0 

U.S. Department 

of Transportation 

Federal Aviation 

Administration 

August 24, 2021 

Dr. R. John Hansman, Ph.D. 

Chair, Research, Engineering and 

Develo ment Advisor Committee 

Dear Dr. Hansman: 

Office of the Administrator 

--

Thank you and the Federal Aviation Administration's (FAA) Research, Engineering, and 

Development Advisory Committee (REDAC) for your June 3, 2021, letter providing 

recommendations on the Fiscal Year 2023 Research and Development (R&D) Portfolio. The 

impo1tant guidance generated during the REDAC Winter-Spring 2021 virtual meeting held on 

April 21, 2021, is sincerely appreciated. 

Your cross-cutting observations about COVID-19 impacts, the need for research to infonn 

system resiliency and operational continuity, and the FAA being well-positioned to contribute to 

the increased national focus on sustainability are appreciated and noted. The Agency has utilized 

effective strategies to mitigate the impact of the pandemic, and these lessons learned will be 

essential for the development of future protocols to mitigate other unanticipated events. 

Additionally, as suggested, the Agency desires a clear, strategic understanding of the 

functionality and acceptable uses of Machine Leaming and Artificial Intelligence and their 

potential applications. 

We have reviewed the 14 recommendations that you have offered, and the enclosed FAA 

Response Repo1t reflects our proposed dispositions and action plans. I appreciate your 

assessment and insightful advice as well as the expe1tise of the RED AC professionals who 

continue to provide valuable guidance and suppo1t of the Agency's R&D programs. 

Steve Dickson 

Administrator 

Enclosure 
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FAA Response to Research, Engineering, and Development Advisory Committee 

(REDAC) Recommendations for the Fiscal Year 2023 Research and Development 

Portfolio

Subcommittee on Human Factors

Finding: Human Factors (HF) for Aircraft Certification - The Federal Aviation 

Administration (FAA) seems to be very responsive to the recent Aircraft Certification, Safety, 

and Accountability Act, however, it is not clear how the identified research requirements are 

being fulfilled and what the timing/funding would be. The Subcommittee was also pleased to 

hear about the FAA's plans for integration of Human Factors into policy and processes for 

certification and flight standards based on scientific, engineering, and operational data, but there 

was no clarity on the mechanisms for doing so.

Recommendation (1): The FAA should pursue the research requirements established in the 

Aircraft Certification, Safety, and Accountability Act and conduct research needed to support the 

integration of Human Factors into policy and processes for certification. This should include 

identifying and engaging research areas associated with the integration of Human Factors into the 

certification process, from identification of metrics and instruments for human performance to 

policy and guidance updates that account for a human system integration approach.

Consequences: Delay to harmonize the industry around appropriate methods to integrate human 

factors may result in multiple approaches that result in partial integration of Human Factors. The 

lack of research and methods to integrate Human Factors into the FAA's certification process 

may result in the certification of advanced aircraft flight deck and flight control systems that 

could have unintended safety consequences.

FAA Response: The FAA concurs with the Committee's finding and recommendation and 

is undertaking the following actions to address its recommendation(s) – The Human Factors 

aspects of the Aircraft Certification, Safety, and Accountability Act (ACSAA) were presented to 

the Subcommittee at the 2021 Winter/Spring meeting. The ACSAA legislation (signed on 

December 22, 2020) included several HF research-related provisions. Some but not all of these 

provisions are being addressed with funded research, such as research on transport pilot training 

and procedures for incorrect pilot response and response time, as well as research on pilot 

interactions with new flight deck technologies. The FAA will provide a status update at the 2021 

Summer/Fall meeting, addressing how the identified ACSAA HF research-related provisions are 

being fulfilled and how the appropriate policy and processes for Aircraft Certification and Flight 

Standards are being updated.

Additionally, the FAA notes that the Flight Deck Human Factors research portfolios will 

continue their longstanding mission to support the integration of Human Factors into policy and 

processes for the Office of Aviation Safety Office functions, including the Aircraft Certification 

Service.

Finding: Improved methods to determine individual proficiency of operational personnel -

The FAA seems engaged in research on training; however, the current research does not 

specifically investigate scientifically valid ways to develop, assess, and maintain full-spectrum 
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(psychomotor, cognitive, etc.) proficiency of operational personnel. Current evaluation methods 

rely on observable compliance with published procedures and performance parameters kept 

within clearly defined limits. Assessing cognitive skills associated with more complex cognitive 

processes, such as information integration, are even more difficult to observe. Proficiency in

cognitive skills is currently assessed mostly by the subjective judgment of instructors/examiners,

whose assessments are very difficult to standardize. Research is needed to determine how 

proficiency and skills are developed, trained, assessed, and maintained, including the length of 

time after training skill proficiency can be expected to be retained.

