Revision of Airworthiness Standards for Normal, Utility, Acrobatic, and Commuter Category Airplanes
Federal RegisterDec 30, 2016
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Parts 21, 23, 35, 43, 91, 121, and 135
[Docket No.: FAA-2015-1621; Amdt. Nos. 21-100, 23-64, 35-10, 43-49, 91-346, 121-378, and 135-136]
RIN 2120-AK65
Revision of Airworthiness Standards for Normal, Utility, Acrobatic, and Commuter Category Airplanes
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Final rule.
SUMMARY:
The FAA amends its airworthiness standards for normal, utility, acrobatic, and commuter category airplanes by replacing current prescriptive design requirements with performance-based airworthiness standards. These standards also replace the current weight and propulsion divisions in small airplane regulations with performance- and risk-based divisions for airplanes with a maximum seating capacity of 19 passengers or less and a maximum takeoff weight of 19,000 pounds or less. These airworthiness standards are based on, and will maintain, the level of safety of the current small airplane regulations, except for areas addressing loss of control and icing, for which the safety level has been increased. The FAA adopts additional airworthiness standards to address certification for flight in icing conditions, enhanced stall characteristics, and minimum control speed to prevent departure from controlled flight for multiengine airplanes. This rulemaking is in response to the Congressional mandate set forth in the Small Airplane Revitalization Act of 2013.
DATES:
Effective August 30, 2017.
ADDRESSES:
For information on where to obtain copies of rulemaking documents and other information related to this final rule, see “How To Obtain Additional Information” in the
SUPPLEMENTARY INFORMATION
section of this document.
FOR FURTHER INFORMATION CONTACT:
For technical questions concerning this action, contact Lowell Foster, Regulations and Policy, ACE-111, Federal Aviation Administration, 901 Locust St., Kansas City, MO 64106; telephone (816) 329-4125; email
lowell.foster@faa.gov
.
SUPPLEMENTARY INFORMATION:
All sections of part 23 contain revisions, except the FAA did not make any changes to the following sections: 23.1457, Cockpit Voice Recorders, 23.1459, Flight Data Recorders, and 23.1529, Instructions for Continued Airworthiness. Sections 23.1459 and 23.1529 were changed to align the cross references with the rest of part 23. The three sections otherwise remain unchanged relative to the former regulations.
Authority for This Rulemaking
The FAA's authority to issue rules on aviation safety is found in Title 49 of the United States Code. 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 Subtitle VII, Part A, Subpart III, Section 44701. Under that section, the FAA is charged with promoting safe flight of civil airplanes in air commerce by prescribing minimum standards required in the interest of safety for the design and performance of airplanes. This regulation is within the scope of that authority because it prescribes new performance-based safety standards for the design of normal, utility, acrobatic, and commuter category airplanes.
Additionally, this rulemaking addresses the Congressional mandate set forth in the Small Airplane Revitalization Act of 2013 (Pub. L. 113-53; 49 U.S.C. 44704 note) (SARA). Section 3 of SARA requires the Administrator to issue a final rule to advance the safety and continued development of small airplanes by reorganizing the certification requirements for such airplanes under part 23 to streamline the approval of safety advancements. SARA directs that the rule address specific recommendations of the 2013 Part 23 Reorganization Aviation Rulemaking Committee (Part 23 ARC).
Table of Contents
I. Overview of Final Rule
II. Background
A. Statement of the Problem
B. History
C. Summary of the NPRM
III. Discussion of the Public Comments and Final Rule
A. Delayed Effective Date
B. Overview of Comments
C. General Public Comments
D. Part 23, Airworthiness Standards
1. Legacy Rules
a. Cockpit Voice Recorders (§ 23.1457)/Flight Data Recorders (§ 23.1459)
b. Instructions for Continued Airworthiness (§ 23.1529)
2. Subpart A—General
3. Subpart B—Flight
4. Subpart C—Structures
5. Subpart D—Design and Construction
6. Subpart E—Powerplant
7. Subpart F—Equipment
8. Subpart G—Flightcrew Interface and Other Information
E. Miscellaneous Amendments (§§ 21.9, 21.17, 21.24, 21.35, 21.50, 21.101, Appendix E to Part 43, and 91.323)
1. Production of Replacement and Modification Articles (§ 21.9)
2. Designation of Applicable Regulations (§ 21.17)
3. Issuance of Type Certificate: Primary Category Aircraft (§ 21.24)
4. Flight Tests (§ 21.35)
5. Instructions for Continued Airworthiness and Manufacturer's Maintenance Manuals Having Airworthiness Limitations Sections (§ 21.50)
6. Designation of Applicable Regulations (§ 21.101)
7. Special Federal Regulations 23 (SFAR No. 23)
8. Altimeter System Test and Inspection (Appendix E to Part 43)
9. Increased Maximum Certification Weights for Certain Airplanes Operated in Alaska (§ 91.323)
10. Additional Emergency Equipment (§ 121.310)
11. Additional Airworthiness Requirements (§ 135.169)
IV. Regulatory Notices and Analyses
A. Regulatory Evaluation Summary
B. Initial Regulatory Flexibility Determination
C. International Trade Impact Assessment
D. Unfunded Mandates Assessment
E. Paperwork Reduction Act
F. International Compatibility and Cooperation
G. Environmental Analysis
H. Regulations Affecting Intrastate Aviation in Alaska
V. Executive Order Determination
A. Executive Order 13132, Federalism
B. Executive Order 13211, Regulations That Significantly Affect Energy Supply, Distribution, or Use
VI. How To Obtain Additional Information
A. Rulemaking Documents
B. Comments Submitted to the Docket
C. Small Business Regulatory Enforcement Fairness Act
Appendix 1 to the Preamble—Current to Proposed Regulations Cross-Reference Table
Appendix 2 to the Preamble—Abbreviations and Acronyms Frequently Used in This Document
I. Overview of Final Rule
This rule amends Title 14, Code of Federal Regulations (14 CFR) part 23 by replacing current prescriptive design requirements with performance-based airworthiness standards. It maintains the level of safety associated with current part 23 except for areas addressing loss of control and icing where a higher level of safety is established, provides greater flexibility to applicants seeking certification of their airplane designs, and facilitates
faster adoption of safety enhancing technology in type-certificated products while reducing regulatory time and cost burdens for the aviation industry and FAA. This final rule also reflects the FAA's safety continuum philosophy,
1
which balances an acceptable level of safety with the societal burden of achieving that level of safety, across the broad range of airplane types certificated under part 23.
1
The FAA's safety continuum philosophy is that one level of safety is not appropriate for all aviation.
This final rule allows the use of consensus standards accepted by the Administrator as a means of compliance to part 23's performance-based regulations. The use of these FAA-accepted consensus standards as a means of compliance will streamline the certification process. However, consensus standards are one means, but not the only means, of showing compliance to the performance-based standards of part 23. Applicants, individuals, or organizations also have the option to propose their own means of compliance as they do today.
In this final rule, the FAA adopts additional airworthiness standards to address certification for flight in icing conditions and enhanced stall characteristics to prevent inadvertent departure from controlled flight. Manufacturers that choose to certify an airplane for flight in Supercooled Large Drops (SLD)
2
must demonstrate safe operations in SLD conditions. For those manufacturers who choose instead to certify an airplane with a prohibition against flight in SLD conditions, this final rule will require a means for detecting SLD conditions and showing the airplane can safely avoid or exit such conditions.
2
SLD conditions include freezing drizzle and freezing rain, which contain drops larger than those specified in appendix C to part 25, and can accrete aft of leading edge ice protection systems.
This final rule adopts additional airworthiness standards to address enhanced stall characteristics to prevent loss of control (LOC). This final rule requires applicants to use new design approaches and technologies to improve airplane stall characteristics and pilot situational awareness to prevent LOC accidents.
Additionally, this final rule also streamlines the process for design approval holders applying for a type design change, or for a third party modifier applying for a supplemental type certificate (STC), to incorporate new and improved equipment in part 23 airplanes. The revised part 23 standards are much less prescriptive; therefore, the certification process for modifications is simplified. Certification of an amended type certificate (TC) or STC under this final rule requires fewer special conditions or exemptions, lowering costs and causing fewer project delays.
This final rule also revises 14 CFR part 21, “Certification Procedures for Products and Articles,” to simplify the approval process for low-risk articles. Specifically, it amends § 21.9 to allow FAA-approved production of replacement and modification articles for airplanes certificated under part 23, using methods not listed in § 21.9(a). This will reduce constraints on the use of non-required, low-risk articles, such as carbon monoxide detectors and weather display systems.
Lastly, this final rule removes Special Federal Regulation No. 23 (SFAR No. 23) and contains conforming amendments to 14 CFR parts 21, 35, 43, 91, and 135. These conforming amendments align part 23 references to the part 23 rules contained in this final rule.
The FAA has analyzed the benefits and costs associated with this rule. This rule responds to the Small Airplane Revitalization Act of 2013 (SARA) and to industry recommendations for performance-based standards. This rule reduces new certification processing by streamlining new certification processing. In addition, this rule improves safety by adding stall characteristic, stall warnings, and icing requirements. The following table summarizes the benefit and cost analysis, showing the estimated cost is substantially less than the benefits resulting from the combined value of the safety benefits and the cost savings. The following table shows these results.
Estimated Benefits and Costs
[2015 $ Millions]
Stall & spin + other costs
Safety benefits + cost savings = total benefits
Total
$0.8 + $3.1 = $3.9
$17.9 + $9.9 = $27.8.
Present value at 7%
$0.8 + $3.1 = $3.9
$6.1 + $4.9 = $11.0.
Present value at 3%
$0.8 + $3.1 = $3.9
$11.1 + $7.1 = $18.3.
* These numbers are subject to rounding error.
Accordingly, the FAA has determined that the rule will be cost beneficial.
II. Background
A. Statement of the Problem
The range of airplanes certificated under part 23 is diverse in terms of performance capability, number of passengers, design complexity, technology, and intended use. Currently, certification requirements of part 23 airplanes are determined by reference to a combination of factors, including weight, number of passengers, and propulsion type. The resulting divisions (
i.e.,
normal, utility, acrobatic, and commuter categories) historically were appropriate because there was a clear relationship between the propulsion and weight of the airplane and its associated performance and complexity.
Technological developments have altered the dynamics of that relationship. For example, high-performance and complex airplanes now exist within the weight range that historically was occupied only by light and simple airplanes. The introduction of high-performance, lightweight airplanes required subsequent amendments of part 23 to include more stringent and demanding standards—often based on the part 25 requirements for larger transport category airplanes—to ensure an adequate level of safety for airplanes under part 23. The unintended result is that some of the more stringent and demanding standards for high-performance airplanes now apply to the certification of simple and low-performance airplanes. Because of this increased complexity, it takes excessive time and resources to certify new part 23 airplanes.
B. History
In 2008, the FAA initiated the Part 23 Certification Process Study (CPS)
3
to review part 23. Collaborating with industry, the CPS team's challenge was
to determine the future of part 23, given products at the time and anticipated future products. The team identified opportunities for improvements by examining the entire life cycle of a part 23 airplane, including operations and maintenance. The CPS recommended reorganizing part 23 using criteria focused on performance and design complexity. The CPS also recommended the FAA implement general airworthiness requirements, with the means of compliance defined in industry consensus standards.
3
See docket number FAA-2015-1621.
In 2010, following the publication of the CPS, the FAA held a series of public meetings to seek feedback concerning the findings and recommendations. Overall, the feedback was supportive of, and in some cases augmented, the CPS recommendations.
One notable difference between the CPS findings and the public feedback was the public's request that the FAA revise part 23 certification requirements for simple, entry-level airplanes. Over the past two decades, part 23 standards have become more complex as industry has generally shifted towards correspondingly complex, high-performance airplanes. This transition has placed an increased burden on applicants seeking to certificate smaller, simpler airplanes. Public comments requested that the FAA focus on reducing the costs and time burden associated with certificating small airplanes by restructuring the requirements based on risk. The risk exposure for most simple airplane designs is typically low, because of the small number of occupants.
On August 15, 2011, the Administrator chartered the Part 23 ARC to consider the following CPS recommendations:
• Recommendation 1.1.1—Reorganize part 23 based on airplane performance and complexity, rather than the existing weight and propulsion divisions.
• Recommendation 1.1.2—Certification requirements for part 23 airplanes should be written on a broad, general, and progressive level, segmented into tiers based on complexity and performance.
The ARC's recommendations took into account the Federal Aviation Modernization and Reform Act of 2012 (Pub. L. 112-95) (FAMRA), which requires the Administrator, in consultation with the aviation industry, to assess the airplane certification and approval process. The purpose of the ARC's assessment was to develop recommendations for streamlining and reengineering the certification process to improve efficiency, reduce costs, and ensure the Administrator can conduct certifications and approvals in a manner that supports and enables the development of new products and technologies and the global competitiveness of the United States aviation industry.
4
FAMRA also directed the Administrator to consider the recommendations from the CPS.
5
4
Public Law 112-95, section 312(c).
5
Public Law 112-95, section 312(b)(6).
ARC membership represented a broad range of stakeholder perspectives, including U.S. and international manufacturers, trade associations, and foreign civil aviation authorities (FCAAs).
The ARC noted the prevailing view within industry was that the only way to reduce the program risk, or business risk, associated with the certification of new airplane designs was to avoid novel design approaches and testing methodologies. Under existing part 23, the certification of new and innovative products frequently requires the FAA's use of equivalent level of safety (ELOS) findings, special conditions, and exemptions. These take time, resulting in uncertainty and high project costs. The ARC emphasized that although industry needs to develop new airplanes designed to use new technology, current certification costs inhibit the introduction of new technology. The ARC identified prescriptive certification requirements as a major barrier to installing safety‐enhancing modifications in the existing fleet and to producing newer, safer airplanes.
The ARC also examined the harmonization of certification requirements between the FAA and FCAAs, and the potential for such harmonization to improve safety while reducing costs. Adopting performance-based safety regulations that facilitate international harmonization, coupled with internationally accepted means of compliance, could result in both significant cost savings and the enabling of safety-enhancing equipment installations. The ARC recommended that internationally accepted means of compliance should be reviewed and voluntarily accepted by the appropriate aviation authorities, in accordance with a process established by those authorities. Although each FCAA would be capable of rejecting all or part of any particular means of compliance, the intent would be to have FCAA participation in the creation of the means of compliance to ease acceptance of the means of compliance.
Based on the ARC recommendations and in response to FAMRA, the FAA initiated rulemaking on September 24, 2013. Subsequently, on November 27, 2013, Congress passed the SARA, which requires the FAA to issue a final rule revising the certification requirements for small airplanes by—
• Creating a regulatory regime that will improve safety and decrease certification costs;
• Setting safety objectives that will spur innovation and technology adoption;
• Replacing prescriptive rules with performance-based regulations; and
• Using consensus standards to clarify how safety objectives may be met by specific designs and technologies.
The FAA has determined that the performance-based-standards component of this final rule complies with the FAMRA and the SARA because it will improve safety, reduce regulatory compliance costs, and spur innovation and the adoption of new technology. This final rule will replace the weight-and propulsion-based prescriptive airworthiness standards in part 23 with performance- and risk-based airworthiness standards for airplanes with a maximum seating capacity of 19 passengers or less and a maximum takeoff weight of 19,000 pounds or less. The standards will maintain or increase the level of safety associated with the current part 23, while also facilitating the adoption of new and innovative technology in general aviation (GA) airplanes.
