[Federal Register Volume 88, Number 140 (Monday, July 24, 2023)]
[Proposed Rules]
[Pages 47650-47739]
[FR Doc No: 2023-14425]

Vol. 88

Monday,

No. 140

July 24, 2023

Part III

Department of Transportation

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Federal Aviation Administration

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14 CFR Parts 1, 21, 22, et al.

Modernization of Special Airworthiness Certification; Proposed Rule

Federal Register / Vol. 88, No. 140 / Monday, July 24, 2023 /
Proposed Rules

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 1, 21, 22, 36, 43, 45, 61, 65, 91, and 119

[Docket No.: FAA-2023-1377; Notice No. 23-10]
RIN 2120-AL50

Modernization of Special Airworthiness Certification

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to amend rules for the manufacture,
certification, operation, maintenance, and alteration of light-sport
aircraft. The proposed amendments would enable enhancements in safety
and performance and would increase privileges under a number of sport
pilot and light-sport aircraft rules. These enhancements include
increasing suitability for flight training, limited aerial work, and
personal travel. This proposed rule would expand what aircraft sport
pilots may operate. This NPRM also includes proposals to amend the
special purpose operations for restricted category aircraft; amend the
duration, eligible purposes, and operating limitations for experimental
aircraft; and add operating limitations applicable to experimental
aircraft engaged in space support vehicle flights to codify statutory
language.

DATES: Send comments on or before October 23, 2023.

ADDRESSES: Send comments identified by docket number FAA-2023-1377
using any of the following methods:
     Federal eRulemaking Portal: Go to regulations.gov and
follow the online instructions for sending your comments
electronically.
     Mail: Send comments to 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.
     Hand Delivery or Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE, Washington, DC 20590-0001 between 9 a.m. and 5
p.m., Monday through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at<PHONE_NUMBER>.
    Docket: Background documents or comments received may be read at
regulations.gov at any time. Follow the online instructions for
accessing the docket or go to the Docket Operations in Room W12-140 of
the West Building Ground Floor at 1200 New Jersey Avenue SE,
Washington, DC 20590-0001, between 9 a.m. and 5 p.m., Monday through
Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: For technical questions concerning
this action, contact James Newberger, Aircraft Certification Service
(AIR-632), Federal Aviation Administration, 800 Independence Ave. SW,
Washington, DC 20591, telephone<PHONE_NUMBER>; email
[email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
    A. Overview of the Proposed Rule
    B. Summary of Costs and Benefits
II. Background
    A. History
    B. Related Actions
III. Authority for This Rulemaking
IV. Discussion of the Proposal
    A. General
    B. Revision of Definitions Applicable to the Certification and
Operation of Light-Sport Category Aircraft
    C. Expansion of Eligibility for Light-Sport Category Aircraft
and Sport Pilots
    D. Certification of Light-Sport Category Aircraft
    E. Sport Pilot Certification and Privileges
    F. Repairman (Light-Sport) Certificates
    G. Maintenance
    H. Operations
    I. Experimental Airworthiness Certificates
    J. Restricted Category
    K. Noise Certification of Aircraft That Do Not Conform to a Type
Certificate
    L. Proposed Effective and Compliance Dates
    M. Amendments Concerning Import and Export of Aircraft
    N. Conforming Amendments
V. Regulatory Notices
    A. Regulatory Impact Analysis
    B. Regulatory Flexibility Act
    C. International Trade Impact Assessment
    D. Unfunded Mandates Assessment
    E. Paperwork Reduction Act
    F. International Compatibility
    G. Environmental Analysis
VI. Executive Order Determinations
    A. Executive Order 13132, Federalism
    B. Executive Order 13175, Consultation and Coordination With
Indian Tribal Governments
    C. Executive Order 13211, Regulations That Significantly Affect
Energy Supply, Distribution, or Use
    D. Executive Order 13609, Promoting International Regulatory
Cooperarion
VII. Additional Information
    A. Comments Invited
    B. Confidential Business Information
    C. Electronic Access and Filing
    D. Small Business Regulatory Enforcement Fairness Act

List of Acronyms Frequently Used in This Document

ASTM--ASTM International
ATD--Aviation Training Device
CAS--Calibrated Airspeed
CFR--Code of Federal Regulations
DOD--Department of Defense
DOT--Department of Transportation
FAA--Federal Aviation Administration
FADEC--Full Authority Digital Electric Control
FR--Federal Register
FSTD--Flight Simulation Training Device
IBR--Incorporation by reference
LSAMA--Light-Sport Aircraft Manufacturers Assessment
MOSAIC--Modernization of Special Airworthiness Certification
MSL--Mean Sea Level (altitude)
NAICS--North American Industry Classification System
NPRM--Notice of proposed rulemaking
NTSB--National Transportation Safety Board
OMB--Office of Management and Budget
PIC--Pilot in Command
PTS--Practical Test Standards
RFA--Regulatory Flexibility Act
RIA--Regulatory Impact Analysis
U.S.C.--United States Code
VFR--Visual Flight Rules
VH--Maximum airspeed in level flight with maximum continuous power
VNE--Maximum never exceed speed
VS1--Maximum Stalling Speed (in clean configuration)

I. Executive Summary

A. Overview of the Proposed Rule

    The FAA proposes to amend rules related to the certification and
operation of light-sport category aircraft. This rule would modernize
the regulatory approach to light-sport aircraft, incorporating
performance-based requirements that reflect advances in technology and
use cases for this type of aircraft. The proposal is designed to
respond to the evolving needs of this sector and provide for future
growth and innovation without compromising safety.
    In 2004, the FAA published the final rule titled ``Certification of
Aircraft and Airmen for the Operation of Light-Sport Aircraft,'' which
established rules for the manufacture, certification, operation, and
maintenance of light-sport aircraft (69 FR 44771; July 27, 2004)
(hereafter ``the 2004 final rule''). That rule provided for the
operation and manufacture of aircraft weighing less than 1,320 pounds
(or 1,430 pounds for aircraft intended for operation on water). These
``light-sport'' aircraft included airplanes, gliders, balloons, powered
parachutes, weight-shift-control aircraft, and gyroplanes. The FAA
bases the rigor of certification requirements and operational
limitations on a safety continuum that assesses the exposure of the
public to

risk for each aircraft and operation; as the risk increases due to
increased operating privileges and aircraft capability, the
requirements and corresponding rigor of requirements and procedures for
certification increase.
    In establishing the 2004 final rule, the FAA intentionally
established a rigor of certification for light-sport category aircraft
between normal category aircraft and aircraft holding experimental
certificates in view of intended operating privileges and aircraft
capability. This preamble uses experimental amateur-built aircraft for
the safety continuum discussions since they are similar to light-sport
category aircraft in this proposal. Amateur-built aircraft are largely
used for recreational purposes, are flown by sport pilots and pilots
with higher grade certificates, and generally have the same flight
envelope and occupancy limits. Amateur-built aircraft are below light-
sport category aircraft on the safety continuum because of their lower
safety assurance for aircraft design and being subject to stringent
operating limitations. Amateur-built aircraft have no regulatory design
requirements for suitability of materials used, structural integrity,
or instruments, equipment, and systems. This proposed rule would
prescribe design requirements for light-sport category aircraft for
these items. This proposed rule would also allow light-sport aircraft
to conduct aerial work operations that have been authorized by the
manufacturer for compensation or hire. Amateur-built aircraft are
limited to non-commercial operations for the purpose of education and
recreation.
    Since the 2004 rule, light-sport category aircraft have shown a
lower accident rate than experimental amateur-built airplanes. The FAA
considers that the successful safety record of light-sport category
aircraft validates certification requirements established in the 2004
final rule and provides support for expanding the scope of
certification for light-sport category aircraft and operations. As a
result, the FAA identified this proposed rule as an opportunity to
expand the 2004 final rule to include a wider variety of aircraft,
increase performance, and increase operating privileges to extend these
safety benefits to more aircraft. 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.
    This proposed rule also addresses other aircraft that hold special
airworthiness certificates. Specifically, the FAA proposes to codify
additional special purpose operations for restricted category aircraft
that the FAA has previously approved under discretion provided in Sec.
21.25(b)(7). In addition, this rule would amend the duration, eligible
purposes, and operating limitations for special airworthiness
certificates issued for experimental purposes.
    The FAA has identified proposals to improve both the safety and
functionality of light-sport category aircraft and light-sport category
kit-built aircraft. This rule would amend aircraft, pilot, maintenance,
and operational requirements to increase both the safety and
performance of these aircraft while mitigating risk. The FAA recognizes
that this is a balancing act--where the risk is increased due to
greater capability in one area, mitigations may be required from the
other areas.
    This proposal would establish performance-based requirements
related to light-sport certificated aircraft. As a fundamental matter,
the proposal would restructure how certification requirements for
light-sport category aircraft are presented in the FAA's regulations.
Currently, issuance of special airworthiness certificates under Sec.
21.190 for light-sport category aircraft, sport pilot certificates
under part 61, subpart J, and repairman (light-sport) certificates
under part 65 are limited by a number of aircraft design limitations
included in the definition of light-sport aircraft in Sec.  1.1. This
proposal would remove that definition and, in its place, write
performance-based standards for aircraft and airman certification into
14 CFR parts 21, 61, and 65, where these requirements for other types
of aircraft and airman certification reside. This would make the FAA's
regulatory approach to light-sport category aircraft more consistent
with its approach to other types of aircraft.
    Another important change proposed under this rule would eliminate
the weight limits for light-sport category aircraft. To enable the
design and manufacture of light-sport category aircraft that are safe
to fly with increased capacity and ability, this proposal would apply
new design and manufacturing requirements. This would allow growth and
innovation within performance-based safety parameters. This proposal
also expands aircraft that sport pilots can operate. Under this
proposal, sport pilots could operate airplanes designed with up to four
seats, even though they would remain limited to operating with only one
passenger. Finally, the proposal would change the name of the repairman
certificate (light-sport aircraft) to repairman certificate (light-
sport). This certificate would apply to existing and new types of
aircraft certificated in the light-sport category, such as rotorcraft
and powered-lift. Related provisions would update the requirements for
maintenance.
    The FAA is also proposing regulations related to noise for light-
sport aircraft, expanding applicability of part 36 noise limits. To
provide flexibility and reduce burdens of compliance with these noise
limits, the FAA is proposing options for compliance: conventional noise
testing per part 36 or means of compliance via FAA-approved, industry
consensus standards. The FAA expects that any consensus standards would
not be limited to physical measurements of noise taken during test
flights. They might instead to be based on empirical data, analytical
modeling, or generally accepted noise prediction methods if the
underlying noise prediction methods are found to be robust.
    In addition to maintenance and manufacturing requirements, the FAA
also proposes to expand the kinds of operations that can be performed
by light-sport category aircraft. Specifically, this proposal would
permit light-sport category aircraft to be used in certain aerial work
operations for aircraft that meet the applicable consensus standard for
that operation.
    Additionally, the FAA is proposing amendments to experimental
aircraft regulations. The proposed regulations create new operating
purposes for former military and kit-built aircraft and amend the
operating purpose for market survey. The proposed regulations also
include new operating limitations, an increased certificate duration,
and new noise requirements. The FAA is further proposing amendments
related to restricted category aircraft, including a codification of
special operating purposes for restricted category aircraft. This NPRM
also includes proposed changes to right of way and operations around
airports in Class G airspace.

B. Summary of Costs and Benefits

    The proposed rule largely expands opportunities for light-sport
category aircraft. These expansions may result in safety and
recreational benefits; there may also be associated design and
production costs. The FAA expects requirements to comply with noise
standards would be minimal using industry consensus standards. The FAA
also does not anticipate more than minimal incremental costs for other
provisions of the proposed rule, such as

training, and does not have data to estimate any cost savings, such as
those that could result from operating certain light-sport category
aircraft in aerial work for compensation.