Recommendation (2): The FAA should pursue research to address the assessment of cognitive 

skills associated with more complex cognitive processes, such as information integration, that are 

difficult to observe and to determine the length of time after training that proficiency can be 

expected to be retained. This research should include the definition of proficiency, qualification 

standards and assessment methods, methods for maintaining and improving proficiency, and 

realistic proficiency retention timelines that are based on scientifically validated principles for 

the operational workforce. The results of this work could provide important methods for 

developing and measuring proficiency and may be extended to include initial definitions of 

proficiency needs for human interaction with autonomy and automation.

Consequences: Failure to identify proper evaluation methods may result in inadequate 

identification and mitigation of risks associated with developing and maintaining proficiency in 

operator skills. This may increase the opportunities for human error and impose additional 

hazards to system performance and operations.

FAA Response: The FAA concurs with the Committee's finding and recommendation and is 

undertaking the following actions to address its recommendation(s) - The FAA is currently 

funding two flight deck research requirements related to this recommendation: 1) cognitive skill 

degradation and 2) manual flight operations, including cognitive and psychomotor skills. This 

work was funded to provide scientific and technical data to inform the FAA's regulatory policy 

and guidance material, such as the draft Flight Path Management Advisory Circular (AC 120-

FPM). Previously, the FAA funded research on air traffic skill degradation related to automated 

decision support tools to explore potential NAS efficiency impacts. At the 2021 Summer/Fall 

meeting, the FAA NextGen Organization, in coordination with a subset of researchers working in 

this area, will provide an overview of the current and prior research related to this 

recommendation. This will enable the Committee and the AVS sponsors to identify research gaps 

in this area.

Subcommittee on Airports

Observations and Commendations: The Subcommittee was pleased to see that the Program's 

research had resumed in the latter half of CY2020, albeit with continuing restrictions on travel 

and certain on-site activities at the FAA William J. Hughes Technical Center. We commend 

Program and Technical Center staff on their work to manage myriad issues associated with the 

pandemic response and their flexibility and initiative in adjusting research activities and 

priorities to reflect COVID-19 realities.

We appreciate FAA's continuing focus on time-critical research projects. These include 
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evaluation of alternative aircraft fire fighting agents and assessment of Unmanned Aircraft 

detection and mitigation systems, both of which are associated with legislative requirements in 

the 2018 FAA Reauthorization Act. With respect to the latter project, the Subcommittee was 

encouraged to learn during our meeting of the FAA's selection of four airports as pilot testing 

sites for UAS detection and mitigation systems: Huntsville International Airport, Rickenbacker

International Airport, Seattle-Tacoma International Airport, and Syracuse Hancock

International Airport. These four airports join Atlantic City International Airport (New Jersey) 

in the program, where preliminary work began in Fall 2020.

We also understand that in spite of best efforts, there will be some delay in these time-sensitive 

research projects. This is of greatest concern for Alternative Firefighting Agent Research, 

where there is a legislative deadline for research findings this year. As noted in our 

recommendations below, the Subcommittee recommends (and supports) the FAA requesting an 

extension to this deadline to ensure that data collection and analysis can be performed.

Finally, we want to acknowledge the successful conclusion of the FAA's Neighborhood 

Environmental Survey research effort, which culminated with the publication of survey results 

in January 2021 (DOT/FAA/TC-21/4). The survey effort, which began in 2014, is a critical 

initial step towards the refinement of U.S. aviation noise policies, noise mitigation approaches, 

and community outreach. The collaborative between the FAA Offices of Environment & Energy 

and Office of Airports and their respective research programs provides a foundation for a 

challenging but necessary conversation regarding aviation noise and its effects on communities.

Finding: Alternative Firefighting Agent Research Project - As we noted in our Fall 2020 

report, the Subcommittee recognizes that disruptions caused by the COVID-19 pandemic have 

delayed time-critical research activities, including those associated with provisions in the FAA 

Reauthorization Act of 2018. The Program's alternative firefighting agent research project is of 

particular concern because:

• The Project's findings are needed to support FAA action regarding Section 332 of the 

FAA Reauthorization Act of 2018. Section 332 included a three-year deadline—ending 

on October 4, 2021—for FAA to "not require the use of fluorinated chemicals to meet the 

performance standards referenced in chapter 6 of AC No: 150/5210–6D and acceptable 

under 139.319(l) of title 14, Code of Federal Regulations."

• Airport operators are under considerable pressure from state and local governments and 

local communities to reduce or eliminate the use of polyfluoroalkyl substances (PFAS) 

at airports.

• There are significant and growing concerns about the human health impacts and 

associated liability associated with PFAS contamination on and near airports.

Based on our discussions of this project during the meeting, it seems that it will be challenging to 

complete necessary testing and analysis this year despite best efforts on the part of Program staff 

to do so, principally because of COVID-19 research disruptions during the first half of 2020.

