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U.S. Department of Transportation

FEDERAL AVIATION

ADMINISTRATION

FINAL RULEMAKING 

REGULATORY EVALUATION

Revision of Airworthiness Standards for 

Normal, Utility, Acrobatic, and Commuter Category Airplanes

14 CFR Part 23

OFFICE OF AVIATION POLICY AND PLANS

ECONOMIC ANALYSIS DIVISION

Nicole Bartolucci

George Thurston

September 12, 2016
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Table of Contents

I. List of Abbreviations ............................................................................................................................. 4

II. Executive Summary ............................................................................................................................... 6

III. Introduction/Background..................................................................................................................... 10

IV. Assumptions and Data Sources............................................................................................................. 16

V. Fleet Discussion.................................................................................................................................... 19

Table 2. Part 23 New U.S. Certifications and Delivered Airplanes...................................................................... 22

VI. Benefits................................................................................................................................................. 23

VI.1. Introduction.................................................................................................................................. 23

VI.2. Safety Benefits .............................................................................................................................. 24

VI.2.a. Stall .............................................................................................................................................. 24

Table 3. Fatality and Aircraft Damage Rate per Aircraft* ................................................................................. 27

Table 4. Projected Future Averted Accidents, Fatalities, and Destroyed Aircraft* ................................................. 28

Table 5. Averted Benefit for Fatalities and Aircraft Damage from Stall Accidents* ............................................... 29

VI.2.b. Icing ............................................................................................................................................. 30

Table 6. – Historical Events Applicable to SLD ................................................................................................ 31

VI.3 Cost Savings..................................................................................................................................... 33

Table 9. Savings from Equivalent Level of Safety Findings (ELOS)* .................................................................. 36

Table 10. Total Cost for Special Conditions, Exemptions, and ELOS*................................................................ 37

VI.4. Qualitative Benefits ......................................................................................................................... 38

VII. Costs.................................................................................................................................................... 40

VII.1. Introduction ................................................................................................................................... 40

VII.2. Discussion of Minimal to No Costs Part 23 Sections....................................................................... 41

VII.3. Discussion of Sections That Will Add Costs ................................................................................... 45

VII.3.a. Annual and Hourly Wages and Benefits ...................................................................................... 45

VII.3.b. Estimated Costs for §23.2150(b)................................................................................................... 46

Table 11. Estimate Costs for § 23.2150(b) (2015 $)............................................................................................ 49

VII.3.c. Estimated Costs for § 23.2150(c) .................................................................................................. 50

Table 12. Estimate Costs for § 23.2150(c) (2015 $) ............................................................................................ 52

VII.3.d. Additional Training Costs ........................................................................................................... 52

Table 13. Training Costs (2015 $)................................................................................................................... 54

VII.3.e. Type Certification Manual Update Costs ..................................................................................... 55

Table 14. Estimate Costs for Updating Engineering Manuals (2015 $)................................................................ 55

VII.3.f. Type Certification Database Update Costs.................................................................................... 56
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Table 15. Estimate Costs for Creating a Certification Database (2015 $).............................................................. 58

VII.3.g. Summary of Costs ....................................................................................................................... 58

Table 16. Total Cost Summary by Category..................................................................................................... 59

Table 17. Average Additional Cost per Type Certificate by Engine Category (2015$)............................................ 59

VIII. Benefit-Cost Summary...................................................................................................................... 59

Table 18. Estimated Benefits and Costs from 2017 to 2036 (2015 $ Millions)....................................................... 60

IX. Sensitivity Discussion....................................................................................................................... 61

Table 19. Part 23 New U.S. Certifications and Delivered Airplanes.................................................................... 63

X. Appendix I ....................................................................................................................................... 65

XI. Appendix II...................................................................................................................................... 66

XII. Appendix III .................................................................................................................................... 71

XIII. Appendix IV..................................................................................................................................... 72

XIV. Appendix V...................................................................................................................................... 74
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I. List of Abbreviations 

AC - Advisory Circular 

ACO - Aircraft Certification Office

APO - Aviation Policy and Plans Office

ARC - Aviation Rulemaking Committee

ASTM - ASTM International

CAA - Civil Aviation Authorities

CAR 3 - Civil Air Regulations part 3

CFR - Code of Federal Regulations

CO - Carbon Monoxide

CPS - Certification Process Study

CS-VLA - Certification Specification for Very Light Aeroplanes

DOT - Department of Transportation

EASA - European Aviation Safety Agency

ELOS - Equivalent Level of Safety Findings

FAA - Federal Aviation Administration

FAR - Federal Aviation Regulations

FAMRA - Federal Aviation Modernization and Reform Act

GA - General Aviation

GAMA - General Aviation Manufacturers Association

LSA - Light-Sport Aircraft

LOC - Loss of Control

MOC - Means of Compliance

NAV/COM - Navigation and Communication
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NORSEE - Non-Required Safety Enhancing Equipment

NPRM - Notice of Proposed Rulemaking

RAD ALT - Radar Altimeter

SARA - Small Airplane Revitalization Act

SC - Special Condition

TCDS - Type Certificate Data Sheet

U.S. - United States

USC - United States Code

VLA - Very Light Airplane
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II. Executive Summary

The current issue with part 23 is the prescriptive regulatory framework does not readily 

allow the adoption of new and innovative technology. This rulemaking will address this issue by 

putting in place a performance-based regulatory structure that will result in the FAA accepting 

new means of compliance based upon industry consensus standards. The FAA believes this 

action will provide a set of requirements that will allow more flexibility in part 23 airplane 

designs and faster adoption of safety enhancing technology while also maintaining a higher level 

of safety with new safety requirements.

Two examples of new and innovative technology that will be certified more quickly 

under this final rule are electric propulsion and computer aided flight control systems. 

Additionally, this rulemaking amends parts 21, 43, 91, 121, and 135 to maintain consistency with 

the new part 23.

This rulemaking project will:

• Comply with Congressional mandates.1 Congress passed the Federal Aviation 

Modernization and Reform Act of 2012, which requires the Administrator, in 

consultation with the aviation industry, to assess the aircraft certification and approval 

process. In response, the FAA initiated this rulemaking on September 24, 2013 and 

published the proposal on March 14, 2016. Subsequently, on November 27, 2013, 

Congress passed the Small Airplane Revitalization Act of 2013, which requires the 

FAA to issue a final rule that revises the certification requirements for small airplanes

by:

 1 Federal Aviation Modernization and Reform Act (FAMRA) of 2012 (Public Law 112-95; 49 USC 40101 note) and 

Small Airplane Revitalization Act of 2013 (Public Law 113-53; 49 USC 44704 note).
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o Creating a regulatory regime that will improve safety and decrease 

certification costs;

o Setting safety objectives that will spur innovation and technology adoption;

o Replacing prescriptive rules with performance-based regulations; and

o Using consensus standards to clarify how safety objectives may be met by 

specific designs and technologies.

• Reorganize part 23 into performance-based requirements by removing most of the 

prescriptive language from the regulatory text of part 23. The detailed design 

provisions will be identified in means of compliance (MOC) documents, accepted by 

the Administrator, to support this effort.2 The rule will also allow for greater use of 

consensus standards, consistent with guidance set forth in OMB Circular A-119, 

Federal Participation in theDevelopment and Use of Voluntary Consensus Standards 

and in Conformity Assessment Activities. Applicants will still have the option to 

propose their own means of compliance as they do today. The process for reviewing 

new means of compliance will not change substantially from the process in place

today.

• Promote harmonization and the adoption of the newly created performance-based 

airworthiness design standards as an internationally accepted approach by the 

majority of other civil aviation authorities, consistent with the direction in Executive 

Order 13609, Promoting International Regulatory Cooperation. These civil aviation 

authorities include Europe, Brazil, Canada, China and New Zealand. In addition, this 

 2 Means of compliance is a documented procedure used by an applicant to show compliance with part 23

airworthiness standards, and accepted by the Administrator. A means of compliance is one method, but not the only 

method, to show compliance with a regulatory requirement. Additionally, if a procedure is used as a meansof

compliance, it must be followed completely to maintain the integrity of the means of compliance.
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project has been designated a pilot cooperative rulemaking project by the FAA and 

European Aviation Safety Agency (EASA).

• Amend part 23 regulatory text to harmonize requirements for the development of 

entry-level airplanes with those certified under the European Certification 

Specification for Very Light Aeroplanes (CS-VLA).

• Increase the FAA’s ability to more readily address the newest technology.

• Amend the stall, stall warning, and spin requirements to reduce fatal accidents.

• Improve crashworthiness by allowing new methods for occupant protection.

• Address icing conditions that are currently not included in part 23 regulations.

The goal of this rulemaking is to create a cost effective approach to certification in

an adaptive regulatory environment that addresses new safety enhancing technologies and

allows for alternative means of compliance.

The FAA has analyzed the benefits and the costs associated with this final 

rulemaking. The factors driving the $3.9 million expected costs of this final rule are the 

controllability, stall and spin, additional training tasks, database development, and manual 

upgrade. Benefits consist of $17.9 million in safety benefits from preventing stall andspin 

accidents and $9.9 million in cost savings from reducing the number of special conditions, 

exemptions, and equivalent levels of safety findings (ELOS) for total benefits of $27.8

million. Another way to consider the expected net benefit to the society is if the rule saves 

only one human life by improving stall characteristics and stall warnings, this alone would

result in benefits which substantially outweigh the costs. The following table shows the 

quantified benefits and costs.
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Table 1. Estimated Benefits and Costs from 2017 to 2036

(2015 $ in Millions)

Stall and Spin + 

Other Costs = 

Total Costs

Safety Benefits + Cost Savings 

= Total Benefits

Total $0.8 + $3.1 = $3.9 $17.9+ $9.9 = $27.8

Present Value at 7 percent $0.8 + $3.1 = $3.9 $6.1 + $4.9 = $11.0

Present Value at 3 percent $0.8 + $3.1 = $3.9 $11.1 + $7.1 = $18.3

 *These numbers are subject to rounding error.

As a result, we determined that this final rule will: have benefits that justify its costs; not 

be an economically “significant regulatory action” as defined in section 3(f) of Executive Order 

12866; be “significant” as defined in Department of Transportation’s (DOT) Regulatory Policies 

and Procedures; have a significant positive economic impact on a substantial number of small 

entities; not create obstacles to international trade; and not impose an unfunded mandate on state, 

local, or tribal governments, or on the private sector. 
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III. Introduction/Background 

In 2012, Congress passed the Federal Aviation Modernization and Reform Act (FAMRA) 

of 2012,

3 which requires the Administrator, in consultation with the aviation industry, to conduct 

an assessment of the aircraft certification and approval process. While this rulemaking is in 

response to the FAMRA, it also responds to the Small Aircraft Revitalization Act (SARA) of 

2013.4 The SARA directs the FAA to create performance-based regulations and provide for the 

use of consensus standards to allow flexibility in the certification of new technology. This is 

different from what is currently done in certification. The current rules were developed to 

address issues with technologies existing when the rules were issued. They impose different 

requirements based on the weight and means of propulsion. They are prescriptive, detailed, and 

include many “how-to” paragraphs that are more appropriate for guidance in developing means 

of compliance. This is acceptable for long-standing, traditional configurations; however, this 

approach may limit innovation and new technology. Applicants incorporating new technologyor 

innovative features are forced to use special conditions, exemptions, or ELOS for certification 

and these processes are time consuming. The text of the SARA also mentions several 

motivations for the changes including: improving safety, reducing regulatory compliance costs, 

spurring innovation and technology adoption. Further, as the title of the law suggests, it is hoped 

that these changes will revitalize the part 23 aircraft manufacturing industry.

The FAA believes that this final rule complies with the FAMRA and the SARA by

improving safety, reducing regulatory compliance costs, spurring innovation, and more quickly 

adopting new technology. This final rule also is consistent with OMB Circular A-119, in 

promoting use of consensus standards to satisfy regulatory requirements. In addition, this final 

 3 Public Law 112-95; 49 USC 40101 note 4 Public Law 113-53; 49 USC 44704 note
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rule satisfies Executive Orders 13563, 13609, and 13610, by protecting public health, welfare, 

safety while promoting economic growth, innovation, competitiveness, and job creation, and

promoting international regulatory cooperation.

The FAA’s strategic initiatives communicate FAA goals to increase safety throughout 

general aviation by enabling and facilitating innovation and the development of safetyenhancing

products. This rulemaking provides an appropriate regulatory structure that will also allow part 

23 airplanes to achieve FAA safety goals through innovation and the use of performance-based 

industry consensus safety standard that will be accepted by the Administrator.

One focus area of this rulemaking’s increased safety goal is loss of control (LOC)

accidents, which continues to be the largest source of fatal general aviation accidents. To address

LOC accidents, the FAA is promulgating new rule language that is performance and risk-based 

and will allow industry to develop multiple approaches through means of compliance that satisfy 

the new standard. These means of compliance will be based on a safety continuum that balances

the level of certitude, appropriate level of safety, and acceptable risk. This means that airplanes 

carrying few passengers who would be endangered in the event of an accident will be subject to 

different requirements than airplanes that carry more passengers. Thisrisk-based approach to 

certification allows for alternative means of compliance to the same rule and has already served 

the FAA and public well in the certification of electronic equipment. An example application of 

thisrisk-based approach is former § 23.1309 for avionics equipment in part 23 airplanes. Former 

§ 23.1309 tailors specific regulatory requirements to the level of risk posed by the aircraft, and

led to the successful introduction of glass cockpits in small general aviation airplanes.5

 5 Section 23.1309 allows for different acceptable values for likelihood of failures based on the severity of thehazard, 

airplane weight, and method of propulsion. These different values encourage the incorporation of equipmentthat 

improves pilot situational awareness and other systems that promote the overall airplane level of safety.
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The FAA has been evaluating the way it sets standards for different types of airplanes

certificated under part 23. In 2009, a joint FAA/industry team finalized the Part 23 Certification 

Process Study (CPS). This team reviewed the life cycle of part 23 airplanes to determine what 

provisions needed improvement. A key recommendation from this team was reorganizing part 23 

based on airplane performance and complexity rather than the existing weight and propulsion 

divisions. The team also recommended that applicants be allowed to use consensus standards to 

satisfy performance-based standards, thus permitting alternative approaches to certification not 

available today.

In 2010, with the CPS as a foundation, the FAA initiated a part 23 regulatory review. As

part of this review, the FAA held meetings with the public and industry to gain input on the 

future of part 23. These meetings confirmed that the public and industry supported the 

recommendations of the CPS regarding the future structure of part 23.