II. Background

A. History

    In the 2004 final rule, the FAA reasoned that new rules for light-
sport category aircraft were necessary to address advancing sport and
recreational aviation technology, the lack of regulations for existing
aircraft, and several petitions for exemptions and rulemaking. The 2004
final rule provided for the manufacture of safe and economical
certificated aircraft beyond the weight limit permitted by part 103;
established the sport pilot certificate; and allowed certificated
pilots to operate light-sport category aircraft for sport and
recreation, carry one passenger, and conduct flight training and towing
in a safe manner. The resulting regulations also placed restrictions on
light-sport category aircraft design and performance requirements
including an aircraft weight limit of less than 1,320 pounds (1,430
pounds for aircraft intended for operation on water). Light-sport
aircraft include airplanes, gliders, balloons, powered parachutes,
weight-shift-control aircraft, and gyroplanes.
    The FAA has granted multiple exemptions for light-sport aircraft
based on safety considerations that include:
     Retractable landing gear to enable takeoffs and landings
from land and water;
     Various weight increases, with the largest allowing up to
1,850 pounds; and
     A VS1 stalling speed increase to 54 knots
calibrated airspeed (CAS). Discussion of the specific grants of
exemption follow in section II.B.1.
    The FAA also amended rules on two occasions for light-sport
aircraft and airmen. In 2007, the FAA amended the definition of light-
sport aircraft to permit development of lighter-than-air light-sport
aircraft and allow retractable landing gear for light-sport aircraft
intended for operation on water. In 2010, the FAA also amended rules
for persons holding a sport pilot certificate and flight instructors
with a sport pilot rating to address airman certification and
operational issues that arose since the 2004 final rule. Detailed
discussion of these amendments is included in section II.B.2.
    In 2010, the FAA completed a Light-Sport Aircraft Manufacturers
Assessment (LSAMA) Final Report, dated May 17, 2010 (the LSAMA Final
Report), following its assessment of 14 light-sport category aircraft
manufacturers to evaluate compliance with the 2004 final rule. On June
28, 2012, the FAA published a notification in the Federal Register (77
FR 38463) (the ``LSAMA Notification'') describing its concerns
identified in the LSAMA Final Report. Specific concerns included:
     Most manufacturing facilities evaluated could not fully
substantiate that the aircraft for which they had issued a statement of
compliance did, in fact, meet the consensus standards identified in
those documents.
     The accuracy of declarations made in a statement of
compliance.
     That more FAA involvement is warranted than originally
intended under the 2004 final rule.
    Considering these concerns, the FAA established an audit program
under FAA Order 8130.36, Special Light-Sport Aircraft Audit Program,
for conducting regular audits of light-sport category aircraft
manufacturers and their associate facilities. Proposed safety
enhancements under this NPRM for new training requirements for
manufacturer's employees who are responsible for compliance findings
and compliance statements are based on concerns described in the LSAMA
Notification and are discussed in sections IV.D.17 and IV.D.19.
    The 2004 final rule was successful in encouraging innovation in
light-sport aircraft. According to FAA Registry data as of January
2023, over 200 models and 5,321 aircraft have been designed and
manufactured under the 2004 final rule, distributed among the various
classes of aircraft as follows:
     4,459 airplanes.
     456 powered parachutes.
     336 weight-shift controlled aircraft.
     70 gliders.
    In addition, FAA airman certification databases show that
approximately 7,000 sport pilots, 1,000 sport pilot instructors, 1,500
repairman (light-sport aircraft) with a maintenance rating, and 10,000
repairman (light-sport aircraft) with an inspection rating are
currently certificated under provisions of the 2004 final rule.
    The FAA views the safety record of light-sport category aircraft
operations as validation of the original certification requirements and
as support for expanding eligibility for aircraft certification, airmen
certifications, and related operating privileges. From working with
applicants for certification of aircraft, pilots, and repairman of
light-sport aircraft since the 2004 final rule took effect, the FAA has
identified many proposals for amending those rules to enhance safety,
performance, and privileges for operating light-sport category
aircraft. The FAA is also proposing amendments concerning certification
and operations of other aircraft that hold special airworthiness
certificates. Detailed discussion of the safety record of light-sport
category aircraft and these proposals are included in section IV of
this NPRM.

B. Related Actions

1. Exemptions to the 2004 Final Rule
    As previously stated, the FAA granted multiple exemptions to the
2004 final rule based on safety considerations. Together, these actions
permitted exempted aircraft to vary from the rule in the following
ways:
     Retractable landing gear to enable takeoffs and landings
from land and water.
     Various weight increases, with the largest allowed weight
of up to 1,850 pounds.

Data, arguments, and findings that enabled the FAA to grant these
exemptions are used as applicable to support proposals herein to codify
these and similar provisions.
2. Amendments to the 2004 Final Rule
    On April 19, 2007, the FAA published the final rule ``Changes to
the Definition of Certain Light-Sport Aircraft'' (72 FR 19661) to amend
the definition of light-sport aircraft to permit development of
lighter-than-air light-sport aircraft and allow retractable landing
gear for light-sport aircraft intended for operation on water. To date,
the FAA has issued no special airworthiness certificates for lighter-
than-air light-sport aircraft. This NPRM proposes to permit retractable
landing gear for all operations to enhance safety more broadly within
the light aircraft community by making light-sport category aircraft
more attractive alternatives to experimental amateur-built aircraft.
    On February 1, 2010, the FAA published the final rule
``Certification of Aircraft and Airmen for the Operation of Light-Sport
Aircraft; Modifications to Rules for Sport Pilots and Flight
Instructors with a Sport Pilot Rating'' (75 FR 5204; Correction
published on March 30, 2010, 75 FR 15609) (hereinafter the 2010 final
rule). The purpose of the 2010 final rule was to amend rules for sport
pilots and flight instructors with a sport pilot rating to address
airman certification and operational issues that arose since
regulations for the certification of aircraft and airmen for the
operation of light-sport aircraft were implemented in 2004.

3. FAA-Industry Listening Session
    On December 12, 2022, the FAA hosted a listening session with
representatives of the light-sport aircraft industry. A record of that
meeting, including participants and their feedback, is included on the
docket for this proposed rule, which is available at FAA-2023-1377.
Importantly, that feedback replicated what the FAA has learned about
the 2004 final rule as discussed previously in this NPRM.

III. Authority for This Rulemaking

    The FAA's authority to issue rules on aviation safety is found in
title 49 of the United States Code (U.S.C.). Subtitle I, section 106
describes the authority of the FAA Administrator. Subtitle VII,
Aviation Programs, describes in more detail the scope of the agency's
authority. This rulemaking is promulgated under the authority described
in 49 U.S.C. 106(f) and (g), which establishes the authority of the
Administrator to promulgate and revise regulations and rules related to
aviation safety. This rulemaking is also promulgated under 49 U.S.C.
44701(a)(2)(A) and (a)(5), which provides that the FAA Administrator
shall promote safe flight of civil aircraft in air commerce by
prescribing regulations and minimum standards: (1) in the interest of
safety for inspecting, servicing, and overhauling aircraft, aircraft
engines, propellers, and appliances, and (2) that the FAA finds
necessary for safety in air commerce and national security; 49 U.S.C.
44703, which provides the general authority of the Administrator to
prescribe regulations for the issuance of airman certificates when the
Administrator finds, after investigation, that an individual is
qualified for, and physically able to perform the duties related to,
the position authorized by the certificate; 49 U.S.C. 40103(b)(1) and
(2), which directs the FAA to issue regulations: (1) To ensure the
safety of aircraft and the efficient use of airspace; and (2) to govern
the flight of aircraft for purposes of navigating, protecting and
identifying aircraft, and protecting individuals and property on the
ground; and 49 U.S.C. 44715, which provides the Administrator the
authority to prescribe regulations to control and abate aircraft noise
and sonic boom. These proposed regulations are within the scope of
those authorities because they are proposing to amend rules for the
manufacture, certification, operation, maintenance, and alteration of
light-sport category aircraft, to amend rules related to restricted
category aircraft and experimental airworthiness certification, and to
amend rules related to sport pilot and repairman certification.
    Additionally, this rulemaking implements the Congressional mandate
set forth in section 581 of the FAA Reauthorization Act of 2018 (Pub.
L. 115-254), which authorizes certain aircraft holding experimental
certificates to conduct space support vehicle flights. Section 581
amends 49 U.S.C. 44737 to allow the operator of an aircraft with a
special airworthiness certification in the experimental category to
operate the aircraft for the purpose of conducting a space support
vehicle flight and conduct such flight under such certificate carrying
persons or property for compensation or hire.

IV. Discussion of the Proposal

A. General

    The FAA is proposing to amend rules for the manufacture,
certification, operation, maintenance, and alteration of light-sport
category aircraft. The proposed changes would enhance the safety,
performance, and operating privileges of light-sport category aircraft.
This proposal would also expand the types and characteristics of
aircraft that sport pilots may operate. The proposed changes would
increase the suitability of light-sport category aircraft for flight
training, limited aerial work, and personal travel. Additionally, the
proposal would further enable the manufacture of safe and economical
light-sport category aircraft. The FAA also proposes to update the list
of approved operations for restricted category aircraft; amend the
duration, eligible purposes, and operating limitations for special
airworthiness certificates issued for experimental purposes; and add
operating limitations applicable to experimental aircraft engaged in
space support vehicle flights to codify a statutory provision.
1. The Evolution of Light-Sport Aircraft
    The FAA acknowledged in the 2004 final rule that ``there are areas
where only time and experience will determine whether these regulatory
provisions meet the FAA's expectations or require modification.'' In
the approximately 20 years since the FAA published that rule, the FAA
has increased its understanding of these aircraft. The 2004 final rule
was successful in encouraging innovation in light-sport aircraft; over
200 models and 5,300 aircraft have been designed and manufactured under
the 2004 final rule. The FAA has also considered several requests for
exemption from the light-sport aircraft rules, granting eleven of them.
This proposal would amend the rules for these aircraft to improve
safety and performance and increase the scope of operations that may be
performed with light-sport category aircraft.
2. A Safety Continuum
    The FAA bases the rigor of certification requirements and
operational limitations on a safety continuum that looks at the
exposure of the public to risk for each aircraft and operation; as the
risk increases due to increased operating privileges and aircraft
capability, the requirements and corresponding rigor of requirements
and procedures for aircraft and airman certification increase. In
establishing the 2004 final rule, the FAA intentionally established a
rigor of aircraft certification for light-sport category aircraft
between normal category aircraft and aircraft holding experimental
certificates in view of intended operating privileges and aircraft
capability. Normal category airplanes can weigh up to 19,000 lbs. and
carry 19 persons. Accordingly, their certification rigor is going to be
greater than an aircraft that has two to four seats because an accident
would result in greater fatalities. However, to mitigate this risk, the
part 23 airplane must be designed and manufactured to more stringent
airworthiness standards. By meeting the more stringent airworthiness
standards, the FAA grants greater operating privileges. Therefore,
since light-sport category aircraft subject fewer people to risk and
have fewer operating privileges when compared to part 23 airplanes, the
2004 final rule and this proposal includes less stringent certification
standards.
    Based on the rigor of aircraft certification established for light-
sport category aircraft in the 2004 final rule, the FAA expected that
light-sport category aircraft fatal accident rates would fall between
experimental and normal category aircraft. To validate this expectation
against fatal accident data, the FAA compared data for light-sport
category airplanes and other aircraft categories or types that were
most similar to light-sport category airplanes: experimental amateur-
built airplanes with single, reciprocating engines, and fixed landing
gear; and small normal category airplanes with single, reciprocating
engines, and fixed landing gear. The fatal accident rate data compiled
since 2011 for these aircraft \1\

