work be added for 3rd part alterations. The amended statement of compliance would provide a record of the aircraft modification for future reference by a manufacturer or a future 3rd party planning a subsequent alteration.

Another check gate is the ability of a manufacturer to issue a safety directive against a potential alteration. We are encouraged that safety directives will continue to be used as stated by the NPRM.

Gaining consensus for a process reflecting a STC in the type certificated world will be difficult.  We believe that much of the opposition to these alterations’ centers on the fact that manufacturers within the consensus process have the opportunity to object. If type certificated manufacturers were given a chance to vote on the STC process, would they vote differently? We therefore ask that the FAA continue to provide support and pressure as necessary to enable the committee to develop a working solution within the consensus process.


This NPRM – along with collaboration between regulators, manufacturers, and the end user community through the consensus process – will deliver safe, market-viable aircraft to the pilot and flight school community for decades to come. The flexibility of this category will adapt to an ever-changing landscape of technology, keeping the part 22 category modern and relevant. We support this rule change and would like to thank the FAA for incorporating feedback from industry and the end user community.  We ask for the continued support of all applicable branches of the FAA in the development of consensus standards and ongoing support of this rule.


Rian Johnson
Vice President and Chief Engineer
ASTM F37 Chairman
Van’s Aircraft
14401 Keil Rd
Aurora, Oregon 97002

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