C. Summary of the NPRM
On March 7, 2016, the FAA issued a notice of proposed rulemaking (NPRM) proposing to revise part 23 in response to the SARA.
6
In the NPRM, the FAA proposed to—
6
See
81 FR 13452.
• Establish a performance-based regulatory regime; and
• Add new certification standards for LOC and icing.
On May 3-4, 2016, the FAA held a public meeting to discuss the NPRM, hear the public's questions, address any confusion, and obtain information relevant to the final rule under consideration.
7
The meeting notice and the transcripts are both in the docket. The FAA considered comments made at the public meeting along with comments submitted by the public to docket number FAA-2015-1621.
7
See
81 FR 20264.
The comment period closed on May 13, 2016.
III. Discussion of the Public Comments and Final Rule
A. Delayed Effective Date
The FAA has decided it is necessary to delay the effective date of this final
rule for 8 months, until August 30, 2017.
This final rule establishes a new performance-based system that will require additional training for both FAA and industry engineers, as noted in the NPRM regulatory evaluation summary. Several commenters expressed concern with the need for additional training and guidance in order to implement the new performance-based standards. The FAA finds that a delayed effective date will alleviate these concerns.
Delaying the effective date will provide the FAA time to conduct the training necessary to implement this rule in a consistent manner. Additionally, the delayed effective date provides the FAA with sufficient time to develop guidance materials to ensure the FAA and industry have sufficient information to implement the new performance-based standards consistently and correctly. Furthermore, while compliance with part 23, amendment 23-62 will remain a means of compliance with this final rule, a delayed effective date will allow industry time to develop new means of compliance and will facilitate the development of harmonized means of compliance among the FAA, industry, FCAAs.
B. Overview of Comments
The FAA received 692 comments. Of the 692 comments, individuals submitted approximately 30 comments and industry and other foreign authorities submitted the remaining comments. The General Aviation Manufacturers Association (GAMA); Aircraft Electronics Association (AEA); Experimental Aircraft Association (EAA); and Aircraft Owners & Pilots Association (AOPA) (hereafter “the Associations”) collected comments from their membership and presented these jointly. The vast majority of commenters overwhelmingly supported the proposed changes and provided constructive feedback so the FAA could clarify the safety intent in various sections of this rule.
The FAA did not receive comments on the proposed changes to the following sections. These sections are adopted as proposed, and the explanations for the changes from the former regulations are contained in the NPRM.
• § 23.1515, “Instructions for continued airworthiness”
• § 35.1, “Applicability”
• § 35.37, “Fatigue limits and evaluation”
• § 91.205, “Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements”
• § 91.313, “Restricted category civil aircraft: Operating limitations”
• § 91.531, “Second in command requirements”
• § 121.310, “Additional Emergency equipment”
• § 135.169, “Additional airworthiness requirements”
C. General Public Comments
1. Rule Organization and Numbering
In the NPRM, the FAA proposed a new organization and numbering scheme for part 23. Appendix 1 to the NPRM preamble contains a cross-reference table detailing how the current regulations are addressed in the proposed part 23 regulations.
The FAA received several comments suggesting the FAA change the regulation numbering scheme for proposed part 23. Commenters expressed concern that confusion or undue complexity would result because the proposed part 23 regulations do not correlate by section number to the former part 23 regulations. Commenters also noted that certain sections of the proposed rule would have shared the same section numbers as former part 23 regulations but would have contained completely different content.
To avoid confusion, EASA proposed a new numbering system for Certification Specification 23 (CS 23)
8
and part 23, where the new regulations would not share numbers with the former regulations to emphasize the difference in content between these two sets of regulations. EASA suggested the numbering for subpart A begin at § 23.2000, for subpart B at § 23.2100, and so on, with the regulations numbers increasing by incremental steps of 5,
i.e.,
§§ 23.2005, 23.2010, and so on.
8
EASA published an Advance Notice of Proposed Amendment (A-NPA) 2015-06 on March 27, 2015, which set forth EASA's concept for its proposed reorganization of Certification Specification 23 (CS-23). EASA also published a Notice of Proposed Amendment (NPA) 2016-05 on June 27, 2016.
The FAA agrees that the proposed numbering scheme would have caused confusion and undue complexity. The FAA has considered EASA's recommended new numbering scheme for part 23 and adopts it in the final rule. This recommendation harmonizes the numbering of part 23 and CS 23 and provides new part 23 with a unique numbering scheme to avoid any confusion with former part 23. The FAA has determined the new numbering scheme also alleviates concerns about situations in which a certification basis would contain a former part 23 rule and a new part 23 rule sharing the same section number, but different subject-matter.
The FAA did not propose to change or renumber §§ 23.1457, 23.1459, and 23.1529; therefore, these sections remain as legacy rules in the new part 23.
9
9
The prescriptive requirements of §§ 23.1457, 23.1459, and 23.1529 are consistent in substance and numbering across parts 23, 25, 27, and 29.
Air Tractor, Inc. (Air Tractor) suggested that the FAA retain former part 23, amendment 23-62, and create a new part (
e.g.,
part 22) for the proposed performance-based regulations. It also suggested that proposed appendix A should remain appendix G to avoid over-writing existing appendix A.
The FAA notes Air Tractor's recommendation to retain former part 23 and to create a new 14 CFR part for the proposed regulations. However, this regulation is a rewrite of part 23 by replacing the prescriptive design requirements with performance-based airworthiness requirements, and the creation of an additional part would result in unnecessary confusion and overlap. However, the FAA will accept the use of the prescriptive means of compliance contained in former part 23 as one way to show compliance with new part 23. This will not apply to the sections containing new requirements, such as §§ 23.2135, 23.2150, and 23.2165 (proposed in the NPRM as §§ 23.200, 23.215, and 23.230). In addition, the FAA is issuing a policy statement identifying the means by which the FAA has addressed errors, findings of ELOS to various provisions of former part 23, and special conditions. This policy should be considered in defining means of compliance based on former part 23.
The FAA also considered Air Tractor's recommendation to not rename appendix G. As proposed in the NPRM, the FAA removed appendixes A through F. However, the FAA is renaming former appendix G to part 23, as appendix A to part 23—Instructions for Continued Airworthiness, because this final rule is a complete rewrite and beginning the appendices at G instead of A may cause confusion.
The following table identifies each requirement, its previously-proposed section in the NPRM, and its corresponding section in this final rule.
NPRM
Title
Final rule
Subpart A—General
§ 23.1
Applicability and definitions
§ 23.2000.
§ 23.5
Certification of normal category airplanes
§ 23.2005.
§ 23.10
Accepted means of compliance
§ 23.2010.
Subpart B—Flight
Performance
§ 23.100
Weight and center of gravity
§ 23.2100.
§ 23.105
Performance data
§ 23.2105.
§ 23.110
Stall speed
§ 23.2110.
§ 23.115
Takeoff performance
§ 23.2115.
§ 23.120
Climb requirements
§ 23.2120.
§ 23.125
Climb information
§ 23.2125.
§ 23.130
Landing
§ 23.2130.
Flight Characteristics
§ 23.200
Controllability
§ 23.2135.
§ 23.205
Trim
§ 23.2140.
§ 23.210
Stability
§ 23.2145.
§ 23.215
Stall characteristics, stall warning, and spins
§ 23.2150.
§ 23.220
Ground and watering handling characteristics
§ 23.2155.
§ 23.225
Vibration, buffeting, and high-speed characteristics
§ 23.2160.
§ 23.230
Performance and flight characteristics requirements for flight in icing conditions
§ 23.2165.
Subpart C—Structures
§ 23.300
Structural design envelope
§ 23.2200.
§ 23.305
Interaction of systems and structures
§ 23.2205.
Structural Loads
§ 23.310
Structural design loads
§ 23.2210.
§ 23.315
Flight load conditions
§ 23.2215.
§ 23.320
Ground and water load conditions
§ 23.2220.
§ 23.325
Component loading conditions
§ 23.2225.
§ 23.330
Limit and ultimate loads
§ 23.2230.
Structural Performance
§ 23.400
Structural strength
§ 23.2235.
§ 23.405
Structural durability
§ 23.2240.
§ 23.410
Aeroelasticity
§ 23.2245.
Design
§ 23.500
Structural design
§ 23.2250.
§ 23.505
Protection of structure
§ 23.2255.
§ 23.510
Materials and processes
§ 23.2260.
§ 23.515
Special factors of safety
§ 23.2265.
Structural Occupant Protection
§ 23.600
Emergency conditions
§ 23.2270.
Subpart D—Design and Construction
§ 23.700
Flight control systems
§ 23.2300.
§ 23.705
Landing gear systems
§ 23.2305.
§ 23.710
Buoyancy for seaplanes and amphibians
§ 23.2310.
Occupant System Design and Protection
§ 23.750
Means of egress and emergency exits
§ 23.2315.
§ 23.755
Occupant physical environment
§ 23.2320.
Fire and High-Energy Protection
§ 23.800
Fire protection
§ 23.2325.
§ 23.805
Fire protection in designated fire zones and adjacent areas
§ 23.2330.
§ 23.810
Lightning protection
§ 23.2335.
Subpart E—Powerplant
§ 23.900
Powerplant installation
§ 23.2400.
§ 23.905
Propeller installation
not adopted.
§ 23.910
Powerplant installation hazard assessment
§ 23.2410.
§ 23.915
Automatic power or thrust control systems
§ 23.2405.
§ 23.920
Reversing systems
§ 23.2420.
§ 23.925
Powerplant operational characteristics
§ 23.2425.
§ 23.930
Fuel system
§ 23.2430.
§ 23.935
Powerplant induction and exhaust systems
§ 23.2435.
§ 23.940
Powerplant ice protection
§ 23.2415.
§ 23.1000
Powerplant fire protection
§ 23.2440.
Subpart F—Equipment
§ 23.1300
Airplane level systems requirements
§ 23.2500.
§ 23.1305(a)(1)
§ 23.1305(a)(3),(b),(c)
Function and installation
Installation and operation
§ 23.2505
§ 23.2605.
§ 23.1310
Flight, navigation, and powerplant instruments
§ 23.2615.
§ 23.1315
Equipment, systems, and installations
§ 23.2510.
§ 23.1320
Electrical and electronic system lightning protection
§ 23.2515.
§ 23.1325
High-intensity Radiated Fields (HIRF) protection
§ 23.2520.
§ 23.1330
System power generation, storage, and distribution
§ 23.2525.
§ 23.1335
External and cockpit lighting
§ 23.2530.
§ 23.1400
Safety equipment
§ 23.2535.
§ 23.1405
Flight in icing conditions
§ 23.2540.
§ 23.1410
Pressurized system elements
§ 23.2545.
§ 23.755(a)(3)
Equipment containing high-energy rotors
§ 23.2550.
§ 23.1457
Cockpit voice recorders
§ 23.1457.
§ 23.1459
Flight data recorders
§ 23.1459.
Subpart G—Flightcrew Interface and Other Information
§ 23.1500
Flightcrew interface
§ 23.2600.
New
Installation and operation
§ 23.2605.
§ 23.1505
Instrument markings, control markings and placards
§ 23.2610.
New
Flight, navigation, and powerplant instruments
§ 23.2615.
§ 23.1510
Airplane flight manual
§ 23.2620.
§ 23.1515
Instructions for continued airworthiness
§ 23.1529.
Appendices
Appendix A to Part 23
Instructions for Continued Airworthiness
Appendix A to Part 23.
2. Level of Safety
In the NPRM, the FAA proposed amendments to part 23 to create an adaptive regulatory environment that could quickly embrace new safety-enhancing technologies and potentially increase the level of safety.
Wipaire, Inc. (Wipaire) viewed the proposal as allowing new and emerging technologies an effective means of certification, but one which offered little economic and certification relief to currently-established methods and technologies.
An individual commenter noted that the proposal would allow industry to push new techniques, materials, procedures, and targets without being hindered by the prescriptive requirements of former part 23. However, the commenter stated that the proposal could allow subpar designs to exist before the data suggests a failure in compliance.
The National Transportation Safety Board (NTSB), while recognizing consensus standards provide “a collaborative framework for standards development,” commented on a situation where, in its view, consensus standards did not provide adequate protection from catastrophic aerodynamic flutter. The NTSB expressed concern that design standards important for safety consideration may be overlooked, and it encouraged the FAA to refine its methodology.
The FAA understands the concerns over the level of safety required by the performance standards. However, by leveraging the expertise of consensus standards organizations and FAA specialists in determining whether those standards are acceptable, those means of compliance should provide at least the same level of safety as under the former process.
The FAA will continue to be responsible for determining that proposed airplane designs meet the applicable standards and ensuring that the proposed standards provide at least the same level of safety as did the former standards. Under new part 23, the first time an applicant presents a new proposal for a means of compliance, the FAA will require sufficient time and resources to determine whether it does, in fact, meet the objectives of those standards. This is the same process as under the former prescriptive standards. However, once the proposed means of compliance is determined to meet these standards, the approval process becomes more efficient. The FAA will no longer be required to issue special conditions (or other formal processes) to approve the means of compliance each time it is proposed, but can accept those means of compliance immediately as it is proposed.
3. Accommodating Hybrid and Electric Propulsion
In the NPRM, the FAA recognized that historical general design and performance assumptions may not be valid today. The FAA noted that former part 23 did not account for airplanes equipped with new technologies, such as electric propulsion systems, which may have features entirely different from piston and turbine engines. The FAA therefore proposed new regulations based on airplane performance and potential risk.
With respect to allowing new technologies, the Associations and Zee.Aero Inc. (Zee) were particularly concerned with the accommodation of alternative engines. The Associations stated that hybrid and electric propulsion is one of the near-term significant technological developments which absolutely must be accommodated into the new part 23 regulations structure.
Zee also commented on the advancements in hybrid and electric propulsion. Zee noted that new hybrid propulsion, control, and airframe configurations are already beginning to blur the lines between the traditional airplane categories. Zee questioned whether the FAA intends to continue to maintain strict airplane categories and create a new “category” every time a new unique category configuration emerges. Lastly, Zee noted that § 21.17(b) currently captures such airplane and wondered whether that section would become the norm for those cases.
The regulations adopted in this final rule do allow for alternative types of propulsion. The FAA does not intend to continue to use § 21.17(b) for unique category airplanes. The FAA plans to shift these unique airplanes from § 21.17(b) to part 23. Unique airplane that more closely resemble rotorcraft may be treated differently.
4. Impact of Rule on FAA Engineers and Designated Engineering Representatives (DERs)
In the NPRM, the FAA proposed changes to part 23 that would eliminate the workload of exemptions, special conditions, and ELOS findings necessary to certificate new part 23 airplanes. The NPRM did not specifically address the role of Designated Engineering Representatives (DERs) in the proposed process.
Several commenters addressed the impacts of the proposed rule changes on FAA engineers and DERs.
NetJets Association of Shared Aircraft Pilots (NJASAP) and Kestrel Aircraft Company (Kestrel) expressed concern that the process intended to streamline technological adoption may significantly increase the FAA's workload. Kestrel contended the increased workload for FAA engineers will create certification bottlenecks at the Aircraft Certification Offices (ACOs) as their staff work to understand and implement the changes.