The Subcommittee also recognizes the need for the FAA's efforts to be coordinated closely with 

complementary research efforts that have been underway within the U.S. Department of 

Defense (DoD).
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Recommendation (1): Consistent with Recommendation 1 from our Fall 2020 report, the 

Subcommittee encourages the FAA to assess whether additional time will be needed to complete 

its alternative firefighting agent research and coordinate this research with the U.S. DoD. The 

Subcommittee would support FAA requests for an extension of the October 4, 2021, legislative 

deadline to address these issues if the FAA seeks them from Congress.

FAA Response: The FAA concurs with the Committee's findings and recommendations 

and is taking the following actions to address it - The FAA will continue to closely monitor 

the ongoing testing of potential Aqueous Film Forming Foam (AFFF) alternatives at the FAA 

William J. Hughes Technical Center, along with research at the DoD. FAA shares the Airports 

Subcommittee's concerns that FAA will likely need additional time to adequately coordinate all 

of the results and complementary research with DoD. We appreciate the Subcommittee's support 

for an extension of the October 4, 2021 legislative deadline and will continue to keep you 

apprised of our path forward.

Finding: Unmanned Aircraft Systems (UAS) - UAS research remains a high priority for the 

Subcommittee. Actions that the FAA has taken in the last six months to facilitate UAS 

operations (e.g., over people, beyond visual line of sight) and facilitate UAS tracking in the 

National Airspace System via remote identification systems coupled with increasing UAS 

capabilities make these aircraft very attractive for a variety of beneficial uses at airports.

Recommendation (2): We encourage the FAA to prioritize its research into beneficial UAS 

use cases and implementation hurdles at airports, expediting this work if possible.

FAA Response: The FAA concurs with the Committee's findings and recommendations 

and is taking the following actions to address it - The FAA will continue its active research 

efforts with beneficial UAS use cases (e.g., pavement inspection, Foreign Object Debris 

detection, perimeter security, wildlife mitigation, firefighting command and control), along with 

mapping potential implementation hurdles at airports, and will prioritize research based on 

ongoing assessment of testing and evaluation results.

Subcommittee on NAS Ops

General Observations: The FAA is pursuing Research, Engineering, and Development 

(RE&D) related to Machine Learning/Artificial Intelligence (ML/AI) technologies for Air 

Traffic Control (ATC), Air Traffic Management (ATM), and increasingly automated air 

vehicles. This work includes applying Safety Risk Management (SRM) processes to identify and 

assess potential safety risks from these new technologies. The Subcommittee applauds these 

activities and also notes that there will be a growing need to ensure that SRM tools and

techniques effectively cover new certification and risk assessment challenges brought about 

from advanced ML/AI systems and how they interact with humans. This will likely result in the 

need to define and tailor research efforts focused on improving and extending the SRM and 

certification processes for ML/AI systems.

The NAS Operations Subcommittee was pleased to learn that the A11.i Air Traffic Control / 

Technical Operations program is beginning to address job task requirements and training gaps 

for personnel at the Air Traffic Control System Command Center (ATCSCC). The 
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Subcommittee feels this work is important to strengthen the capabilities and performance of 

these critical personnel who may not have had directly relevant training or experience with the 

strategic traffic management challenges addressed at the ATCSCC. The Subcommittee looks 

forward to hearing updates on this activity in the future.

Research Landscape Updates: The NAS Operations Subcommittee reviewed the FAA 

Research Landscape for the National Airspace System and provided several recommendations

for extensions and enhancements based on members' understanding of the changing aerospace 

landscape. These included:

• There is continuing interest in mixed operations, issues handling mixed equipage, and 

certification of new technologies. There is a need to harmonize mixed equipage traffic 

within the airspace, as this is inhibiting some of the potential benefits from NextGen. 

One example is the challenge in extracting benefits from Required Navigation 

Performance (RNP) procedures when some regional jets do not carry the necessary 

equipage. The Landscape should ensure that mixed-equipage challenges areconsidered 

where relevant.

• Certification of new entrant concepts and operations, including Urban Air Mobility and 

the rapid growth in Commercial Space Transportation, is seen as a key challenge that will 

require a focused research and development plan to accomplish. This also includes 

defining future communication, navigation, and surveillance requirements for these 

operations – which will need to expand beyond CONUS to global coverage to enable 

many of these operations.

• There is increased interest in new vehicles and missions and, in particular, a move

toward de-carbonization and advanced fuels and energy storage. There will be a 

transition to new energy sources and sustainable aviation fuels, some of which are 

available now but require support. In particular, it was noted that hydrogen and electric 

vehicles needmore attention from DOE, DOT, and NASA.

• The Subcommittee noted strong environmental Research and Development (R&D) 

initiatives in Europe have extended beyond vehicles to include other targets to reduce 

environmental impact, such as the operation of navaids or applying novel energy

sources at airports.