In 2011, based on the results of the CPS and the part 23 regulatory reviews, the FAA 

formed the Part 23 Reorganization aviation rulemaking committee (ARC). The committee’s 

chartered tasks included considering the recommendation of the CPS to reorganize part 23 based 

on airplane performance and complexity versus the existing weight and propulsion divisions. 

The ARC was also tasked to investigate the use of consensus standards.

After considering the ARC’s recommendation, the FAA published the Notice of 

Proposed Rulemaking (NPRM) for this rule on March 14, 2016. After the publication of the 

NPRM, the FAA held meetings with the public and industry from May 3, 2016 to May 4, 2016 

to discuss each of the subparts of the NPRM. On May 13, 2016, the comment period for the 

NPRM closed.
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The ARC included participants from several foreign Civil Aviation Authorities6 and 

domestic and international members from almost every General Aviation (GA) manufacturer of 

both airplanes and avionics. The ARC also included several Light-Sport Aircraft (LSA) 

manufacturers who are interested in certificating their products using the airworthiness standards 

contained in part 23. These manufacturers shared their insights from the GA manufacturer 

perspective. This perspective was focused on the need to certify safer airplanes by taking 

advantage of new safety enhancing technologies.

The ARC emphasized that industry needs to develop airplanes designed to use new 

technology from the outset. The ARC noted that certification costs resulting from uncertainty 

create project risk and prevent introduction of this new technology. The ARC further noted the 

FAA’s rules are based on historical design concepts. The ARC’s observation of the part 23 

industry was that the only way to reduce risk in the certification process is to design new 

airplanes just like old airplanes. Any approach to a new airplane design is met withuncertainty 

with respect to how the FAA will address the new design. The certification of newand

innovative products today frequently requires the use of ELOS, special conditions, and 

exemptions, resulting in uncertainty and high project costs. The ARC recommendations to revise 

part 23 echo the CPS recommendations and target the factors that have kept part 23 airplanes 

unchanged for four decades.

Two additional factors driving the need for this rulemaking are safety and cost. In order 

to improve the future GA fleet’s safety level over that of today’s aging fleet, the FAA believes 

that industry needs to build new part 23 certificated airplanes that incorporate today’s current 

safety enhancing technologies. Although a number of new part 23 airplanes are being built, 

 6 The international regulatory agencies included participants from Brazil, Canada, China, Europe, and NewZealand.
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many were originally certified to the Civil Air Regulations part 3 (CAR 3), or very early 

amendment levels of part 23, and reflect the level of safety technology available when they were 

designed decades ago.

Light-sport aircraft (LSA) and experimental airplanes are incorporating modern 

aerodynamics and crashworthiness technologies that employ lessons from the automotive 

industry. Aerodynamic designs that improve low speed control, improve stall characteristics and 

provide warning to the pilot when operating close to the airplane’s limits help avoid loss of 

control accidents. Improved occupant restraints including better seat belts and air bags provide 

protection for occupants during a crash. Automobile experience shows that vehicles designed 

with a strong cabin surrounded by “crumple zones” also help to improve survivability in a crash.

The FAA believes these advances will reduce accidents and improve crash survivability and we 

would like to see these technologies used to improve the safety of the smaller part 23 airplanes.

Aircraft owners and manufacturers have demonstrated in the past several years that they 

are willing to purchase and install many types of non-required safety enhancing equipment in

part 23 airplanes when the equipment is perceived to be affordable. We have seen positive 

impacts on reducing both controlled flight into terrain accidents and weather related accidents 

that coincide with the increased use of some of this equipment. NTSB accident data for general 

aviation shows a 50 percent decline in fatal CFIT (Controlled Flight into Terrain) accidents from 

2002 through 2012. This coincides with large scale increased use of GPS-based electronic maps 

including terrain displays in small airplanes. The GA fatal accident data also shows more than a 

35 percent reduction in weather related accidents from 2009 to 2013 that is at least partially 

attributable to the increased use of weather displays in the cockpit. 

Examples of this equipment include:
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• GPS navigation with moving maps

• Terrain displays

• Real-time weather displays in the cockpit

• Traffic displays in the cockpit

• Angle of Attack (AoA) displays

• Autopilot installations

• Enhanced and Synthetic Vision displays

• Envelope protection autopilot systems

• Easy button for auto recovery (airplane upset, pilot disorientation, etc....)

• Easy button for auto landing (engine failure, pilot incapacitation, etc....)

• Backup attitude display

• Simplified radar altimeter (RAD ALT)

• Installations of ballistic parachutes

• Installations of inflatable restraints

• Crush zones in structure

• High visibility lights

• Carbon Monoxide (CO) detectors,

• Secondary radio navigation and communication (NAV/COM) with flip-flop

• Amphibious Gear Advisory Systems

Few GA owners or operators can afford the high cost of a new part 23 airplane that 

incorporates the latest safety enhancing features. Instead, pilots and owners are migrating to 

experimental aircraft and LSA, in part because of the lower costs. Chapter 1 of the 2013 FAA 

General Aviation Survey shows the experimental fleet has increased by 30 percent while the 

part 23 piston fleet has decreased by about 11 percent in the last 10 years.7 In other words, 

aircraft owners believe they can get an acceptable level of safety for less cost in experimental 

aircraft and light sport aircraft (LSA) than in certified Civil Air Regulations part 3 (CAR 3)

and part 23 airplanes. The FAAbelieves that revising the standards for entry-level part 23 

airplanes will reduce certification costs.

The part 23 ARC noted that development and certification cost of working with the

FAA to get a new part 23 entry-level airplane to market is too high. The two new U.S.

manufactured 4-place airplanes, the Cessna Corvalis and Cirrus SR-20/22, are certified to 

 7 http://www.faa.gov/data_research/aviation_data_statistics/general_aviation/
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more recent amendment levels of part 23 and are often perceived as too expensive for typical 

GA uses such as primary flight training or rental and are not considered entry-level airplanes. 

These airplanes are priced in the $400,000 to $800,000 range. In contrast, the European 

Diamond DA-40 typically sells for $300,000-$400,000. A U.S. manufacturer told the FAA it 

spent about $30 million to type certificate a high performance single engine airplane, and, 

accordingto another aircraft manufacturer, a more recent 2-seat part 23 airplane cost the 

company about $55 million to certificate. The FAA’s goal with this final rule is for a new 

part 23 type certificate for a similar airplane of this size will greatly reduce the certification 

costs. The problem of high certification cost has also been recognized by EASA, which is 

actively working with several applicants to get the right oversight and cost balance for them 

to develop and certify new 4-place, entry-level part 23 airplanes.

To summarize, the purpose of this rule is to revise Title 14, Code of Federal Regulations 

(14 CFR) part 23 as a set of requirements that focus on the safety intent of historic part 23 and 

allow alternative approaches to type certificate new part 23 airplanes through consensus 

standards. This rulemaking effort also follows from the part 23 ARC recommendations along 

with satisfying the intent of the FAMRA, the SARA, and Executive Orders 13609 and 13610.

IV. Assumptions and Data Sources

The benefit and cost analysis for the regulatory evaluation is based on the

following factors/assumptions:

• The analysis is conducted in constant dollars with 2015 as the base year.

• The final rule will be effective in 2017.

• The primary analysis period for costs and benefits extends for 20 years, from

2017 through 2036. This period was selected because annual costs and 

benefits will have reached a steady state by 2036.
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• Future part 23 type certifications and deliveries are estimated from historical part 

23 type certifications and deliveries.8

• Costs for the new part 23 type certifications forecasted in the “Fleet Discussion”

section will all occur in year 1 of the analysis interval.

• Airplane deliveries from the forecasted part 23 type certificates will start in year 

5 of the analysis interval. Therefore, accident reduction benefits will begin five 

years after the rule is in effect.

• The FAA uses a three and seven percent discount rate for the benefits and 

costsas prescribed by OMB in Circular A-4.

• The baseline for estimating the costs and benefits of the rule will be part 23, 

through the current amendment level.

• Based on FAA Small Aircraft Directorate expert judgment, the FAA estimates 

335 FAA part 23 certification engineers will require additional training as a result 

of this final rule. The FAA assumes that the same number of industry part 23

certification engineers will also require additional training as a result of this final 

rule.

• The FAA calculated its training needs to be 16 hours for its staff. The FAA would 

anticipate that industry part 23 certification engineers also would need 16 hours 

of training.

• Since this training program will be on-line, we estimate no travel costs for the 

engineers.

• FAA pay-band tables and the Bureau of Labor Statistics (BLS) determines the

hourly wages used to estimate the costs to the FAA and applicants.

 8 See the “Sensitivity Discussion” chapter for further details.
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• Using the U.S. Department of Transportation guidance, the wage multiplier for

employee benefits is 1.17.9 

 9 On January 30, 2014, the DOT published a memo on “Estimating Total Costs of Compensation Based on Wage 

Rates or Salaries.” The memo directs the FAA that when a rule requires incremental hours per existing employee, 

the wage/salary multiplier is of smaller magnitude because not all categories of employer provided benefits increase

with additional hours worked by an individual employee.
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V. Fleet Discussion

As in the initial regulatory evaluation, in order to estimate the costs and benefits of this 

final rule, we need to forecast the life cycle of the affected part 23 airplanes. This analysis 

discusses the future new part 23 type certifications, and their reciprocating engine, turboprop, 

and turbojet airplane deliveries, which will be affected by this rulemaking. The life cycle of an 

airplane begins with a part 23 type certification, then production, delivery, active service, and 

ends with retirement. This section will discuss how we forecasted each component for the length 

of the life cycle for future part 23 airplanes by using historical databases of part 23 airplanes. 

These historical databases provides the FAA with data to calculate the average number of part 23 

type certificates over a specific historical time frame, the average number of annual deliveries 

per type certificate, and the average number of years a part 23 airplane is in production and in 

service. We then use these calculations in our forecast of future delivered airplanes from new 

part 23 certifications that are affected by this final rule. In section III above, FAA stated that it 

believes that this rulemaking will lead to a reversal in the declining rate of certificated part 23 

aircraft. Accordingly, FAA explores this potential trend later, in the “Sensitivity Discussion” 

chapter, the FAA discusses a sensitivity analysis by using historical deliveries between 2008 

through 2015, instead of 1998 through 2015, in order to determine if a shorter analysis interval 

affects the cost/benefit analysis. 

The FAA obtained a database of historical part 23 airplane deliveries, manufactured by 

U.S. owned companies from 1947 to 2013, from the General Aviation Manufacturers 

Association (GAMA). Due to data limitations, we eliminated any airplane that was in 
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production prior to 1947, after 2015, or had less than 10 years of delivery history after 1947 or 

before 2015.

10 

We used the FAA Type Certificate Data Sheets (TCDS) database11 from the FAA 

website, in conjunction with the GAMA delivery database, to calculate the average historical 

part 23 airplane’s production life. The TCDS contains information relevant to the certification of 

a particular airplane, such as when the airplane was initially certificated, while the GAMA 

database shows, for each part 23 type certificated airplane, how many years the airplanes were 

delivered.

12 For the NPRM, we calculated the average historical part 23 airplane’s production 

life to be approximately 26 years. With the additional two years of data, and EXCEL rounding 

off to the nearest whole number, for the final rulemaking, we calculated the average historical 

part 23 airplane’s production life to be approximately 25 years. 

We estimated the active service time, and retirement age, of a part 23 airplane by 

analyzing the ages of all US-operated airplanes from Table 7.3 of the FAA 2014 General 

Aviation and Part 135 Activity Survey. Table 7.3 shows 184,388 airplanes in 5-year age 

groupings from 0 to over 60 years old. On average, these airplanes were in service for 34 years. 

 10 The following are examples of aircraft we deleted from the GAMA database in order to have a more accurate 

weighted average reflecting a full production cycle. The Navion is a United States single-engine, unpressurized, 

retractable gear, four-seat aircraft originally designed and built by North American Aviation in the 1940s. GAMA’s 

last record of the Navion production was in 1947 with no prior history provided. Similarly, Air Tractor produced the 

AT-400, AT-500, AT-600, and AT-800 series turboprop of agricultural aircraft starting in 2011 with only three 

years of delivery history. Also, Air Tractor aircraft were removed from this analysis because the aircraft are type 

certificated to a restricted category, which may endorse parts of FAR 23 but not FAR23 in its entirety. All 

American Aircraft Inc. was an aircraft manufacturer established in 1945 at Long Beach, California by Ernest and 

Gerald Adler and produced aircraft until 1948. The firm built prototypes of a light plane design by Ernest, the 

Ensign, but was unable to find buyers to make mass production viable. Alon built the A-2 aircraft only in 1966 and 

1967. Alon was then purchased and the company redesigned the fuselage from the cockpit back creating a new 

aircraft.

11 http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFrameSet 12 Appendix 1 shows airplane manufacturers and type certification numbers we used to estimate the average 

production life.
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Thus the estimated active service time, and retirement age, of a part 23 airplane is 34 years.13

The FAA notes that this is the same part 23 airplane average age we calculated for the NPRM. 

Since the life cycle equals the production life (25 years), plus the active service life which 

ends in the airplane’s retirement (34 years), we calculated the life cycle of a historical part 23 

airplane to be 59 years (25 + 34 = 59). Therefore, for this analysis, we use 59 years as the life 

cycle of a part 23 airplane in our forecast of future type certificates and deliveries affected by 

this rule making. For an estimate of the total number of affected airplanes over the 59 year life 

cycle, we now forecast the number of new type certifications and their deliveries. 

New type certifications, and the type certification’s airplane deliveries, are estimated by 

calculating the historical average number of type certificates and the average number of 

deliveries using the GAMA and TCDS database. We calculate the average number of historical 

type certificates from the 1940’s to today, by reciprocating engine, turboprop, and turbojet 

airplane, for each U.S. manufacturer, in Appendix 2, over decade (10-year) periods. The decade

periods consist of the years in the following decade groups: 1940s, 1950s, 1960s, 1970s, 1980s, 

1990s, 2000s, and 2010s. Appendix 2 shows the number of new certifications, by manufacturer, 

by reciprocating engine, turboprop, or turbojet airplane, for each decade group. For example, 

Appendix 2 shows that the manufacturer Adam/AAI/Triton only had one type certificate in two 

decades; therefore the average annual number of type certificates in a 10-year period for this 

manufacturer is 0.5 (1 certification / 2 decades). 