show that light-sport category aircraft fatal accident rates fall
between experimental and normal category aircraft, validating that the
rigor of certification requirements and procedures of the 2004 final
rule falls, as intended, between experimental and normal category
aircraft. This validation also supports proposals described in this
NPRM for modest expansions of eligibility for certification of light-
sport category aircraft, performance limitations for sport pilots,
eligibility for certification of repairman (light-sport), and
corresponding operating privileges for additional but similar operating
privileges and risks. As described in section IV.C, the FAA has also
identified other opportunities to improve the safety of light-sport
category aircraft and experimental light-sport category kit-built
aircraft.
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    \1\ Light aircraft fatal accident trends are included on the
docket at FAA-2023-1377. These trends are shown beginning in 2011
because of limitations on available data and since ten-year trends
seem sufficient for this proposal.
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    Additionally, the lower accident rate of light-sport category
aircraft as compared to experimental amateur-built airplanes has led
the FAA to examine opportunities for expanding the 2004 final rule to
include a wider variety of aircraft, increase performance, and increase
operating privileges. The FAA intends for these expansions to increase
safety by encouraging manufacturers to design and construct, and
prospective aircraft owners to choose, aircraft higher on the safety
continuum and, therefore, meet higher aircraft certification
requirements.
    The FAA used the safety continuum to analyze other aircraft as
well; in addition to modifying the requirements for light-sport
category aircraft and experimental light-sport category kit-built
aircraft, this rule would also address the operation of other aircraft
that hold special airworthiness certificates. Specifically, the FAA
proposes to codify additional special purpose operations for restricted
category aircraft that the FAA has previously approved under the
discretion provided in part 21. In addition, this rule would amend the
duration, eligible purposes, and operating limitations for special
airworthiness certificates issued for experimental purposes, including
an administrative change to add a new experimental purpose for former
military aircraft, and codifying a statutory provision for space
support vehicle flights. The FAA has referred to this combined set of
proposals as the Modernization of Special Airworthiness Certification
(MOSAIC) since these proposals primarily concern the regulation of
aircraft that operate under special airworthiness certificates.
3. Expanding Light-Sport Category Aircraft and Related Provisions for
Airman, Maintenance, and Operations
a. Eliminating the Definition of Light-Sport Aircraft
    Currently, light-sport aircraft is defined in Sec.  1.1, General
definitions. Uniquely, the definition affects the scope of
certification for light-sport category aircraft, sport pilots, and
repairman (light-sport aircraft). Section 21.190 applies this
definition to limit the scope of aircraft that may be issued a special
airworthiness certificate for light-sport category aircraft. Part 61
uses this definition to specify which aircraft a sport pilot may
operate. The FAA notes that, per part 61, a sport pilot may operate any
aircraft that meets the definition of light-sport aircraft, including
certain normal category, primary category, light-sport category, and
experimental aircraft. This proposal would eliminate this definition of
light-sport aircraft in Sec.  1.1 and would instead specify separate
requirements for aircraft, pilot, and repairman certification in 14 CFR
part 21, 61, or 65, respectively. Although the FAA considered retaining
and expanding this definition, deleting the definition and establishing
separate certification requirements in part 21, 61, or 65 would better
align with the location of such requirements for other categories of
aircraft and for other airmen.
b. Changes to Aircraft Certification Requirements for Light-Sport
Category Aircraft
    The FAA has granted eleven exemptions to enable airworthiness
certification of light-sport category aircraft with weights that exceed
those in the definition of light-sport aircraft. These grants of
exemption were based on FAA findings that relieving weight limits would
enable significant safety enhancements not contemplated in the original
regulations, reduce the likelihood of fatal accidents, and foster
innovation in light-sport category aircraft. Consistent with the FAA's
analysis of the safe operations accomplished under those exemptions,
this proposal would eliminate the weight limits for light-sport
category aircraft. As discussed in section IV.C.2, eliminating weight
limits for light-sport category aircraft would provide manufacturers
opportunities to:
     Incorporate additional safety-enhancing designs and
equipment,
     Design airframes that are more rugged for the flight-
training environment,
     Increase fuel load and aircraft range,
     Allow for greater cabin size to enable greater occupant
heights and weights,
     Improve aircraft handling in gusts, turbulence, and
crosswinds, and
     Increase the suitability of light-sport category aircraft
for other intended operating purposes, including recreation, personal
travel, and certain aerial work.\2\
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    \2\ The FAA does not explicitly define aerial work; however, the
FAA broadly interprets the term to mean work done from the air for
compensation that does not involve the carriage of persons or
property.
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    This proposal would apply new design and manufacturing requirements
for light-sport category aircraft so that light-sport category aircraft
are able to fly safely with increased capacity and ability. The FAA is
further proposing to increase airplane stalling speed to enable
increased aircraft weights to enable more robust airframes,
installation of safety enhancing equipage, higher fuel capacity, and
more seating capacity. The FAA proposes to eliminate limitations on
classes of eligible aircraft, propellers, and landing gear; allow
airplanes with up to 4 seats for increased utility and improved flight
training opportunities; and increase the maximum airspeed for more
practical personal travel. This proposal would require training for
manufacturer employees who are responsible for safety findings and for
signing a statement of compliance. This NPRM does not propose to amend
requirements that limit manufacture of kits for light-sport category
aircraft for make and model aircraft that were previously certificated
as light-sport category aircraft. Accordingly, most of the proposals
for expanding the eligibility for certification of light-sport category
aircraft would carry over to light-sport category kit-built aircraft.
This proposal would remove the requirement to display the mark ``Light-
Sport'' on light-sport category aircraft. These proposed changes are
discussed in greater detail in section IV.D.20.
c. Changes to the Aircraft That Sport Pilots May Operate
    This proposal would also expand what aircraft sport pilots can
operate. Under this proposal, sport pilots could operate heavier
aircraft than currently allowed under the Sec.  1.1 definition and
airplanes with up to four seats, even though they would remain limited
to carrying only one passenger. This one passenger limitation would
also apply to a flight instructor with a sport pilot rating conducting
flight training in a four-seat airplane. Additionally, this proposal
includes expansions to certain

proposed sport pilot privileges through training and endorsements for
airplanes that hat have a controllable pitch propeller, for aircraft
with a retractable landing gear, and to conduct night operations. This
proposal would also make corresponding changes to regulations affecting
the privileges and limitations of a flight instructor certificate with
a sport pilot rating. These proposed changes are discussed in greater
detail in section IV.E.
d. Changes to Requirements for Repairman (Light-Sport) Certificates
    This proposal would revise the name of the ``repairman certificate
(light-sport aircraft)'' to ``repairman certificate (light-sport)'' and
would allow for issuance of a repairman certificate (light-sport) for
the new, proposed classes of aircraft that could be certificated in the
light-sport category (i.e., helicopter and powered-lift). Additionally,
the proposal would remove the hours-based training requirements for a
light-sport repairman maintenance rating and instead require that
applicants complete a training course, accepted by the FAA, that aligns
with the Aviation Mechanic General, Airframe, and Powerplant Airman
Certification Standards (Mechanic ACS). The training course would be
required to include only those subject areas and knowledge, risk
management, and skill elements of the Mechanic ACS that are appropriate
to the category of aircraft the training course covers. The proposal
would also codify existing policy for repairman certificate (light-
sport) training course providers to administer an examination, provide
students with a certificate of completion, and require facilities,
equipment, materials, and instructors that are appropriate to the
training course content being taught. These proposed changes are
discussed in greater detail in section IV.F.
e. Changes to Requirements for Maintenance of Light-Sport Category
Aircraft
    This proposal would require all repairs performed on light-sport
category aircraft to meet applicable consensus standards, allow minor
alterations to be accepted under the provisions of 14 CFR part 43, and
remove the restriction that the Administrator approve aircraft-towing
devices installed on these aircraft. These proposed changes are
discussed in greater detail in section IV.G.
f. Changes to Requirements for Operating Light-Sport Category Aircraft
    In addition to expanding eligibilities for issuance of special
airworthiness certificates for light-sport category aircraft and
experimental light-sport aircraft and aircraft that sport pilots may
operate, the FAA proposes to expand the kinds of operations that can be
performed by light-sport category aircraft. Specifically, this proposal
would permit light-sport category aircraft to be used in certain aerial
work operations for aircraft that meet the applicable FAA-accepted
consensus standard for that operation. This proposal would also remove
the requirement for owners/operators of light-sport category aircraft
to comply with safety directives issued by the aircraft manufacturer;
mandatory compliance with FAA Airworthiness Directives would remain
unchanged. These proposed changes are discussed in greater detail in
section IV.H.1.
4. Changes to Certain Experimental Certificates
a. Duration
    This proposal would increase the duration of certain experimental
certificates from one to three years. These proposed changes are
discussed in greater detail in section IV.I.1.
b. Changes for Former Military Aircraft
    This proposal would add operating former-military aircraft as an
additional purpose for which experimental certificates may be issued.
Operations of former-military aircraft are currently authorized under
other experimental certificates. These proposed changes are discussed
in greater detail in section IV.I.5.
c. Codifying the Authorization for Space Support Vehicles
    This proposal would codify the statutory language in 49 U.S.C.
44740 permitting the operator of an aircraft with a special
airworthiness certification in the experimental category to operate the
aircraft for the purpose of conducting a space support vehicle flight
while carrying persons or property for compensation or hire. These
proposed changes are discussed in greater detail in section IV.H.3.
Such operations would be limited to aircraft that takeoff and land at a
single launch or reentry site that is operated by an entity licensed to
operate the launch or reentry site under 51 U.S.C. chapter 509; are
owned or operated by or on behalf of a launch or reentry vehicle
operator licensed under 51 U.S.C. chapter 509; and is either a launch
vehicle, reentry vehicle, or a component thereof. These operations
would only be allowed to simulate space flight conditions in support of
training for potential space flight participants, government
astronauts, or crew; testing hardware to be used in space flight; or
conducting research and development tasks, which require the unique
capabilities of the aircraft conducting the flight.
5. Changes for Restricted Category Aircraft
    This proposal would enhance the requirements for the certification
of former-military aircraft in the restricted category by requiring the
aircraft to have a service history with the U.S. Armed Forces. Under
the provision in Sec.  21.25(b)(7), the FAA has approved additional
special purpose operations for which restricted category aircraft may
be certificated. Currently, those additional purposes are only listed
in FAA policy documents for type and airworthiness certification of
these aircraft. This proposal would amend Sec.  21.25 to expand the
list of special purpose operations for which restricted category
aircraft may be certificated to include these additional purposes.
6. Changes for Noise
    This proposal would apply 14 CFR part 36 noise standards to light-
sport category aircraft and experimental light-sport category aircraft
certificated after the effective date of the rule, or that are altered
in a manner that changes the noise profile of light-sport category
aircraft and certain experimental light-sport category aircraft. This
proposal would require light-sport category aircraft and certain
experimental light-sport category aircraft to demonstrate compliance to
the part 36 noise limits using an FAA-approved consensus standard or a
combination of current part 36 procedures that are appropriate for the
aircraft seeking an airworthiness certificate for a light-sport
category aircraft or an experimental light-sport category aircraft. The
FAA anticipates the industry developing acceptable and appropriate
consensus standards for noise that would provide simple, low-cost
methods of compliance with part 36. For example, a modeling-based
consensus standard would be expected to significantly reduce the cost
of noise compliance. Not only would there not be a need to physically
test every model (or aircraft) but the proposal would also allow
manufacturers to use predictive analysis to guide and support aircraft
design decisions in earlier phases, avoiding costly future redesign or
modifications. The proposed noise requirements are discussed in greater
detail in section V.K.