• Autonomous vehicles at airports, including airport Ground Service Equipment (GSE), 

will involve a transition to hydrogen power and "carbon-aware" GSE. It was noted that 

there are more than 40,000 Hydrogen-powered forklifts across the U.S. which have had 

a great impact on improved air quality in warehouses. More than 4,000 cellphone 

towers have shifted from diesel to Hydrogen backup power sources. Microsoft and 

others are using Hydrogen for backup power. Research should continue into similar 

efforts at airports and other facilities.

• Risk-based decision-making research should extend not just to safety risks, as currently 
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covered in the Landscape document, but also to include operational decision-making 

from the air traffic management perspective. An example would be the use of weather 

forecast confidence information in making a risk-balanced traffic managementdecision.

• There are growing spectrum issues, especially with the existing and planned evolutions 

from 4G to 5G to 6G. The rapid growth in small Unmanned Aircraft Systems (sUAS) 

will place additional pressure on the communications spectrum. This may warrant anew 

research topic in the Landscape or a more detailed extension to the "Increased 

Connectivity by Cyber-Physical Systems (Internet of Things)" research element.

Finding: Weather-related RE&D funding - The Subcommittee received briefings on the 

overall Research, Engineering, and Development (RE&D) budget followed by updates from the 

A11.k Weather Program, A11.q NextGen – Weather Technology in the Cockpit (WTIC) 

program, and A11.o Wake Turbulence program.

The FY21 Enacted RE&D budgets for A11.k, A11.q, and A11.o show significant reductions 

from prior-year levels: down to approximately 40%, 55%, and 55% relative to their FY19 

funding levels, respectively. Although major weather-related air carrier accidents are rare, they 

continue to be a concern, especially for general aviation and helicopter operations. Weather 

remains the largest single cause of air traffic delay, and it is likely that weather-related delays 

will become increasingly problematic as the nation returns to pre-COVID-19 traffic levels over 

the next few years. Research is needed to ensure that the improvements afforded by NextGen 

decision support capabilities are robust to weather conditions. At the same time, growing 

interest in small Unmanned Aircraft Systems (sUAS) and Advanced Air Mobility (AAM) 

concepts will require consideration of weather impacts on these new types of vehicles and 

missions to enable them to operate safely and effectively. These operations pose unique 

requirements for aviation meteorology knowledge in the Earth's boundary layer (below 1,000 

feet AGL).

Also, the technologies to enable options for services are expanding rapidly, including the 

evolution of the Low Earth Orbit Satellite Communication (sitcom) WiFi and 5G services from 

companies OneWeb, Kuiper (Amazon), Starlink (SpaceX), and SpaceMobile (AST Science). Of 

particular concern are the needs for improved weather sensing away from traditional airports and 

the need to better understand, model, and forecast low-level and urban-area weather. Concerns 

about aircraft wake turbulence also relate to the ability to model and forecast winds, and research 

may need to be expanded to safely enable upper-altitude (Upper E) operations involving 

particularly sensitive air vehicles such as long-endurance balloons. Given these new drivers of 

demand and technology enablers, now would be a good time to increase funding for the FAA 

Weather Program, not reduce it.

Recommendation (1): The NAS Operations Subcommittee recommends that the FAA make a 

directed effort to improve awareness of the importance of weather-related research and the 

impacts that the FAA's prior weather research has had on improving the safety and efficiency of 

the National Airspace System.

FAA Response: The FAA concurs with the Committee's finding and recommendation and 

is undertaking the following actions to address its recommendation(s) - The FY2022 

President's Budget includes an increase to both the Weather program and the Weather in the 
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Cockpit Program.

Recommendation (2): The Subcommittee also recommends that the weather-related RE&D 

programs strengthen connections with major FAA programs and strategic thrusts, including 

Trajectory Based Operations (TBO), Future Flow Management, Unmanned Traffic Management 

(UTM), Advanced Air Mobility (AAM), and NAS Integration of Transiting Operations (NITRO) 

to ensure that weather considerations are included and that a robust prioritized list of weather 

RE&D initiatives are identified to support those programs.

FAA Response: The FAA concurs with the Committee's finding and recommendation and 

is undertaking the following actions to address its recommendation(s) – The FAA will 

continue working with these groups, as well as other stakeholders within and outside the FAA 

via the established weather requirements process that was briefed to the REDAC in September 

2020. In addition, a Weather Community of Interest has been established to manage weather 

information across the FAA and resolve mission-specific, information-sharing challenges 

affecting the use of weather information.