The number of future affected airplanes equals the forecasted number of new type 

certificates multiplied by the average number of new deliveries per future type certificate. We 

 13 Although the FAA believes that in practice retirement ages may decline under the system of certification as new 

designs become available, we are limited to the data provided in the FAA 2013 General Aviation and Part 135 

Activity Survey report and have no basis to decide by how much we should adjust our estimate. In the NPRM we 

requested comments, with supporting data, on our retirement age estimate and received no comments therefore we 

use the same retirement age for the final rule analysis as we did with the analysis for the NPRM.
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base the forecast for future type certificates and deliveries of new part 23 U.S. manufactured 

airplanes upon the average number of new type certifications, and their deliveries, over the 1998 

through 2015 time period. We use the 1998 through 2015 analysis interval as a baseline for 

forecasting future part 23 type certifications and deliveries,. 

For each airplane manufacturer and for each of their part 23 type certifications, we 

calculate the average annual number of airplanes delivered from 1998 through 2015 by summing 

the number of deliveries by the number of years the deliveries occurred and then dividing this 

sum by the number of years the deliveries occurred. We then calculated the weighted average 

number of airplanes per type certificate and the number of forecasted new type certificates and 

rounded the result to the nearest whole number. 

Appendix 2 shows the details we used to derive the forecast for the number of future new 

part 23 certifications and airplane delivery results and provides examples, from the tables, how 

the results were calculated. Table 2 summarizes our estimate of part 23 U.S. airplanes that 

manufacturers will certificate and produce. 

Table 2. Part 23 New U.S. Certifications and Delivered Airplanes

Recip TurboProp Turbojet

Weighted Average Number of AC per TC per Year 63 46 33

New Part 23 Certifications in a 10-year Period 2 1 2

New Part 23 Certificated Airplanes deliveries per year 126 46 66

Based on this forecast of part 23 type certificates and their deliveries from Table 2, U.S. 

manufacturers will produce 126 reciprocating engine, 46 turboprop, and 66 turbojet airplanes 

annually, with deliveries beginning five years after the effective date of the rule and continuing 

for 25 years. From the second through the twenty-fifth delivery year the cumulative part 23 

fleet will grow by a total of 238 (126 + 46 + 66) airplanes annually. From the twenty-sixth 

through the thirty-fourth delivery year, the newly certificated cumulative part 23 fleet will
23| Page

remain constant. In the thirty-fifth delivery year, the airplane models that are 34 years old will

retire. By the fifty-ninth delivery year, all airplanes produced from the forecasted part 23 

certificates will be retired. Appendix 3 shows our forecast of the cumulative number of newly 

certificated part 23 airplanes delivered and affected by this rule over the 60-year timeframe. The 

FAA notes that the column titled “Delivery Year” in Appendix 3 lags the first year of the 

analysis interval (or the effective date of the final rule) by five years. Similarly accident 

reduction benefits will begin five years after the rule is in effect.

VI. Benefits

VI.1. Introduction

Part 23 standards are largely based on experience with airplanes designed in the 1950’s 

and 1960’s. Over the past five decades part 23 certification regulations have become prescriptive 

as a result of codifying specific, detailed design requirements to address and respond to the 

introduction of new technologies, specific problems encountered during various certification 

projects, and specific recommendations from the National Transportation Safety Board (NTSB). 

While the intent of the prescriptive rules was to increase safety and prevent confusion or 

certification ambiguities, manufacturers felt constrained to use outdated design philosophies, 

which created a barrier for the introduction of novel safety enhancing technologies. 

Furthermore, the FAA is concerned that the current part 23 regulatory prescriptive 

structure does not effectively address the safety continuum, particularly the low performance end 

(single piston-engine airplane) of the continuum. The safety continuum refers to higher level of 

safety as the airplane that carry more people have a higher level of risk. Recent part 23 

amendments have increasingly focused on high-performance, complex airplanes. These 

requirements have been applied across the board and may not be necessary or appropriate for 
24| Page

low-performance airplanes. This has created an unintended barrier to new safety enhancing 

technology in low-performance airplanes. 

In 2012, Congress passed the FAMRA14, which required the Administrator, in 

consultation with the aviation industry to conduct an assessment of the aircraft certification and 

approval process. A year later, Congress passed the SARA15, which is the basis for this 

rulemaking effort. This rulemaking addresses the SARA mandate by (1) creating a regulatory 

regime for small airplanes that will improve safety and decrease certification costs; (2) setting

safety objectives that will spur innovation and technology adoption; (3) replacing prescriptive 

rules with performance-based regulations; and (4) using consensus standards to clarify how 

safety objectives may be met by specific designs and technologies.

These standards begin with the safety intent of current part 23 requirements and add 

enhanced standards for icing conditions, resistance to departure from controlled flight, and loss 

of control for multiengine airplanes as current accidents are often associated with these causal 

factors.

VI.2.Safety Benefits 

VI.2.a. Stall

The largest number of accidents for part 23 airplanes is caused by loss of control, 

including stalls and spins. LOC accidents are typically initiated by an inadvertent departure from 

controlled flight. In the case of a stall, LOC occurs when the pilot allows the airplane to slow 

down to a speed where the wing cannot continue to maintain lift. The prevention of this event 

can be designed into the airplane’s flight characteristics, or the airplane can use a systems-based 

approach such as a stick pusher or envelope protection. A pilot’s lack of awareness of the state of 

 14 Public Law 112-95; 49 USC 40101 note 15 Public Law 113-53: 49 USC 44704 note
25| Page

the airplane and the airplane’s low speed handling characteristics are the main causes of these 

accidents. Stall and other LOC accidents are generally fatal if the airplane is too low for the pilot 

to recover before impact with the ground. Furthermore, inadvertent stalls generally occur close to 

the ground because that is where the airplane is slowed for takeoff and landing. The new rule, 

section 23.2150, “Stalls characteristics, stall warning, and spins,” improves safety by requiring a 

combination of better stall warning, better natural stall characteristics, and system-based 

protection that will reduce stall and LOC accidents. 

The FAA recognizes that the means of compliance will be very important in the success 

of this requirement to improve safety. The FAA adopts a general performance-based requirement 

in § 23.2150(b) to enable numerous alternative approaches to meet the requirement. For this 

reason, it is impossible to specify a single set of flight test requirements. The flight test 

requirements will depend on the applicant’s approach to complying with this rule and the means 

of compliance it uses. It would have been impossible to adopt requirements for all combinations 

of safety features and characteristics that reduce the tendency to inadvertently depart controlled 

flight in the requirements themselves. However, applicants can still use the spin resistance 

requirements from former § 23.221 for spins, and a stick pusher compliant with former § 23.691 

for artificial stall barrier systems. Additionally, ASTM is developing an expandable matrix 

concept that will allow credit for combinations of stall warning, stall/envelope protection, and 

flight characteristics. This matrix should result in not only encouraging manufacturers to install 

more safety enhancing equipment, but more importantly, it will also encourage the development 

of innovative approaches to preventing inadvertent departure because of the speed at which new 

technology can be incorporated into the certification process. To address the wide range of 

airplane characteristics and solutions, the FAA is adopting a standard that the airplane may not 

have tendency to inadvertently depart controlled flight.
26| Page

The NPRM identified 74 stall or loss of control related accidents investigated by NTSB 

from January 2008 to December 2013. For the final rule, to remain consistent with the NPRM in 

analyzing the most recent 6 year accident history, the FAA removed all 28 stall or loss of control 

accidents investigated in 2008 and added 20 new accidents that took place in 2013 and 19 

accidents from 2014. The FAA also removed 7 accidents with level 1 and level 2 multiengine 

airplanes as the final rule narrows the requirement to only single engine airplanes. There are a 

total of 78 accidents listed in Appendix IV from 2009 to 2014. These accidents represent the type 

of accidents that could be prevented by the stall and LOC requirements in the rule. An 

assessment is made by the FAA’s Office of Accident Investigation and Prevention (AVP-210) 

for each accident to estimate how effective the rule will be in preventing a similar accident. 

AVP-210 assessed the probability that the rule is effective for each of the accidents using the 

applicable portions of the Commercial Aviation Safety Team (CAST) methodology.16 The 

assessment effectiveness results in a classification of low, medium, or high effectiveness rate. Of 

the 78 NTSB stall and LOC accidents there are 36 accidents with a high effectiveness, which had 

61 fatalities, 18 medium effectiveness accidents with 35 fatalities, and 24 low effectiveness 

accidents with 43 fatalities over 6 years. All of these accidents resulted in a destroyed or 

substantially damaged aircraft. As in the initial regulatory evaluation, given the high level of 

damage, to estimate the benefit of preventing such aircraft damage in the future, the FAA 

assumes full replacement cost for all 78 aircraft. 

To predict accidents among future type certificated aircraft that will be prevented by the

final rule, the FAA estimates an accident, fatality, and destroyed aircraft rate for part 23 aircraft 

using these historic accidents. Rates are estimated by dividing the average number of fatalities 

 16 JIMDAT Process Handbook 6-28-04 

http://cfapp.icao.int/fsix/cast/JIMDAT%20Process%20Handbook%206-28-04%20Draft.pdf
27| Page

and destroyed aircraft in each effectiveness category by the average active number of airplanes.17

Table 3 shows the results of these calculations.18

Table 3. Fatality and Aircraft Damage Rate per Aircraft*

Effective

A

Avg. Yearly 

Accident

(2009 – 2014)

B

Avg. Yearly 

Fatalities

(2009 – 2014)

C

Avg. Yearly 

Destroyed Aircraft 

(2009 – 2014)

D

Avg. Number of 

GA Aircraft 

(2009 – 2014)

A / D

Accident 

Rate

B / D

Fatalities 

Rate

C / D

Destroyed 

Aircraft Rate

High 6 10 6 168,830 0.00004 0.00006 0.00004

Medium 3 6 3 168,830 0.00002 0.00003 0.00002

Low 4 7 4 168,830 0.00002 0.00004 0.00002

*These numbers are subject to rounding error. 

The fatality and aircraft damage rate from Table 3 is then applied to the yearly number of 

future newly certificated part 23 airplanes (reciprocating engine, turboprop, and turbojet) shown 

in Appendix III. The FAA projects that the final rule will take effect in 2017, with the first new 

type certificated aircraft being delivered in 2022. The analysis period is 20 years, but the 

accident rate applies to 15 years to account for the 5 year manufacture production cycle and 

delivery of new aircraft. 

Based on the above methodology and the effectiveness of this rule in preventing a similar 

accident, the following approximate number of accidents will be averted for newly certificated 

part 23 airplanes:

• 1.01 accidents with high effectiveness

• 0.51 accidents with medium effectiveness

• 0.68 accidents with low effectiveness

This rule is expected to result in averting a combined total of 4 fatalities and 2 destroyed

aircraft as shown in Table 4. Averted accidents and fatalities increase over time as the fleet 

 17 Table 3.1, (Fix Wing Piston, Turboprop, Turbojet) 2009-2014 General Aviation and Air Taxi Number of Active 

Aircraft by Primary Use by Aircraft Type;

https://www.faa.gov/data_research/aviation_data_statistics/general_aviation/CY2014/

18 The FAA is unable to construct a rate per person flying or per person-mile. The FAA is not aware of any reliable 

estimates of the number of persons who flew in part 23 GA aircraft over the time period.
28| Page

increases. The estimated future accidents, fatalities, and destroyed aircraft are calculated by 

summing the rows for each category in Table 4, and then summing the high, medium, and low 

columns. By summing the results of the low, middle, and high effectiveness rates for averted 

accidents from Table 4, approximately 3 accidents are averted on newly certificated part 23 

airplanes.

Table 4. Projected Future Averted Accidents, Fatalities, and Destroyed Aircraft*

YEAR

Averted Accidents Averted Fatalities Aircraft Damage

High Medium Low High Medium Low High Medium Low

2017 0 0 0 0 0 0 0 0 0

2018 0 0 0 0 0 0 0 0 0

2019 0 0 0 0 0 0 0 0 0

2020 0 0 0 0 0 0 0 0 0

2021 0 0 0 0 0 0 0 0 0

2022 0.01 0.00 0.01 0.01 0.01 0.01 0.01 0.00 0.01

2023 0.02 0.01 0.01 0.03 0.02 0.02 0.02 0.01 0.01

2024 0.03 0.01 0.02 0.04 0.02 0.03 0.03 0.01 0.02

2025 0.03 0.02 0.02 0.06 0.03 0.04 0.03 0.02 0.02

2026 0.04 0.02 0.03 0.07 0.04 0.05 0.04 0.02 0.03

2027 0.05 0.03 0.03 0.09 0.05 0.06 0.05 0.03 0.03

2028 0.06 0.03 0.04 0.10 0.06 0.07 0.06 0.03 0.04

2029 0.07 0.03 0.05 0.11 0.07 0.08 0.07 0.03 0.05

2030 0.08 0.04 0.05 0.13 0.07 0.09 0.08 0.04 0.05

2031 0.08 0.04 0.06 0.14 0.08 0.10 0.08 0.04 0.06

2032 0.09 0.05 0.06 0.16 0.09 0.11 0.09 0.05 0.06

2033 0.10 0.05 0.07 0.17 0.10 0.12 0.10 0.05 0.07

2034 0.11 0.05 0.07 0.19 0.11 0.13 0.11 0.05 0.07

2035 0.12 0.06 0.08 0.20 0.12 0.14 0.12 0.06 0.08

2036 0.13 0.06 0.08 0.21 0.12 0.15 0.13 0.06 0.08

Total 1.01 0.51 0.68 1.72 0.99 1.21 1.01 0.51 0.68

*These numbers are subject to rounding error.

The FAA used the Department of Transportation’s value of a statistical saved life that is 

$9.6 million19 in 2015 dollars. As in the initial regulatory evaluation, the FAA uses 3 aircraft 

values based on projected newly certificated aircraft types: a 1967 model Cessna 172 for 

reciprocating engine aircraft at $33,366; a 1982 model Beechcraft King Air C90 at $667,322 for 

turboprop; and a 1999 model Cessna Citation Jet 525 $1,608,722 for turbojet. These 2013 

 19 Memorandum: TREATMENT OF THE VALUES OF LIFE AND INJURY IN ECONOMIC ANALYSIS

https://www.faa.gov/regulations_policies/policy_guidance/benefit_cost/media/econ-value-section-2-tx-values.pdf
29| Page

average retail values for destroyed aircraft came from the Aircraft Bluebook Price Digest 

Summer 2013 Edition and they are adjusted to 2015 using Gross Domestic Product (GDP).20 

Multiplying the individual future part 23 certifications with the corresponding aircraft values 

provides a weighted average value for destroyed aircraft. For example, out of the 238 aircraft 

projected for 2022, 126 are reciprocating engine, 46 are turboprop, and 66 are turbojet. These 

aircraft are projected to grow in the same proportion every year for a blended average retail price 

of $592,759 for a destroyed aircraft. 