B. Revision of Definitions Applicable to the Certification and
Operation of Light-Sport Category Aircraft

1. Revision of the Definition of Consensus Standard
    OMB Circular A-119 establishes policy for the Federal use and
development of voluntary consensus standards and conformity assessment
activities. Federal goals for using consensus standards include
providing incentives and opportunities to establish standards that
serve national needs, encouraging long-term growth for U.S.
enterprises, and promoting efficiency and economic competition through
harmonization of standards. Voluntary consensus standards are developed
or adopted by consensus standards bodies with broad participation of
interested stakeholders, including manufacturers and the FAA.
    Because of the general acceptance and use of consensus standards
throughout the aviation community, this rule proposes a broader
definition for consensus standards than that currently found in Sec.
1.1. The current definition was adopted as part of the 2004 final rule.
As such, the definition for consensus standards currently is only
applicable for certificating light-sport aircraft. The proposed
definition would apply to a wider variety of certification functions
applicable under 14 CFR.
    The proposed definition would adopt a description of a consensus
standard that better aligns with the provisions of OMB Circular A-119.
The proposed rule would establish the characteristics that a consensus
standard must have to meet the definition of a consensus standard.
Accordingly, to be considered a consensus standard under this proposed
rule, a consensus standard would need to have been adopted under
procedures which provide an opportunity for input by persons interested
and affected by the scope or provisions of the standard. These persons
would also have had to reach substantial agreement on its adoption.
Additionally, to be used as a means of compliance for aircraft design,
operation, production, maintenance, or airworthiness, a consensus
standard would have to be accepted by the FAA. For the purposes of this
proposed definition, the FAA considers ``airworthiness'' to include
noise and continued operational safety requirements.
    After a consensus standard has been adopted by a consensus
standards body, the FAA would review the standard for acceptance. The
FAA typically advises the public of the agency's acceptance of these
consensus standards through a notice of acceptance which is published
in the Federal Register. This review and acceptance process is not
intended to restrict industry's ability to develop consensus standards,
but rather to enable the FAA to advise the public when an industry-
developed consensus standard for aircraft design, operation,
production, maintenance, or airworthiness complies with the proposed
performance-based regulatory requirements.
    Currently, consensus standards for the airworthiness certification
of light-sport category aircraft that have been developed by ASTM
International (ASTM) and accepted for use by the FAA would meet the
proposed definition.\3\ The current process for developing consensus
standards by ASTM for the certification of light-sport category
aircraft would be consistent with the provisions of the proposed
definition.
---------------------------------------------------------------------------

    \3\ For example, the FAA published a notice titled ``Consensus
Standards, Light-Sport Aircraft, Notice No. NOA-21-01'' (87 FR
10275; February 23, 2022) in which the FAA designated ASTM
Designation F2245-20, ``Standard Specification for Design and
Performance of a Light Sport Airplane'' (F2245-20) as a consensus
standard that is available and acceptable for use. F2245-20 applies
to aircraft design and, as described in ASTM's ``The Handbook for
Standardization,'' has been developed with input by a broad array of
interested stakeholders.
---------------------------------------------------------------------------

    The FAA notes that consensus standards have also been developed to
comply with the performance-based airworthiness standards for the
certification of airplanes found in amendment 64 of 14 CFR part 23.
They serve as a means of compliance to the regulatory requirements
contained in part 23 and have been accepted by the FAA.\4\ Consensus
standards have also been used as a means of compliance for operation of
small unmanned aircraft systems (small UAS) over people under part 107
and remote identification of unmanned aircraft under part 89.
---------------------------------------------------------------------------

    \4\ See 71 FR 12771, 75 FR 58016, 79 FR 78553 concerning
electric wiring systems before part 23, amendment 61. For part 23,
amendment 64, see 87 FR 13911.
---------------------------------------------------------------------------

    The FAA anticipates an increased use of consensus standards to
comply with new performance-based regulations and has also proposed
their use as part of the special airworthiness certification process to
comply with the noise requirements in part 36. Accordingly, the agency
determined that it would be appropriate to broaden the current
applicability of this definition to a potentially wider range of
aircraft certification activities than light-sport category aircraft
only.
    The revised definition would require that the consensus standards
process include participants that are impacted by the consensus
standards. For the development of these consensus standards,
organizations and participants in the consensus standards development
process could consist of, but not be limited to, aircraft
manufacturers, pilots, maintainers, aviation associations, and
government regulators. The FAA contends that the use of a consensus
standards process to develop means of compliance to performance-based
regulations should provide both the FAA and industry with a means to
rapidly adapt to changing technology and better respond to market
conditions while continuing to enable safe operations within the
national airspace system.
    Alternatively, the FAA is considering removing the definition of
consensus standard from Sec.  1.1. Consensus standard is a commonly
accepted term used by industry and across \5\ the Federal Government
and may not require a definition in Sec.  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 Sec.  1.1
altogether or revise the definition as proposed.
---------------------------------------------------------------------------

    \5\ Such as pursuant to the National Technology Transfer and
Advancement Act (NTTAA) of 1995, and OMB Circular A-119, Federal
Participation in the Development and Use of Voluntary Consensus
Standards and in Conformity Assessment Activities.
---------------------------------------------------------------------------

2. Removal of Definition of Light-Sport Aircraft From 14 CFR 1.1
    Section 1.1 currently defines ``light-sport aircraft'' as an
aircraft other than a helicopter or powered-lift that, since its
original certification, has continued to meet several designated
parameters (for example, aircraft weight, seating, stalling speed,
maximum speed, engine type, propeller type, etc.). Uniquely, the
definition affects the scope of certification for light-sport category
aircraft, sport pilots, and repairman (light-sport aircraft). Section
21.190 applies this definition to limit the scope of aircraft that may
be issued a special airworthiness certificate in the light-sport
category. Part 61 uses this definition to specify which aircraft a
sport pilot may operate. Because of the common definition, all aircraft
certificated under Sec.  21.190 are light-sport aircraft and thus can
be flown by sport pilots. However, a sport pilot is not limited to only
Sec.  21.190 aircraft and may operate any aircraft that meets the
definition of light-sport aircraft, including certain normal category,

primary category, light-sport category, and experimental aircraft.
    The FAA is proposing to remove the definition of light-sport
aircraft from Sec.  1.1 because the regulatory definition contains
substantive requirements. A regulatory definition should define a term
used in a particular title, chapter, or part of the CFR. Accordingly,
the substantive aircraft certification requirements for light-sport
category aircraft would be relocated with modifications into proposed
Sec.  21.190 and part 22, while requirements establishing the
parameters for the aircraft in which a sport pilot may act as pilot in
command (PIC) would be incorporated into part 61.
    The current Sec.  1.1 definition of light-sport aircraft was
created to establish parameters for the airworthiness certification of
light-sport category aircraft using consensus standards, as well as to
identify aircraft that can be safely operated by pilots exercising the
privileges of a sport pilot certificate. Currently, under Sec.  61.315,
sport pilots are only permitted to operate aircraft that meet the
definition of a light-sport aircraft as defined in Sec.  1.1. Replacing
the Sec.  1.1 definition with separate certification requirements for
aircraft, pilots, and repairman would allow more flexibility using the
proposed certification procedures in Sec.  21.190 and intended
operations. In other words, this proposed rule would decouple
certification requirements for light-sport category aircraft
certification and sport pilot certification. One effect of placing the
proposed requirements in separate parts and the expansion of light-
sport category aircraft certification requirements is that an aircraft
certificated in the light-sport category under Sec.  21.190 may exceed
the parameters of an aircraft that a sport pilot may act as PIC of
under the separate requirements in part 61.
    Persons exercising the privileges of a sport pilot certificate or a
flight instructor certificate with a sport pilot rating would no longer
be restricted to operating light-sport aircraft as defined in Sec.
1.1. In this proposed rule, these airmen would be able to exercise the
privileges of their certificate in any aircraft that does not exceed
the aircraft performance limitations derived from the current Sec.  1.1
definition and set forth in the proposed new Sec.  61.316. The FAA's
proposal concerning airmen certification is discussed in section IV.E.

C. Expansion of Eligibility for Light-Sport Category Aircraft and Sport
Pilots

1. Certification of Additional Aircraft Classes
    The current Sec.  1.1 definition of light-sport aircraft excludes
helicopters and powered-lift from being considered as light-sport
aircraft. The FAA proposes to allow the airworthiness certification of
rotorcraft and powered-lift as light-sport category aircraft under
Sec.  21.190, provided these aircraft are certificated in accordance
with the proposed performance-based requirements in part 22 using an
FAA-accepted consensus standard as a means of compliance. This proposed
rule would allow any class of aircraft \6\ to be eligible for
certification in the light-sport category, so long as the aircraft
meets the proposed performance-based requirements of part 22 and the
eligibility criteria in proposed Sec. Sec.  21.190 and 22.100. The FAA
anticipates that industry would develop acceptable and appropriate
consensus standards to comply with the performance-based requirements
in part 22. The FAA contends that such action would maintain a level of
safety appropriate to the certification of these aircraft while
fostering innovation.
---------------------------------------------------------------------------

    \6\ See 14 CFR 1.1, which defines class, for purposes of the
certification of aircraft, as a broad grouping of aircraft having
similar characteristic of propulsion, flight, or landing.
---------------------------------------------------------------------------

    Unmanned aircraft are precluded from certification as light-sport
category aircraft. The FAA considered expanding the scope of the
proposed eligibility requirements to evaluate the potential
certification of unmanned aircraft; however, due to the novelty,
technical complexity, and significant operational differences between
unmanned and manned aircraft, the FAA chose not to address unmanned
aircraft certification as a part of this rulemaking. Accordingly, as
proposed in Sec.  21.190(a), this proposal does not apply to the
certification of unmanned aircraft in the light-sport category.
    The FAA also chose not to consider powered lift privileges for
sport pilots, given the complexity and ongoing development of those
aircraft designs and associated pilot certification and operational
rules that the FAA is considering. However, the FAA expects that future
rulemaking may consider these aircraft and associated operations if
they can fit within the constraints of sport pilot operations and
aircraft certification requirements.
    As discussed later in the preamble, the FAA is also proposing to
expand sport pilot privileges to include helicopter privileges.
2. Maximum Takeoff Weight
    Section 1.1 currently limits the maximum takeoff weight for light-
sport category aircraft to 1,320 lbs., or 1,430 lbs. for aircraft
intended for operation on water. This proposal would eliminate the
maximum takeoff weight limitations for light-sport category aircraft.
Although this proposal removes the specific weight limits for light-
sport category aircraft, this proposed rule would indirectly limit
aircraft weight via stalling speed limitations, as discussed in
sections IV.C.2 and IV.C.4. As noted in those sections, the stalling
speed limit would indirectly limit the weight at around 3,000 pounds.
Although still limiting aircraft weight, the proposed VS1
stalling speed would enable aircraft with heavier weights than the
definition permits for light-sport aircraft. Enabling heavier weights
would enable manufacturers to include safety-enhancing designs and
equipment such as advanced stall resistant airframes, increased load
factor resilience, improved passenger cabin crash safety mechanisms,
ballistic safety parachutes, passenger airbags, stronger and more
durable landing gear, and greater fuel capacity.
    From its work with manufacturers, flight schools, and individual
aircraft owners since the 2004 final rule took effect, the FAA
anticipates that allowing heavier aircraft would result in more robust
airframe designs to meet the needs of aircraft owners. A ``robust
airframe design'' is more reliable, resilient, and does not fail as
easily under a given load as a less robust airframe would. In addition,
an aircraft in motion with more mass requires more force to disrupt its
current flight path. Accordingly, heavier aircraft tend to be more
stable during turbulent or windy conditions and, in turn, reduce the
workload on the pilot attempting to maintain control and a desired
course. Specifically, lighter aircraft get jostled around more in
turbulence, which causes the pilot to work harder to maintain aircraft
control.
    The weight limitations in the definition of light-sport aircraft
preclude many of these design and safety features and is representative
of why the FAA has granted 11 exemptions to the weight limit for
certain light-sport category aircraft with safety features installed.
These exemptions allowed airworthiness certification of certain,
heavier light-sport category aircraft to enable improved airframe
designs and the installation of various safety enhancing devices.
    In summary, the current weight limitation precludes the design and

installation of many safety enhancements. Therefore, this NPRM proposes
to remove weight as an eligibility requirement for certification of
light-sport category aircraft and as a limitation on what aircraft
sport pilots may fly. Sport pilots would be permitted to operate these
heavier aircraft if the aircraft satisfy the performance limitations in
the proposed Sec.  61.316 including the Vs1 limitation that
will indirectly limit the weight to around 3,000 pounds. The FAA does
not find that this increased weight would appreciably alter a sport
pilot's ability to fly the aircraft, provided the aircraft satisfies
the design and performance limitations proposed in Sec.  61.316.\7\
---------------------------------------------------------------------------

    \7\ See section IV.E of this preamble for a discussion of the
design and performance limitations proposed in Sec.  61.316, which
would limit the aircraft that a sport pilot could fly to an aircraft
that requires skill comparable to the skill required to fly an LSA
today.
---------------------------------------------------------------------------

3. Maximum VH Airspeed in Level Flight
    The Sec.  1.1 definition of light-sport aircraft limits light-sport
aircraft to a VH of not more than 120 knots CAS under
standard atmospheric conditions at sea level. A VH speed
limit would not be retained for the airplanes or gliders in the
proposed Sec.  61.316 performance and design limitations for aircraft
that a sport pilot could operate. Although an airplane or glider's
maximum airspeed is typically limited to approximately three to four
times the aircraft's VS1 under ideal conditions, proposed
Sec.  22.100(a)(4) would include a VH limit of 250 knots CAS
for light-sport category aircraft to account for potential advances in
technology and manufacturing practices that could enable higher speeds.
Furthermore, after approximately 20 years of experience with the
operation of light-sport category aircraft, the FAA has not noted any
definitive data that links cruise speed as a contributing factor in
accidents involving light-sport category aircraft. This experience
informs the FAA's current rulemaking proposal, including its proposal
to increase the airspeed limitation.
    Analysis of performance data for 117 type-certificated, light-sport
category, and amateur-built airplanes with stalling speeds less than or
equal to the proposed 54 knots CAS stalling speed limit shows a maximum
speed of 220 knots CAS, with the majority below 190 knots CAS. Allowing
a maximum speed of 250 knots CAS is intended to provide an upper limit
appropriate for a category of aircraft intended for recreation, flight
training, and limited aerial work while providing sufficient margin to
avoid practical constraints of new airplane designs by this limit.\8\
---------------------------------------------------------------------------