Subcommittee on Aircraft Safety

Finding: Visibility in the Source of Research, Engineering, and Development (RE&D) 

Funding - The Subcommittee on Aircraft Safety (SAS) found that some FAA Research, 

Engineering, and Development activities are being sponsored and managed under Facilities and 

Equipment (F&E) funding. Furthermore, SAS learned that some research topics such as Air 

Traffic Management (ATM) and Communication, Navigation and Surveillance (CNS) were 

moved from RE&D funding to F&E funding in the late 1990s. Additionally, the SAS learned 

that Unmanned Aircraft Systems (UAS) Pilot Programs research is being managed with F&E 

funding. Some Research, Engineering, and Development being conducted under F&E funding 

also serve to inform FAA aviation safety policy, regulations, and rulemaking. Lack of SAS 

visibility into projects sponsored and managed under F&E funding leads to an incomplete SAS 

review of research related to aviation safety policy, regulations, and rulemaking. In addition, the 

potential exists for regular F&E activities, pressures, and priorities to overcome and negatively 

impact the prioritization and resources for mid- and long-term research.

Recommendation (1): The SAS recommends that the FAA brief the SAS on the process by 

which the Research, Engineering, and Development sponsored and managed within the RE&D 

funding and F&E funding is coordinated and ensure mid- and long-term research objectives 

prioritization is appropriately maintained. The SAS recommends that the FAA include F&E 

Research, Engineering, and Development, which inform FAA aviation safety policy, regulations, 

and rulemaking BLI and/or projects in future SAS briefings.

FAA Response: The FAA concurs with the Committee's recommendation and with the 

noted exceptions and clarifications, intends to undertake the following actions to 

address this recommendation - The FAA Research and Development program 

encompasses the following types of work in three distinct budget areas -

• Research, Engineering & Development – Applied research to develop information and tools 
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necessary for the FAA to develop the regulations and standards necessary to accomplish their 

certification and oversight role. All but the Commercial Space RE&D BLI is presented to 

the REDAC across the five subcommittees for Findings and Recommendations. The 

Commercial Space BLI is informational only for the REDAC as it is covered by a separate 

Commercial Space Advisory Committee.

• Facilities and Equipment, Activity 1 – Capital improvement projects necessary to 

accomplish FAA's mission by providing funds to establish, replace, relocate, or improve air 

navigation facilities and equipment and aviation safety systems. The work under this budget,

except for work concerning standards and procurement activities beyond research, is 

presented to the REDAC NAS OPs Subcommittee for Findings and Recommendations.

• Facilities and Equipment, Activity 4 – Projects providing the FAA workforce with system 

engineering, integration, logistics, technical services, and transitional support for the National 

Airspace System. The work under this budget, except for work concerning standards and 

procurement activities beyond research, is presented to the REDAC NAS OPs Subcommittee 

for Findings and Recommendations.

The FAA will provide an informational briefing with more detail on the research-related portions 

of all of these budgets (i.e., not the standards and procurement work) at the next Aircraft Safety 

Subcommittee meeting.

Finding: Ice Crystal Icing (ICI) - The Subcommittee appreciates the FAA research in A11D 

budget line item for Research on Ice Crystal Icing Conditions to Address Fundamental 

Knowledge of High-Altitude Icing on Turbine Engine Damage and Power loss. The project is 

currently un-funded through the 2023 fiscal year. Further in-depth research can aid current 

rulemaking work to address this issue appropriately.

Prior funding was used for several flight campaigns, however, the data analysis portion requires 

additional funding for an additional flight test campaign evaluating the effects of atmospheric 

aerosol content on ice crystal concentrations at high altitude. Additionally, as many projects are 

put on hold during the COVID-19 pandemic, funding should be available for ongoing work,

including additional testing for modeling and testing for ICI accretion behind the fan.

Recommendation (2): The FAA should consider prioritization for further Ice Crystal Icing 

research for Fiscal years 2021 and beyond to ensure it is adequately addressed in certification 

and rulemaking. The FAA should consider additional research in the following fields:

 Aerosol testing to determine the effects on high altitude ice crystal concentrations

 Continental vs. Oceanic Mesoscale Convective Systems and lapse rates and their 

effecton High Altitude ICI

 Basic physics studies of ice formations within turbine engine flow paths from high 

altitude ice crystal icing in mesoscale convective systems

FAA Response: The FAA concurs with the Committee's recommendation and is 

undertaking the following actions to address its recommendations - The FAA agrees with all 
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recommended fields of research:

 Currently, the FAA is in the planning stages for preparing to perform aflight campaign in 

2023 in a high aerosol atmosphere to measure the anthropomorphic aerosol effects on the 

formations and concentrations of high altitude ice crystal icing. A partnership with 

NASA, Nagoya University, Collins Aerospace, and Honeywell Aerospace has been 

formed. This research currently has FY21 funding.

 The FAA has initiated a study looking at Airbus flight test measurements to determine if 

the Airbus data is sufficient to answer the question about differences between continental 

vs. oceanic mesoscale convective systems during the formation of high-altitude ice

crystals, which have been shown to cause aircraft engine damage and power loss, as well 

as, air data probe malfunction from clogging. If the Airbus data turns out to be 

insufficient, then additional flight studies may be required to address this rulemaking 

committee question.