Accidents labeled low effectiveness are assigned a .2 accident effectiveness rate, .5 for a 

medium accident effectiveness rate, and .8 for high accident effectiveness rate.

21 Table 5 

quantifies the benefits of averted fatalities by calculating the projected future averted fatalities 

from Table 4 times the VSL times the accident effectiveness rates above for the accidents labeled 

low, medium, or high. In a similar manner, Table 5 calculates the averted aircraft damage by the 

projected future averted aircraft damage from Table 4 times the average future aircraft value 

discussed above times the accident effectiveness rates. Table 5 below shows these results. As the 

fleet increases each year with additional deliveries, potential accidents increase, and so do the 

benefits of reducing such accidents.

Table 5. Averted Benefit for Fatalities and Aircraft Damage from Stall Accidents*

($ in thousands)

YEAR

Effectiveness Averted 

Fatalities

Effectiveness Aircraft 

Damage TOTAL 7 Percent

P.V.

3 Percent

High Medium Low High Medium Low P.V.

2017 $0 $0 $0 $0 $0 $0 $0 $0 $0

2018 $0 $0 $0 $0 $0 $0 $0 $0 $0

2019 $0 $0 $0 $0 $0 $0 $0 $0 $0

2020 $0 $0 $0 $0 $0 $0 $0 $0 $0

2021 $0 $0 $0 $0 $0 $0 $0 $0 $0

2022 $27.5 $39.5 $77.6 $1.0 $1.3 $2.7 $149.5 $93.1 $121.6

2023 $55.0 $78.9 $155.2 $2.0 $2.5 $5.3 $299.0 $174.0 $236.0

 20 http://www.whitehouse.gov/omb/budget/Historicals/; Table 10.1—GROSS DOMESTIC PRODUCT AND 

DEFLATORS USED IN THE HISTORICAL TABLES: 1940–2021 21 JIMDAT Process Handbook 6-28-04 

http://cfapp.icao.int/fsix/cast/JIMDAT%20Process%20Handbook%206-28-04%20Draft.pdf
30| Page

2024 $82.6 $118.4 $232.8 $3.0 $3.8 $8.0 $448.5 $244.0 $343.8

2025 $110.1 $157.9 $310.4 $4.0 $5.0 $10.7 $598.0 $304.0 $445.0

2026 $137.6 $197.4 $388.0 $5.0 $6.3 $13.4 $747.5 $355.2 $540.0

2027 $165.1 $236.8 $465.5 $6.0 $7.5 $16.0 $897.1 $398.3 $629.2

2028 $192.6 $276.3 $543.1 $7.0 $8.8 $18.7 $1,046.6 $434.3 $712.7

2029 $220.1 $315.8 $620.7 $8.0 $10.0 $21.4 $1,196.1 $463.9 $790.7

2030 $247.7 $355.2 $698.3 $9.0 $11.3 $24.1 $1,345.6 $487.7 $863.7

2031 $275.2 $394.7 $775.9 $10.0 $12.5 $26.7 $1,495.1 $506.4 $931.7

2032 $302.7 $434.2 $853.5 $11.0 $13.8 $29.4 $1,644.6 $520.6 $995.0

2033 $330.2 $473.7 $931.1 $12.0 $15.0 $32.1 $1,794.1 $530.8 $1,053.9

2034 $357.7 $513.1 $1,008.7 $13.0 $16.3 $34.8 $1,943.6 $537.4 $1,108.4

2035 $385.2 $552.6 $1,086.3 $14.0 $17.5 $37.4 $2,093.1 $540.9 $1,158.9

2036 $412.8 $592.1 $1,163.9 $15.0 $18.8 $40.1 $2,242.6 $541.6 $1,205.5

Total $3,302.1 $4,736.6 $9,310.8 $120.3 $150.4 $320.9 $17,941.2 $6,132.3 $11,136.1

*These numbers are subject to rounding error.

Estimated safety benefits of avoiding roughly 2 accidents on newly certificated part 23 

airplanes over a 20-year period sums to about $17.9 million ($6.1 million at a seven percent 

present value rate and $11.1 million at a three percent present value rate), however benefits will

continue indefinitely into the future.

VI.2.b. Icing 

Currently, part 23 regulations define airplane performance, flight characteristics, power 

plant, and systems requirements for a part 23 applicant seeking optional certification for flight in 

icing conditions. Part 23 references Appendix C to part 25 as the icing conditions for which the 

above requirements must be shown. Certain icing conditions can be encountered which are not 

addressed in Appendix C to part 25. In the 1990s, the FAA became aware that the icing 

conditions considered during the certification of airplanes and turbine aircraft engines needed to 

be expanded to increase the level of safety during flight in icing conditions. The NTSB issued 

safety recommendation A-96-054 to revise the icing criteria published in 14 Code of Federal 

Regulations (CFR), Part 23 and 25.

22 The FAA determined that the revised icing certification 

standards should include supercooled large drops (SLD, which consist of freezing drizzle and 

freezing rain), mixed phase, and ice crystals. In the part B of the Background section of the part 

 22 http://www.ntsb.gov/_layouts/ntsb.recsearch/Recommendation.aspx?Rec=A-96-054
31| Page

23 NPRM,23 references icing events in which research related to operations in severe icing

conditions was conducted by the Part 23 ARAC. These systems are designed for the icing 

conditions defined in Appendix C of part 25, which is the current standard for part 23 airplanes. 

This ice accretion can cause large aerodynamic penalties not accounted for in the type design. 

Additionally, accident and incident investigations, along with FAA sponsored research,

discussed in the below paragraph, have shown that high altitude ice crystal conditions can cause 

erroneous airspeed indications and unacceptable engine operation. Initially, only transport 

category airplanes were addressed. The FAA published amendments 25-140 and 33-34, 

Airplane and Engine Certification Requirements in Supercooled Large Drop (SLD), Mixed 

Phase, and Ice Crystal Icing Conditions, on November 4, 2014 (79 FR 65508) that expanded 

icing requirements for transport category airplanes and engines. However on February 19, 2010 

an ARC was chartered to review and modify proposed part 23 icing regulations and provide 

associated guidance for part 23. 

The part 23 icing ARC examined incidents and accidents from three data sources—NTSB 

data, the FAA Accident/Incident Data System, and the NASA Aviation Safety Reporting 

System. Table 6 lists the U.S. accidents for part 23 airplanes, from 2005 to 2010, in which SLD 

was a probable cause or factor. For a fuller discussion see their February 2012 Part 23 Icing 

Aviation Rulemaking Committee Report.24 

Table 6. – Historical Events Applicable to SLD

DATE AC TYPE LOCATION FATAL INJURY HULL LOSS

01/03/2009 BE-58 Brainerd, MN 0 0 Substantial Damage

02/16/2007 CE-340A Council Bluffs, IA 4 0 Yes

 23 See the notice of proposed rulemaking (NRPM), Airworthiness Standards for Normal, Utility, Acrobatic, and 

Commuter Category Airplanes, March 2016, p.13457, Docket No. FAA-2015-1621, accessible at 

www.regulations.gov. 24 PART 23 ICING AVIATION RULEMAKING COMMITTEE REPORT (FEB 2012 - Revision B)

http://www.faa.gov/regulations_policies/rulemaking/committees/documents/media/SLD%20ARC%20Report.RevB.

Feb%2010%202012.pdf
32| Page

03/20/2006 PA-23-250 Emporia, KS 0 1 Substantial Damage

01/25/2006 CE-421C Carson, WA 1 0 Yes

01/11/2005 BE-65-E90 Rawlins, WY 3 1 Yes

Accidents listed in Table 6 prompted the part 23 icing ARC to recommend adopting most 

of the part 25 proposed rules, including the requirement to either show an airplane could safely 

fly in SLD conditions or show it can detect and safely exit those conditions. This rule requires

manufacturers that choose to certify for flight in SLD must show that the airplane can operate 

safely in SLD. For those manufacturers who choose to prohibit flight in SLD and only certify to 

the icing conditions of part 25, appendix C, the rule requires a means for detecting SLD and 

showing the airplane can safely exit icing conditions (detect and exit).

25 Current FAA guidance 

in Advisory Circular 23.1419-2D is an acceptable means of compliance for detect and exit. 

Based on the service history of part 23 airplanes certified to the current icing standards, the 

accidents listed in Table 6 could possibly have been prevented by the rules requirements. The 

FAA reached out to industry about costs associated with meeting these icing requirements. 

Industry responded that these requirements will not impose additional costs because many 

manufacturers have already equipped their aircraft to meet these standards for detecting and 

exiting SLD in accordance with current FAA guidance. The rule does allow for manufacturers to 

voluntarily certify that the airplane can operate safely in SLD, which would increase 

functionality over the former regulations. When compliance is voluntary, or no change in 

industry practice will occur from a new regulation, the FAA determines both costs and benefits 

to be zero.

 25 The FAA published Airplane and Engine Certification Requirements in Supercooled Large Drop, Mixed Phase, 

and Ice Crystal Icing Conditions, on November 4, 2014 (79 FR 65508) that expanded 14 CFR parts 25 and 33 icing 

requirements.
33| Page

VI.3 Cost Savings

The current part 23 aircraft certification and approval process is prescriptive with specific

performance and design requirements that impact the industry’s ability to introduce new 

technology or to modify aircraft. The FAA currently accommodates the introduction of new and 

innovative technology or modifications by requiring an applicant to provide additional 

information that explains the deviation from the existing rule. This process typically results in 

the issuance of special conditions, exemptions, and ELOS.

26 Instead of the prescriptive 

requirements found currently in part 23, this rule will streamline the certification process and 

encourage the installation of new technology, thus obviating the need for many of the 

exemptions, special conditions, and ELOS.

The revisions to part 23 airworthiness standards will replace current prescriptive design 

requirements with risk based and performance-based regulatory standards. To comply with the 

new performance-based standards, manufacturers could continue to use the existing design 

standards as a means of compliance, but could also use industry consensus standards, such as the 

ones currently being developed by ASTM, as well as any other means the manufacturer develops 

to demonstrate compliance with the standard. This use of consensus standards is not a new 

practice. Industry standards bodies like the Radio Technical Commission for Aeronautics 

(RTCA), Inc., SAE International (SAE), ASTM International (ASTM), and the European 

Organization for Civil Aviation Equipment (EUROCAE) have provided consensus standards that 

the FAA has accepted as a means of compliance with the certification standards. . The rule will

provide a broad set of requirements that allows more flexibility in airplane designs and faster 

 26 Special Conditions give the manufacturer permission to build the aircraft, engine or propeller with additional 

capabilities not addressed in the regulations. A petition for exemption is a request to the FAA by an individual or 

entity asking for relief from the requirements of a regulation. ELOS are made when literal compliance with a 

certification regulation cannot be shown and compensating factors exist which can be shown to provide an ELOS. 

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgWebcomponents.nsf/HomeFrame?OpenFrameset
34| Page

adoption of safety enhancing technology and significantly reduce the need and cost incurred for 

special conditions, exemptions and ELOS. 

A reduction in the number of special conditions, ELOS, and exemptions reduces

paperwork and processing time for both the FAA and industry. It also maintains the fundamental 

safety requirements from the current part 23 regulations and allows more flexibility in airplane 

designs, faster adoption of safety enhancing technology, and reduces the regulatory cost burden. 

To estimate savings driven by this change, the FAA counted the special conditions, ELOS, and 

exemption applications submitted to the FAA for part 23 aircraft between 2012 and 2014 and 

divided the number by three years for an average of 37 applications per year.27 The ARC report 

also offered an average of 37 applications per year.28 Additionally, the FAA counted the number 

of pages per application to obtain an average number of pages per application. For special 

conditions, there were approximately 21 pages, 16 pages for an exemption, and 15 pages per 

ELOS application. The FAA estimates that the applicant and each FAA office that reviews the 

application spend 8 hours on research, coordination, and review per page. The ARC also noted 

“an ELOS finding or exemption can take the FAA between 4 to12 months to develop and 

approve. The applicant spends roughly the same amount of time as the FAA in proposing what 

they need and responding to FAA questions for SC, exemption, or ELOS.”29 

The number of applications is multiplied by the number of pages and by the hourly wage 

for the applicant and different FAA offices to account for the cost to the FAA and the applicant. 

 27 https://my.faa.gov/org/linebusiness/avs/offices/air/tools/cert.html 28 A report from the 14 CFR Part 23 Reorganization Aviation Rulemaking Committee to the Federal Aviation 

Administration; Recommendation for increasing the safety of small general aviation airplanes certificated to 14 CFR 

part 23, June 5, 2013, Table 7.1 – Special Conditions, Exemptions, ELOS, Page 55. 29 Ibid, 54.
35| Page

The estimated hourly wage is $74.84 for a Small Airplane Directorate employee30, $51.26 for an 

Aircraft Certificate Office employee31, and $62.20 for an engineer32 employed by the applicant. 

Annual cost equals the sum of the associated costs of special conditions, exemptions, plus ELOS. 

Yearly cost totals roughly $391,984 for the Small Airplane Directorate, $268,493 for Aircraft 

Certificate Offices, and $325,771 for the applicants. Tables 7, 8, and 9 show cost by office and 

applicant as well as by special condition, exemption, and ELOS. 

Table 7. Savings from Special Conditions (SC)*

Part 23 Section

Avg. Number 

of SC 

(2012-2014)

Avg. 