The FAA recognizes workload during the transition to the new system may increase temporarily for industry and the FAA. Under the former part 23, the FAA had a workload of exemptions, special conditions, and ELOS findings necessary to certificate new part 23 airplanes. However, the FAA has determined in the long term, the workload for industry and the FAA will be less than the workload under former part 23. As estimated in the NPRM's regulatory evaluation summary, there will be savings resulting from streamlining the certification process by reducing the issuance special conditions, exemptions, and ELOS findings. The NPRM and final rule regulatory evaluation provides details for these cost savings and the methodology the FAA employed to estimate the cost savings.
Other commenters expressed concerns about how the DER process will fit in with the new regulations. Air Tractor questioned whether DERs will find compliance with accepted means of compliance. The National Air Traffic Controls Association (NATCA) asked whether DERs will issue acceptance statements or approvals. NATCA asked how the FAA will change the designee policy and asked whether the FAA intends to accept or approve the standards. Textron Aviation (Textron) requested clarification of the FAA's transition plan regarding Organization Designation Authorization (ODA) and DER delegations, in particular regarding continuity of authority from the old amendments to the new.
In response to concerns regarding the role of the DERs and ODA engineers, the FAA is developing transition training for the FAA engineers, ODA engineers, and the DERs. The FAA is also reviewing the relevant orders and policies for needed changes, but does not expect changes to the basic certification process as the FAA engineers and industry designees will still be responsible for finding compliance to the requirements in part 23. Furthermore, the FAA is developing a change management plan that will include formal training for both FAA engineers and staff and industry designees. Under existing policies and processes, designees must demonstrate the capability to make correct determinations of compliance with particular regulations before they are authorized to do so. This is unchanged by this rule. To the extent an applicant uses previously-accepted methods of compliance for which the designee has demonstrated such capability, the FAA may delegate compliance findings. If an applicant is proposing a new method of compliance, the designee's authority may be limited to only recommending a finding of compliance.
Kestrel contended standardization among ACOs would likely decrease due to lack of clearly-defined criteria and that divergent certification expectations would exacerbate existing issues of inconsistent application and interpretation of requirements.
While this final rule adopts high-level performance standards, the FAA intends to ensure consistent application through the process for determining the acceptability of their means of compliance. The FAA's certification standards staff will determine whether proposed consensus standards are acceptable and, if so, will publish a notice of availability of those standards in the
Federal Register
. The FAA will also maintain a publicly-available list of consensus standards that have been found to be acceptable as methods of compliance.
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For methods of compliance submitted by individual applicants, the FAA will continue to use the existing issue paper process, which includes full coordination with the standards staff to ensure standardization. The FAA recognizes the importance of having an internationally accepted means of compliance for part 23 airplanes. The FAA believes once there are internationally accepted means of compliance available, manufacturers may be reluctant to bypass these harmonized means to develop their own, unless they have an innovative process or new technology not already addressed. In either case, the FAA's processes should ensure flexibility and transparency to the extent permitted without violating proprietary interests of entities developing methods of compliance. Allowing for innovation and new technology is a major goal of this rule.
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As discussed in the NPRM, the FAA will have a similar process for determining whether a previous acceptance of a method of compliance should be rescinded, based on new information or service experience.
In response to NTSB's concerns about new technology, the FAA finds that shifting compliance emphasis to industry consensus standards is critical to ensuring the safety of new
technology. This shift will allow the FAA to leverage technical experts from across the aerospace industry and from outside the traditional aerospace industry to develop standards for new technologies.
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11
National Transportation Safety Board,
Auxiliary Power Unit Battery Fire, Japan Airlines Boeing 787-8, JA829J, Boston, Massachusetts, January 7, 2013,
AIR-14/01 (Washington, DC: NTSB, 2014).
5. Necessity of Training
In the NPRM's regulatory evaluation, the FAA assumed that FAA and industry part 23 certification engineers would require additional training as a result of this rule.
Some commenters expressed concern with training needs required by a new system. Kestrel noted the proposed rule would increase the workload of DERs, primarily because they will require additional training and FAA coordination to ensure proper understanding and implementation of the new certification process. NATCA noted the significant changes to part 23 will necessitate training of all FAA engineers, DERs, and ODA engineers. In particular, NATCA said designees and ODAs cannot be authorized to find compliance to part 23 until trained or demonstrated competence. NATCA recommended the FAA amend its delegation and ODA policy documents to reflect the changes to part 23 and implement training as soon as possible.
The NTSB expressed concern about increased demand on FAA engineers to evaluate new technologies as a result of the proposed changes to part 23. It suggested the FAA may face challenges similar to those encountered with the certification of the lithium-ion batteries in the Boeing 787, including insufficient guidance and education to ensure compliance with applicable requirements. The NTSB pointed to several safety recommendations it issued to the FAA in the wake of a lithium-ion battery incident in a Boeing 787 in 2013, which centered around developing and providing adequate written guidance and training to certification engineers.
The FAA agrees guidance and training are necessary and has delayed the effective date of this rule in order to complete the training development and implementation for ACOs, DERs, and industry. The FAA will continue to review orders and policies for needed changes.
6. Need for Revised or New Agency Guidance and Directives
The FAA proposed Advisory Circular (AC) 23.10,
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Accepted Means of Compliance, to provide applicants guidance on the process of submitting proposed means of compliance to the FAA for consideration by the Administrator. The FAA also indicated in the NPRM that it would provide guidance as it determines what satisfies the performance-based standards.
12
See docket number FAA-2015-1621.
NATCA requested the FAA publish new or revised Orders and policy documents for public review and comment prior to the issuance of the final rule. For example, how would a certification engineer recognize what is a “good compliance showing” to a new part 23 requirement and how would that engineer explain the compliance showing to an authorized representative of the Administrator. Also, how would a certification engineer minimize or avoid allegations from an applicant that the engineer is being inequitable in the application of the new part 23 requirement compared to how the requirements have been applied to other applicants.
NATCA noted applicants often use legal processes for approval of type design changes to obtain less expensive or extensive certification requirements for a design proposal, and that the “number of seats” has been used previously to finesse operating requirements applicability. NATCA questioned whether the FAA will permit this under new part 23 as established by the airplane certification levels and whether there will be any check or limitation or safety judgment made on this potential use of new part 23. NATCA requested the FAA publish an Order or policy addressing this issue.
One commenter was concerned the FAA will eventually leave the task of developing ACs for means of compliance to consensus bodies and individual applicants and opposed a system where public domain guidance must be purchased from a private entity. The commenter suggested that even if the FAA decides to discontinue updating its guidance, it should retain control and continue to permit the use of its existing guidance as well as provide a list of guidance with its status.
The FAA agrees with NATCA that updated guidance is needed and is in the process of reviewing current orders and policies and will use existing processes to implement those changes. The FAA also recognizes the potential that some applicants will attempt to “finesse” the applicability of requirements for higher airplane certification levels by limiting the maximum passenger capacity of their proposed designs. This potential is inherent in any attempt to establish different levels of safety based on the concept of the “safety continuum.” The disincentive for such finessing is the reduction of functionality, and therefore profitability, of the resulting design.
The FAA will continue to use all applicable ACs associated with part 23. Applicants will need to use the cross-reference table in this final rule preamble because the ACs will continue to reference the former section numbers. The FAA will expand the guidance in these ACs to better address the range of part 23 airplanes identified in industry consensus standard documents. The FAA has no plans to cancel the current ACs because they are still needed for older airplane modifications; therefore, the applicable ACs will still be available to applicants. Consensus standards bodies will develop means of compliance with the new regulations. The FAA will continue to develop ACs, as needed, to provide guidance to the public on what means of compliance would be acceptable. These functions are distinct, but complementary.
7. Inconsistent Language
In the NPRM, the FAA proposed to remove prescriptive design requirements and replace them with performance-based airworthiness standards.
Some commenters expressed concern with the lack of concreteness in the proposed regulations. Transport Canada stated the standards required the definition of a safety objective to clarify the meaning of some terms. The National Agricultural Aircraft Association (NAAA) was concerned the proposed regulations could result in inconsistent interpretations. NATCA viewed the rules as too “stripped down” for non-experienced people and commented that the use of “vague” terms would make it difficult to apply the new rules. Air Tractor contended the proposed rules consolidated existing requirements into fewer “general” or “vaguely” worded rules.
Other commenters addressed perceived inconsistencies in the language of the proposed revisions to part 23. The Associations noted some of the proposed rules focused on the applicant while others focused on the airplane.
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These commenters observed
it is important that the language of part 23 does not contradict part 21, which establishes the procedures for obtaining design approvals. The commenters recommended the FAA adopt the regulatory language used elsewhere in the airworthiness standards, which impose requirements on the airplane design.
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For example, some of the proposed rules stated “the applicant must show” or “the applicant must
demonstrate,” while others stated “the airplane must.”
The FAA recognizes the final rule uses high-level performance standards, and in some cases, the requirements are not tightly specified. However, the FAA finds that tight specification is not needed as this final rule is consistent with the safety objectives of the former prescriptive standards. The cross-reference table in this final rule identifies what sections of this final rule are intended to meet the safety objectives of the former regulations. Because this final rule is intended to achieve at least the same level of safety as the former regulations, this comparison may be used as a guide to the various levels of acceptable risk associated with each section.
In response to the comment raised by GAMA and others, part 21 imposes obligations on applicants for design approvals; therefore, the references to the applicant in this final rule are consistent.
8. Need for Additional Provisions in Part 23
NATCA recommended the FAA add several provisions to part 23, including a requirement about loss of propeller or propeller control, provisions defining the levels of software certification needed, requirements that address impact protection from unmanned aircraft systems (UAS), and provisions about the introduction of new technologies.
The FAA considered NATCA's comments; however, the FAA declines to adopt NATCA's recommendations at this time. The FAA is not adding requirements about loss of propeller or propeller control and provisions defining the levels of software needed because these are more appropriately addressed in means of compliance. The FAA also finds it unnecessary to include specific provisions about the introduction of new technologies because all the regulations in new part 23 are intended to allow the introduction of new technologies. Furthermore, it would be outside the scope of this rulemaking to add requirements addressing impact protection from UAS.
9. Development of Standards
In the NPRM, the FAA described how industry groups associated with the Part 23 ARC discussed the development of consensus standards and how the ARC selected ASTM as the appropriate organization to initiate this effort.
NATCA expressed concerns the FAA was relinquishing standardization and stated the FAA needed to articulate an expected minimum technology maturity level.
The FAA's process for reviewing applicant's submissions to verify compliance with the safety standards will address NATCA's concern regarding technology. This review process will not change from the way the FAA currently reviews an applicant's regulatory compliance. One of the purposes of this rule is to provide greater flexibility to applicants in showing they meet the objectives of the safety standards, and thus “standardization” in the strictest sense goes against this purpose. Similarly, with respect to minimum technology level, another purpose of this rule is to spur innovation and technology adoption. Therefore, requiring a certain technology maturity level would contradict that purpose.
10. Restricted Category Agricultural Airplanes
In the NPRM, the FAA did not specifically address single-engine agricultural airplanes.
The NAAA commented that AC 21.25-1, Issuance of Type Certificate: Restricted Category Agricultural Airplanes, is currently used by the FAA to determine which part 23 certification requirements should not be part of an airplane's TC under § 21.25. NAAA questioned how the requirements found inappropriate for single-engine agricultural airplanes in AC 21.25-1 will influence the certification process.
The FAA notes the cross reference table located in this final rule correlates the sections referenced in AC 21.25-1 with the new regulations and associated means of compliance. Long term, the FAA recommends NAAA work with the FAA to develop means of compliance specific to restricted category agricultural airplanes.
11. International Cooperation Efforts
In the NPRM, the FAA indicated the part 23 rulemaking was a harmonization project between the FAA and EASA. EASA published an Advance Notice of Proposed Amendment (A-NPA) 2015-06 on March 27, 2015, which set forth EASA's concept for its proposed reorganization of CS 23. The FAA received several comments on harmonization.
Garmin International (Garmin) and Agencia Nacional De Aviacao Civil Brazil (ANAC) commented on the significant differences between the NPRM and EASA's A-NPA. Garmin encouraged the FAA and EASA to resolve all differences before publishing their final regulations. Textron stressed the importance of harmonizing rule language with other major global certification authorities because a lack of harmonization would call into question whether one set of consensus standards would be adequate to achieve certifications worldwide. Textron expressed disappointment that the FAA's NPRM and EASA's A-NPA were not better aligned prior to publication. Textron explained the goal should be 100 percent harmonization with no exceptions. Garmin and Textron both commented on the significant costs that non-harmonized regulations would have on the industry.
EASA commented on the importance of using, as much as possible, the same text in CS 23 and part 23. EASA explained, however, that CS 23 was more of a technical standard, while proposed part 23 addressed the applicant's responsibility. To better align with CS 23, EASA suggested that the FAA require “the applicant's design” to meet certain requirements rather than “the applicant.”
Optimal Aerodynamics Ltd (Optimal) recognized the harmonization efforts that have taken place, but sought reassurance from the FAA that revisions to part 23 would not lead to greater differences with other CAA's certification standards. Assuming CS 23 aligns with part 23, Optimal asked if it would be possible to base compliance on EASA's revised CS 23 when applying to the FAA for certification under new part 23.
The FAA agrees that harmonization with EASA's standards is important. While identical language is not the goal, the FAA has worked closely with EASA to ensure the same basic requirements for part 23 and CS 23 in order that both authorities can accept the same set of industry means of compliance. For example, as discussed previously, references to the applicant's obligations (“the applicant must”) are consistent with part 21 and with EASA's counterpart requirement that applicants “show” compliance. To further this effort, the FAA has met with EASA,
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received comments from EASA, and submitted comments on EASA's A-NPA. EASA incorporated many of the
FAA's comments on its A-NPA into its Notice of Proposed Amendment (NPA), published on June 23, 2016. In addition, the FAA incorporated many of EASA's comments to the NPRM into this final rule, such as including two new sections in Subpart G.
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See docket number FAA-2015-1621-0062.
12. Part 23 ARC Recommendations and the Existing Fleet
As previously discussed in more detail, the FAA chartered the Part 23 ARC in 2011 to consider the reorganization of part 23 based on airplane performance and complexity and to investigate the use of consensus standards. The Part 23 ARC's recommendations were published in 2013 and are available in the docket.
Textron, Garmin, and several individuals commented on those ARC recommendations that were not proposed in the NPRM. In particular, these commenters requested the FAA adopt changes to 14 CFR part 21, “Certification Procedures for Products and Articles”; part 43, “Maintenance, Preventive Maintenance, Rebuilding, and Alteration”; and part 91, “General Operating and Flight Rules”; as recommended by the ARC. These comments related to type certification procedures and airplane maintenance and operations. Similarly, several commenters requested the FAA adopt the ARC's recommendation to establish a “Primary Non-Commercial Category” (PNC), which also would have required revisions to part 21.
Several individual commenters noted that regulations applicable to existing airplanes make it difficult and expensive to implement safety improvements on those airplanes. These commenters questioned whether this rulemaking will address those issues.
While the FAA recognizes the commenters' concerns regarding the need to minimize the certification process burden, the FAA is not making additional changes to parts 21 or 43 because they are outside the scope of this rulemaking. The intent of this rulemaking is to remove the prescriptive design requirements from part 23 and replace them with performance-based airworthiness requirements. The FAA is, however, contemplating a future rulemaking that would make additional changes to part 21.
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15
The Part 21 SMS ARC published its recommendation reports (appendix A-G and appendix H-P) on January 14, 2015. Copies can be downloaded from the FAA Advisory and Committee site at
http://www.faa.gov/regulations_policies/rulemaking/committees/documents/
.