 The FAA has partnered with the National Research Council of Canada in developing a 

highly innovative scaled turbomachinery compressor section, which can be highly 

instrumented and operated in a simulated altitude ice crystal environment, so that ice 

accretion formations and their mechanisms can be studied. Initial tests have shown 

promising results. After preliminary small-scale testing shows viability, the 

development of a scaled-up version is planned to start in the 2023 time frame. The 

large-scale rig should be fabricated, and the testing should be completed in 2026, with 

the final data analysis completed in 2027.

Finding: Machine Learning/Artificial Intelligence (ML/AI) - The SAS was pleased to learn 

about the ongoing and planned research on Machine Learning and Artificial Intelligence.

Future advancements in control system technologies will depend upon an artificial learning 

process that has the potential to impact the basis of certification for such systems. The demands 

of industrial or ground-based systems differ greatly from those requirements for aircraft systems. 

If not fully researched and understood, the impact on aviation safety-critical systems is 

significant. While both industry and academia are placing a large emphasis on the development 

of ML/AI, more research is required to better understand the means to establish criteria to judge 

the confidence and validation of such systems that ultimately can lead to a basis of certification 

of these same systems. Furthermore, there is significant standards development work being 

conducted by the Radio Technical Commission for Aeronautics (RTCA), Society of Automotive 

Engineers (SAE), and American Society for Testing Materials (ASTM) on these technologies 

across the entire aviation ecosystem, both airborne and ground, addressing both manned and 

unmanned systems. This includes Unmanned Traffic Management (UTM) solutions.

Recommendation (3): The SAS recommends that FAA place a priority on research in ML/AI. 

This research will enable the FAA to work toward achieving a means of compliance by 

addressing the added challenge of better understanding the current and future scope of

technology. On a more strategic basis, we further recommend identifying the unique attributes 

where those ML/AI applications can safely be used.

Recommendation (4): In addition, the SAS recommends close collaboration with industry to 

understand the FAA requirements and FAA to understand the technology to develop/modify 
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requirements based on new technology. On a more strategic basis, we further recommend 

identifying the unique attributes where those ML/AI applications should be used.

FAA Response: The FAA concurs with the Committee's recommendation(s) and with the 

noted exceptions and clarifications intends to undertake the following actions to address its 

recommendation(s) - The FAA has been focusing on the challenges AI/ML applications and 

implementations pose to the safe operations of airborne systems. This focus is supported by 

research on assurance challenges, gaps in the current standards and guidance, and verification 

alternatives. The FAA is committed to working with industry to assess new areas of innovation 

and to support their safe incorporation into the National Airspace System. The FAA has 

established a Policy and Innovation Division within the Aircraft Certification Service (AIR-600) 

and is engaging earlier with industry to facilitate certification of new technologies. We are 

actively interfacing with standards committees, industry, federal organizations, and other 

certification authorities.

Subcommittee on Environment and Energy

General Observations: The Subcommittee focused on reviewing the Research and 

Development (R&D) Portfolio for the Office of Environment and Energy (AEE) that was 

developed based on the Research, Engineering, and Development (RE&D) budget for FY 21that 

was enacted on December 27, 2020. During the meeting, the staff from the Office of 

Environment and Energy (AEE) provided updates on all of the major research areas within the 

portfolio. Work on programs such as the Aviation Sustainability Center of Excellence 

(ASCENT); Continuous Lower Energy, Emissions and Noise (CLEEN); Commercial Aviation 

Alternative Fuels Initiative (CAAFI), and the Aviation Environmental Design Tool (AEDT) 

have been progressing. The updates highlighted accomplishments, since our last meeting, that 

have been realized both locally and on the international front directly linked to the ongoing 

research. These accomplishments further validate the need for sound research when developing 

regulations and policies and procedures.

Despite the COVID-19 concerns that we had expressed in our previous report, the Subcommittee 

was very impressed with the job the leadership and staff of AEE has been doing. The 

presentations were well done and reflected impacts and or potential impacts because of 

COVID-19, to the research that is being done and is proposed in the future. The presentations 

outlined a high level of communication between AEE staff and their partners to continue these 

necessary research efforts, but they also showed the challenges associated with COVID-19 

restrictions and how they have impacted many projects, be it financial or time delays.

The overall impacts of COVID-19 on the citizens of the world are unprecedented! The aviation 

industry is currently going through a crisis of historic magnitude, and the road to recovery and 

future growth still has many uncertainties. The dramatic reduction in air travel and aviationrelated activities has brought significant attention to the environmental impacts associated with 

the aviation industry. Members of this Subcommittee believe that the FAA and the aviation 

industry are at a unique point in history, and AEE and its partners are well-positioned to address 

the additional environmental questions that are being asked on noise and emissions. The 

answers to the questions can only be found through additional research and development with

financial support from the U.S. government. We have already seen where other governments 
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have pledged support to their environmental research agenda.