Number 

of Pages

FAA SAD FAA ACO Applicant

Manhours Savings Manhours Savings Manhours Savings 

143 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

171 0.67 20.8 111 $8,344 111 $5,715 111 $6,934

173 0.67 20.8 111 $8,344 111 $5,715 111 $6,934

175 0.67 20.8 111 $8,344 111 $5,715 111 $6,934

177 0.67 20.8 111 $8,344 111 $5,715 111 $6,934

251 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

361 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

562 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

572 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

573 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

574 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

613 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

627 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

629 1.00 20.8 166 $12,453 166 $8,530 166 $10,350

901 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

939 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

951 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

961 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

973 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

977 1.00 20.8 166 $12,453 166 $8,530 166 $10,350

1141 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

1301 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

1305 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

1308 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

1309 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

1329 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

1337 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

1521 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

1557 0.67 20.8 111 $8,302 111 $5,687 111 $6,900

3Pt Restraint with Airbag 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

Inflatable Restraint 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

Electronic Engine Controls 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

 30 2015 FAA Pay Band, Average K Band Salary (Rest of the U.S.) plus wage multiplier for benefits 

https://employees.faa.gov/org/staffoffices/ahr/program_policies/policy_guidance/hr_policies/hrpm/comp/comp_ref/

2015payadjustment/

31 2015 FAA Pay Band, Average I Band Salary (Rest of the U.S.) plus wage multiplier for benefits 

https://employees.faa.gov/org/staffoffices/ahr/program_policies/policy_guidance/hr_policies/hrpm/comp/comp_ref/

2015payadjustment/

32 National Occupational Employment and Wage Estimates United States, May 2015; Aerospace Engineer mean 

hourly wage, NAIC code 17-2011 plus wage multiplier for benefits http://www.bls.gov/oes/current/oes_nat.htm#17-

0000. A more detailed discussion is provided in the “Costs” section below.
36| Page

Fuel Jettisoning 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

Load Alleviation System 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

Side Facing Seat with Airbag 0.33 20.8 55 $4,151 55 $2,843 55 $3,450

Totals 2942 $220,172 2942 $150,809 2942 $182,981

*These numbers are subject to rounding error.

Table 8. Savings from Exemptions*

Part 23 

Section

Avg. Number 

Exemptions 

(2012-2014)

Avg. 

Number of 

Pages

FAA SAD FAA ACO Applicant

Manhours Savings Manhours Savings Manhours Savings 

1359 0.33 15.6 42 $3,113 42 $2,132 42 $2,587

1549 0.33 15.6 42 $3,113 42 $2,132 42 $2,587

177 1.33 15.6 166 $12,422 166 $8,509 166 $10,324

49 0.67 15.6 83 $6,227 83 $4,265 83 $5,175

562 0.67 15.6 83 $6,227 83 $4,265 83 $5,175

1419 0.33 15.6 42 $3,113 42 $2,132 42 $2,587

629 0.33 15.6 41 $3,082 41 $2,111 41 $2,562

181 0.33 15.6 41 $3,082 41 $2,111 41 $2,562

Totals 540 $40,379 540 $27,658 540 $33,559

*These numbers are subject to rounding error.

Table 9. Savings from Equivalent Level of Safety Findings (ELOS)*

Part 23 

Section

Avg. Number 

ELOS 

(2012-2014)

Avg. Number 

of Pages

FAA SAD FAA ACO Applicant

Man-hours Savings Man-hours Savings Man-hours Savings 

145 0.67 14.9 79 $5,947 79 $4,074 79 $4,943

207 0.67 14.9 79 $5,947 79 $4,074 79 $4,943

672 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

777 1.6 14.9 191 $14,273 191 $9,777 191 $11,862

779 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

781 1.4 14.9 167 $12,489 167 $8,555 167 $10,379

807 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

815 0.6 14.9 72 $5,352 72 $3,666 72 $4,448

841 0.67 14.9 79 $5,947 79 $4,074 79 $4,943

973 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1092 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1145 0.67 14.9 79 $5,947 79 $4,074 79 $4,943

1305 1.6 14.9 191 $14,273 191 $9,777 191 $11,862

1311 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1325 0.2 14.9 24 $1,784 24 $1,222 24 $1,483

1353 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1357 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1397 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1401 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1419 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1443 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1505 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1545 0.33 14.9 40 $2,974 40 $2,037 40 $2,471

1549 2 14.9 238 $17,842 238 $12,221 238 $14,828

Totals 1756 $131,433 1756 $90,026 1756 $109,232

*These numbers are subject to rounding error.

Using these yearly cost estimates, over 20 years $19.7 million in man-hours will be spent 

on applying for and processing special conditions, exemptions, and ELOS. However under the

rule, the need to demonstrate compliance through special conditions, exemptions, or ELOS will

largely be eliminated. Instead new products will simply need to demonstrate compliance by 
37| Page

following consensus standards acceptable to the Administrator, or by submitting their own 

proposed means of compliance using the process outlined in AC 23.10.

33 As a conservative 

estimate, the FAA estimates that special conditions, exemptions, and ELOS will be reduced by 

half for a savings to the FAA and applicant of roughly $9.9 million ($4.9 million present value). 

Savings by year is shown in the chart below.

Table 10. Total Cost for Special Conditions, Exemptions, and ELOS*

Year FAA SAD FAA ACO Applicant Total 

2017 $195,992 $134,247 $162,886 $493,124

2018 $195,992 $134,247 $162,886 $493,124

2019 $195,992 $134,247 $162,886 $493,124

2020 $195,992 $134,247 $162,886 $493,124

2021 $195,992 $134,247 $162,886 $493,124

2022 $195,992 $134,247 $162,886 $493,124

2023 $195,992 $134,247 $162,886 $493,124

2024 $195,992 $134,247 $162,886 $493,124

2025 $195,992 $134,247 $162,886 $493,124

2026 $195,992 $134,247 $162,886 $493,124

2027 $195,992 $134,247 $162,886 $493,124

2028 $195,992 $134,247 $162,886 $493,124

2029 $195,992 $134,247 $162,886 $493,124

2030 $195,992 $134,247 $162,886 $493,124

2031 $195,992 $134,247 $162,886 $493,124

2032 $195,992 $134,247 $162,886 $493,124

2033 $195,992 $134,247 $162,886 $493,124

2034 $195,992 $134,247 $162,886 $493,124

2035 $195,992 $134,247 $162,886 $493,124

2036 $195,992 $134,247 $162,886 $493,124

Total $3,919,840 $2,684,932 $3,257,714 $9,862,485

*These numbers are subject to rounding error.

Additionally, current standards for the production approval can create a barrier for 

adoption of new, non-required and low risk articles suitable for installation on type-certificated 

aircraft in the existing fleet. To encourage and enable the installation of voluntary safety 

enhancements on these aircraft, the FAA will provide applicants with an alternative means to 

obtain FAA approval to produce replacement and modification articles. This change will provide 

a means that could be used to streamline the approval of these articles, which will facilitate the 

retrofit of safety enhancing equipment in the existing fleet. Examples of such articles include 

 33 See Section VI. Discussion of the Regulatory Amendments of the preamble for a discussion of the process.
38| Page

carbon monoxide detectors, weather display systems, clocks, small hand-held fire extinguishers, 

and flashlights. In many cases, these articles are “off-the-shelf products.” It is frequently difficult 

for a person to install these articles on a type certificated aircraft because the level of design and 

production details necessary for these articles to meet the provisions of current § 21.9, as 

expected for more critical articles, is frequently unavailable.

Therefore, the FAA will revise § 21.9, Replacement and Modification Articles, to provide 

applicants with an alternative method to obtain FAA approval to produce replacement and 

modification articles. The FAA intends to use the flexibility provided by this change to 

streamline the approval process for non-required safety enhancing equipment and other articles 

that pose little or no risk exposure to aircraft occupants and the public. 

Moreover, an applicant for supplemental type certificate can elect to comply with the new 

requirement, instead of the original certification basis for the airplane and could possibly see the 

same benefits expected for new type certificates. As such, a certain number of STCs submitted 

yearly will benefit from this requirement. 

VI.4. Qualitative Benefits

The FAA Office of Aviation Policy and Plans (APO) asked the Volpe Center34 to 

investigate whether performance-based regulation or streamlining of regulatory approval using

industry consensus standards in other sectors resulted in the positive outcomes anticipated in 

relation to the part 23 reorganization and to provide a report to the FAA. 

Regarding the use of performance-based regulation, the Volpe research found the 

following:

 34 https://www.volpe.dot.gov/
39| Page

• The available literature is practically unanimous in the assertion that performance-based 

regulation would result in lower costs for industry, i.e. higher efficiency. 

• Performance-based standards will not by themselves spur innovation and progress toward 

new safety features. 

• If the regulating agency wishes to promote diffusion of certain technologies, 

performance-based regulation is capable of serving that function.

• To the extent that design standards inhibit competition in a market, moving to 

performance standards may increase competition and foster growth in the market. In 

addition, the use of performance-based regulation can facilitate the use of cost saving 

measures and remove barriers to innovation. In turn, lower prices and innovative product 

features can spur demand and revitalize an industry.

• Based on the experience of the LSA segment, it appears that using consensus standards as 

a way of streamlining the aircraft certification process has resulted in lower costs of 

certification and facilitated the introduction of new and innovative designs.

Based on the Volpe findings, it appears likely that adopting performance-based regulation

as a method of safety regulation for part 23 small general aviation aircraft could result in many 

of the positive impacts mentioned as objectives of the SARA. However, the magnitude of the 

positive impacts would be determined by how much freedom and flexibility the new 

performance standards actually provide. Providing guidance on “means of compliance” through 

consensus standards would assist manufacturers in developing methods for meeting the 

performance standards. However, Volpe warns that those consensus standards may turn out to be 

de facto design standards and erode the potential benefits of adopting performance-based 

regulation. The FAA notes that the final rule preamble and the AC indicate that the FAA will 

consider means of compliance other than consensus standards. 
40| Page

For more details, see “The Economic and Safety Impacts of Performance-Based 

Regulation and Consensus Standards” Volpe document in the docket.35

VII. Costs

VII.1. Introduction

The Federal Aviation Administration (FAA) is revising the airworthiness standards for 

normal, utility, acrobatic, and commuter category part 23 airplanes by removing current weight 

and propulsion based prescriptive airworthiness requirements and replacing those requirements 

with performance- and risk-based regulatory standards. The majority of the prescriptive design 

requirements and methods of compliance found in current rules are expected to be incorporated 

into means of compliance documents. Industry may continue to use the existing part 23 

requirements as a means of compliance, at no additional costs, to type certificate new part 23 

aircraft, without having to purchase standards documents from industry organizations that set 

consensus standards and avoiding the general delay and confusion associated with any change. 

The FAA believes this final rule will provide a set of requirements that will allow more 

flexibility in airplane designs and faster adoption of safety enhancing technology while 

maintaining a high level of safety. 

The FAA is also reorganizing part 23. In the final rule, the FAA provides a conversion

table from the former part 23 sections to the final rule sections.

36 The FAA expects that many of 

the current part 23 requirements will not change but will be transferred to other documents; use 

of these standards cost/safety neutral. These other documents include MOC, AC, Airworthiness 

Design Standards (ADS), and ASTM documents. In the following section, we discuss this in 

more detail. 

 35 The Volpe document can be found at http://www.regulations.gov/ with a docket number FAA-2015-1621 36 The final rule can be found at http://www.regulations.gov/ with a docket number FAA-2015-1621.
41| Page

In December 2014, the FAA met and discussed the proposed part 23 requirements with 

the part 23 Reorganization ARC. We then provided the ARC with a draft document, which

included the revisions we intended to propose. The costs estimated in this section are based on 

the discussions and documents FAA provided the ARC in the December 2014 meeting and 

comments submitted to the docket for the NPRM. 

This chapter also discusses the FAA’s estimate of costs for the rule’s changes that will

add requirements to the part 23 certification process for new applicants. Other costs include 

additional training costs for engineers to familiarize themselves with the new rule, type 

certification manual update costs, and type certification database update costs.

VII.2. Discussion of Minimal to No Costs Part 23 Sections

Currently, the ASTM standards organization is developing a set of consensus standards 

based on the current part 23 regulations for FAA acceptance. The ASTM standards will be one 

way, but not the only way, to demonstrate compliance to the part 23 performance standards.

37 

At this time, the FAA has not accepted any consensus standards as a means of 

compliance. The FAA will still conduct an assessment to make sure that the airplane design and 

the consensus standards meet the performance standards in the current regulations. In addition, 

once the FAA has accepted a design feature in a consensus standard, other designers and 

manufacturers that wish to include that feature could reference the standard. The assumption of 

minimal cost to most of the rule’s changes assumes these consensus standards become available

for use as a means of compliance.

38

 37 If a manufacturer chose to use its own means of compliance, we will use the same process used today to evaluate 

alternatives.

38 FAA believes that it may experience some workload increase during the transition period to using the new rule 

along with means of compliance. But this has been accounted for in the transition training effort and we believe that 

the increased means of compliance review will be offset by the reduced number of issue paper related rulemaking 

(special conditions). We also believe that in the long term, after FAA and industry are comfortable with the new 

system, the workload on the FAA will be lower than today.
42| Page

The FAA will continue to accept compliance with current part 23 as a means of 

compliance for new type certifications with the exception of the new provisions, which will need 

to be included in the certification. The new part 23 regulations will make the retrofit of new 

technology more straightforward without the need for as many special conditions, ELOS, or 

exemptions. The FAA believes these regulations will also remove barriers to bringing new, safer 

airplane designs to market with similar benefits. The final rule will decrease the time and 

expense to the FAA and the industry of working in the current prescriptive regulatory 

environment while concurrently improving the safety and health of GA. The international 

aviation industry, including representatives from the world’s leading aviation authorities not only 

agree with this approach, but are currently working with us to meet this goal. This final rule will

clear paths to compliance for a multitude of technologies, which will be available through the 

consensus standards approach. For the majority of this rule, the means of compliance with the 

FAA’s performance regulations will be cost and safety neutral because the means of compliance 

in the ASTM or other documents will be no more burdensome than today’s prescriptive part 23 

requirements established through the current amendment level. After the final rule is effective, 

we believe that manufacturers will choose the least costly means of compliance since the current 

part requirements would still be available.

Current section 23.2005 will require that airplanes approved for spins be certificated to 

aerobatic standards. An airplane designed with traditional handling qualities and designed to 

allow spin training is more susceptible to inadvertent departure from controlled flight. The FAA 

believes that maintaining the current utility category for airplanes approved for spinning and 

limited aerobatic maneuvers will negate the single largest safety gain expected from this 

rulemaking action—this change will result in a significant reduction in inadvertent stall-related 

departures from controlled flight. 
43| Page

The FAA believes this new requirement will have little effect on the industry. 

Manufacturers will be able to certificate new airplanes that are approved for spins and meet the 

aerobatic requirements. In fact, many flight schools use acrobatic airplanes for spin training 

today. Also, spin training was removed from the required private pilot training curriculum 

decades ago and the only FAA required spin training is during training for flight instructors. The 

schools that use utility category airplanes for spin training now can continue to use their existing 

fleet for spin training and any utility airplanes in current production can continue to be produced. 