The FAA also considers the commenters' recommendations to create a PNC category for aging General Aviation (GA) airplanes to be outside the scope of the NPRM. The FAA did not propose to create a PNC category for aging GA airplanes, as the ARC recommended, because it is also out of scope of this rulemaking. However, the FAA is working to address the ARC recommendations that focused on the existing fleet and part 21 processes.
With respect to the existing fleet, the FAA does not expect the revisions to part 23 to provide immediate benefits to older airplanes. However, when an owner of an older airplane applies for a change to the airplane's TC in accordance with § 21.101, the applicant may choose to use the more flexible performance-based standards. In addition, as discussed later, the revision to § 21.9 will enable expedited approval of certain parts that will benefit the existing fleet.
13. Impacts of the Proposed Rule on the Existing Fleet and on Open/Active Projects
The FAA received several comments on impacts to the existing fleet and on open/active projects.
Kestrel and Garmin asked how, under the proposed rule, the FAA will address active projects, derivative airplanes and changes to existing models. Kestrel noted § 21.101 requires regulatory compliance with the latest amendment while permitting certification on a case-by-case basis to an earlier amendment for changes to existing models and derivative airplanes. Kestrel noted it is common for applicants to receive significant compliance credit on the basis of “similarity/identicality.” Kestrel asked how the FAA would grant permission for an applicant for a derivative airplane to certify entirely to a previous amendment.
As discussed in the NPRM, the applicant has the option of using former part 23, amendment 23-62, as a means of compliance with new part 23 (except in the areas where this final rule raises the level of safety, as discussed previously). Since the new rule, combined with this accepted means of compliance, is identical to the former part 23 requirements (with exceptions noted in this preamble), methods of showing compliance—including “similarity/identicality”—are not affected for changes to existing airplane models. Furthermore, § 21.101 only requires regulatory compliance with the latest amendment for airplanes weighing more than 6,000 pounds. Section 21.101 also provides relief for airplanes weighing more than 6,000 pounds when the change is not significant or when compliance with a later amendment would not contribute materially to the level of safety or would be impractical
Garmin requested more details on the changes the FAA believes would streamline the process for design approval and lower costs and project delays. Garmin also asked the FAA to clarify how existing special conditions, ELOS findings, and exemptions would be handled if an applicant wants to “step up” to the new amendment.
The FAA has determined the cost and time savings will result from the greater flexibility afforded by this final rule to both applicants and the FAA to find compliance for innovative new technologies. For traditional designs, the FAA expects applicants will be able to use the new part 23 in the same way older Civil Air Regulation, part 3 (CAR 3) airplanes are modified using former part 23 regulations. The FAA will still find compliance with the regulations, and since the new regulations allow greater flexibility by relying on accepted means of compliance, there should be little need for special conditions, ELOS findings, or exemptions, all of which require additional cost and time.
An individual and Air Tractor expressed concern over third-party modifiers of airplanes who were not part of the original certification process. The commenters suggested a third-party modifier could propose its own means of compliance and regard it as proprietary, which may conflict with the means of compliance used in the original basis of certification. The commenters were concerned an STC or field approval could become more difficult and create more work for the FAA.
The FAA notes the situation raised by the commenters currently exists with proprietary means of compliance, and this will not change with the new performance-based regulations. As under the former regulations, STC applicants will continue to be required to demonstrate that their changes, and areas affected by the changes, comply with the applicable regulations. The FAA anticipates no increased potential for conflict with the original design.
NATCA recommended the FAA make changes to the general definitions of 14 CFR 1.1 concurrently with the part 23 rewrite, including revising the definition of “consensus standard” because it applies to more than Light-Sport Aircraft (LSA), adding the definition of “proprietary standard,” and reconciling the differences between the International Civil Aviation Organization (ICAO) airplane categories and the new definitions in part 23.
The FAA has determined there is no need to define the terms, “consensus
standard” and “proprietary standard” in this final rule. The current definition of “consensus standard,” by its terms, applies only to LSA. For purposes of this final rule, “consensus standard” has the meaning established in SARA, as discussed previously. The FAA does not use the term “proprietary standard” in the regulations adopted by this final rule. Finally, the FAA notes the definitions of the categories need to remain the same because this final rule does not change their applicability to the existing fleet of airplanes. Also, the difference between the ICAO airplane standards and part 23 categories is based on weight and this rule does not affect that difference.
While NJASAP supported the LOC In-Flight and SLD safety enhancements, it stated runway excursions are another significant risk. NJASAP supported requiring secondary or emergency braking systems and recommended a requirement for powerplant reversing systems to be installed on all level 3 and 4 high-speed airplanes to help reduce the top three accident types. For the goal of reducing loss-of-control accidents, NJASAP supported—along with other aerodynamic improvements—the FAA requiring a device that gives a trained pilot immediate feedback on the status of the airplane's wing. NJASAP recommended level 3 high-speed airplanes be included in the safety enhancements required for level 4 airplanes because they will be flying similar missions, and Original Equipment Manufacturers (OEMs) will target the level 3 certification category and stop certifying as many level 4 airplanes.
The FAA finds that requiring emergency braking systems and powerplant reversing systems is beyond the scope of this rulemaking and would add additional costs. Requiring a device that gives a trained pilot immediate feedback on the status of the wing is also beyond the scope of this rulemaking, but a device like this could be used (and the FAA encourages its use) as part of the low-speed stall protection. Furthermore, the design specific nature of these recommendations is inconsistent with the FAA's goal of performance-based requirements in this rule revision. The new rule structure will allow for these alternative devices.
The FAA considered NJASAP's recommendation that level 3 airplanes be included in the level 4 safety enhancements because of levels 3 and 4 airplanes' similar missions. In this final rulemaking, the FAA retains the traditional approach of drawing safety distinctions based on airplane capacity and operational risk.
The NTSB commented on the proposed rule's focus on qualitative design methodologies, but recommends the use of both quantitative and qualitative design methodologies as the FAA has done historically. The NTSB pointed to proposed §§ 23.305 and 23.1315 and the continued reliance on the requirements of former § 23.1309, which only addresses the effects of single failures. The NTSB contended that the consideration of multiple failures should be required in the revised part 23 when active systems may potentially be used in commercial operations and the airplane may be more complex.
The FAA's intent in this rule is to maintain the current level of safety. The FAA is currently engaged in rulemaking for transport airplanes to address the NTSB's concerns. Depending on the outcome of that rulemaking, the FAA may consider similar rulemaking for part 23 in the future.
14. Legal Issues
In the NPRM, the FAA proposed to accept consensus standards as a means of compliance with the new part 23 performance-based regulations. Abbott Aerospace SEZC, Ltd. (Abbott) and Kestrel questioned the legality of using ASTM as a means of compliance.
Abbott stated the proposed change is illegal as the new ASTM standards constitute de facto law despite being labelled “advisory” and are the only realistic path to certify an airplane. Abbott claimed this mislabeling will lead to confusion and cause industry to incur the cost of purchasing the ASTM standards under the belief that they constitute law and that compliance is mandatory.
Kestrel also questioned the legality of relinquishing FAA guidance to a private entity and of using ASTM as the single standards body. Kestrel opposed handing over public domain guidance to a private entity for creation of its own standards, which will be provided back to the industry for a fee. Kestrel suggested the FAA retain control and continue to permit the use of its existing guidance.
In light of the comments, the FAA reviewed its approach to use consensus standards as means of compliance with this rule. On November 27, 2013, the President of the United States signed SARA whereby Congress mandated the FAA use consensus standards to clarify how safety objectives may be met by specific designs and technologies. SARA also requires the FAA to comply with the “National Technology Transfer and Advancement Act of 1995” (NTTAA), which directs Federal agencies to use voluntary consensus standards in lieu of government-mandated standards when practicable. This rulemaking also complies with the Office of Management and Budget (OMB) Circular A-119, “Voluntary Consensus Standards,” which provides guidance on how to comply with NTTAA. OMB Circular A-119 specifically addresses the issues raised by the commenters and establishes the policy that agencies should consider cost to regulated entities of using consensus standards as one factor in determining whether those standards are “reasonably available.” The FAA has considered the cost of ASTM standards and determined, for purposes of this rulemaking, ASTM standards are reasonably available because the interested parties have access to them through their normal course of business and the price is low enough that interested parties can easily purchase them.
In addition, ASTM will not create de facto law nor be the single standard-setting body, or custodian of public domain documents. The FAA expects to accept means of compliance from individuals, companies, and other standards bodies, including ASTM. While the use of a previously accepted means of compliance will likely expedite the certification process, no applicant will be required to use ASTM or any other means of compliance. Instead, an applicant may propose its own means of compliance for acceptance, or demonstrate compliance to the new rule by using the prescriptive provisions in former part 23 and supporting guidance—all of which will remain publically available. As discussed in the NPRM, the long-term benefit and cost reduction provided by this rule is that it will allow the introduction of new technologies without the formal processes that currently increase certification costs and inhibit innovation.
The American Association of Justice (AAJ) commented that the new part 23 performance standards should not preempt state tort law because state tort law functions as a necessary adjunct to federal regulations that impose only minimum standards of care. AAJ urged the FAA to avoid any language that could allow the new standards to be construed as preempting state law for defectively designed or produced airplane, or characterizing the standards beyond what is authorized by the Federal Aviation Act.
AAJ's comment regarding preemption of state tort law in aviation cases was
not a topic of this rulemaking. Rather, it is the subject of current litigation in federal court regarding interpretation of the FAA's enabling legislation. The outcome of that litigation is neither the subject of this rulemaking, nor will this rulemaking affect that outcome. However, as noted by the Supreme Court in previous litigation, it is the applicant's obligation to comply with airworthiness standards; the FAA cannot guarantee such compliance.
15. Regulatory Evaluation
The FAA received comments from five commenters (four companies and one individual) on the summary of the regulatory evaluation published as part of the NPRM. In the NPRM regulatory evaluation, the FAA requested that commenters include data supporting their comments, but no commenter submitted any cost or benefit data with its comments.
a. General
Kestrel stated that all applicants will benefit from decreased certification costs and hopes the cost savings are tangible and can be realized in a short time frame; however, Kestrel anticipates an increased workload after the rule is adopted to train its personnel on the new standards. Abbott, Air Tractor, and one individual commenter characterized the cost benefit analysis as incomplete.
In the NPRM, the FAA stated that if the proposed rule saves only one human life—for example, by improving stall characteristics and stall warning—that alone would result in the benefits outweighing the costs of the rule change. Air Tractor characterized this statement as “vacuous.” Air Tractor went on to comment that its industry places a high value on protecting human life and expends enormous energy, talent, and resources to protect it.
The FAA intended this statement as a simplified break-even analysis of the likely benefits of the proposed rule. It was not intended to replace the costs and benefits detailed in the regulatory evaluation. The complete regulatory evaluation, located in the docket, is more comprehensive than the summary that appears in the NPRM preamble and contains the estimates provided to the agency by industry.
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16
See Docket Number FAA-2015-1621.
Abbott stated there was no clear indication of how the proposed change would reduce net cost or expedite the certification process. Abbott concluded there were “potential significant additional” costs created by the proposed rule, but no obvious or defined cost reduction. Abbott characterized the proposed regulations as having an unknown cost impact and stated these unknown costs represent a yet-unassessed and unavoidable cost for airplane developers. Abbott also stated that any additional cost the proposed rule places on industry that is not offset by cost reduction elsewhere does harm to the industry.
The FAA notes that under the proposed rule, applicants may choose to use an industry consensus standard, the former part 23 standards (available at no cost), or its own means of compliance accepted by the Administrator. The FAA presumes an applicant will use these options to make the best economic choices given the circumstances of design and development for its product. Such choices are an inherent strength of a performance-based standard, but cannot effectively be analyzed for costs or benefits, especially if a design encompasses new technology that was never subject to the former regulation. Similarly, the FAA cannot predict the viability of the products or the financial health of an unknown start-up company under a regulation that allows for, but does not require, its products be used in any airplane design.
b. Impact on Small Entities
Air Tractor commented the FAA's analysis of the proposed rule impact on small entities did not include Air Tractor and Thrush Aircraft (Thrush).
Air Tractor was concerned that data from only 5 entities was used in the regulatory flexibility analysis. It noted the FAA should have included every company that has active manufacturing activities and the data used were non-representative of the overall industry. Air Tractor also indicated the inclusion of Thrush and itself would have doubled the number of employees and annual revenues represented in the analysis. Additionally, Air Tractor believed the FAA should have also included the TC holders of small airplanes that are no longer being manufactured but require TC support and STC holders that certificate products to the part 23 standards.
Finally, Air Tractor concluded that the omission of non U.S.-owned entities that “operate” in the United States presented a “distorted view of the true impact” of the proposed rule on the general aviation industry in the United States.
The FAA conducted its analysis in accordance with the “Small Business Regulatory Flexibility Act.” For each regulatory flexibility analysis, an agency is required to provide a description of and, where feasible, an estimate of the number of small entities to which its proposed rule would apply. Many, if not most, small entities do not provide publically available information such as employment data that would allow an agency to determine if a business qualifies as a small entity under the guidelines of the Small Business Administration (SBA). Nor is there publicly available revenue data for these entities that make it possible to determine the burden of a proposed or final rule on these entities. The FAA does not have the authority or the means to require any entity to report its employment or revenue data. Accordingly, the FAA does not have the requisite knowledge of every company that still has active manufacturing activities that might be subject to the proposed rule.
The small business entities the FAA used in its analysis had provided data on their employment and revenue either through the regulations of U.S. DOT Form 41, the Securities and Exchange Commission, or through news releases that the entities made public. Neither Air Tractor nor Thrush have such data on record, and Air Tractor did not provide employment or revenue data for itself as part of its comment.
The five entities examined as part of the FAA's analysis qualified as small entities under the SBA criteria and were either actively manufacturing airplane or were under new ownership and had publically announced they were working toward setting up an airplane manufacturing line that would be subject to part 23. Airplanes previously certificated under part 23 will not be affected by the regulations affecting new certifications, so TC holders of operating airplanes who are not actively seeking some certification are not appropriately excluded from the analysis. The same holds true for STC holders that used the part 23 standards in effect at the time of these airplane original certifications.
The regulatory flexibility analysis conducted for the proposed rule did not include any non-U.S. entities because, similar to the domestic firms referenced above, the employment and revenue information required for the analysis was not publicly available.
c. Icing
Textron stated that although the FAA identified a need for improved certification standards for operation in severe icing conditions, it did not provide a cost benefit analysis to show that part 23 airplanes would benefit from them.
The FAA did conduct a cost benefit analysis of the icing requirement. Flying into icing is risky and the ARC identified part 23 airplane icing
accidents. The FAA contacted industry, and some Part 23 ARC members indicated to the FAA that the new rule and standards reflect current industry practices for detecting and exiting icing conditions. Additionally, the rule to certify that the airplane can operate safely in SLD is voluntary. When compliance is voluntary, or no change in industry practice will occur from a new regulation, the FAA determines the rule to be minimal cost. This determination was made in the initial regulatory impact analysis and is made in the final regulatory impact analysis.
In the NPRM, the FAA proposed that for a part 23 airplane to be certificated to fly in known icing conditions, an applicant would have to demonstrate operation in the icing conditions defined in part 25 appendix C. This requirement did not change from the former part 23 requirements. As a safety matter, for many years airplanes currently certificated under part 23 have demonstrated the ability to detect and safely exit from freezing rain and freezing drizzle conditions.