The U.S.A must maintain its leadership position at the global stage in order to protect the U.S. 

aviation industry as we continue down the path of recovery and address new growth. This 

leadership position can be sustained by further expanding the Environmental and Energy R&D 

Portfolio using the proven blueprint that was presented to this Subcommittee. The expected

results of current and future research under this portfolio will also help us address the concerns 

within the U.S.A as well. We know where we want to be. We need to use our partnerships with 

other federal agencies, universities, and businesses and our research portfolio to get there.

The Subcommittee believes that AEE is doing a good job and has once again presented a 

balanced portfolio. We believe that the research priorities that the Subcommittee has previously 

identified, growth from Commercial Subsonic traffic, Urban Air Mobility (UAM), Unmanned 

Aerial Systems (UAS), Supersonic Civil aircraft, and Commercial Space vehicles, do not need 

to be adjusted. The Subcommittee was happy with the briefings we received on a number of 

new research projects that have been added to address these priorities. The Subcommittee 

members realize that there is still additional research required to address ongoing areas of 

concern. There were additional discussions among the members on whether there are any 

research opportunities that currently exist because of the impacts that COVID 19 has had on the 

aviation industry.

The Subcommittee is comfortable that AEE, the ASCENT Center of Excellence, CLEEN 

Program, CAAFI, and others efforts, as well as and their partners, including NASA, are working 

together to realistically address the impacts that the COVID-19 pandemic has had on continued 

research efforts. The long-term impacts of this pandemic on the citizens of the world and the 

aviation industry are still not known, but we believe that AEE has a proven blueprint that can be 

used to address future research needs. Guided by the updates and presentations, the 

Subcommittee has proceeded with the following "Findings and Recommendations." The 

recommendations offered are all for inclusion in the REDAC report.

Finding: Noise Research- Aviation noise is and will continue to be one of the biggest 

environmental impacts related to the aviation industry, and it requires ongoing research in order 

to address the concerns of the citizens. The overall reduction in aircraft movements as a result of 

the pandemic has definitely increased the focus on noise. The Subcommittee realizes that there 

is much research that is still necessary to address the ongoing topic of aviation noise. Whether 

there are new technologies or new procedures that can be implemented to help reduce the 

impacts of noise as the aviation industry rebuilds needs to be evaluated. AEE has research 

projects that are looking at the impacts of noise on children's learning, sleep impacts, community 

annoyance, and cardiovascular health.

AEE is looking at the certification requirements for Supersonic aircraft, as well as Unmanned 

Aircraft System (UAS) and Advanced Air Mobility (AAM) vehicles. AEE is also examining 

how to reduce the noise from commercial aircraft and helicopters through changes in operational

procedures. There are a number of new research projects that have been added to address issues

related to new entrants into the aviation system. There also have been significant upgrades made 

to the Aviation Environmental Design Tool (AEDT). FAA has also launched an initiative to 

partner with airports to gather more noise data resulting from noise complaints. Finally, AEE is 

working with industry to accelerate the development of technologies that reduce noise through 
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the CLEEN Program.

Recommendation (1): The Subcommittee strongly supports and recommends the continued 

prioritization of noise research! Noise is a source of everlasting "headaches" for the aviation 

community, and despite the great improvements made by the FAA, communities have 

become less tolerant of noise.

FAA Response: The FAA concurs with the Committee's finding and recommendation and 

is undertaking the following actions to address it - The FAA is committed to developing 

meaningful and equitable solutions to the complex and nuanced issue of aviation noise. On 

January 13, 2021, we published an Overview of FAA Aviation Noise Policy and Research 

Efforts on the Federal Register. This Federal Register Notice ("notice") contained a 

comprehensive overview of FAA R&D efforts on noise, and it sought input from the public on 

research activities to inform aircraft noise policy. We are currently in the process of reviewing 

the more than 4,100 submitted comments to inform the scope of additional areas of noise 

research. We will continue to support the R&D portfolio outlined in the notice while also 

looking for opportunities to expand our work, including through the inputs provided by the 

aforementioned comments.

The notice also contained results from the Neighborhood Environmental Survey, which 

quantified the annoyance of those experiencing aircraft noise in airport communities. Theresults 

show there has been a substantial increase in annoyance levels compared to surveys conducted in 

decades past, with roughly two-thirds of respondents to the survey reporting being highly 

annoyed at the level of noise used to define significance within the National Environmental 

Policy Act.

We are also taking steps to begin a policy review that builds on our work to advance the 

scientific understanding of noise impacts, as well as the development of analytical tools and 

technologies. This effort will build on our partnerships with academia, industry, and government 

to better understand, manage, and reduce the environmental impacts of aviation, including but 

not limited to noise. This effort will incorporate the FAA's updated understanding of aviation 

noise and human response so that we are able to promulgate well-reasoned, scientificallygrounded policies.