For these reasons the FAA does not believe the elimination of utility category for newly 

certificated models will have a significant negative impact on flight schools and spin training.

The final rule eliminates the current stall characteristics and spin testing approach to 

address the largest cause of fatal accidents in small airplanes. Section 23.2150 in subpart B will

omit the one turn/three second spin requirement for normal category airplanes, but it will

increase the stall handling characteristics and stall warning requirements so the airplane will be 

substantially more resistant to stall-based departures than the current rules require. Flight school

representatives on the ARC stated that because they have not had problems we should not 

change the rule from what we have today. The FAA notes that an airplane that meets the stall 

characteristics can be used for spin training if designed to allow a maintenance change to an

alternative configuration. The final rule changes are discussed in the preamble and the 

additional cost are discussed below in the “Discussion of Sections That Could Add Costs” 

section.

This final rule is also adding regulations to improve the safety of part 23 airplanes 

certified for flight in icing by addressing icing conditions that are not currently included in part
44| Page

23. The rule incorporates recommendations from the part 23 Icing ARC.39 Prior to the Part 23 

Reorganization Aviation Rulemaking Committee (ARC), the Part 23 Icing ARC recommended 

revising part 23 to incorporate supercooled large drop (SLD) icing requirements into subparts B, 

E, and F. The final rule’s icing regulations will require airplanes certificated to fly into known

icing conditions to meet the same safety standards in SLD icing conditions as currently required 

in part 25, if the applicant chooses to certify the airplane for flight in all or a portion of SLD. For 

those airplanes that only certify to the icing conditions in appendix C to part 25, these regulations 

will require a means for detecting SLD and showing the airplane can safely exit the icing 

conditions. The FAA determined that the service history of part 23 airplanes certified to the latest 

icing standards have shown these standards to provide an adequate level of safety for SLD 

“detect and exit” airplanes.

In December 2014, the FAA met and discussed the Icing ARC’s proposed icing 

recommendations with the part 23 Reorganization ARC. The icing recommendations discussed 

with the ARC do not differ from those set forth in this rule. Since this meeting, industry has 

reviewed the icing requirements we provided along with the draft ASTM icing standards. Based 

on this information, industry believes the icing requirements are cost and safety neutral as the 

rule reflects current industry practices for detecting and safely exiting SLD conditions. Industry 

has informed us that they do not believe they will certify a part 23 airplane for flight in SLD 

conditions. 

Additionally, this final rule will amend parts 21, 43, 91, 121, and 135 to maintain 

consistency and alignment with the new part 23. These will be conforming changes and are not 

expected to add costs. 

 39 The Part 23 Icing ARC report can be found at http://www.regulations.gov/ with a docket number FAA-2015-

1621.
45| Page

VII.3. Discussion of Sections That Will Add Costs 

When the FAA and members from the part 23 Reorganization ARC met in December 

2014, the FAA provided the ARC with a draft document, which included provisions we intended 

to propose. The costs estimated in this section are based on the discussions and documents the 

FAA provided the ARC in the December 2014 meeting and the assumption that the baseline for 

estimating the costs of the rule would be part 23, through the current amendment level and 

comments submitted to the docket for the NPRM.

The FAA analyzed the expected costs of the final rule over the analysis interval. The 

major factors driving the expected costs of this final rule are the additional training tasks, 

database development, and documentation that must be submitted to the FAA and industry part 

23 certification engineers. The following sections discuss the FAA estimate of the number of 

part 23 certification and industry engineers who will have to receive training because of this 

rulemaking. We also discuss the FAA estimate of their salaries in order to estimate training 

costs. We then discuss the provisions that add costs, and the methodology the FAA employed, to 

estimate the total incremental costs of this final rule, over what is currently required, based upon

FAA and industry unit cost estimates.

VII.3.a. Annual and Hourly Wages and Benefits

In this section, we discuss the part 23 certification engineering wages the FAA uses in 

this analysis. This section also discusses the source we used for the wages. We received no 

comments on this section in the NPRM, hence we will use the same methodology in the final 

rule.

The new part 23 requires engineers to perform additional engineering duties in designing, 

constructing, training, and testing airplanes from what is currently required. These engineers may 

conduct basic and applied research to evaluate adaptability of materials and equipment to 
46| Page

airplane design and manufacture and may recommend improvements in testing equipment and 

techniques. 

In May 2015, BLS published the National Industry-Specific Occupational Employment 

and Wage Estimates for Support Activities for Air Transportation. The May 2015 Occupational 

Profile code for Architecture and Engineering Occupations is 17-0000.

40 The major group for 

Aerospace Engineers under the 17-0000 code is 17-2011. 41 The FAA believes that the 17-2011 

survey is the appropriate wage to estimate the salary of the part 23 certification engineers 

affected by the rule. The BLS survey lists the mean hourly wage for aerospace engineer as 

$53.16. The cost analysis uses the mean hourly wage of $53.16 for part 23 certification 

engineers to estimate the additional costs the rule adds for training tasks. The FAA notes that the 

survey does not included overhead and lists the annual mean salary range for aerospace 

engineers, by area in the continental United States, from $67,850 to $158,700, which is 

consistent with the mean hourly wage of $53.16. 

In addition, aerospace engineer benefits (such as health benefits, vacation, sick time, etc.) 

must be added to estimate the costs for this analysis. Using the guidance from the “Employer 

Costs for Employee Compensation – December 2014” study of employee benefits,

42 the FAA 

uses the wage multiplier for benefits equaling 1.17. Therefore, the FAA calculated the mean 

hourly wage, plus benefits, for a part 23 certification engineer to be $62.20 ($53.16 + $9.04).

VII.3.b. Estimated Costs for §23.2150(b) Stall characteristics, stall warning, and spins

There is a detailed discussion in the preamble on the FAA eliminating commuter, utility, 

and acrobatic airplane categories from part 23, retaining only normal category for all new part 23 

 40 http://www.bls.gov/oes/current/oes_stru.htm 41 http://www.bls.gov/oes/current/oes172011.htm 42 On January 30, 2014, the DOT published a memo on “Estimating Total Costs of Compensation Based on Wage 

Rates or Salaries”. The memo directs the FAA that when a rule requires incremental hours per existing employee, 

the wage/salary multiplier is of smaller magnitude because not all categories of employer provided benefits increase 

with additional hours worked by an individual employee.
47| Page

type certificated airplane design approvals and instead using the following airplane certification 

levels:

• Level 1 – for airplanes with a maximum seating configuration of 0 to 1 passengers.

• Level 2 – for airplanes with a maximum seating configuration of 2 to 6 passengers. 

• Level 3 – for airplanes with a maximum seating configuration of 7 to 9 passengers. 

• Level 4 – for airplanes with a maximum seating configuration of 10 to 19 passengers. 

In order to estimate costs for § 23.2150(b) in this section, and 23.2150(c) in the following 

section, we also discuss the methodology the FAA used to map the reciprocating, turboprop, and 

turbojet airplanes presented in the “Fleet Discussion” section into the airplane certification levels

above.

The FAA is increasing the stall requirements for single engine airplanes, to provide some 

level of spin resistance or protection from inadvertently departing controlled flight. The FAA 

and industry believes that the majority of the changes to § 23.2150 are not significantly different 

than what is currently required today and therefore the testing costs for this new requirement 

would not be significant. 

Additionally, FAA did not estimate any increases in manufacturing costs as a result of 

this requirement. Manufacturers have already indicated that the changes to § 23.2150 will not 

require a great deal of complexity and therefore would result in minor costs increases.This final 

rule allows manufacturers flexibility to comply with new part 23 stall and spin type certification 

requirements. Applicants can design aerodynamic configurations that do not have a tendency to 

depart controlled flight, and in fact some already exist. There are existing airplanes that have 

been designed successfully with these aerodynamic characteristics. Applicants can also choose 

to include control system designs that prevent the tendency to depart controlled flight by 

avoiding aerodynamic stall. There are existing airplanes that have been designed using such 
48| Page

systems. Innovative applicants can also develop new methods to prevent the tendency to depart 

controlled flight and propose a new method of compliance for FAA acceptance. 

Section 23.2150(b) is a new requirement that will likely increase the burden for all newly 

certificated, single engine reciprocating, turboprop, and turbojet airplanes not certified for 

aerobatics. Section 23.2150(b) requires these airplanes must not have a tendency to inadvertently 

depart controlled flight. In the NPRM, we proposed to require level 1 and level 2 multiengine 

airplanes to meet the same § 23.2150(b) requirement as the level 1 and level 2 single-engine 

airplanes, but the FAA has eliminated this requirement to level 1 and level 2 multiengine 

airplanes in the final rule. In both the NPRM and this final rule, § 23.2150(b) requires only 

single engine level 3 airplanes to comply; therefore, there has been no change for these airplanes. 

With the changes between the NPRM and final rule for § 23.2150(b), there now is a requirement 

for level 4 airplanes to comply. Although the § 23.2150(b) in the final rule imposes a new 

requirement to level 4 airplanes, since currently, commuter airplanes are required to have two 

engines, and level 4 airplanes are commuter airplanes, the final rule is relieving by allowing level 

4 airplanes to be certificated with only one engine. Since the FAA has no information on part 23 

manufacture’s plans to type certificate a new level 4 single airplane, we were unable to cost this 

new requirement or estimate the costs of the final rule now enabling level 4 single engine 

airplanes.

From Appendix 2 and the “Fleet Discussion” section, 100 percent of the historical 

reciprocating engine airplanes had six or fewer seats and would fall under either a level 1 or level 

2 airplane classification. Also from Appendix 2 and the “Fleet Discussion” section, 100 percent 

of level 1 and 93 percent of level 2 reciprocating engine airplanes were single engine aircraft. 

Therefore, since the overwhelming majority of historically delivered level 1 and level 2 airplanes 
49| Page

are single engine, the two new future part 23 reciprocating engine type certificates, calculated in 

the “Fleet Discussion” section, will have to comply with this section.

In addition, 97 percent of the historical turboprop airplanes, analyzed in Appendix 2 and 

the “Fleet Discussion” section, had 10 or more seats. Also from Appendix 2 and the “Fleet 

Discussion” section, all level 1 turboprop airplanes were multiengine aircraft and 96 percent of 

level 2 turboprop airplanes were multiengine aircraft. Therefore, we assume that any new part 23 

turboprop airplane certifications will be a level 4 multiengine airplane and would already meet 

the new requirements for this section and therefore have no additional costs.

Lastly, 61% of the historical turbojet airplanes, analyzed in Appendix 2 and the “Fleet 

Discussion” section, have fewer than 10 seats. Also from Appendix 2 and the “Fleet Discussion” 

section, all level 1 turbojet airplanes were multiengine aircraft and over three quarters of the 

level 2 turbojet airplanes were multiengine aircraft. From Appendix 2 and the “Fleet Discussion” 

section, we also estimated that there will be two new future part 23 turbojet type certificates. 

Therefore, these two new part 23 turbojet engine U.S. type certificates will have to comply with 

this section. 

For the NPRM, the FAA consulted with ARC members from industry and they believe

the § 23.2150(b) change could cost somewhere in the range of $100,000 to $150,000 in 2014 

dollars for a new type certificated airplane. For this final rule, the FAA adjusted the 2014 dollars 

to 2015 dollars to obtain a range of $100,119 to $150,179 for a new type certificated airplane. 

Therefore, the FAA uses $125,149 (($100,119 + $150,179)/2) as an average cost to demonstrate 

and test for this change. This will be a one-time cost per new type certification.

Table 11 shows the total costs for the changes to the controllability section. 

Table 11. Estimate Costs for § 23.2150(b) (2015 $)

Airplane

Number of Estimated New 

Type Certificates Costs Total
50| Page

Recip 2 $125,149 $250,298 

Turboprop 0 $125,149 $0 

Turbojet 2 $125,149 $250,298

Total $500,595

VII.3.c. Estimated Costs for § 23.2150(c) Stall characteristics, stall warning, and spins

Section 23.2150(c) should prevent level 1 and 2 multiengine airplanes from losing directional 

control after a critical loss of thrust. The FAA and industry believe that § 23.2150(c) will

increase the burden for certain multiengine airplanes because it may require additional testing

costs and include a cost for a change to a limitation or performance number in the flight manual. 

We note that the final rule requirements for § 23.2150(c) were originally in proposed § 

23.200 of the NPRM. We received no comments on the cost estimates for proposed § 23.200 in

the NPRM, hence we will use the same methodology to estimate the costs for § 23.2150(c) as we 

did in the NPRM for proposed § 23.200. What is currently being discussed is a relatively simple 

test that could be performed as part of a single test plan doing multiple tests on a flight. ARC 

members from industry believe that this is a simple test to comply with the rule’s changes and 

has provided the FAA with estimated costs of $100,000 to $200,000 in 2014 dollars. Using the

CPI inflator provided from BLS, the FAA converted these 2014 dollar costs to 2015 dollars.43 

Therefore, the FAA uses $150,179 (($100,119 + $200,238)/2) as an average cost to demonstrate 

and test for this more prescriptive requirement. This will be a one-time cost per new type 

certification.

In addition, § 23.2150(c) could result in a change to an operator limitation or a set of 

airplane performance numbers in the flight manual. ARC members from industry believe that 

 43 http://www.bls.gov/data/inflation_calculator.htm
51| Page

making this change could cost from $100,000 to $150,000 in 2014 dollars. As these estimates 

were used in the NPRM, the FAA continues to use them. Again, for this final rule, the FAA 

converted the 2014 dollars to 2015 dollars using a CPI inflator. Therefore, the FAA uses 

$125,149 (($100,119 + $150,179)/2) as an average cost for this change. 

There will also be additional paperwork associated with this requirement that is not part 

of the costs discussed above. The FAA estimates the paperwork costs for these provisions by 

multiplying the number of hours the FAA estimates for each page of paperwork, by the number 

of pages for the training courseware, or flight manual, by the hourly rate of the person 

responsible for the update. The Small Airplane Directorate of the FAA provided average hourly 

times and the number of additional pages of paperwork the final rule will add. The FAA 

estimates that this section will add a total of four pages to the training courseware and flight 

manual. The FAA also estimates that it will take a part 23 certification engineer eight hours to 

complete the one page required for each new type certification. 

Therefore, the FAA estimates the total paperwork costs for § 23.2150(c) will be about 

$1,990 (8 hours * 4 pages * $62.20 per hour). 