The standards and requirements for the various icing certification levels were discussed extensively with the Part 23 Icing ARC (Icing ARC) and the Part 23 ARC. The new rule and standards for detecting and exiting freezing drizzle and freezing rain are consistent with and include significant parts of the Icing ARC's recommendations.
d. Part 23 Limitation
Textron recommended the FAA change the limitation on part 23 airplanes from its proposed gross takeoff weight limit of 19,000 pounds (maintaining the current part 23 limit) to a maximum payload limitation of 6,000 pounds. Textron stated the change would have a dramatic positive impact on the potential costs and benefits of the proposed change.
This change is beyond the scope of this rulemaking for the FAA to consider. This change was not proposed by the FAA and would be a fundamental change to part 23 that could potentially affect certification of airplanes under part 25.
e. Reporting and Recordkeeping Requirements
The FAA stated it expected minimal new reporting and recordkeeping requirements would result from the proposed rule and requested comments on this finding. The FAA received no comments on reporting or recordkeeping requirements.
Therefore, the FAA adopts the regulations as proposed, and will make no change to the regulatory evaluation regarding the reporting and recordkeeping requirements.
16. Out of Scope Statement
Several commenters requested changes to regulations or to existing FAA processes and guidance materials that are not directly related to this rulemaking. The FAA is not addressing these comments specifically because they are beyond the scope of this rulemaking.
D. Part 23, Airworthiness Standards
1. Legacy Rules
a. Cockpit Voice Recorders (§ 23.1457)/Flight Data Recorders (§ 23.1459)
In the NPRM, the FAA proposed to use the same cockpit voice recorder (CVR) and flight data recorder (FDR) standards that exist in former §§ 23.1457 and 23.1459. The proposed rule included revised references to other sections of proposed part 23, but no substantive changes to those standards.
The NTSB stated it is pleased the NPRM retained the needed prescriptive design standards in proposed §§ 23.1457 and 23.1459. The NTSB added it would be appropriate for the FAA to include a requirement for image recorders, which it described in its Safety Recommendation A-13-12, dated May 6, 2013.
The FAA considered the NTSB's request to add requirements for image recorders. No functional or operational requirements to record images has ever been proposed or evaluated for costs and benefits. Any such requirements would constitute significant rulemaking and require public participation, and therefore exceeds the scope of this rule.
EASA and the Associations stated the CVR and FDR requirements stem from ICAO annex 6 requirements, which are already based upon EUROCAE industry standards ED-155; ED-112A, “MOPS for Crash Protected Airborne Recorder System;” and ED-155, “MOPS Lightweight Flight Recording Systems.” They suggested the FAA redraft the regulations to be more performance-based and number the regulations in accordance with any new numbering scheme, and change the references from the operating regulations as soon as practical.
The interplay between operation and certification regulations remains the reason for carrying the current standards unchanged into the new part 23. Redrafting them to objective standards, as suggested by EASA and the Associations could result in varying data sets between operators without any discernible benefit for such variation. Changing the standards only for part 23 airplanes certificated after a particular date would also require significant changes to the regulations under which the airplanes operate, adding complication without any noted benefit.
NJASAP supported the FAA's decision to maintain the current standards for cockpit voice recorders (§ 23.1457), noting that removing the current prescriptive requirements could hinder the conduct of future accident investigations. NJASAP did not comment on § 23.1459, “Flight data recorders”.
Commenters opposed to retaining the standards generally characterized them as too prescriptive. While accepting the need to maintain the numbering system to align with other regulations, EASA found the unchanged content to be detailed, design specific, and not providing the safety intent. The EASA-suggested language referenced recorder systems with more generalized statements regarding installation and technical specifications. BendixKing stated that it “seems binary” that the “specifics are invoked” only “if recording is required.” It also noted that the standards use approximately 1,000 words when 100 would be adequate in stating the safety intent. It concluded the requirement as written will hurt safety in the future by either retarding the technology or creating an environment where manufacturers will avoid recording. BendixKing included the identical comment for both recorder sections.
The primary use of both CVRs and FDRs is for accident investigation. Over the past 30 years, the FAA has worked with the NTSB to adopt and refine the specific requirements that document both flightcrew communication and the functions of airplane that form the basis for airplane accident and incident investigation. The FAA adopted the first significant flight data recorder upgrades in 1997 and made a concerted effort to standardize the operational and certification requirements across the operating and certification parts. The primary requirements for recording voice and data are not contained in the certification regulations, but in the operating regulations. When an airplane is required by an operating rule to record voice or flight data, the operating rule references back to the standards for the equipment in the certification part that applies to the airplane. This is true for large and small airplanes and for helicopters.
Airplane certification requirements do not align perfectly with operating regulations. A part 23 airplane may be operated under part 91 or 135; therefore,
the requirement to have and use CVRs and FDRs may differ depending on how the airplane is operated. But the standards for the equipment—when required—do not differ, and are intended to function the same way regardless of the airplane's certification basis. This consistency is central to the needs of the NTSB and all investigative bodies. It makes the design, certification, and function of the equipment standard for the industry as a whole. The FAA last amended the recorder regulations in 2008 to reflect investigative experience with the functions of newer recorder and flight management tools.
Therefore, the FAA finds it appropriate to retain these well-known requirements. The current integration of the operating and certification regulations is well established and functioning as intended. The need for investigative data following accidents and incidents is not forecasted to change. The commenters did not specify which of the current requirements were inappropriate or unnecessary, but merely expressed general concerns that the standards might inhibit safety in future designs. The FAA has long acknowledged the safety intent of flight recorders in providing investigators with the tools to recognize trends and malfunctions following accident and incidents. Consistency in the equipment and data that come from the equipment remains the goal.
BendixKing's observation that the certification rules are invoked only when “recording is required” is accurate. As explained, the certification requirements for installation and use of this equipment are only effective when required by an operating rule. Once required, all the equipment must function to the same standards. The fact that recording is required under different operating regulations, and the certification regulations referenced in those operating regulations, is the reason for not changing them for one certification part. If an airplane is not required by operational rule to record voice or data, then the specificity of the certification regulations is not an issue. The commenters did not include proposed design or functional changes for new airplane that might affect the requirements as stated. If a novel design is proposed in the future that affects recorder function, before approval, the FAA would coordinate with the applicant to ensure such design features meet the needs of accident and incident investigation.
Textron commented on proposed § 23.1457(c), which retains the current language requiring each CVR to be installed so that specified communications are recorded on a separate channel. The regulation currently and as proposed specifies four separate channels—the first channel for the first pilot, the second channel for the second pilot, the third channel at the cockpit-mounted area microphone, and the fourth channel for the third and fourth crewmembers. Textron commented that these CVR channel assignments are a “legacy” from magnetic tape recorders and there is no physical effect of such assignment on current solid-state recorders. Textron stated the current channel assignments are different and, therefore, paragraph (c) language should be revised to allow for flexibility in channel assignment or be aligned with the assignments manufacturers currently use. In addition, Textron noted that a proposed rule of EASA does not specify channels, but instead references the more detailed requirement of an ASTM standard.
Textron's comment—that the requirement for separate channels does not reflect the reality of currently-manufactured equipment—is limited in its view. While the regulation does require separated recording of different voice communication channels, the rule is flexible enough to avoid the issue raised by Textron. Regardless of an applicant's CVR channel numbering scheme, the regulation is satisfied if the CVR is designed to record audio sources on dedicated channels. This remains the FAA's policy on this regulation, which includes Textron's products already installed in airplanes that meet the former regulation.
An individual commenter noted the proposed rule seemed to anticipate an onboard storage system that must withstand a crash.
17
The commenter suggested that because recordings may not be stored onboard in the future, but rather wirelessly transmitted to the ground or a satellite, the FAA should revise the provision to reflect this possibility rather than “locking in old technology.”
17
See docket number FAA-2015-1621-0083. The comment was referenced as “23.1457 Flight Data recorder.” Section 23.1457 covers cockpit voice recorders, while 23.1459 addresses flight data recorders. It is unclear if the comment addressed one or both sections, but the FAA's response would not change since both require crash protected recording devices.
The FAA is aware that, at some point in the future, recordings may no longer need to be stored on board airplane. The FAA participates in international working groups that monitor these technology trends. There are many technical and legal issues attached to wireless transmission of voice and data communications. A change to allow such transmission and storage would affect several parts of the CFR and the functions of the NTSB, which were not proposed or discussed as part of this rulemaking.
b. Instructions for Continued Airworthiness (§ 23.1529)
In the NPRM, the FAA proposed to relocate the requirements for Instructions for Continued Airworthiness from § 23.1529 to proposed § 23.1515. The FAA also proposed to remove appendixes A through F, and rename Appendix G to Part 23—Instructions for Continued Airworthiness, as Appendix A to Part 23—Instructions for Continued Airworthiness.
Upon further consideration, the FAA has decided to retain the requirements for Instructions for Continued Airworthiness in § 23.1529. A change to § 23.1529 would affect many other parts and guidance documents, which reference the section. Because of the new numbering scheme in part 23, § 23.1529 is located in the “Legacy Regulations” section of the final rule. The appendix for Instructions for Continued Airworthiness is now located in Appendix A to Part 23, as proposed.
2. Subpart A—General
a. Applicability and Definitions (Proposed § 23.1/Now § 23.2000)
In the NPRM, proposed § 23.1 (now § 23.2000) would have prescribed airworthiness standards for issuance of type certificates, and changes to those certificates, for airplanes in the normal category. It also would have deleted references to utility, acrobatic, commuter category airplanes. Proposed § 23.1 also would have included definitions for the following terms specific to part 23: Continued safe flight and landing, designated fire zone, and empty weight.
Air Tractor asked why it was necessary to use the term “category” if there is only one “normal” category.
The FAA notes that there is a need to retain the concept of different categories because other parts of the FAA's regulations, including the certification and operating rules, set certain requirements based on an airplane's category.
An individual commenter opposed the elimination of the utility category as related to spin training for existing airplanes. The commenter would support elimination of the utility category if there would be a reevaluation of the airplanes allowed to be used for spin training. This
commenter also questioned whether the proposed change would result in a revision and reformatting of the current Type Certificate Data Sheet (TCDS) and whether the airplane would be considered not airworthy until re-placarded to conform to the new standards.
This rule does not affect the category of existing airplanes, nor does it require the TCDS be revised or reformatted. Airplanes currently certified in the utility category for spin training retain that capability under this new rule. Furthermore, the airworthiness of the existing fleet will not be affected by this rule.
An individual commenter recommended the FAA clarify whether the term “continued safe flight and landing” would not consider weather, environmental, or surface conditions in the event of a forced landing.
The FAA agrees that it should clarify that in the event of a forced landing, the definition of “continued safe flight and landing” does not include consideration of weather, environmental, or surface conditions beyond those already taken into account by the FAA's operating rules. The FAA expects that a pilot will conduct his or her flight within the FAA's operating rules and the airplane's normal operating envelope, and finds doing so will help ensure the pilot has safe landing options. The FAA's intent was to maintain the existing level of safety for small airplanes. Historically, single-engine and light twin-engine airplanes have been required to have characteristics that minimized the resulting hazards when a loss of engine forced an off-airport landing. The requirements for larger, multiengine part 23 airplanes are based on the requirement to continue flight back to an airport after the loss of an engine. This rule retains this requirement as it applies to part 23 airplanes that cannot maintain altitude after a critical loss of thrust. The FAA will provide additional clarification in guidance. It is not appropriate for the FAA to establish airworthiness standards for “continued safe flight and landing” that would require all airplane designs to account for extreme conditions—such as mountainous terrain—and extreme weather, because pilots who decide to fly over dangerous terrain or in weather have chosen to greatly reduce their options for safe landing.
The FAA proposed including a definition of “designated fire zone” that was flexible enough to capture both the historical understanding of fire zones and those areas in airplanes that incorporate novel design concepts that merit the increased safety measures. However, the FAA finds including a definition of “designated fire zone” will cause confusion and result in less flexibility. Rather than include a definition, the FAA will maintain the same understanding as the historical use of the term “fire zone,” a well-understood term that has been in use for decades and generally includes the areas of an airplane in which a powerplant, or some portion thereof, resides. Accordingly, the FAA will remove the definition from the rule and will determine which areas are designated fire zones in the specific means of compliance. Furthermore, specific sections of the new rule have added the term “fire zone” back into the rule so there is a clear link to means of compliance.
EASA commented the proposed definition of “empty weight” is too design specific and should be eliminated. EASA noted future technological developments would necessitate changes and future rulemakings, which is at odds with the objective to make objective rules change resistant for the next 20 years.
The FAA agrees the definition of “empty weight” is too design specific because the list of traditional features included may not apply to all airplanes in the future. Accordingly, the FAA deletes the definition from the final rule and will rely on means of compliance to address the requirements for each airplane. This will allow the FAA to capture the appropriate features for new propulsion systems and configurations without losing the means of compliance for traditional airplanes.
Air Tractor recommended the FAA provide a definition for “minimum flying weight” that would include the weight of the necessary crew and the minimum fuel required for legal operation for the lightest equipped airplane that complies with type design requirements. It asserted there is no point in the FAA certifying an airplane as safe for operation below the minimum weight at which the airplane can be operated.
The FAA finds Air Tractor's recommended definition of “minimum flying weight” is not an appropriate substitute for empty weight. Empty weight is used to provide a baseline for an airplane; establishing a “minimum flying weight” would not work for that purpose.
Embraer suggested the FAA include definitions for “Aircraft Power Unit,” “Fuel,” “Critical lightning strike,” and “Fuel system” in proposed § 23.1(b).
The FAA notes Embraer's suggestion to add definitions to proposed § 23.1(b); however, these definitions are addressed in their respective subparts. The terms “Aircraft Power Unit,” “Fuel,” and “Fuel System” are addressed in subpart E, and the term “Critical lightning strike” is addressed in subpart D. Furthermore, adding these definitions could lead to more confusion than clarification.
b. Certification of Normal Category Airplanes (Proposed § 23.5/Now § 23.2005)
In the NPRM, proposed § 23.5 (now § 23.2005) would have applied certification in the normal category to airplanes with a passenger-seating configuration of 19 or less and a maximum certificated takeoff weight of 19,000 pounds or less. Proposed § 23.5 would have also established certification levels based on the passenger seating configuration and airplane performance levels based on speed. Proposed § 23.5 also would have established a “simple” airplane classification.
Normal Category
Air Tractor and Textron questioned the imposition of a weight-based limitation for certification in the “normal” category in proposed § 23.5(a). Both commenters indicated that tying the applicability of part 23 to a maximum takeoff weight of 19,000 pounds would not meet the FAA's objective of replacing the current weight and propulsion divisions in small airplane regulations with performance- and risk-based divisions. Air Tractor also commented there was no basis for weight differentiation between normal and transport category airplanes on the FAA's safety continuum and suggested it would be more consistent to only use certification levels and speed categories. Air Tractor further suggested that applicants should be free to decide between certification under part 23 and certification under “the greater rigor” of part 25. Textron recommended the FAA replace the 19,000-pound maximum takeoff weight limit with a 6,000-pound maximum payload limit.
The FAA notes Air Tractor's and Textron's comments to extend the scope of the normal category. However, these comments are beyond the scope of this rulemaking. The NPRM proposed to replace the prescriptive airworthiness standards of part 23 with performance-based standards, not to change the scope of applicability of part 23.