    \8\ Given that the vast majority of light-sport category
aircraft operations would occur below 10,000 feet mean sea level
(MSL), where part 91 limits airspeed below 250 knots indicated
airspeed, the maximum 250 knot CAS limitation is appropriate for the
light-sport category.
---------------------------------------------------------------------------

    For pilot certification purposes, the FAA does not propose to
retain or include a VH airspeed limitation in the proposed
Sec.  61.316 aircraft performance limitations because the FAA
determined that, the proposed maximum stalling speed VS1 of
54 knots (as explained in section IV.C.4) for airplanes and the
existing maximum stalling speed VS1 of 45 knots for gliders,
will indirectly limit the cruise airspeeds \9\ for the aircraft that
sport pilots may fly under the proposed performance limitations in part
61. The FAA recognizes helicopter design and aerodynamic flight
limitations inherently limit the VH speed. The existing
fleet of two seat helicopters do not exceed 150 knots in cruise flight.
Therefore, the FAA does not propose or need a prescriptive speed limit
for two seat helicopters that a sport pilot can operate.
---------------------------------------------------------------------------

    \9\ As previously stated, an airplane's maximum airspeed is
generally limited to three to four times the aircrafts
Vs1 under ideal conditions. If the maximum stalling speed
is 54 knots, then the airplane's maximum airspeed would be limited
to a maximum airspeed of 216 knots (54 multiplied by 4).
---------------------------------------------------------------------------

    In 2018, the FAA codified additional training and endorsement
privileges for flight instructors with a sport pilot rating.\10\ This
provision authorized these flight instructors to provide additional
training and endorsements for sport pilot applicants who wish to
conduct cross-country flights in light-sport airplanes with a
VH greater than 87 knots CAS.\11\ These amendments reinforce
that additional training and a subsequent flight instructor endorsement
can properly qualify sport pilots to operate various aircraft safely in
the national airspace system.
---------------------------------------------------------------------------

    \10\ Regulatory Relief: Aviation Training Devices; Pilot
Certification, Training, and Pilot Schools; and Other Provisions, 83
FR 30232 (June 27, 2018).
    \11\ 83 FR 30254-57.
---------------------------------------------------------------------------

    Additionally, the FAA notes that student pilots, who receive
training and a validating flight instructor endorsement, can operate
aircraft at speeds greater than 120 knots as pilot-in-command. The FAA
contends that, since the implementation of the training and instructor
endorsement requirements permitting sport pilots to operate airplanes
up to the current VH speed limitation of 120 knots,
instructor training and endorsements have been demonstrated to be a
proven, effective method for validating that sport pilots can safely
operate faster aircraft in the national airspace system, just as is
allowed for student pilots with a lower grade of pilot certificate.
This reflects the incongruities between the allowed operations for
student pilots and sport pilots. For example, student pilots can
operate aircraft at faster speeds than individuals that hold a sport
pilot certificate, even though a sport pilot certificate is a higher
grade of pilot certificate than a student pilot certificate. Thus, the
FAA reasons that sport pilots can be permitted to operate faster
aircraft safely in the national airspace system using instructor
training and endorsements for validating pilot proficiency.
4. Maximum Stalling Speed (VS1)
    The light-sport aircraft definition in Sec.  1.1 limits the maximum
VS1 for light-sport aircraft to 45 knots CAS at the
aircraft's maximum certificated takeoff weight and most critical center
of gravity. The proposal would retain the 45 knots CAS maximum
VS1 for gliders and weight-shift-control aircraft. The FAA
is proposing to increase the maximum VS1 to 54 knots CAS for
airplanes. Regulatory provisions addressing VS1 would remain
inapplicable to rotorcraft and lighter-than-air aircraft (e.g.,
balloons and airships), and would be removed for powered parachutes.
    The 45-knot limitation indirectly prohibits the use of heavier
airplanes due to the correlation between stalling speed and aircraft
weight. Because the FAA is seeking to accommodate greater airplane
weights to enable more robust airframe designs and availability of
safety enhancements, the FAA selected this proposed VS1
speed limit at nine knots above the current limitation for light-sport
aircraft. The FAA determined that an airplane with a maximum
VS1 limitation of 54 knots would permit airplane designs up
to approximately 3,000 pounds. As proposed in Sec. Sec.  22.100(a)(3)
and 61.316(a), the new stalling speed limitation would apply to
airplanes at the maximum certificated takeoff weight.
    In the absence of a specific weight limitation in the proposed
rule, the new VS1 limit would provide flexibility for
aircraft manufacturers to build more robust airframes and include
desirable safety enhancements. This proposed change would expand
aircraft that sport pilots may operate to include any existing aircraft
that meets the sport pilot performance limitations as specified in
proposed Sec.  61.316. For airplanes, the proposed VS1 limit
is not more than 54 knots CAS for sport pilots.

    The FAA has monitored the accident history of light-sport category
aircraft since 2004. As of 2021, there have been 984 accidents or
incidents involving light-sport category aircraft, with approximately
half of those accidents or incidents occurring during the landing
phase. Of the 501 landing accidents, seven resulted in a fatality. The
second highest number of accidents or incidents, 164, occurred during
an emergency descent. The FAA chose a VS1 of 54 knots CAS to
strike a balance between allowing heavier aircraft to accommodate
increased safety features, while increasing the stalling speed no more
than necessary to retain low speeds during approach and landing. While
the FAA recognizes that low stalling speeds will reduce kinetic energy
levels and serve to improve occupant survivability in the event of an
aircraft accident, enabling the addition of safety enhancing designs
commensurate with increased weight could also improve occupant
survivability.
    The FAA has determined that retaining the current VS1
restriction of 45 knots CAS for light-sport category airplanes would
overly restrict the ability of aircraft manufacturers to produce
heavier airplanes with additional safety features that this rule is
intending to enable. A maximum VS1 of 54 knots CAS for
airplanes would facilitate the production of heavier, more robust
airplanes without unduly compromising the ability of these airplanes to
be safely operated. Although the FAA considered increasing the proposed
maximum stalling speed of airplanes above 54 knots CAS, the agency's
review of current aircraft performance data showed that this proposal
would be sufficient to produce four-seat airplanes.
    Although the FAA proposes to permit the certification of rotorcraft
under the proposal, stall speed restrictions, such as a maximum
VS1, are inapplicable for aircraft that depend principally
for their support in flight by the lift generated by one or more
rotors. Rotorcraft have the ability to hover or remain in place in the
air with no horizontal movement. In the event of engine failure, they
can autorotate in a controlled descent to the ground. Accordingly,
rotorcraft are not subject to a maximum stall speed in this proposed
rule.
    Stalling speed restrictions are also not being proposed for
powered-lift due to their ability to operate in various flight mode
configurations, including thrust-borne or hover, similar to a
rotorcraft. The designs of lighter powered-lift typically do not have
large wing surface areas and therefore have higher stalling speeds
during wing-borne (airplane) flight mode. However, these aircraft also
can transition to semi-thrust borne mode where the powerplant shares
the responsibility of producing lift as airspeed transitions between
enroute airspeeds and hover. Therefore, as discussed under proposed
Sec.  22.115 and consistent with the airworthiness criteria from
Federal Register notifications for the Joby Aero Inc., Model JAS4-1 and
Archer Aviation Inc., Model M001 powered-lift, this NPRM proposes to
require the determination of minimum safe speeds for various flight
configurations for powered-lift rather than a maximum stalling
speed.\12\
---------------------------------------------------------------------------

    \12\ Airworthiness Criteria: Special Class Airworthiness
Criteria for the Joby Aero, Inc. Model JAS4-1 Powered-Lift (87 FR
67399; November 8, 2022), and Airworthiness Criteria: Special Class
Airworthiness Criteria for the Archer Aviation Inc. Model M001
Powered-Lift (87 FR 77749; December 20, 2022).
---------------------------------------------------------------------------

    As discussed, the proposed stalling speed would generally limit the
weight of airplanes. However, similar proposed limits would not have
the same effect for other classes of aircraft. The FAA recognizes that
while restrictions on maximum seating capacity and limitations on
aerial work may effectively limit a manufacturer's interest in building
larger aircraft, the absence of any aerodynamic or other prescriptive
design restriction would not otherwise limit the potential weight of
these aircraft. The FAA specifically requests comments on appropriate
parameters to limit the weight of light-sport category rotorcraft and
powered-lift.
5. Maximum Seating Capacity
    The current Sec.  1.1 light-sport aircraft definition limits light-
sport aircraft to a maximum seating capacity of no more than two
persons, including the pilot. This requirement from the 2004 rule
provided for a low-risk design that would be appropriate for operation
by a sport pilot. With the performance expansions proposed in this rule
for the design of light-sport category aircraft and the intention to
decouple these aircraft from sport pilot restrictions, there is no
longer a need to restrict all light-sport category aircraft to two
seats. This proposed rule, in Sec.  22.100, would keep the maximum
seating capacity of not more than two persons, including the pilot, for
all classes of light-sport aircraft except airplanes. This proposal
would allow airplanes to have a maximum seating capacity of not more
than four persons, including the pilot.
    When the 2004 final rule published, the FAA was focused on allowing
a flight instructor in the aircraft to provide flight instruction and,
eventually, allowing sport pilots to carry a single passenger.\13\ At
that time, the FAA did not foresee an expanded market for light-sport
category aircraft that could be operated by pilots with a higher grade
of certificate who can exercise the privilege of carrying more
passengers. For example, an individual with a private pilot certificate
may operate an aircraft that has more than two seats and can carry more
than one passenger. In this proposed rule, the performance limits of
Sec.  61.316 would allow four-seat airplanes but maintain the
restriction for sport pilots to carry one passenger, keeping the intent
of the 2004 final rule restriction for sport pilots. For this proposal,
the holder of a higher grade of pilot certificate at the private pilot
level or above could operate a four-seat light-sport category airplane
and carry up to three passengers.
---------------------------------------------------------------------------

    \13\ See 69 FR 44820.
---------------------------------------------------------------------------

    Allowing four seats for light-sport category airplanes would
increase the utility of these aircraft for recreational and personal
use. With the increased utility because of four-seat designs, light-
sport category airplane operations by pilots holding higher levels of
certification would likely increase. The FAA anticipates an increase to
the overall experience level of pilots that operate light-sport
category airplanes, and this generally would have a positive safety
benefit.
    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. In this proposed
rule, all light-sport category aircraft would be built to FAA-accepted
consensus standards that meet performance-based requirements in part 22
for design, production, and airworthiness, unlike amateur-built
aircraft, which do not have any similar regulatory requirements. As
previously discussed, amateur-built aircraft are lower on the FAA's
safety continuum than light-sport category aircraft.
    The four-seat design for light-sport category airplanes in this
proposal would match the seating limit of primary category airplanes
certificated under Sec.  21.24. Primary category rules and the
proposals for light-sport category airplanes would result in these
categories sharing similar weight and seating limitations for aircraft
built for the purpose of personal use.
    Although 14 CFR does not impose a seating limitation on amateur-
built aircraft, nearly all such aircraft have four or fewer seats. Of
the 27,486

amateur-built aircraft in the FAA Registry, only 131 have more than
four seats.\14\ Accordingly, the light aircraft community has shown
overwhelming support for recreational and personal use aircraft being
designed with four or fewer seats.
---------------------------------------------------------------------------

    \14\ Data from FAA Registry dated December 1, 2022.
---------------------------------------------------------------------------