From Appendix 2 and the “Fleet Discussion” section above, we calculated there would be 

two part 23 reciprocating engine future type certificates. From Appendix 2 and the “Fleet 

Discussion” section, 96% of all historical reciprocating engine airplanes delivered had oneengine; therefore, § 23.2150(c) will not add costs to future type certificated part 23 reciprocating 

engine airplane. 

Also from the Appendix 2 and the “Fleet Discussion” section, 100 percent of the 

historical turbojet airplanes delivered had two engines, but about 46 percent could be produced 

with only six seats. Therefore the FAA assumes that §23.2150(c) will add costs to one of the 

new part 23 turbo jet airplane type certificates estimated in the “Fleet Discussion” section above. 
52| Page

Again, from Appendix 2 and the “Fleet Discussion” section, 55 percent of the historical 

turboprop airplanes delivered had two engines, but 96 percent have greater than six seats. 

Therefore the FAA assumes that § 23.2150(c) will not add costs to future type certificated 

multiengine turboprop airplanes. 

The FAA and industry believe that for the rest of the changes in the controllability 

section, there is no significant cost impact because there is no difference than what is required 

today, although in the future, there may be some cost savings once consensus standards have 

been developed.

Table 12 shows the total costs for the changes to the controllability section.

Table 12. Estimate Costs for § 23.2150(c) (2015 $)

Airplane

Number of Estimated 

New Type Certificates

Affected by § 

23.2150(c)

Training 

Costs

Changes to 

Flight Manual

Paper 

Work Total

Recip 0 $150,179 $125,149 $1,990 $0 

Turboprop 0 $150,179 $125,149 $1,990 $0 

Turbojet 1 $150,179 $125,149 $1,990 $277,318 

Total $277,318 

*These numbers are subject to rounding error.

The FAA notes that a multiengine part 23 aircraft manufacturer could choose to comply 

with § 23.2150(c) by making the airplane capable of climbing after a critical loss by installing 

larger engines. Both the FAA and industry believe that this option will reduce the practicality of 

the airplane so much it would not be a marketable product. We stated this in the NPRM and 

received no comments on this position.

VII.3.d. Additional Training Costs 

FAA and industry certification engineers will need training on how to implement the new 

requirements. A significant portion of the training is expected to involve explaining the new 

process and how to relate the accepted means of compliance to the new regulations. In this 
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section, we first discuss our estimate of the number of part 23 FAA and industry certification 

engineers that will require additional training because of this rulemaking. Next, we describe the 

costs to develop the training programs necessary to implement the rule. We then estimate the 

training costs for this final rule to both FAA and industry. 

The Planning and Program Management Division of the FAA Aircraft Certification 

Service (AIR-500) provided the number of engineers who currently support the part 23 

certification requirements. Once the rule is published, there will be an initial effort on both the 

part of the FAA and industry to train their engineers. 

There are currently 669 part 23 FAA certification engineers and we expect the number of 

engineers will stay reasonably flat. As in the NPRM, the FAA estimates that 50 percent of these 

part 23 FAA certification engineers, or 335, will require additional training to implement this 

rule.

44 The FAA estimates that the same number of industry part 23 certification engineers will

also require additional training necessary to implement the rule; therefore, we assume that there 

are 335 industry certification engineers who will also require training.

Due to retirement or attrition, the FAA and industry will have to hire new part 23 

certification engineers. The initial training program for new engineers will include the training 

necessary to implement the rule when they are hired, and therefore we believe that there will not 

be any recurrent costs from this final rule to newly hired part 23 FAA and industry certification 

engineers.

The FAA estimates that it will cost $250,298 in 2015 dollars to develop the structured 

training on part 23 for the FAA certification engineer staff. The cost to deliver the training is 

dependent on the type of training developed, but at this time, we plan on providing the course 

on-line so that the course could be delivered to FAA staff. The FAA estimates that it will take 

 44 We believe that engineers who will be needed to focus on part 23 projects and older small airplanes represent

about half of our engineering workforce.
54| Page

most engineers two days (16 hours) to take the on-line training. This will be a one-time cost per 

new type certification. The FAA is anticipating the two days of training will encompass the 

following topics:

1. Background/history – addressing why we are making this change to part 23,

2. Rule language – go over the specific new language, how it relates to amendment 

62 languages, and the intent of the new language,

3. Means of Compliance – go over the means of compliance and how it links to the 

rule language. This would be interwoven with item #2, and

4. Work through a number of examples focusing on difficult and unusual STC 

projects.

The FAA assumes it will cost the same for industry to develop their structured training 

class and that the same number of industry part 23 certification engineers will also require 

additional training from this rule. 

The FAA notes that any paperwork costs associated with this section will be part of the 

initial $250,298 cost to develop the training materials. 

Therefore, the FAA estimates the total training costs to FAA and industry part 23 

certification engineers will be about $500,595 (2 * $250,298) to develop the on-line training 

material and about $667,000 (2 * (16 hours * 335 engineers * $62.20 per hour)) to train the 

engineers. Table 13 shows the calculation of these training costs to both the FAA and industry.

Table 13. Training Costs (2015 $)

Development of 

on-line training

Training 

Hours

Number of 

Engineers

Hourly

Wage Total

FAA $250,298 16 335 $62.20 $583 690

Industry $250,298 16 335 $62.20 $583,690

Total $1,167,379

*These numbers are subject to rounding error.
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VII.3.e. Type Certification Manual Update Costs 

The FAA is expecting part 23 airplane manufacturers to update their engineering 

procedures manuals to reflect the changes from this rulemaking. However, most of the 

engineering procedures manuals are not written around the requirements of part 23, but around 

the requirements of part 21. Part 21 covers certification procedures for products, articles, and 

parts. Since the part 23 changes will have minimal impact on the part 21 requirements, there 

should be little change in the engineering procedures manuals. 

Conversations with industry indicate that there may need to be some changes to the 

engineering manuals to describe how the accepted means of compliance must be related to the 

regulations. Depending on the complexity of each company’s manual, ARC members from 

industry estimates that these changes could run from about $50,060 up to $200,238 in 2015 

dollars. This will be a one-time cost per new type certification. This approach was used in the 

initial regulatory evaluation. Since we received no comments, the FAA continues to use to same 

approach for the final rule.

Since the FAA is unable to determine the complexity of each company’s manual, we 

assume that the manufacturers of the two new part 23 reciprocating engine airplane type 

certifications, discussed in the “Fleet Discussion” section, will spend $50,060 to make the 

changes to the engineering manual. We also assume that the one new part 23 turboprop airplane 

certification and the two new part 23 turbojet airplane certifications, discussed in the “Fleet 

Discussion” section, will use the more complex and costly approach of $200,238. 

Table 14 shows the total costs for the changes to the controllability section. 

Table 14. Estimate Costs for Updating Engineering Manuals (2015 $)

Airplane

Number of Estimated 

New Type Certificates

Simple 

Approach

Complex 

Approach Total

Recip 2 $50,060 $0 $100,119

Turboprop 1 $0 $200,238 $200,238
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Turbojet 2 $0 $200,238 $400,476

Total $700,833

*These numbers are subject to rounding error.

VII.3.f. Type Certification Database Update Costs 

Currently, manufacturers have certification compliance databases that are used to create a 

compliance checklist that is used to identify who in the organization is showing compliance to 

each regulation, how they are showing compliance, (i.e. analysis, test, etc.), and where the 

substantiation is documented such as a report number, revision, title, etc. The manufacturers 

may also tie a schedule or other facts pertaining to the regulation in the compliance checklist 

database. This may be one of the more significant one-time costs to revise the programs to 

accommodate the new regulation because this database has to reference the methods of 

compliance associated with the regulation, or this could be a cross-reference between the various 

old regulations and the regulations, or this could contain the testing or analysis necessary to 

comply with the rule. 

The FAA understands from discussions with ARC members from industry that part 23 

airplane manufacturers plan to use a product similar to Microsoft EXCEL to create this 

certification database in a spreadsheet with cross reference tables. This approach may not be 

acceptable for large companies with large production capacity, more complicated airplanes, and 

multiple certification processes. As we received no cost estimates from the comments on the 

approach used for the NPRM, we continue to use the same approach for the final rule.

For a company that is using an EXCEL spreadsheet to perform this tracking, ARC 

members from industry estimate that the total cost to make the necessary changes to a 

spreadsheet database to range from $100,119 to $200,238, in 2015 dollars, per certification. 

Therefore, the FAA uses $150,179 (($100,119 + $200,238)/2) as an average cost to make the 

necessary changes to a spreadsheet database for a small manufacturer. Since the FAA is unable 
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to determine whether a manufacturer will be using a simple EXCEL spreadsheet to create this 

certification database, as in the initial regulatory evaluation, we assume that the manufacturers of 

the two new part 23 reciprocating engine airplane type certifications, estimated in the “Fleet 

Discussion” section, will use the simple approach.45

For manufacturers that have a production capacity and multiple certification processes, 

ARC members from industry estimates that a programmer could spend up to six months of full 

time programing to make this change to a simple compliance database. A more complex 

program may take between one to one and a half years for a programmer to make the necessary 

programming changes. ARC members from industry estimate that the cost for the programming 

changes to the certification database will range from $100,119 to $300,357 in 2015 dollars. 

Therefore, the FAA uses $200,238 (($100,119 + $300,357)/2) as an average cost to make the 

necessary programming changes to a more complex certification database. 

In addition, this task will also require some engineering support effort that ARC members 

from industry estimate could be about 25 percent to 50 percent of the time that a programmer 

takes. ARC members from industry estimate that the cost for engineer support could range from 

$37,545 to $225,268, depending on the complexity of the aircraft, to assist in making the 

programming changes to the certification database.46 Therefore, the FAA uses $131,406

(($37,545 + $225,268)/2) as an average cost for engineering support to make the necessary 

changes to a more complex certification database. This will be a one-time cost per new type 

certification.

 45 We received no comments on this assumption in the NPRM, hence we will use the same methodology as in the 

final rule. 46 Part 23 aircraft range from simple reversible control, low technology aircraft to complex irreversible control, high 

technology aircraft which affects the amount of programming necessary for a certification database.
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The FAA notes that either the simple EXCEL approach or the more complex approach to 

creating this certification database could also either take place in house or could be contracted 

out to a consultant.

Since the FAA is unable to determine whether a manufacturer will have a more complex 

production capacity and multiple certification processes involved with creating this certification 

database, we assumed, in the initial regulatory evaluation, that the manufacturers of the one new 

part 23 turboprop airplane certifications, and two new part 23 turbojet airplane certifications, 

estimated in the “Fleet Discussion” section will use the more complex and costly approach. We 

continue to use the same methodology as in the initial regulatory evaluation since we received no 

comments. 

Table 15 shows the total costs for the changes to the controllability section. 

Table 15. Estimate Costs for Creating a Certification Database (2015 $)

Airplane

Number of Estimated 

New Type Certificates

EXCEL 

approach

Programming 

support 

Engineering 

support Total

Recip 2 $150,179 $0 $0 $300,357

Turboprop 1 $0 $200,238 $131,406 $331,644

Turbojet 2 $0 $200,238 $131,406 $663,288

Total $1,295,290

*These numbers are subject to rounding error.

VII.3.g. Summary of Costs 

The final rules’ major costs are the engineer training costs and the certification database 

creation costs. Additional costs will also accrue from the controllability and stall sections that 

increase scope over current requirements and the manual upgrade costs.

In Table 16, we summarize the total estimated compliance costs by category. The FAA 

notes that since we assumed that all costs occurred in Year 1 of the analysis interval, for the 

purposes of this analysis, the 2015 dollar costs equal the present value costs.
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Table 16. Total Cost Summary by Category

Type of Cost

Total Costs

(2015$) and P.V.

§23.2150(c) Controllability $277,318 

§23.2150(b) Stall characteristics, stall warning, and spins $500,595 

Engineer Training Costs $1,167,379 

Certification Database Costs $1,295,290 

Manual Upgrade Costs $700,833 

Total Costs $3,941,414 

 *These numbers are subject to rounding error.

The FAA estimated the average additional cost from this rule, per reciprocating engine 

airplane, turboprop airplane, and turbojet airplane type certification by dividing the total costs by 

category the number of estimated new certifications from the “Fleet Discussion” section. We 

then summed these average costs by category. The results are shown in Table 17 below.

Table 17. Average Additional Cost per Type Certificate by Engine Category (2015$)

Engine §23.2150(c) §23.2150(b) Training Database Manual Total

Recip $0 $125,149 $233,476 $150,179 $50,060 $558,863 

TP $0 $0 $233,476 $331,644 $200,238 $765,358 

TJ $277,318 $125,149 $233,476 $331,644 $200,238 $1,167,824 

 *These numbers are subject to rounding error.

VIII. Benefit-Cost Summary

The major safety benefit of this final rule is to add stall characteristics and stall warnings 

that will result in airplane designs that are more resistant to inadvertently depart controlled flight. 

The largest number of accidents for part 23 airplanes involves a stall or departure-based LOC in 

flight. Additional benefits are that the current part 23 regulations are prescriptive and hinder the 

industry’s ability to introduce new technology; this final rule will result in cost savings by 

streamlining the certification process and encouraging new and innovative technology. 

Streamlining the certification process will reduce the issuance of special conditions, exemptions, 

and ELOS.
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The final rule’s major costs are the engineer training costs and the certification database 

creation costs. Additional costs will also accrue from the controllability and stall sections that 

increase requirements over former standards and the manual upgrade costs. 

Another way to consider the expected net benefit to the society is if the revisions adopted 

in the final rule save only one human life by improving stall characteristics and stall warnings

that alone will result in benefits which substantially outweigh the costs. Accordingly, the FAA 

has determined that the final rule will be net beneficial.

The FAA has analyzed the benefits and the costs associated with this final rule. The 

following table shows these results. 

Table 18. Estimated Benefits and Costs from 2017 to 2036 (2015 $ Millions)

Stall and Spin + 

Other Costs = 

Total Costs

Safety Benefits + Cost Savings 

= Total Benefits

Total $0.8 + $3.1 = $3.9 $17.9 + $9.9 = $27.8

Present Value at 7 percent $0.8 + $3.1 = $3.9 $6.1 + $4.9 = $11.0

Present Value at 3 percent $0.8 + $3.1 = $3.9 $11.1 + $7.1 = $18.3

 *These numbers are subject to rounding error.
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IX. Sensitivity Discussion

Earlier in this analysis the FAA discussed both the the Small Airplane Revitalization Act 

of 2013 and how performance-based regulations, or streamlining of regulatory approval via use 

of industry consensus standards, could result in decreasing certification costs. The use of 

consensus standards as a means of compliance to the performance based regulations review 

could reduce the cost of introducing new designs and increase the number of future part 23 type 

certificates. 