Textron recommended the FAA include considerations for airplane functional or system complexity as a determining factor in certification requirements.
The FAA notes this rule already considers system complexity during certification. The requirements applicable to an airplane depend on reliable indicators of complexity—the airplane's designed cruising speed or maximum operating limit speed, and the maximum number of passengers. The airworthiness standards accommodate all degrees of complexity, which will specifically be addressed in accepted means of compliance.
Airplane Certification and Performance Levels
NATCA opposed the FAA's proposal to create certification and performance levels based on passenger capacity and airspeed in proposed § 23.5(b) and (c). NATCA noted that this approach was not consistent with how some foreign authorities with whom the United States has bilateral agreements “bucket” airplane classifications, including EASA, which classifies certification levels based on weight.
The FAA is not required to use the same metrics to classify airplanes as its bilateral partners. For example, Article 15 of the Agreement between the United States of America and the European Union on Cooperation in the Regulation of Civil Aviation Safety expressly reserves the authority for the United States to determine the level of protection it considers appropriate for civil aviation safety and to make changes to its regulations, procedures, and standards. Additionally, foreign authorities, including EASA, have been involved in the FAA's part 23 rulemaking effort since its inception with the Part 23 ARC. All foreign authorities involved in the part 23 reorganization effort agreed on the need to eliminate the divisions in part 23 based on weight and propulsion. Furthermore, the FAA's actions are consistent with EASA's actions.
NATCA also contended the FAA should retain a weight criterion because it relates to crash energy.
The FAA notes the risk associated with operating a 19,000-pound, level 1, low-speed airplane is accounted for in this rule by directly addressing the technologies installed on the airplane. For example, an airplane approved for instrument flight rules (IFR) has to meet the reliability requirements for IFR, regardless of level. Also, the FAA's operating rules mitigate the airplane's operational risk.
NATCA also asked the FAA to clarify that an applicant would not qualify for a lower certification level simply by removing seats and to publish guidance on determining certification levels.
The FAA notes, as set forth in § 23.5 (now § 23.2005), an airplane's certification level depends only on its maximum passenger seating configuration. This number does not include flightcrew. The maximum passenger seating capacity is known during the certification process; therefore, the airplane must comply with the standards applicable to that certification level. An airplane operator's decision to remove a passenger seat after certification does not affect the standards applicable to that airplane.
NATCA also recommended the FAA review the proposed part 23 certification levels to incorporate LSA and primary category airplane and create equivalent regulations as necessary.
The FAA notes that NATCA's suggestion is beyond the scope of this rulemaking. This rulemaking's purpose is to replace prescriptive design requirements of part 23 with performance-based standards, not expand the scope of part 23's applicability. The LSA and primary category certification processes exist as separate certification paths for airplane that qualify as either a LSA or primary airplane.
NATCA further commented by asking—
• Whether the intent is for airplane models with multiple configurations to have each configuration listed on the TCDS;
• Whether there can be dual or more categories on one TC; and
• Whether an airplane can be moved between levels and speed definitions during operational usage and, if so, whether this needs to be captured as different options on the TCDS.
In response to NATCA's question regarding multiple configurations, the FAA notes that if an airplane model has multiple configurations, the applicant will have to accept as the certification basis the requirements of the most stringent certification and performance levels available in the configuration list. If the applicant chooses not to comply with the most stringent requirements applicable to the configurations, the applicant will have to address each model individually on the TCDS. With respect to the number of categories on a TC, the FAA is eliminating the commuter, utility, and acrobatic airplane categories in part 23 for the reasons explained in the NPRM. Therefore, airplanes certified under new part 23 have only one category: normal.
Lastly, with respect to NATCA's question regarding airplanes moving between certification levels and speed definitions, an applicant either accepts the most stringent certification basis or addresses each model individually on the TCDS or by an STC. In order to move to a higher level, it will be necessary to recertify the airplane to the higher-level standard.
NJASAP supported the proposal to use passenger capacity and airspeed to establish airplane certification and performance levels, but expressed concerns the methodology may go too far in generalizing a very diverse group of airplanes.
The FAA understands NJASAP's concern, but notes the certification and performance levels are used to replace the weight and propulsion divisions in the former requirements. The levels are general to allow the accepted means of compliance to more accurately address the various technical differences.
Kestrel supported the FAA's proposed airplane certification levels, but expressed concern with the impact of migrating the Airplane Classes in former § 23.1309 (I, II, III, IV)
18
to the proposed combined airplane certification and performance levels. Kestrel noted that Airplane Classes were currently used in the System Safety Analysis process to establish allowable quantitative probabilities. Kestrel asked the FAA to specify what the expected allowable quantitative probabilities would be for each of the eight possible combinations of certification and performance levels (
i.e.,
low-speed levels 1-4 and high-speed levels 1-4).
18
These Classes are described in AC 23.1309-1E, paragraph 15.
The FAA notes that there is no direct connection between the systems-based airplane classes from AC 23.1309-1E
19
and the airplane certification and performance levels in § 23.2005, which apply to all subparts. The airplane classes reflect the safety continuum concept in that it may be acceptable for simpler airplanes or airplanes at lower certification levels to have a higher probability of failure for equipment. The airplane's certification level is strictly based on the number of passenger seats. The different means of compliance will address the safety continuum.
19
The Airplane Class Levels from former § 23.1309 are still addressed in subpart F of this rule.
Air Tractor commented generally that it does not see a big difference in the certification effort required by the different certification and performance levels. Air Tractor suggested there could be a difference in required levels of safety for equipment, but indicated it was impossible to tell because the FAA had not yet defined the levels of
safety.
20
Air Tractor suggested the FAA codify the required levels of safety because the rule preamble would not be given the weight of law.
20
Air Tractor pointed out proposed § 23.1300.
The FAA acknowledges that Air Tractor is correct in that there could be a difference in the required levels of safety between two airplanes based on the FAA's safety continuum philosophy. Differences in products and their associated risks justifies using different levels of safety. While the high-level performance requirements are the same for all products, the required level of safety is best addressed using means of compliance so that each project is assigned the appropriate level of safety. Although language in the preamble does not supersede the language of the regulation itself, the preamble is evidence of the FAA's contemporaneous understanding of its proposed rules, and may serve as a source of evidence concerning contemporaneous agency intent.
21
21
Wyoming Outdoor Council
v.
U.S. Forest Service,
165 F.3d 43, 53 (D.C. Cir. 1999).
Several commenters questioned the meaning of “passengers” as used in the descriptions of certification levels in proposed § 23.5(b), particularly for airplanes that may require 1 or 2 crew depending on operating regulations.
The FAA elects to use the term “passenger” to align with the operating rules, and because passenger count has historically correlated to risk tolerance. The term “passenger” excludes “flightcrew” members. The FAA recognizes the concerns over confusion because the ARC discussed this issue at length and it was again discussed within the FAA. Based on these discussions, the FAA finds “passenger” is the most appropriate term. As one of the commenters noted, the “crew” could include one or more “occupants.” Part 23 airplanes can include special use airplanes that may require multiple flightcrew members, but have no provisions for passengers. Part 23 is also used for airplanes that carry no “flightcrew” or “passengers” today (
i.e.,
unmanned aircraft systems), and may also address airplanes with passengers and no flightcrew in the future. For airplanes that require different numbers of flightcrew for different operations, the applicant must use the smallest number of flightcrew required for any operation, which is typically one, the most conservative number. The FAA finds the approach proposed § 23.5 (now § 23.2005) will allow the most flexibility, least confusion, and focus on risk tolerance, which aligns part 23 with the operating rules.
Several organizations commented specifically on the proposed airspeed limits for the low-speed and high-speed performance levels established in proposed § 23.5(c). NATCA suggested the use of design cruising speed (V
C)
and maximum operating limit speed (V
MO
/M
MO
) may not be appropriate for untrained persons, and recommended the FAA either define those terms or use more common measurements. NATCA also commented that the FAA needs to clarify what “speed” means (
i.e.,
cruise speed versus some other speed standard). NATCA expressed concerns over the use of “common” terms versus speeds used for certification, which are also used in operations.
The FAA notes both V
C
and V
MO
are defined in 14 CFR 1.2. V
C
means design cruising speed and V
MO
/M
MO
means maximum operating limit speed. The FAA finds that V
C
, V
MO
, and M
MO
are appropriate for engineering determinations as they relate to structural speeds as well as flight-testing speeds. Furthermore, the FAA clearly states these are calibrated speeds, which typically are used in certification.
Transport Canada commented specifically on the parameters for the low-speed performance level in proposed § 23.5(c)(1). In particular, Transport Canada said V
C
and V
MO
should both be less than 250 Knots Calibrated Airspeed (KCAS) for an airplane to qualify as low speed. Therefore, Transport Canada concluded the phrase “V
C
or V
MO
” in this provision should actually read “V
C
and
V
MO
”.
The FAA agrees with Transport Canada concerning the use of “and” versus “or” and revises the rule accordingly.
Air Tractor contended that the parenthetical references to M
MO
limits in proposed § 23.5(c)(1) and (c)(2) are confusing because they are not clear if these values represent either new absolute constraints, or if they are intended to provide an approximate context for what 250 KCAS might mean at some higher altitude. Air Tractor noted that Mach 0.6 corresponds to 250 KCAS at about 23,400 feet in a standard atmosphere, but wondered what performance level would be assigned to an airplane with a V
C
of 250 KCAS and an M
MO
of 0.65.
Garmin commented that some airplanes do not have a M
MO
, but have a maximum speed of more than Mach 0.6. For example, Garmin noted an airplane with a V
MO
of 240 KCAS up to its certified ceiling of 35,000 feet and no M
MO
would be classified as a low-speed airplane but will actually be going Mach 0.71 at 35,000 feet. Garmin recommended the FAA revise the low-speed and high-speed performance levels to remove M
MO
from parentheticals, clarify that a low-speed airplane must have a V
C
or V
MO
equal to or less than 250 KCAS and a M
MO
less than or equal to Mach 0.6, and that a high-speed airplane is anything that does not qualify as low speed.
The FAA agrees that the proposed rule was unclear and revises the final rule to clarify that M
MO
is one of the criteria, not an approximation of the KCAS cutoff. Accordingly, an airplane must satisfy all of the V
C
, V
MO
, and M
MO
requirements to qualify as low speed. If an airplane does not satisfy all three, then it is considered a high-speed airplane. After further review, the FAA determined that V
C
and V
MO
are not directly parallel because V
C
is a structural speed and V
MO
is a performance speed. For this reason, the FAA replaces V
C
with V
NO
. V
MO
historically was a performance value used by turbine-powered airplanes while V
NO
historically was a performance value used by piston-powered airplanes. By replacing V
C
with V
NO
, the values now reflect parallel operational speeds.
ANAC commented that the FAA should use stall speed instead of V
MO
and M
MO
to define performance levels because it would help address loss of control and prevent an applicant from arbitrarily limiting an airplane's V
MO
and M
MO
below the airplane's capabilities to avoid more stringent certification standards. ANAC asked the FAA to elaborate on the connection between an airplane's V
MO
and M
MO
and takeoff risk.
The FAA does not agree that stall speed is the best parameter to use for determining performance levels. Although an airplane's top speed generally has been aerodynamically limited to a multiple of stall speed that varied depending on propulsion, this is not true for all airplanes and does not provide the necessary flexibility to address airplanes that incorporate new technology. For example, there are airplanes in development that have very low-stall speeds—the airplane can land and takeoff in very little space, or even vertically—but may have V
NO
or V
MO
greater than 250 KCAS, making them a high-performance airplane.
Simple Airplane Classification
The FAA proposed to define “simple” airplanes to recognize the entry-level airplane. Simple airplanes would have been limited to airplane designs that allow no more than one passenger, are limited to VFR operations, and have a low top speed and a low stall speed.
The FAA asked for comments concerning the value of creating a simple airplane sublevel given that a simple airplane would have characteristics very similar to a certification level 1, low-speed airplane.
ICON, Transport Canada, BendixKing, NATCA, and two individual commenters supported the inclusion of a separate “simple” airplane classification. However, Zee and the Associations commented that the FAA should not create a “simple” airplane classification, and that each of the proposed certification and performance levels should stand on its own based solely on performance and complexity of operations. The commenters against inclusion of a “simple” category contended that it was more appropriate to address this sort of classification in the means of compliance.
The FAA has decided not to adopt a “simple” airplane classification. The FAA finds the addition of a simple category does not produce benefits over those already provided by the new rule. The FAA finds it is more appropriate to address the requirements for a level 1, low-speed airplanes. Additionally, in the NPRM, the FAA proposed allowing simple airplanes to use non-type-certificated engines and propellers to allow those airplanes to use electric propulsion. The FAA can achieve the same flexibility by approving electronic propulsion as part of an airframe for a level 1, low-speed airplane; therefore, the FAA revises the propulsion requirements in this rule to provide that flexibility.
Airplanes Certified for Aerobatics
The FAA proposed to eliminate the acrobatic airplane category in part 23, but still allow a normal category airplane to be approved for aerobatics provided the airplane was certified to address the factors affecting safety for the defined limits for that kind of operation.
Velica S.A.S. (Velica) recommended the FAA define “aerobatic category” in proposed § 23.5 to include airplanes without any maneuver restrictions, other than those shown to be necessary as a result of required flight tests.
For the reasons explained in the NPRM, the FAA removed the acrobatic category from part 23. The FAA agrees with Velica that the limitations for an airplane certified for aerobatics should be based on flight tests, but believes more specificity is warranted. Therefore, the FAA will require airplanes certified for aerobatics to comply with the limitations established under subpart G of part 23 in this rule.
c. Accepted Means of Compliance (Proposed § 23.10/Now § 23.2010)
In the NPRM, proposed § 23.10 (now § 23.2010) would have required an applicant to show the FAA how it would demonstrate compliance with this part using a means of compliance, which may include consensus standards accepted by the Administrator. Proposed § 23.10 would have also required a person requesting acceptance of a means of compliance to provide the means of compliance to the FAA in a form and manner specified by the Administrator. Proposed § 23.10 would have created flexibility for applicants in developing means of compliance and also specifically identify consensus standards as a means of compliance the Administrator may find acceptable.
General Comments
The Associations recommended the FAA revise paragraph (a) to require an applicant to “comply” with part 23, rather than “show the FAA how it will demonstrate compliance” with part 23, using a means of compliance. The Associations also recommended revising paragraph (b) to require an acceptable means of compliance to be in a form and manner specified by the Administrator.
The Associations also argued that, without these changes, the proposed rule could have been interpreted as requiring each applicant to come to agreement with the FAA on acceptable means of compliance for each certification project, when it appears the FAA intends to issue acceptance of methods of compliance in, for example, standards that are already deemed acceptable. The commenters also noted that part 21 does not currently require a showing of compliance in all cases. The commenters stated that today, and potentially more so in the future, the FAA may accept compliance through demonstration or even a statement of compliance. The commenters contended the above-referenced revisions to proposed § 23.10 are necessary to ensure the designs meeting part 23 can continue to fully utilize part 21.
The FAA agrees with the commenters that proposed § 23.10(a) (now § 23.2010(a)) may have had the unintended result of requiring applicants to get approval from the FAA for each means of compliance even when the FAA had already accepted a means of compliance. This would have been counter to the FAA's intention that a means of compliance, once accepted by the FAA, may be used for future applications for certification unless formally rescinded. The FAA adopts the commenters' recommendation for paragraph (a).