    Increasing the allowed number of seats above four for light-sport
category aircraft would require a significantly heavier aircraft,
challenging aircraft designers to comply with the proposed stalling
speed limit and adding increased complexity to the aircraft and
powerplant. In establishing a prescriptive limit for the number of
seats, four seats strikes a balance between risk and utility that is
appropriate for a category of aircraft intended for recreation and
personal use.
    Additionally, proposed Sec.  91.327(f) would limit the number of
occupants in light-sport category aircraft to not exceed the aircraft's
seating capacity.
    The proposed rule would retain the current maximum seating capacity
of not more than two persons for other classes of light-sport aircraft,
including, gyroplanes, gliders, weight-shift control aircraft, powered
parachutes, balloons, and airships. These classes of light-sport
category aircraft are operated strictly for recreation. With weight and
balance challenges due to unusual seating configurations, additional
passengers on these classes of aircraft would increase risk and not be
appropriate for certification as light-sport category aircraft.
    Although this proposal would enable certification of new types of
light-sport category aircraft such as rotorcraft and powered lift, this
proposal would limit these aircraft to two seats. The FAA has little
experience on the safety metrics associated with these classes of
light-sport category aircraft, as such, the FAA finds that the maximum
seating capacity of two is appropriate. The FAA may consider future
rulemaking to increase the proposed two seat limitation for these
classes of aircraft as experience increases and consensus standards are
developed.
    Regarding pilot certification, the FAA is proposing to allow sport
pilots to operate airplanes that have a maximum seating capacity of
four persons under Sec.  61.316(c). However, sport pilots will continue
to be limited to carrying only one passenger under Sec.
61.315(c)(4).\15\ The FAA contends that the piloting skills necessary
to operate a four-seat airplane do not differ from those skills
required to operate a two-seat airplane if the airplane satisfies the
sport pilot design and performance limitations listed in proposed Sec.
61.316. The number of seats (two versus four) does not affect the skill
necessary to control an airplane. The FAA proposes to increase the
seating capacity for airplanes that sport pilots may operate because
the revised maximum stalling speed, as previously described, would
permit sport pilots to operate additional existing and future
certificated single-engine production airplanes with four seats.\16\
Per the safety continuum concept, increasing the number of persons
aboard should require an increased rigor of certification including a
higher grade of pilot certificate. Allowing sport pilots to operate
four-seat airplanes (even with only two persons aboard) would ease
barriers in flight training for sport pilots given the availability of
legacy, four-seat airplanes in flight schools. This proposed amendment
is like that imposed on recreational pilots that can operate four-seat
airplanes but can only carry one passenger,\17\ equating the risk
associated with these operations to the appropriate level of pilot
privileges, consistent with the FAA's safety continuum.
---------------------------------------------------------------------------

    \15\ ``You may not act as pilot in command of a light-sport
aircraft . . . [w]hile carrying more than one passenger.'' See: 14
CFR 61.315(c)(4).
    \16\ For example, this proposed amendment would permit sport
pilots to operate existing certificated single-engine production
aircraft.
    \17\ See 14 CFR 61.101(a)(1) and (e)(1)(i).
---------------------------------------------------------------------------

    The FAA contends that the proposed maximum seating capacity
requirements would provide appropriate utility for recreation,
training, personal travel, and certain aerial work while maintaining an
appropriate level of safety.
6. Engine and Motors (If Powered)
    The current Sec.  1.1 light-sport aircraft definition limits light-
sport aircraft to those with a single reciprocating engine if the
aircraft is powered. This requirement from the 2004 rule provided for a
simple engine design that would be appropriate for operation by a sport
pilot. With the performance expansions proposed in this rule for the
design of light-sport category aircraft and the intention to decouple
from sport pilot limitations, there is no longer a need to restrict
light-sport category aircraft to a single reciprocating engine. This
proposed rule would omit the single reciprocating engine limitation as
an eligibility requirement in Sec.  22.100. Accordingly, this proposed
rule would allow light-sport category aircraft to be built with any
number and type of engines or motors. The performance limitations for
aircraft that a sport pilot may act as pilot in command of would not
include the limitation on a single reciprocating engine if the aircraft
is powered.
    Since this powerplant limitation was established in 2004, full
authority digital engine control (FADEC) technology has evolved
significantly. FADEC \18\ automates and simplifies the operation of a
turbine powerplant. Today, many turbine-powered aircraft use FADEC
automation to manage powerplant performance and simplify aircraft
powerplant operations, reducing pilot workload. As a result, many
turbine-powered aircraft are no longer directly associated with
excessive speed or complexity. Advancements in simplified designs of
turbine-engine technology have led to the use of small turbine engines
in a variety of aircraft, including self-launching gliders. The FAA
recognizes that because of automation, many modern turbine powerplants
are now easier to operate than many existing piston-powered aircraft.
Modern automated powerplants reduce the complexity previously
associated with piloting aircraft that use powerplants other than non-
turbine engines.
---------------------------------------------------------------------------

    \18\ FADEC combines throttle, prop, and mixture controls into a
single control. With a FADEC system, there is no direct pilot
control over the engine or manual control mode. FADEC systems are
autonomous, self-monitoring, self-operating, and redundant. These
systems can decrease pilot workload and provide engine monitoring
capability that can alert operators of certain mechanical problems.
---------------------------------------------------------------------------

    The FAA also reasons that removal of a specific engine requirement
will encourage ongoing development, innovation, and increased
efficiency of various types of powerplants for aircraft. The FAA seeks
to encourage flexibility for aircraft manufacturers to include simple-
to-operate powerplants of any design that will provide benefits to
include reduced cost, ease of operation, and reduced emissions--
especially for electric-powered aircraft. In summary, limiting the
number and type of powerplants for light-sport category aircraft is no
longer necessary and any risk associated with their use would be
appropriately mitigated by aircraft and pilot certification processes.
7. Use of a Controllable Pitch Propeller
    The Sec.  1.1 definition of a light-sport aircraft currently
requires a fixed or ground adjustable propeller if the aircraft is a
powered aircraft other than a powered glider. The light-sport aircraft
definition also requires that powered gliders have a fixed or
feathering propeller system. These requirements from the 2004 rule
provided for simple

designs that would be appropriate for a sport pilot to operate.
    With the performance expansions proposed in this rule for the
design and certification of light-sport category aircraft, as well as
the decoupling from sport pilot aircraft limitations tied to the light-
sport aircraft Sec.  1.1 definition, there would no longer be a need to
restrict propeller designs for light-sport category aircraft. This
proposed rule would omit propeller limitations from the light-sport
category eligibility requirements in Sec.  22.100. Accordingly, this
proposed rule would allow light-sport category aircraft to be built
with any type of propeller design that meets an FAA-accepted consensus
standard.\19\
---------------------------------------------------------------------------

    \19\ ASTM standard F2506--Standard Specification for Design and
Testing of Light Sport Aircraft Propellers.
---------------------------------------------------------------------------

    Although the operation of controllable-pitch propellers and their
associated systems can impose some additional workload on pilots, the
FAA considers these propeller designs to be safe and reliable, as they
have been used in general aviation aircraft for decades. While
controllable-pitch propeller designs can increase workload because they
require attention and adjustment by the pilot, the FAA considers the
overall design of these systems to be relatively simple to operate and
appropriate for inclusion in light-sport category aircraft.
    However, proposed Sec.  61.316, which would provide the performance
and design limitations for aircraft that may be flown by sport pilots,
would retain some propeller limitations and training requirements for
sport pilots. Specifically, for powered aircraft other than powered
gliders, proposed Sec.  61.316 would permit sport pilots to fly
aircraft with a fixed or ground-adjustable propeller, but also allow
those with an automated controllable-pitch propeller. Aircraft with an
automated controllable-pitch propeller would enable pilots to take
advantage of the improved performance associated with these aircraft
without imposing additional workload. The current requirement for
powered gliders would be relocated to proposed Sec.  61.316.
    Due to the significant increase in climb and cruise performance,
the FAA is also proposing to permit sport pilots who receive additional
training and an instructor endorsement to operate airplanes designed
with controllable-pitch propellers that are not automated. The FAA
contends that permitting the design and use of a controllable-pitch
propeller on airplanes increases safety by taking advantage of the
improved climb performance associated with that propeller system design
to avoid and clear obstacles during the climb and departure phase of a
flight.
    The FAA proposes two allowances to this requirement in the proposed
Sec.  61.316(e). First, the FAA proposes that, for powered aircraft
other than powered gliders, the airplane may also be equipped with an
automated controllable-pitch propeller. These propellers are easy to
use and increase airplane performance and efficiency. Specifically,
allowing use of an automated controllable-pitch propeller, in addition
to fixed or ground-adjustable propellers, increases safety because of
increased climb and cruise performance associated with a controllable
pitch propeller design.
    Second, under the proposed Sec.  61.331, sport pilots would be
required to obtain additional flight training and a flight instructor
endorsement validating sport pilot proficiency to operate an airplane
with a controllable-pitch propeller that is not automated. The FAA
contends that additional training and instructor endorsements would
appropriately validate that sport pilots can safely operate airplanes
with a manually operated controllable-pitch propeller.
8. Fixed-Pitch, Semi-Rigid, Teetering-Two Blade Rotor System (if a
Gyroplane)
    The current Sec.  1.1 definition of light-sport aircraft requires
gyroplanes to have fixed-pitch, semi-rigid, teetering two blade rotor
systems. This proposal would omit this as an eligibility requirement in
Sec.  22.100 to enable industry to develop new designs for gyroplane
rotor systems. However, under proposed Sec.  61.316(a)(6), the FAA
would continue to limit sport pilots to operate gyroplanes that have a
fixed-pitch, semi-rigid, teetering-two blade rotor system.
9. Retractable Landing Gear
    Per the current light-sport aircraft definition in Sec.  1.1, a
light-sport aircraft, except for an aircraft intended for operation on
water or a glider, must have a fixed landing gear. The proposed rule
would remove this limitation as an eligibility requirement in Sec.
22.100. Accordingly, this rule would allow light-sport category
aircraft to be designed with fixed or retractable landing gear, or with
floats for aircraft intended for operation on water.
    In the 2004 rule, the requirement for fixed landing gear was
intended to enable aircraft designs that would be simple to operate by
persons exercising the privileges of a sport pilot certificate. With
the performance expansions proposed in this rule for the design of
light-sport category aircraft and the decoupling from sport pilot
restrictions, there is no longer a need to restrict light-sport
category aircraft to fixed landing gear. This rule would provide for
more robust structures and greater weight allowances that would
accommodate necessary enhancements needed for retractable landing gear.
    The FAA recognizes that additional training and instructor
endorsements can validate that sport pilots can operate aircraft with
retractable landing gear safely. The FAA is proposing to permit sport
pilots to operate aircraft with a retractable landing gear by requiring
additional training and obtaining a flight instructor endorsement
validating proficiency, as discussed later in section IV.E. By
proposing to establish separate airman and aircraft certification
requirements, manufacturers would be provided with the ability to
create a wider range of aircraft designs that may be operated by any
appropriately rated pilot. Pilots could then pursue the appropriate
level of pilot certification necessary to operate light-sport category
aircraft and any other aircraft. This would enable greater flexibility
for both aircraft manufacturers and pilots.