ASTM International has developed light sport aircraft (LSA) consensus standards. In a 

paper available on the ASTM website, ASTM cites the success of its LSA consensus standards

resulting in numerous new aircraft designs has been developed. ASTM believes the LSA 

consensus standards substantially reduce the cost to certify a new LSA aircraft model relative to 

the traditional part 21 requirements.

47 In 2008, ASTM reported that 76 new aircraft designs 

were developed as a result of the ASTM design standards.48 Currently there are over 130 new 

LSA designs suggesting that over the last six years, on average nine new designs per year have 

been introduced. This is an example of how industry has taken advantage of consensus standards 

to increase the number of new airplane designs.

The FAA believes that once promulgated, this rule could enable new part 23 

manufacturers to both enter the marketplace and permit current part 23 manufacturers to develop 

new cost-effective part 23 airplanes that are cheaper to design and purchase.

Although it is difficult for the FAA to quantify the outcome, we believe that through the 

flexibilities offered in this rule, the general aviation community could reverse the trend of 

 47 Stephenson, James and Deborah Stephenson, “Light Sport Aircraft Industry Takes Flight on ASTM International 

Standards,” ASTM Standardization News November/December 2008. 48 Ibid.
62| Page

decreasing part 23 certified fleet (11 percent in the last 10 years as determined from the 2013 

FAA General Aviation Survey) and could increase deliveries. 

After this rule becomes effective, part 23 manufacturers may seek certification for at least 

one or two new reciprocating engine airplanes in addition to what we estimated in the “Fleet 

Discussion” section. As a result of this rule, every additional part 23 type certification could 

increase the total cost of the rule, but the benefits would also increase in proportion to the costs. 

Sensitivity Analysis Using Historical Deliveries between 2008 through 2015

As a check of how the number of deliveries affects the costs and benefits, the FAA 

conducted a sensitivity analysis using historical deliveries between 2008 through 2015 instead of 

1998 through 2015 to forecast future deliveries to determine the effect on the cost benefits of this 

rulemaking.

Utilizing the same methodology from the “Fleet Discussion” section to calculate the 

growth of the expected affected future part 23 fleet, we analyzed the annual airplane deliveries 

from U.S. manufacturers in the years2008 through 2015. For each airplane manufacturer and for 

each of their type certifications, we calculated the average annual number of airplanes delivered 

from 2008 through 2015. While the turboprop and the turbojet market is essentially the same in 

this shorter period of analysis, the reciprocating airplane market has less than half the airplanes 

produced over the longer 1998 through 2015 analysis period. The sensitivity analysis resulted in 

one less type certification and a significant drop in deliveries for reciprocating airplanes over the 

base case forecast. For the sensitivity analysis, the base case forecast of the number of type 

certifications remained constant for turboprop and turbojet aircraft. For the sensitivity analysis, 

deliveries slightly increased for turboprop and slightly decreased for turbojet airplanes. Table 19 
63| Page

summarizes our estimate of part 23 U.S. airplanes that manufacturers will certificate and produce 

for this sensitivity analysis. 

Table 19. Part 23 New U.S. Certifications and Delivered Airplanes

Recip TurboProp Turbojet

Weighted Average Number of AC per TC per Year 46 50 32

New Part 23 Certifications in a 10-year Period 1 1 2

New Part 23 Certificated Airplanes deliveries per year 46 50 64

Using the values from Table 19, and following the same methodology from the “Fleet 

Discussion” section for this sensitivity analysis, with no change in the average production life 

and the 34 years airplane service life, we forecasted the cumulative number of newly certificated 

part 23 airplanes, delivered and retired annually. Appendix 5 shows these results.

For this sensitivity analysis, we then estimated benefits by flowing the adjusted 

forecasted part 23 cumulative deliveries from Appendix 5, through the same benefit 

methodology, the same fatality and aircraft damage rates, the same projected future averted 

accidents, fatalities, and destroyed aircraft, the same value of saved life, the same aircraft values, 

and the same blended average retail price of a destroyed aircraft from the “Safety Benefit” 

section.

Similarly, for this sensitivity analysis, we estimated costs using forecasted new part 23 

certifications from Table 19, with the same methodology, the same annual and hourly wages and 

benefits, the same industry provided unit costs, the same FAA-estimated hours and pages for 

paperwork, and the same training time from the “Costs” section. 

Shortening the period of analysis leads to a 30 percent decline in the number of 

reciprocating airplane deliveries as compared to the base case. Consequently, there is a decline in 

safety benefits of 22 percent over the base case. There was only a slight drop in costs for the 
64| Page

sensitivity analysis because of the reduction in type certificates for reciprocating airplanes and no 

change in the type certifications for turboprop and turbojet airplanes. 

Table 20 shows for this sensitivity analysis, the benefits also exceed the costs.

Table 20. Sensitivity Analysis Using Historical Deliveries between 2008 through 2015

to Estimate Benefits and Costs from 2017 to 2036 (2015 $ Millions)*

Costs

Safety Benefits + Cost Savings 

= Total Benefits

Total $3.6 $12.2 + $9.9 = $22.1

Present Value at 7 percent $3.6 $4.2 + $4.9 = $9.1

Present Value at 3 percent $3.6 $7.6 + $7.1 = $14.7

 *These numbers are subject to rounding error.
65| Page

X. Appendix I
66| Page

XI. Appendix II

For an example of how we calculated the average annual number of airplanes delivered per manufacturer, the following table shows that for 

the manufacturer Adam/AAI/Triton, since they only delivered aircraft for the three years 2005, 2006 and 2007, the average annual number of 

airplanes delivered is 3 ((2+4+3) / 3). 
67| Page

*These numbers are subject to rounding error.
68| Page

*These numbers are subject to rounding error.
69| Page

For an example of how we calculated the weighted average number of airplanes per type 

certificate, the following table shows that for turboprops, we used the formula 

( ( (0.25*87.9)+ (0.5*18.2) + (0.29*58.8) ) / (0.25+0.5+0.29) )and then rounded the result to the 

nearest whole number 46. The following table also shows and example of how we calculated the 

new part 23 certificates for turboprops was (0.25+0.5+0.29) and then rounded to the nearest 

whole number 1.

*These numbers are subject to rounding error.

This table shows how we calculated the number of new certifications, by manufacturer, by 

reciprocating engine, turboprop, and turbojet airplane, for each decade group.

*These numbers are subject to rounding error.
70| Page

This table is used in the cost section to calculate the percentages for the historical 

airplanes delivered with one or two engines and various seat groupings.

Type 

Certificate Type Engines # of a/c Seats

3A12 R 1 4,986 4

3A13 R 1 3,423 4

3A15 R 1 934 6

3A16 R 2 609 4-6

3A23 R 1 369 4-5

A00003SE R 1 810 4

A00009DE R 1 9 6

A21CE R 1 557 2

A4CE R 1 1,556 6

A-759 R 1 428 2

3A20 T 2 618 10

A00007SE T 1 164 4

A24CE T 2 1,500 13

A37CE T 1 1,583 10

A00001AC J 2 4 7

A00010WI J 2 292 6-7

A00014WI J 2 462 6

A1WI J 2 1,279 6-10
71| Page

XII. Appendix III
72| Page

XIII. Appendix IV

NTSB Stall and Spin Loss of Control Accidents

NTSB_no Date Fatalities acft_make acft_model Damage Applicability 

to Rule

ERA09LA131 1/6/2009 1 PIPER PA-25-235 SUBS Low

CEN09FA147 2/1/2009 1 MOONEY M20C SUBS High

WPR09FA112 2/5/2009 3 BEECH A36 SUBS High

ERA09FA169 2/17/2009 2 CIRRUS DESIGN CORP SR20 SUBS High

CEN09FA178 2/27/2009 3 CESSNA 182M SUBS Low

WPR09FA150 3/14/2009 2 PIPER PA28-236 DEST High

WPR09FA200 4/18/2009 2 CHAMPION 7ECA SUBS Low

CEN09FA340 6/7/2009 2 Gulfstream American Corp AA-5B SUBS Medium

CEN09FA363 6/16/2009 1 Cirrus Design Corporation SR22 DEST Low

WPR09FA398 8/16/2009 2 CESSNA 152 SUBS Medium

CEN10LA031 10/27/2009 2 AERONCA 7AC DEST Medium

WPR10FA078 12/10/2009 2 PIPER PA-38-112 SUBS Low

CEN10FA114 2/6/2010 4 BEECH A36 SUBS Medium

ERA10FA154 2/27/2010 1 BEECH P35 SUBS High

ERA10LA233 4/16/2010 1 CESSNA 172H SUBS Low

CEN10FA233 5/2/2010 2 JetProp DLX Piper PA46 SUBS High

ERA10FA259 5/10/2010 2 CIRRUS DESIGN CORP SR22 SUBS Medium

CEN10FA364 7/1/2010 2 BEECH F33A SUBS Low

CEN10FA385 7/11/2010 3 CESSNA 177B SUBS Low

WPR10FA383 8/4/2010 1 CIRRUS DESIGN CORP SR22 SUBS High

CEN11FA075 11/17/2010 1 Hawker-Beechcraft 

Corporation A36 SUBS High

WPR11FA050 11/17/2010 2 DIAMOND AIRCRAFT IND 

INC DA20-C1 SUBS High

CEN11LA194 2/15/2011 1 TAYLORCRAFT DCO-65 SUBS Low

CEN11FA267 4/4/2011 1 CIRRUS DESIGN CORP SR-22 SUBS Medium

WPR11FA248 6/4/2011 1 PIPER PA-24-250 SUBS Low

ERA11FA332 6/9/2011 2 CESSNA 152 SUBS Medium

ERA11FA354 6/23/2011 2 BEECH C24R SUBS High

WPR11FA331 7/17/2011 2 MOONEY M20F SUBS Medium

WPR11FA335 7/18/2011 3 MOONEY M20C SUBS Low

ERA12FA163 1/29/2012 1 PIPER PA-28-180 SUBS High

CEN12FA164 2/20/2012 2 PIPER PA-24-250 SUBS High

CEN12FA170 2/26/2012 2 MOONEY M20E SUBS High

ERA12FA303 4/27/2012 1 CIRRUS DESIGN CORP SR22 SUBS Medium

CEN12FA617 9/9/2012 1 BEECH A36 SUBS Medium

CEN13FA002 10/3/2012 2 CIRRUS DESIGN CORP SR22 SUBS Medium

CEN13FA060 11/18/2012 2 GRUMMAN AMERICAN 

AVN. CORP. AA-1B SUBS Medium

WPR13FA141 3/9/2013 1 MAULE M5 SUBS Low

WPR13FA236 5/18/2013 2 CESSNA 170B SUBS Low

CEN14FA084 12/12/2013 3 PIPER PA 24-250 SUBS Low

WPR13FA086 1/6/2013 2 BEECH V35A DEST High

ERA13FA115 1/16/2013 1 PILATUS PC-12/45 SUBS High

CEN13FA214 3/29/2013 1 CESSNA 152 SUBS High

ERA13FA227 5/4/2013 2 NEWGENT, BARRY S6S DEST High

WPR13FA244 5/28/2013 2 RAYTHEON AIRCRAFT 

COMPANY A36 DEST Low

ERA13FA259 5/31/2013 1 DIAMOND AIRCRAFT IND 

INC DA 20-C1 SUBS Low

ERA13LA270 6/5/2013 1 MAULE BEE DEE M-4-210 SUBS Low

CEN13FA327 6/8/2013 2 PIPER PA-28-140 SUBS Medium

CEN13FA351 6/15/2013 2 PIPER PA-24-260 DEST High

WPR13FA288 6/24/2013 1 BEECH J35 SUBS High
73| Page

NTSB_no Date Fatalities acft_make acft_model Damage Applicability 

to Rule

ERA13FA309 6/30/2013 2 NANCHANG CHINA CJ-6A DEST Low

CEN13FA416 7/17/2013 2 TAYLORCRAFT BC12-65 DEST High

WPR13FA368 8/12/2013 1 BEECH E35 SUBS High

WPR13FA370 8/13/2013 2 CHAMPION 7GCAA DEST High

WPR13FA376 8/16/2013 2 URBAN AIR SRO SAMBA XXL SUBS High

ANC13FA084 8/24/2013 2 CESSNA 150L SUBS Medium

WPR13FA388 8/26/2013 2 AMERICAN AVIATION AA-1A SUBS High

ANC13FA090 8/29/2013 2 CHAMPION 7ECA SUBS Low

ERA13FA385 8/29/2013 1 PIPER PA-28-161 DEST High

CEN14FA057 11/17/2013 2 CESSNA 152 SUBS Medium

WPR14LA119 2/23/2014 1 SABRENA DRAGONFLY SUBS Low

WPR14FA132 3/8/2014 1 CESSNA 120 DEST Medium

CEN14FA167 3/22/2014 5 SOCATA TBM 700 SUBS High

CEN14FA265 5/31/2014 2 CESSNA 150 SUBS High

CEN14FA266 6/1/2014 1 YAKOVLEV YAK-55M SUBS Low

WPR14FA234 6/7/2014 2 PIPER J3C SUBS High

WPR14FA239 6/9/2014 2 AMERICAN AVIATION AA-1A DEST Low

ERA14FA282 6/9/2014 2 LIBERTY AEROSPACE 

INCORPORATED XL-2 DEST Medium

WPR14FA252 6/18/2014 1 CESSNA 175 DEST High

CEN14FA328 6/30/2014 3 PIPER PA 28-235 DEST Medium

ERA14LA329 7/5/2014 1 FLIGHT DESIGN GMBH CT-SW 2006 SUBS Low

ERA14FA328 7/6/2014 2 CESSNA 150J SUBS High

ERA14FA337 7/12/2014 1 CULVER LFA SUBS High

ERA14FA345 7/19/2014 3 MOONEY M20F DEST High

WPR14FA320 7/30/2014 1 MOONEY M20L - NO SERIES SUBS High

CEN14FA453 8/25/2014 4 CESSNA 172R DEST Low

ERA14FA416 8/31/2014 1 PIPER PA-25-260 SUBS High

CEN15FA060 11/30/2014 1 BELLANCA 17-30A SUBS High

CEN15FA083 12/22/2014 1 CESSNA 172M DEST High
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XIV. Appendix V