The FAA does not adopt recommendation for paragraph (b) however, because it would not meet the intent of the requirement. Paragraph (b) addresses the situation in which an applicant proposes its own means of compliance, either as an alternative to an accepted means of compliance or as a new means of compliance for new technology. The FAA intended paragraph (b) to require applicants requesting acceptance of a means of compliance to do so in a form and manner specified by the FAA, not to require already-accepted means of compliance to be documented in a form and manner specified by the FAA. In light of the comment, the FAA revises the proposed rule language to clarify that paragraph (b) applies to applicants who are requesting FAA review and acceptance of a proposed means of compliance.
Air Tractor questioned the need for a new rule specifying that all means of compliance must be accepted by the FAA and asked whether an applicant would need to obtain FAA approval for each means of compliance at the beginning of the process or any time prior to showing compliance.
This final rule is necessary because Congress directed the FAA to issue a rule that replaces the prescriptive requirements of part 23 with performance-based regulations.
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This change means that applicants for a TC may use any number of unique design elements to attempt to comply with the performance-based requirements but only the FAA can accept these as means of compliance because the FAA is responsible for finding that an airplane satisfies the performance-based requirements in part 23 before issuing a TC. Although the means of compliance process is not new, the FAA adopts § 23.2010 to make the process clear to all applicants and to highlight that applicants have the opportunity to develop alternative approaches to complying with the part 23 performance-based requirements. While an applicant is not required to obtain FAA acceptance of means of compliance at the beginning of the certification process, it is advisable to seek acceptance as soon as possible, or preferably before, to mitigate the risk of having to redesign the airplane should the FAA not accept the means of compliance.
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Small Airplane Revitalization Act of 2013 (Pub. L. 113-53, 49 U.S.C. 44704 note).
NATCA commented the FAA should require the accepted means of
compliance be included on the published certification basis so products can be standardized and post-TC modifiers can know the certification basis used for the underlying product. NATCA also commented that maintenance personnel returning an airplane back to service will need access to adequate documentation on how an airplane is compliant with the rule so they can verify the airplane remains compliant. Assuming the standards are listed, NATCA asked the FAA to clarify how they would be listed in the airplane certification basis.
The FAA partially agrees with NATCA's concerns. Because many of the detailed requirements are no longer in part 23 and will move to means of compliance, it may be hard to know how an applicant showed compliance. That said, many means of compliance today are proprietary, and modifiers and maintenance personnel have no way of knowing what the original manufacturer did to show compliance. The FAA is working with its project support personnel to determine how much of the means of compliance information needs to be listed on the FAA TCDS to address concerns relating to post-TC modifiers and maintenance personnel. This information will be included in the training currently being developed for the ACO engineers and industry designees.
NATCA also recommended the FAA permit design change applicants to use their own alternate means of compliance to gain approval rather than relying on the original means of compliance used for the underlying TC. NATCA suggested this would be in line with the FAA's statements that it is open to a means of compliance without preferring one over the other.
This option is currently permitted and will continue to be permitted under the new part 23. Applicants requesting a change to type design may propose their own means of compliance rather than using the original means of compliance. However, the FAA will review the request depending on the complexity of the design change or the alternative means of compliance. While this is the current process, AC 23.2010 provides guidance on how to submit a proposed means of compliance to part 23 for FAA acceptance.
NATCA asked the FAA to clarify how the certification basis would be handled for industry consensus standards. NATCA also asked whether an applicant must at least partially use industry consensus standards, or whether an applicant may choose not to use consensus standards at all. Finally, NATCA asked if an applicant could get a part 23 TC by only using the standards in ACs. Air Tractor suggested the FAA revise proposed § 23.10 to mention that the standards included in ACs are an accepted means of compliance.
The FAA notes that the certification basis will be the same as it is today: Applicants must show compliance with part 23. An applicant may choose not to use any consensus standards, or a combination of consensus standards and other means of compliance, as long as the applicant's proposed means of compliance complies with part 23 and is accepted by the Administrator. The FAA finds it unnecessary to revise the proposed rule language as Air Tractor suggested. An applicant may already use ACs as means of compliance to part 23, where applicable, under § 23.2010.
Use of Applicant-Proposed Means of Compliance
Air Tractor contended the use of applicant-proposed means of compliance standards would lead to a significant loss in transparency of the certification process, as individual applicants may choose to make both the results and the process of showing compliance a matter of proprietary intellectual property. ANAC commented that the FAA should establish a method to publicize information about approved means of compliance that are not part of a consensus standard. To preserve proprietary information, ANAC recommended the FAA only publish summaries as it currently does for exemptions, special conditions, and ELOS findings. NATCA questioned how the FAA will handle proprietary specifications within a certification basis, arguing it is not in the public interest to have “secret” certification requirements. NATCA recommended the certification basis be published in the
Federal Register
for public comment. NATCA also recommended the certification basis for proprietary information be “explicitly identified” on the TCDS or STC. Finally, NATCA asked the FAA to clarify whether the FAA will publish FAA issue papers when an applicant uses an applicant-proposed means of compliance and, if so, noted that several FAA orders and policies would need to be revised.
The FAA has a responsibility to protect an applicant's proprietary information, including a proprietary means of compliance. As such, the FAA will not make the proprietary portions of applicant-proposed means of compliance publicly available. The FAA plans to address applicant-proposed means of compliance as it does today, by summarizing the information. The FAA will identify the certification basis (
i.e.,
the applicable airworthiness standards) on the TCDS or STC as is done today. The FAA has not published, and does not plan to publish, the certification basis or FAA issue papers in the
Federal Register
for public comment. Each applicant's certification basis is based on part 23 and is agreed to between the applicant and the FAA. The FAA is not required to elicit public comment on proposed means of compliance.
Garmin asked whether the FAA will accept portions of a previously accepted means of compliance, or whether an applicant must use that entire means of compliance. Garmin recommended the FAA revise proposed § 23.10 (now § 23.2010) to permit whole or partial implementation of a previously-accepted means of compliance or, alternatively, ensure AC 23.10 permits this.
The FAA agrees with Garmin and points out that this is acceptable today. The FAA can be flexible in accepting mixed, partial, or entire means of compliance from industry consensus standards as applicable to the specific product. The FAA recognizes that new product innovations will make this flexibility more important in the future. An industry consensus standard can state that, for credit in meeting that standard, the applicant has to meet the entire set of requirements. But the FAA may tailor acceptable consensus standards based on what is appropriate for the intended function.
Use of Current Part 23 as Means of Compliance
Embraer recommended the FAA revise proposed § 23.10(a) (now § 23.2010(a)) to acknowledge that an applicant may use the prescriptive requirements in former part 23 as an alternate means of compliance. Kestrel asked whether the FAA will require issue papers to permit the use of these former prescriptive requirements.
In the NPRM, the FAA noted it will accept the use of the prescriptive means of compliance contained in former part 23 as alternate means of compliance, except for those sections where the level of safety has increased specifically for stall characteristics and icing protection. The FAA does not need to codify this decision to retain this flexibility and is therefore not revising the proposed language for § 23.10. For applicants relying on satisfaction of the prescriptive requirements in former part 23, amendment 23-62, as a means of compliance, the FAA will only require the G-1 certification basis issue paper to list the means of compliance as “amendment 23-62”.
NATCA asked whether the FAA will permit an applicant to use older prescriptive regulations, such as Aeronautics Bulletin, amendment 7a, “Airworthiness Requirements for Aircraft”; CAR 3; and previous versions of part 23, as a means of compliance. If not, NATCA asked the FAA to clarify why those regulations are not appropriate and acceptable for the proposed design.
The FAA will consider the use of the older, prescriptive regulations in cases where it is appropriate for the airplane in question. There have been instances where applicants have approached the FAA with projects to “remake” new versions of vintage airplanes. The FAA has allowed and will continue to allow the use of appropriately-selected design standards on vintage airplanes. However, applicants wanting to use this approach should expect to use newer industry practices where the old standards and practices have, over time, not proven to meet the minimum acceptable safety standard for that class of airplane in part 23.
Manner in Which Applicant Must Present Means of Compliance
Textron asked how the FAA will document the acceptance of a non-industry standard means of compliance and whether acceptance of a Project-Specific Certification Plan (PSCP) is adequate proof of the FAA's acceptance of the means of compliance.
The FAA plans to include information on the acceptance of non-consensus standards on its Small Airplane Directorate Web site. The G-1 issue paper and agreement on the certification basis and compliance checklist will suffice. PSCP acceptance is adequate proof of FAA acceptance of a means of compliance if a G-1 issue paper is not used.
Textron also asked whether there would be a system set-up similar to repair specifications where an applicant could have pre-defined methods for making certain changes to its products, and whether there would be a method for the FAA to accept deviations to the accepted standards.
The Part 23 ARC did not consider and the NPRM did not propose repair specification; therefore, it is beyond the scope of this rulemaking effort.
Air Tractor and Kestrel contended the process proposed by draft AC 23.10—which states that an applicant should list the means of compliance and consensus standards they intend to use to show compliance with part 23 in a certification plan or compliance checklist—is premature and would slow the certification process. The details of an airplane's design are often incomplete when an application is submitted and it can take years to obtain FAA acceptance of a PSCP. Air Tractor suggested that establishing a means of compliance during the process of negotiating the PSCP should be limited to picking one or more of the following: Analysis, tests, design review, physical inspection, etc. Air Tractor also commented that a requirement for the FAA to review and approve of particular methods before the analysis can be presented would be new for most regulations. It would also require a new level of required response from the FAA that would drastically slow the process of either establishing the certification plan or showing compliance. Air Tractor also questioned how this requirement compares with the FAA and Industry Guide to Product Certification.
The FAA finds that including the means of compliance in the PSCP or the compliance checklist will not alter the current practice for new technology because some of the compliance requirements may not be known at the time of application. This initial uncertainty means the agreed compliance may remain as a draft during the development and certification process until the specific means of compliance are determined and agreed upon. This may be a common issue with new technology during the first few years after the new part 23 is implemented. It will take some time to get accepted means of compliance into consensus standards, resulting in these means of compliance being developed during the project. In the long term, the new approach should shorten the time needed for an applicant to get FAA agreement on its means of compliance.
Finally, the FAA clarified the intent of the form and manner of the means of compliance. The FAA does not intend to “specify” the form and manner of means of compliance; the form and manner only need to be “acceptable.”
3. Subpart B—Flight
a. Weight and Center of Gravity (Proposed § 23.100/Now § 23.2100)
In the NPRM, proposed § 23.100 (now § 23.2100) would have required an applicant to determine weights and centers of gravity that provide limits for the safe operation of the airplane. Additionally, it would have required an applicant to show compliance with each requirement of this subpart at each combination of weight and center of gravity within the airplane's range of loading conditions using tolerances acceptable to the Administrator. Proposed § 23.100 would have also required the condition of the airplane at the time of determining its empty weight and center of gravity be well defined and easily repeatable.
The Associations recommended a clarifying change to proposed § 23.100(a) that would require the applicant to determine limits for weights and centers of gravity that provide for the safe operation of the airplane, rather than determine weights and centers of gravity that provide limits.
The FAA adopts the Associations clarifying change. Accordingly, § 23.2100(a) now requires the applicant to determine limits for weights and centers of gravity that provide for the safe operation of the airplane.
Additionally, the Associations recommended changing proposed § 23.100(b) to require the applicant to comply with each requirement of subpart B at critical combinations of weight and center of gravity. The commenters explained that it is appropriate to demonstrate compliance at critical combinations of weight and center of gravity, but showing compliance at each combination “would present an infinite matrix of test points.”
The FAA also adopts the Associations recommended change to proposed § 23.100(b) (now § 23.2100(b)). While proposed § 23.100(b) could have been interpreted to require an infinite matrix of test points, this was not the FAA's intent. Accordingly, § 23.2100(b) now requires the applicant to comply with each requirement of subpart B at critical combinations of weight and center of gravity within the airplane's range of loading conditions using tolerances acceptable to the Administrator.
The Associations also stated that the determination of empty weight and center of gravity in proposed § 23.100(c) is “somewhat confusing and potentially unnecessary.” The commenters suggested clarifying changes that would replace “empty weight” with “weight” and delete “well” and “easily repeatable,” thereby requiring the condition of the airplane at the time of determining its weight and center of gravity to be defined. Similarly, Textron recommended deleting the terms “well” and “easily” from proposed § 23.100(c) because they are vague and subject to interpretation.
The FAA is retaining the terms “well defined” and “easily repeatable” in § 23.2100(c). In the NPRM, the FAA explained proposed § 23.100 would capture the safety intent of § 23.29. Section 23.29 has contained the terms
“well defined” and “easily repeated” since it was published in amendment 23-0
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with no challenges. Furthermore, “easily” is an important modifier for “repeatable” because it ensures that the condition of the airplane at the time of determining its empty weight and center of gravity is not hard for a mechanic to reproduce.
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29 FR 17955, December 18, 1964.
The FAA also retains the term “empty weight” in § 23.2100(c). Determining empty weight is fundamental to baselining an airplane. Removing this term would leave the weight value for baseline open to any weight between empty to gross weight. The ambiguity of not defining the baseline weight would create confusion and problems.
b. Performance Data (Proposed § 23.105/Now § 23.2105)
In the NPRM, proposed § 23.105 (now § 23.2105) would have required—
• An airplane to meet the performance requirements of this subpart in various conditions based on the airplane's certification and performance levels for which certification is requested;
• An applicant to develop the performance data required by this subpart at various altitudes and at high temperatures, while also accounting for losses due to atmospheric conditions, cooling needs, and other demands on power sources; and
• The procedures used for determining takeoff and landing distances to be executed consistently by pilots of average skill in atmospheric conditions expected to be encountered in service.
EASA and the Associations stated that some designs may have performance limitations at low temperatures rather than high temperatures, such as batteries in electric propulsion systems. The commenters recommended revising the proposed language to require performance data for low temperatures that can be expected during operation, if those low temperatures could have a negative effect on performance.
The FAA agrees proposed § 23.105(b) (now § 23.2105(b)) should account for possible performance degradation due to the effect of cold temperatures on electric propulsion systems. Proposed § 23.105 was intended to capture the safety intent of former § 23.45, which required the determination of performance data in various conditions that could negatively affect performance. Historically, propulsion systems were gas powered and negatively affected by high temperatures, which resulted in a corresponding negative effect on performance. This explains why former § 23.45 required the determination of performance data at a temperature from standard to 30 degrees Celsius above standard, as performance degradations historically resulted from operation at high temperatures.
As stated in the NPRM, the FAA intended the proposal to account for airplanes equipped with new technologies, such as electric propulsion systems. Additionally, the FAA intended proposed § 23.105(b) to account for various conditions that could affect airplane performance. However, proposed § 23.105(b) would only have accounted for performance degradations that could result from the operation of systems at high temperatures, as the proposed language reflected former § 23.45. Because cold temperatures, rather than high temperatures, may have a negative performance effect on an electric propulsion system or a hybrid system, the FAA revises the proposed language to account for performance degradations at low temperatures. The FAA also removes the prescriptive language that would have required the determination of performance data at a temperature from standard to 30 degrees Celsius.