D. Certification of Light-Sport Category Aircraft

1. Compliance With Design, Production, and Airworthiness Requirements
    As a condition for eligibility for certification in the light-sport
category, the proposal would require an aircraft to meet performance-
based aircraft design, production, and airworthiness requirements using
a means of compliance consisting of consensus standards accepted by the
FAA. The proposal would provide the regulatory authority to deny
airworthiness certification for a light-sport category aircraft if any
applicable requirements in Sec.  21.190(c) or part 22 have not been
met. The proposed performance-based requirements are discussed further
in section IV.D.
2. Establishment of Performance-Based Requirements
    This proposal would include performance-based requirements for the
certification of aircraft in the light-sport category. The FAA would
evaluate any proposed consensus standard against the regulatory
requirement to determine whether the consensus standard would
constitute an acceptable means of compliance. By proposing these
performance-based requirements, the FAA would be providing clear
direction to standards-setting organizations regarding the content of
consensus

standards that would be proposed as a means of compliance to meet
regulatory requirements. The FAA expects that this proposal should not
only facilitate the more rapid development of these consensus
standards, but also result in more comprehensive consensus standards
that are better able to address the design, production, and
airworthiness of aircraft intended for certification in the light-sport
category.
    The design, production, and airworthiness requirements proposed in
part 22 would represent the minimum requirements a consensus standard
would be required to address to be an acceptable means of compliance
for certification of light-sport category aircraft. The proposed
requirements would enable the implementation of new technologies and
encourage innovation. This proposed rule would allow manufacturers to
incorporate new technologies in their aircraft due to the removal of a
prescriptive weight limit that previously limited the installation of
safety equipment. This proposed rule would also encourage innovation,
such as aircraft designed with simplified flight controls discussed in
proposed Sec.  22.180. The requirements proposed in this section would
provide safety requirements appropriate for the light-sport category
within the context of the FAA's safety continuum. A discussion of each
proposed performance-based requirement follows.
3. Performance-Based Requirements for the Certification of Light-Sport
Category Aircraft
a. General
    The proposed expansion of the classes of aircraft eligible for
certification under the proposal and the increase in the size and
performance of these aircraft requires the adoption and use of more
detailed performance-based requirements. These new requirements would
serve to guide consensus standards bodies in developing appropriate
consensus standards that would be acceptable to the FAA for the
expanded certification of aircraft in the light-sport category.
    Manufacturer compliance with the performance-based design,
production, and airworthiness requirements proposed in this NPRM is
necessary for the safety of the wide range of light-sport category
aircraft to be certificated under this proposal. The FAA expects that
compliance with these requirements would reduce the occurrence of
design and production defects, resulting in aircraft that are safe for
their intended operations.
    In accordance with their place in the safety continuum, light-sport
category aircraft would be subject to a certification process more
stringent than that applicable to experimental amateur-built aircraft,
but less rigorous than that used for the certification of normal
category aircraft. When comparing current certification requirements
for light-sport category aircraft to the certification requirements
applicable to other aircraft, amateur-built aircraft issued
experimental airworthiness certificates are not required to the meet
performance-based design, production, and airworthiness requirements
that light-sport category aircraft would be required to meet. As
experimental aircraft occupy a level on the safety continuum with a
lesser demand for safety assurance than light-sport category aircraft,
amateur-built aircraft are subject to more stringent operating
limitations. In contrast, aircraft issued standard airworthiness
certificates are required to meet airworthiness standards contained in
part 23, 25, 27, 29, or 31 and must be produced pursuant to an FAA
design and production approval. Accordingly, normal category aircraft
are subject to fewer operating restrictions than light-sport category
aircraft. As light-sport category aircraft would not be designed or
manufactured pursuant to an FAA design or production approval, these
aircraft would be subject to the eligibility requirements in proposed
Sec.  22.100 and the more restrictive operating limitations in proposed
Sec.  91.327.
    The FAA retains oversight authority of light-sport category
aircraft manufacturers. Like certification rigor, the rigor of FAA
oversight of light-sport category aircraft manufacturers would be
consistent with the safety continuum. Policies and procedures for that
oversight are included in FAA Order 8130.36.\20\ To support this
proposed rule, the FAA would expand its oversight to verify successful
accomplishment of training by the manufacturer's compliance staff per
proposed Sec.  22.190, as well as the training and certification of
manufacturer's staff who sign its statements of compliance in proposed
Sec.  21.190(d)(1).
---------------------------------------------------------------------------

    \20\ FAA Order 8130.36, Special Light Sport Aircraft Audit
Program.
---------------------------------------------------------------------------

    The FAA does not believe it would be appropriate to include the
proposed performance-based design, production, and airworthiness
requirements within current part 21 as that part is largely limited to
prescribing certification procedures, not certification requirements.
Accordingly, the FAA is proposing to include these requirements within
subpart B of part 22. By placing these new design, production, and
airworthiness requirements within separate sections of part 22, each
functional requirement would be more readily discernable to users, be
better able to be individually addressed, and result in the development
of a clearer and more understandable manufacturer's statement of
compliance.
    With certain exceptions, part 22 would apply to non-type
certificated aircraft. As aircraft with experimental airworthiness
certificates are not certificated using performance-based requirements,
proposed part 22 would not be applicable to those aircraft.
Additionally, the proposed part would not be applicable to aircraft
operating under a special flight permit. Although those permits are
issued to aircraft that are safe for flight, aircraft operating under a
special flight permit do not have to meet applicable airworthiness
requirements. Part 22 would also not be applicable to unmanned
aircraft, as the proposed requirements would address the design,
production, and airworthiness of aircraft used to carry passengers and
would not be appropriate to address the design of an aircraft that
could be remotely operated. Requirements for manned aircraft, for
example, would need to address occupant protection and egress while
proposed requirements for unmanned aircraft would need to address
certain flight control system requirements that would be inapplicable
to manned aircraft. The FAA notes, however, that requirements for non-
type certificated unmanned aircraft could be proposed at a later date.
    The FAA has accepted a variety of ASTM consensus standards for the
certification of light-sport category aircraft. The FAA has found these
consensus standards to be sufficient for the certification of aircraft
that meet current eligibility requirements. The FAA has also reviewed
currently accepted ASTM consensus standards and evaluated them against
the proposed performance expansions and new aircraft designs that would
be eligible for certification as light-sport category aircraft.
Currently accepted consensus standards would not be sufficient for the
certification of the wide range of aircraft with enhanced performance
capabilities that could be certificated under this proposal. The FAA
anticipates that industry would develop acceptable and appropriate
consensus standards to comply with the proposed performance-based
requirements in part 22. These proposed

performance-based requirements would serve as the underlying regulatory
requirements for the development of new or revised consensus standards.
    The FAA currently uses performance-based requirements for the
certification of other aircraft, most notably normal category airplanes
certificated under the requirements of part 23. The FAA recognizes that
the performance-based requirements it is proposing for certificating
light-sport category aircraft are not of the same scope and detail as
those standards. The FAA contends, however, that the greater
specificity contained in the part 23 standards reflects the increased
rigor of the type certification process and resultant need to develop
more detailed consensus standards to comply with those more detailed
requirements. The performance-based requirements proposed in this NPRM
respond to the need to apply a set of broad-based requirements to a
wider range of aircraft that would not be required to meet the more
exacting design requirements of type certification. They also provide
industry with the flexibility to develop consensus standards applicable
to the certification of a wide range of dissimilar aircraft.
    Under the proposed rule, a consensus standard would have to meet
the following performance-based requirements before the FAA would
accept that standard as a means of compliance. A manufacturer would
need to meet the appropriate FAA-accepted consensus standards to obtain
an airworthiness certificate in the light-sport category.
b. Control and Maneuverability
    Proposed Sec.  22.105 would require aircraft to be consistently and
predictably controllable and maneuverable through the normal use of
primary flight controls at all loading conditions, during all phases of
flight. Additionally, the aircraft would not have a tendency to
inadvertently depart controlled flight or require exceptional piloting
skill, alertness, or strength.
    The proposed rule is necessary because if the aircraft's design
prevents the pilot from inadvertently departing controlled flight,
instances of unintentional unusual attitudes, loss of control of the
aircraft, or aircraft structural damage would be reduced. A requirement
for control and maneuverability would assist with the consistency and
predictability of an aircraft's maneuvering flight characteristics
throughout the aircraft's entire flight envelope. The aircraft would
not have a tendency to depart controlled flight, meaning that it should
be inherently stable. Additionally, the FAA considers that this
requirement would result in aircraft that operate in repeatable, smooth
transitions between turns, climbs, descents, and level flight.
    Accordingly, flight controls would need to operate easily,
smoothly, and positively enough to allow proper performance of their
functions. Configuration changes, such as flap extension and
retraction, or landing gear extension and retraction would also have to
result in safe, controllable, and predictable handling characteristics.
The proposed performance requirement would also enable stability, ease
of flight, and consistent outcomes of control inputs for light-sport
category aircraft throughout their center of gravity limits and flight
envelope. The FAA considers that if an aircraft meets these parameters,
exceptional piloting skill, alertness, or strength would not be
required to operate the aircraft.
    The FAA has accepted consensus standards for current light-sport
category aircraft that address the controllability and maneuverability
of aircraft intended for certification as light-sport category
aircraft.\21\ Although the controllability and maneuverability
standards vary across the consensus standards for the different classes
of light-sport category aircraft, the general provisions of these
standards align closely with the elements of proposed Sec.  22.105. The
consensus standards currently address controllability and
maneuverability, applicable phases of flight, pilot strength and skill,
and normal use of flight controls. Proposed Sec.  22.105 would meet the
level of rigor the FAA considers appropriate for light-sport category
aircraft and its place on the safety continuum between experimental
aircraft and normal category airplanes. Proposed Sec.  22.105 would
require light-sport category aircraft to be controllable and
maneuverable with no adverse handling characteristics. In this context,
no adverse handling characteristics would mean the aircraft would be
consistently and predictably controllable and maneuverable and would
not have a tendency to inadvertently depart controlled flight.
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    \21\ ASTM F2245 Standard Specification for Design and
Performance of a Light Sport Airplane; ASTM F2564 Standard
Specification for Design and Performance of a Light Sport Glider;
ASTM F2317/F2317M Standard Specification for Design of Weight-Shift-
Control Aircraft, ASTM F2244 Standard Specification for Design and
Performance Requirements for Powered Parachute Aircraft, and ASTM
F2355 Standard Specification for Design and Performance Requirements
for Lighter-Than-Air Light Sport Aircraft.
---------------------------------------------------------------------------

    The FAA expects that some existing consensus standards would need
to be updated to account for the proposed expansion of eligibility for
aircraft to be certified as light-sport category aircraft.
Additionally, those portions of currently accepted consensus standards
addressing aircraft controllability and maneuverability would need to
be updated to address the specific requirement that aircraft control
and maneuverability be consistent and predictable.
    The proposed rule would facilitate the manufacture of simple
designs that result in the stable, predictable, and controllable
operation of the aircraft through the use of primary flight controls.
Primary flight controls consist of ``traditional'' flight controls,
such as an aircraft yoke, stick, control column, collective, throttle,
or rudder pedals. 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. The proposed
rule would also contain specific provisions for the certification of
aircraft that may be designed and constructed without primary flight
controls, but rather with ``simplified flight controls.'' Specific
requirements for aircraft with simplified flight controls are addressed
in proposed Sec.  22.180 in the preamble.
    The proposed rule would require that existing consensus standards
be revised to account for the requirement that operation of the
aircraft not require exceptional piloting skill, alertness, or
strength. Aircraft meeting this performance requirement would be stable
enough to be easily flown by pilots with a minimum of flight experience
and would not have handling characteristics that would cause undue
pilot fatigue or distraction. Accordingly, these aircraft would provide
a more stable platform than other currently available non-type
certificated aircraft, thereby aiding in preventing inadvertent loss of
control accidents. Although some consensus standards specifically
address the forces necessary to pilot the aircraft, not all existing
consensus standards meet this requirement. The proposed rule would
require that aircraft certificated in the light-sport category have
aerodynamic and handling qualities that would not result in unstable
flight characteristics or require exceptional pilot skill to keep the
aircraft within its flight envelope.
    Additionally, the handling characteristics of these aircraft would
make light-sport category aircraft a viable alternative for use in the
flight training environment and provide both student pilots and flights
schools with