Section 23.2105(b)(2) now requires the applicant to develop performance data at temperatures above and below standard day temperature that are within the range of operating limitations, if those temperatures could have a negative effect on performance. This requirement is consistent with the NPRM as it replaces the prescriptive design requirements from the regulation with performance-based airworthiness standards that accommodate new technologies, such as electric and hybrid propulsion systems. Additionally, § 23.2105(b)(2) more accurately reflects the safety intent of former § 23.45 because it requires the development of performance data in conditions that could negatively affect performance, including conditions that account for new technologies.
As a general matter, under § 23.2105(b)(2), an applicant seeking certification of a gas-powered propulsion system must develop performance data at temperatures above standard that are within the airplane's operating limitations, because high temperatures could have a negative effect on the airplane's performance. Alternatively, an applicant seeking certification of an electric or hybrid propulsion system must develop performance data at temperatures both above and below standard that are within the airplane's operating limitations, if these temperatures could have a negative effect on performance.
Garmin pointed out that limited airflow in a climb configuration may cause non-propulsion systems to overheat during long hot climbs, requiring a different climb speed or configuration for system cooling than addressed in proposed § 23.105(b). Garmin recommended the FAA include the phrase “other essential equipment” in addition to propulsion cooling in paragraph (b)(2).
The Associations similarly suggested that there may be some cases where the performance of equipment other than the propulsion system may drive cooling requirements for hot conditions. The commenters recommended revising the proposed language to include cooling requirements for these equipment, in situations other than climb.
The FAA understands the concerns of Garmin and the Associations, for paragraph (b)(2) to address cooling requirements for more than the propulsion system. However, subpart B—including § 23.2105—is intended to address airplane performance. Therefore, § 23.2105 should only address systems that affect airplane performance. For example, § 23.2105 may apply to avionics that also control propulsion, or flight controls and lift systems needed to develop repeatable airplane performance. Traditional avionics that do not affect performance are addressed in subpart F, which contains requirements for equipment. Therefore, the FAA is not adopting the phrase “other essential equipment” because it may be interpreted to include systems that do not affect performance, such as oxygen or navigation systems. This would be a new requirement that has not been identified as a safety need, increasing the scope and possibly the cost of this rule. For the same reasons, the FAA is not expanding the scope of the rule to include cooling requirements for equipment other than propulsion systems, in situations other than climb.
Nevertheless, in light of the comments, the FAA acknowledges there may be systems associated with propulsion that are necessary for consistent performance, such as batteries or engine controllers, that could be affected by temperature. Section 23.2105 should address these types of systems. Therefore, § 23.2105(b)(2) will apply to systems associated with electric or other propulsion systems if those systems could negatively affect performance at temperatures above or below standard.
c. Stall Speed (Proposed § 23.110/Now § 23.2110)
In the NPRM, proposed § 23.110 (now § 23.2110) would have required an applicant to determine the airplane stall speed or the minimum steady flight speed for each flight configuration used in normal operations, accounting for the most adverse conditions for each flight configuration, with power set at idle or zero thrust.
The Associations recommended removing the proposed requirement for power to be set at idle or zero thrust for each determination to enable the introduction of new technologies such as distributed propulsion with reliable electric power. The commenters explained that proposed § 23.110 must account for distributed lift systems because the concept of distributed lift along a wing may be used to facilitate low-speed handling, and reliable systems of this type may dictate operational stall speeds. The commenters asserted their recommended change would ensure that distributed propulsion, with an appropriate reliability level, could be used in a landing condition accounting for a lower stall speed based upon the effects of this equipment.
The FAA agrees that proposed § 23.110 (now § 23.2110) should account for distributed propulsion systems used for thrust, flight controls, and high lift systems. However, the rule must define a thrust level for standardization because stall speeds are important to the development of the performance-based speeds. The FAA finds it appropriate to require traditional designs to determine stall speeds and minimum steady flight speeds with power set at idle or zero thrust. Accordingly, § 23.2110(a) now requires the power to be set at idle or zero thrust for propulsion systems used primarily for thrust. To accommodate distributed propulsion systems, the FAA is adding new § 23.2110(b), which requires a nominal thrust for propulsion systems used for thrust, flight control, and/or high-lift systems. These changes will allow § 23.2110 to accommodate the new technologies identified by the commenters.
Additionally, the FAA revises the proposed rule language to clarify the “stall speed or minimum steady flight speed determination” must account for the most adverse conditions for each flight configuration. This change is consistent with the proposed rule, which would have required “each determination” to account for the most adverse conditions for each flight configuration, because “each determination” referred to the “stall speed or minimum steady flight speed determination.”
d. Takeoff Performance (Proposed § 23.115/Now § 23.2115)
In the NPRM, proposed § 23.115 (now § 23.2115) would have required an applicant to determine airplane takeoff performance, which would have included the determination of ground roll and initial climb distance to 50 feet, accounting for stall speed safety margins, minimum control speeds, and climb gradients. Proposed § 23.115 would have also required the takeoff performance determination to include accelerate-stop, ground roll and initial climb to 50 feet, and net takeoff flight path, after a sudden critical loss of thrust for levels 1, 2, and 3 high-speed multiengine airplanes, multiengine airplanes with a maximum takeoff weight greater than 12,500 pounds, and level 4 multiengine airplanes.
The Associations suggested the FAA revise proposed § 23.115 to capture the performance-based standards at a “higher objective based level” because the proposed section was too detailed and prescriptive. Textron recommended the FAA adopt language similar to EASA's A-NPA 2015-06, which leaves determination of detailed standards appropriate to airplanes with different certification and performance levels to the means of compliance standards.
The FAA disagrees with the comment, because it is important to ensure the consistency of takeoff performance data across part 23 airplanes. This consistency aids private pilots, who often operate a variety of part 23 airplanes, in determining the airports from which they may operate.
Several commenters recommended the FAA remove the 12,500-pound cutoff in proposed § 23.115(c).
The FAA agrees and removes the weight discriminator from the rule language. Although the FAA proposed to remove the commuter category, along with weight- and propulsion-based certification divisions, and to replace them with divisions based on risk and performance, the FAA also proposed to require multiengine airplanes with a maximum takeoff weight of more than 12,500 pounds to comply with the increased takeoff performance requirements in paragraph (c). Proposed paragraph (c) was intended to ensure that larger business jets carrying fewer than 10 passengers, which would have been considered commuter category under the former rule, were captured under the takeoff performance requirements because these airplanes would not necessarily fall under level 4. The FAA recognizes that applying paragraph (c) to multiengine airplanes with a maximum takeoff weight of more than 12,500 pounds is redundant. Those airplanes, which are equivalent to airplanes under the former commuter category, are captured by applying paragraph (c) to levels 1, 2, and 3 high-speed multiengine airplanes and to all level 4, multiengine airplanes. Furthermore, while paragraph (c) does not apply to levels 1, 2 and 3 low-speed multiengine airplanes, the FAA may issue special conditions if there is a configuration that presents a higher-than-anticipated risk.
Several commenters objected to requiring the determination of takeoff performance for all airplanes to include the determination of initial climb distance to 50 feet above the takeoff surface. The commenters noted that under the former rule, takeoff distance for commuter category airplanes and multiengine jets weighing more than 6,000 pounds required the initial climb distance be calculated using 35 feet above the takeoff surface. Textron recommended the FAA revise proposed § 23.115(b) to apply the 50-feet-above-takeoff-surface requirement only to single-engine airplanes and levels 1, 2, and 3 low-speed multiengine airplanes rather than to all airplanes. Textron also recommended revising proposed § 23.115(c)(2) from “50 feet” to “35 feet” above the takeoff surface, noting the 35-foot standard has been demonstrated as safe for the classes of airplane to which it has been applied.
The FAA agrees with the commenters and revises proposed § 23.115(b) (now § 23.2115(b)) to require only single-engine airplanes and levels 1, 2, and 3 low-speed, multiengine airplanes to include the distance required to climb to a height above 50 feet when calculating takeoff performance. The FAA is also changing the altitude for the initial climb in § 23.2115(c)(2) to 35 feet. The service history of airplanes that would be classified as levels 1, 2, and 3 high-speed multiengine airplanes and level 4 multiengine airplanes under this rule, which were certified using a 35-feet-initial-climb requirement, has been sufficiently safe to support the proposition that the 35-feet requirement provides an adequate level of safety for high-speed multiengine airplanes and level 4 airplanes.
The Associations suggested revising proposed § 23.115(b) and (c) to require takeoff performance to include the determination of “ground roll distance required to takeoff,” rather than “ground roll.”
The FAA notes using “ground roll distance required to takeoff” is not necessary for clarity. The term “ground
roll” in the context of takeoff is well-understood.
Several commenters recommended revising proposed § 23.115(b) to include two subparagraphs in what the FAA interprets as an effort to clarify that the applicant must provide two distances, one for ground roll and another for the distance required for the initial climb to 50 feet.
The FAA finds it unnecessary to reorganize paragraph (b) as the commenters proposed. The format, as proposed and adopted, is sufficiently clear.
The Associations suggested the FAA revise the proposed rule language in proposed § 23.115(c)(1) to require the takeoff performance determination to include the distance determination of “an aborted take-off at critical speed,” rather than “accelerate-stop.”
The FAA agrees that “accelerate-stop” is not as clear a description of the objective of the maneuver as “aborted take-off at critical speed”. Therefore, the FAA revises paragraph § 23.2115(c)(1) to reflect the commenters' recommendation.
Embraer recommended the FAA provide special consideration—including freezing the certification bases—for previously-approved light jets with certification bases that include special conditions measuring the takeoff distance as the distance required to takeoff and climb to a height of 35 feet above the takeoff surface. Embraer feared the potential cost associated with an upgrade or modification.
The FAA finds a special consideration unnecessary. There is already a process, prescribed by § 21.101(b), that allows applicants for a change to a TC to show that the change complies with an earlier amendment of a regulation if the newer requirement would not contribute materially to the level of safety of the product or would be impractical.
ANAC recommended the FAA make it clear that takeoff airspeed and procedures must be determined. The FAA disagrees with ANAC's comment as such a change would be redundant with what we proposed for § 23.105 (now § 23.2105).
e. Climb Requirements (Proposed § 23.120/Now § 23.2120)
In the NPRM, proposed § 23.120 (now § 23.2120) would have required an applicant to demonstrate various minimum climb performances out of ground effect, depending on the airplane's certification level and performance capability.
In light of comments received, the FAA revises proposed § 23.120 (now § 23.2120) by withdrawing paragraphs (b)(4), (b)(5), and (c)(1), and renumbering paragraphs (c)(2) and (c)(3) as (c)(1) and (c)(2) respectively. This section discusses these changes in more detail.
Textron commented that regulations have historically applied to the airplane, not to the applicant, with demonstration of compliance through flight testing. Textron recommended the FAA offer alternative rule language that reflected its comment. The Associations similarly recommended the FAA change the opening of proposed § 23.120 to focus on the design rather than the applicant. These commenters also recommended re-designating the opening as paragraph (a).
The FAA notes that, historically, the airplane-specific requirements focused on the airplane, and the part 21 certification requirements were targeted more to the applicant. Many sections in this rulemaking effort tried to include applicant accountability, which was why the proposed rule focused on the “applicant.” However, based on the comments received, the FAA revises the proposed language throughout this rule by removing “applicant” where the requirement is more logically based on the airplane.
Textron commented on the proposal to apply discriminators based on weight divisions and detailed quantitative climb criteria conflicted with the stated intent of the rulemaking to remove weight-based divisions and develop standards reflecting the diversity of future airplane designs. Textron recommended the FAA adopt language similar to proposed CS 23.120, which leaves determination of detailed standards appropriate to airplanes with different certification and performance levels to means of compliance. The Associations recommended the FAA make the calculation of performances more general, to facilitate the use of standard means of compliance, which may exist in consensus-based standards. An individual commenter similarly stated the prescriptiveness of proposed § 23.120 was contrary to the stated objective of the proposal. The commenter stated the text of proposed § 23.120 would be more appropriate as a standard rather than a rule. The commenter recommended that the FAA use the language of proposed § 23.125, which would have required the determination of climb performance in certain conditions and configuration, in proposed § 23.120. The commenter also noted the current version of the ASTM standard for climb requirements already fully covers the language of proposed § 23.120.
In response to Textron's comment, the FAA revises proposed § 23.120 so it no longer contains weight divisions. Instead, the requirements of this section are based on certification levels, performance levels, and number of engines. Section 23.2120 does, however, contain quantitative climb criteria. On this topic, the FAA did not adopt the EASA proposed CS 23.120 language as recommended by Textron. While the idea of removing all climb gradient requirements was discussed in the Part 23 ARC, the FAA finds it is not in the best interest of safety to eliminate all required climb gradients. Therefore, the FAA is including the minimum climb gradients in this performance-based rule. But, the FAA consolidated the climb gradient requirements of former part 23 to simplify the requirement. The FAA finds doing so will maintain the former level of safety while reducing the certification burden. The FAA acknowledges the ASTM means of compliance contain the climb gradients in more detail than required from the requirements of this section. However, the ASTM means of compliance has not been accepted by the FAA as of the publication of this rule.
The FAA finds that, while removing as many prescriptive requirements as possible is important for creating a performance-based rule, some requirements should remain because they have been proven over decades of service and are already based on performance. The FAA finds the climb requirements are one such case.
In response to the comment that the FAA should use the language of proposed § 23.125 (now § 23.2125) in proposed § 23.120 (now § 23.2120), the FAA notes that § 23.2125 only requires the performance information be determined for the airplane flight manual (AFM). There is no minimum climb gradient in § 23.2125 as with § 23.2120. The Part 23 ARC discussed this issue at length with the objective of defining a clear, minimum performance-based metric that would allow the prescriptive climb gradients to move to means of compliance. The climb gradients in former §§ 23.65 through 23.77 came from early CAR 3 and have been in place for more than half a century, with the exception of some commuter category requirements, which came from early part 25. Since the FAA has established measureable gradients, any alternative approach would need to maintain the same gradients to provide an equivalent level of safety as the former climb requirements. The ARC considered numerous options, but in every case the proposed metric was subjective such that the FAA may be
required to evaluate various other climb gradient schemes against the former climb gradients, when the intent was to maintain the former climb gradients. Finally, the FAA determined keeping the prescriptive climb gradients from the former rules remains the best approach. Furthermore, supporting this position, the FAA could not envision new and novel configurations that could not meet these climb gradients, but would offer the same level of safety. All the new and novel configurations that have been shared with the FAA have performance that will meet or exceed the minimum gradients proposed in the NPRM. For these reasons the FAA is retaining the proposed language.
Furthermore, it may not have been clear in the NPRM that the FAA intended proposed § 23.120 to address the required minimum climb gradients in former §§ 23.63, 23.65, 23.67, and 23.77, and proposed § 23.125 (now § 23.2125) to address the required publication of the measured performance in former §§ 23.66, 23.69, and 23.71. Therefore, the FAA is not including language similar to proposed § 23.125 (now § 23.2125) in § 23.2120, because § 23.2120 includes required climb gradients, not information requirements.
Textron stated that proposed § 23.120(a) would have applied to the all engines operating (AEO) takeoff climb and that a common terminology should be used. Textron recommended the FAA replace the undefined phrase “initial climb configuration” in proposed paragraph (a) with the unambiguous phrase “takeoff configuration”, and remove the phrase “at takeoff” from proposed paragraph (a)(2). Textron also recommended the FAA remove the phrase “at sea level” from proposed paragraph (a)(1) because the FAA already proposed § 23.105 to require an airplane, unless otherwise prescribed, to meet the performance requirements of this subpa
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