a potentially lower cost, alternate fight training platform. Although
the proposed rule would permit the use of technology to enhance the
flying qualities of the aircraft, the technology should also not
increase the pilot's workload to the detriment of the goal to have
simple and easy to fly aircraft. The pilot should not be task-saturated
in maintaining control of these aircraft.
    Proposed Sec.  22.105 would help prevent inadvertent unusual
attitudes and loss of control accidents. Per National Transportation
Safety Board (NTSB) accident statistics, the largest number of fatal
accidents for general aviation aircraft result from inflight loss of
control; the proposed standard would result in the development of
consensus standards for light-sport category aircraft that would assist
in mitigating this risk.
    Powered-lift or certain rotorcraft that could experience failures
resulting in asymmetric thrust would need to be designed with safe,
controllable, and predictable characteristics that permit a pilot with
limited flight experience from becoming task-saturated while
maintaining control of the aircraft. The aircraft could also be
designed and constructed to include an automated system or provide for
some combination of pilot action and automation that would enable the
pilot to maintain effective aircraft control. The provisions of this
proposed requirement would be consistent with proposed Sec.  22.145,
which would require that any propulsion system thrust asymmetry be
automatically compensated for, or be capable of being readily
compensated for, with no adverse effect on the aircraft's handling
qualities.
c. Structural Integrity
    Proposed Sec.  22.110 would require that the design and
construction of the aircraft provide sufficient structural integrity to
enable safe operations within the aircraft's flight envelope and
intended lifecycle. It would also require that the aircraft be able to
withstand all anticipated flight and ground loads when operated within
its operational limits.
    The proposed performance requirements are necessary to ensure that
light-sport category aircraft are designed and constructed to withstand
any foreseeable flight and ground loads that may be experienced
throughout the aircraft's flight envelope and intended lifecycle.
Failure to establish and validate adequate strength, stiffness, and
durability to accommodate anticipated loads encountered during flight
or ground operations could result in structural failure of the
aircraft.
    When comparing the proposed requirements for the certification of
light-sport category aircraft to the certification of amateur-built
aircraft, the FAA notes that amateur-built aircraft have no regulatory
requirement to incorporate design features or be constructed to provide
sufficient structural integrity for their intended operations. Amateur
builders may experiment with different materials and construction
techniques in the design and construction of their aircraft. In
contrast, type-certificated aircraft must meet the extensive
airworthiness standards for structures in parts 23, 25, 27, 29, and 31
that address areas such as strength, durability, design envelope,
loads, aeroelasticity, materials, protection, fabrication processes,
and performance. The level of rigor proposed for the structural
integrity of light-sport category aircraft would not be as extensive as
that required for aircraft intended for type-certification yet would
establish minimum requirements for structural integrity that are not
applicable to the certification of amateur-built aircraft.
    FAA-accepted consensus standards currently used for the
certification of light-sport category aircraft have provisions
addressing structures that generally include provisions for items such
as loads, factors of safety, strength and deformation, proof of
structure, flight loads, design airspeeds, specialized structures, and
emergency landing conditions.\22\ As a result of the expansion in the
performance and capabilities of aircraft that would be certificated as
light-sport category aircraft under the proposal, the proposed
requirements would require consensus standards for light-sport category
aircraft designs to address aircraft structural integrity under a wider
range of environmental conditions and operational parameters.
Additionally, the prevention of material and structural failures due to
foreseeable causes of strength degradation and protection against
deterioration or loss of structural strength due to any cause likely to
occur throughout the aircraft's lifecycle would also need to be
addressed by consensus standards organizations.
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    \22\ ASTM F2245, F2564, F2317/F2317M, F2244, and F2355.
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    The proposed rule would require the aircraft to have the ability to
withstand all anticipated flight and ground loads without detrimental
permanent deformation or interference with the safe operation of the
aircraft. The inclusion of a requirement to address structural
integrity in light-sport category aircraft designs would improve the
ability of these aircraft to be consistently dependable, structurally
reliable, and fully capable of safely conducting intended operations
throughout the aircraft's lifecycle. The proposed requirements would
enable aircraft design and manufacturing processes used in construction
to attain structural integrity of aircraft with the use of adequate
material strength and properties that can accommodate anticipated loads
when operated within specified flight envelopes.
d. Powered-Lift Aircraft: Minimum Safe Speed
    Proposed Sec.  22.115 would require manufacturers of powered-lift
aircraft to establish the minimum safe speed for each flight condition
encountered in normal operation, including applicable sources of lift
and phases of flight, to maintain controlled safe flight. The minimum
safe speed determination would be required to account for the most
adverse conditions for each configuration.
    Because powered-lift aircraft would be newly eligible for
certification as light-sport category aircraft, the FAA has proposed
this specific requirement for powered-lift aircraft. The proposed rule
is necessary for pilots of these aircraft to be aware of the specific
minimum safe speeds at which their specific model of powered-lift
aircraft can be operated in each of the aircraft's various
configurations. Requiring these speeds to be determined would provide
pilots with the essential knowledge to avoid operating these aircraft
below minimum safe speeds, thereby reducing the potential for aircraft
loss of control.
    The proposed requirement to determine minimum safe speeds for
powered-lift aircraft addresses all modes of flight (wing-borne,
thrust-borne, and semi-thrust borne) in which these aircraft may be
operated and the various modes in which lift supporting the aircraft is
produced. In the wing-borne flight mode, the wing produces the
aircraft's lift. In thrust-borne flight, commonly called hover mode,
the powerplant produces the aircraft's lift. In the semi-thrust borne
mode, the aircraft is in a transition stage between thrust-borne and
wing-borne modes of flight with both the wings and powerplant providing
aircraft lift. Although most powered-lift aircraft are designed with
the ability to automatically transition from high-speed wing-borne
flight to slow-speed thrust-borne flight or hover, the proposed
requirement would further the pilot's understanding of the handling
qualities of the aircraft and facilitate

their ability to make a smooth change from one configuration to another
without exceeding the limitations of the aircraft's flight envelope.
    The FAA does not consider the imposition of a limiting stalling
speed or minimum steady flight speed such as VS1 to be
practical for application to the design of powered-lift aircraft that
would be eligible for certification as light-sport category aircraft.
Many of the designs for these smaller powered-lift aircraft have wing
sizes that do not provide significant lift in wing-borne flight. As a
result of this small wing area and other design features, these
aircraft may have stalling or minimum steady flight speeds that are
much higher than comparably sized aircraft of other classes that rely
primarily on wings to produce lift. Accordingly, the FAA considers the
use of a maximum stalling speed as a limitation for these aircraft to
be unnecessary.
    As powered-lift aircraft can be operated in a variety of flight
configurations, the FAA considers the determination of a minimum safe
flight speed for each flight condition to be essential. Similar
requirements for the determination of minimum flight speeds have also
been proposed in two Federal Register notices of proposed airworthiness
criteria for powered-lift aircraft designs currently involved in the
type-certification process.\23\ The more extensive requirements set
forth in the airworthiness criteria for these powered-lift aircraft
designs currently undergoing type-certification would not be required
since aircraft subject to this proposal would be certificated as light-
sport category aircraft and subject to the operating limitations
contained in proposed Sec.  91.327.
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    \23\ Airworthiness Criteria: Special Class Airworthiness
Criteria for the Joby Aero, Inc. Model JAS4-1 Powered-Lift (87 FR
67399; November 8, 2022), and Airworthiness Criteria: Special Class
Airworthiness Criteria for the Archer Aviation Inc. Model M001
Powered-Lift (87 FR 77749; December 20, 2022).
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    The proposed requirement is necessary so that the aircraft has
controllable minimum safe speed flight characteristics in all flight
conditions with a clear and distinctive minimum safe speed warning that
provides sufficient margin to prevent inadvertent deceleration below
minimum safe speed. Production acceptance flight testing would verify
that the minimum safe speeds account for the most adverse conditions,
such as operating at maximum gross weight, in the determination of the
minimum safe speeds for each flight condition.
4. Special Requirements for Light-Sport Category Aircraft Used for
Aerial Work Operations
    Proposed Sec.  22.120 would require that if an aircraft is
designated by the manufacturer as suitable for the performance of any
aerial work operation, the design and construction of the aircraft must
provide sufficient structural integrity to enable safe operation of the
aircraft during the performance of that operation and ensure that the
aircraft is able to withstand foreseeable flight and ground loads.\24\
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    \24\ The FAA does not define construction or manufacture in
Sec.  1.1. The terms are used interchangeably in this section and
mean the same.
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    The FAA broadly interprets the term aerial work to mean work done
from the air for compensation that does not involve the carriage of
persons or property.\25\ Aerial work could include operations such as
those performed in support of agriculture or construction activities,
aerial photography, surveying, observation and patrol, search and
rescue, and aerial advertisement. Patrolling of powerlines or railroad
tracks, for example is a task that could be readily accomplished by a
light-sport category aircraft that meets the proposed requirements.
However, patrolling over long distances and at low altitudes can put
increased stresses on aircraft structures due to the greater prevalence
of turbulence at low altitude. The proposal would require manufacturers
to design and construct aircraft to be able to withstand potentially
greater stresses when engaged in designated aerial work operations than
would potentially be experienced during recreational flights.
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    \25\ FAA Order 8900.1, Volume 2, Chapter 2, Section 2, Paragraph
2-127C Aerial Work Operations. While 14 CFR does not define ``aerial
work,'' the FAA has consistently interpreted the term to mean work
done from the air where: the aircraft must depart and arrive at the
same point; no property of another may be carried on the aircraft;
and only persons essential to the operation may be carried on board.
See Legal Interpretation to Jeffrey Hill, from Rebecca B.
MacPherson, Assistant Chief Counsel for Regulations, (March 10,
2011). See 14 CFR 119.1(e)(4).
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    This proposed performance requirement is necessary so that aircraft
designated to conduct aerial work operations are designed and
constructed to withstand foreseeable flight and ground loads that may
be experienced during those operations. Failure to establish and
validate adequate material strength and design properties to
accommodate a designated aerial work operation could cause structural
failure resulting in loss of aircraft control.
    The proposed requirement would only apply to those light-sport
category aircraft designated by a manufacturer to conduct specific
aerial work operations. In accordance with the principles of the FAA's
safety continuum, the proposed requirement is intended to apply a level
of certification rigor appropriate to provide for the airworthiness of
light-sport category aircraft during the conduct of these designated
operations.
    Amateur-built aircraft issued experimental airworthiness
certificates have no regulatory requirement to incorporate design
features necessary to provide sufficient structural integrity of the
aircraft to enable safe aerial work operations. These aircraft are
built solely for the purpose of education or recreation and are issued
operating limitations which limit their use to education or recreation.
Accordingly, aircraft issued these operating limitations are prohibited
from aerial work operations by Sec.  91.9, which prohibits the
operation of a civil aircraft contrary to its operating limitations. In
contrast, type-certificated aircraft meeting the airworthiness
standards for structures in part 23, 25, 27, 29, or 31 may be used to
conduct aerial work operations since these aircraft are issued standard
airworthiness certificate and are not restricted by operating
limitations that restrict their use to recreation or education or by
regulatory provisions limiting their ability to carry persons or
property for compensation or hire as set forth in Sec.  91.319(a)(2).
    Light-sport category aircraft are currently precluded by Sec.
91.327 from conducting operations for compensation or hire, except to
tow a glider or an unpowered ultralight vehicle or to conduct flight
training. As the proposal would enable aerial work operations, the
proposal would revise Sec.  91.327 to permit the conduct of any aerial
work operation specified in the aircraft's pilot operating handbook or
operating limitations, as applicable, and specified in the
manufacturer's statement of compliance for that aircraft.
    The aircraft's design and construction would need to be sufficient
to protect against deterioration or loss of strength and prevent
structural failures due to foreseeable causes of strength degradation
that would be likely to occur throughout the aircraft's flight envelope
during aerial work operations. Additionally, the aircraft would need to
be able to withstand all anticipated flight and ground loads during
these operations without incurring detrimental permanent deformation or
jeopardizing the safe operation of the aircraft. Failure to adhere to
proper design and manufacturing processes in the development and
production of parts or using materials not suitable or

lacking durability for in-service environmental conditions in aerial
work operations could result in loss of aircraft performance or
critical functionality, thereby resulting in loss of aircraft control.
Accordingly, these concerns would be appropriately addressed in the
aircraft's design and manufacture under this proposal.
5. Environmental Conditions
    Proposed Sec.  22.125 would require the aircraft to have design
characteristics to safely accommodate all environmental conditions
likely to be encountered during its intended operations.
    The proposed requirement is necessary to enable aircraft to be
properly designed and constructed to conduct safe ground and flight
operations in the specific operating environments for which the
aircraft is designated to operate in. Manufacturers would need to
account for weather extremes encountered within the United States and
the designed maximum altitude of the aircraft to comply with this
requirement. Aircraft systems and structures may not function as
intended if all operating conditions are not accounted for in an
aircraft's design. Improperly functioning systems or structures may
lead to loss of aircraft control and an aircraft accident or incident.
    There are no regulatory requirements for amateur-built aircraft to
be designed with characteristics necessary to safely accommodate
environmental conditions. If an amateur-built aircraft has been
designed for flight at night or instrument meteorological conditions
(IMC) as specified in its operating manual, the aircraft would be
issued an operating limitation under the regulatory authority of Sec.
91.319(i) specifying that it must meet the instrument and equipment
requirements of Sec.  91.205.
    In contrast, aircraft manufactured in accordance with the
airworthiness standards set forth in part 23, 25, 27, or 29 are subject
to specific design and installation requirements for systems and
equipment. Installed systems and equipment must perform their intended
function throughout the operating and environmental limits for which
the aircraft is certificated. Based on the performance level of the