Finding: Public-Private Partnerships - The Subcommittee wishes to acknowledge and support 

the fact that the Office of Environment and Energy (AEE) has proven over decades to be a very 

good steward of taxpayer money. The leadership team at AEE has used their budgeted amounts 

to conduct and coordinate the research necessary to produce informed, data-driven policies, 

facilitate technological advances in the aviation industry, and produced models and data that 

have positioned the U.S. as both a State leader at International Civil Aviation 

Organization/Committee on Aviation Environmental Protection (ICAO CAEP) and on the global 

aviation stage.

The execution of this research portfolio has been accomplished by working collaboratively with 

private industry, major universities through the ASCENT Center of Excellence, other federal 

departments, and foreign governments. Three-quarters of Environment and Energy research 

funds generate 100% plus cost matching from non-federal partners (CLEEN, CAAFI, and 

ASCENT). This leverages scarce FAA R&D funds to accomplish significant advances and 
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improvements. In addition, we believe that government funding has been used and executed 

effectively to lower the risk of new and emerging technologies such that they can be adopted by 

industry. The benefits of these partnerships have clearly been proven over time and are very 

apparent in most of the current projects. To date, the CLEEN and CLEEN II programs 

sponsored by the FAA have been responsible for the maturation of aircraft technologies 

responsible for significant decreases in fuel burn/CO2, decreases in NOx emissions, and noise 

reductions that would not have happened otherwise.

Recommendation (2): The Subcommittee continues to endorse Public-Private Partnerships like 

the Continuous Lower Energy, Emissions and Noise (CLEEN), Commercial Aviation 

Alternative Fuels Initiative (CAAFI), and Aviation Sustainability Center of Excellence 

(ASCENT) programs to leverage resources and recommends that FAA should continue to 

allocate robust funding for these programs. Given the current drop in air traffic levels, now is 

the perfect time for Phase III of the CLEEN program to develop and mature technologies that 

would have an even more substantial impact on aviation environmental concerns.

FAA Response: The FAA concurs with the Committee's finding and recommendation and 

is undertaking the following actions to address it - The FAA is maximizing the impact of 

taxpayer dollars by partnering with industry, academia, federal agencies, and other governments. 

The vast majority of the Environment and Energy R&D program has been leveraging resources 

from the private sector via public-private partnerships. CLEEN, CAAFI, and ASCENT have all 

been successful because of their strong engagement with industry. Each of these programs have 

had strong partnerships with and support from, industry for over a decade. The FAA is in the 

process of finalizing the awards for the third phase of CLEEN, which will ensure the 

continuation of this model of public-private partnership on aircraft technology development 

through 2025. The FY2022 President's Budget includes a new Aviation Climate Research 

budget line item that would expand the use of public-private partnerships, such as ASCENT, 

CAAFI, and CLEEN. This new effort would see the FAA invest in high-risk, accelerated 

research that has transformative impact potential to reduce greenhouse gas emissions from 

aviation in support of the 2030 and 2050 U.S. climate change goals. We are also working in 

partnership with the Department of Energy, the U.S. Department of Agriculture, and NASA on 

our research to ensure that our efforts are complementary and directed toward the 

Administration's goals. Finally, we are also collaborating with a number of international 

research institutions through the ASCENT COE and CAAFI. We have worked diligently to 

develop all of these partnerships over many years and intend to continue to do so going forward.

Finding: Sustainable Aviation Fuels (SAFs) - Significant gains have been realized in the 

Sustainable Aviation Fuel (SAF) Program (including efforts in CAAFI, CLEEN, and ASCENT. 

SAFs are a critical component of the industry's emissions reduction strategy and must be 

developed if industry is to get to their carbon-neutral growth goals after 2020 and their 50%

emissions reduction goals in 2050. This research has helped with the creation of a number of 

companies that have the potential to benefit the rural economies of several states and the U.S. 

Aviation industry. In 2020, 4.6M gallons of SAF were used by the U.S. Aviation Industry, a 

190% increase over 2019, and this increased consumption happened in spite of the current 

downturn in aviation traffic.

Business aviation has also seen significant interest in SAF. Based on industry data, there should 

be a significant increase in production and consumption in the coming years. Recent support 
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from a number of agencies, including from DOE and USDA, will further support SAF 

production. The FAA is working through the International Civil Aviation 

Organization/Committee on Aviation Environmental Protection (ICAO CAEP) to ensure that a 

wide range of sustainable aviation fuels are included in Carbon Offsetting and Reduction System 

for International Aviation (CORSIA). The FAA has also been conducting research to examine 

whether other types of fuel besides SAF could be used in different kinds of air vehicles. This 

work should prove insightful for understanding how Hydrogen could be used by aviation, both 

in the near and longer terms.

Recommendation (3): It is still the position of this Subcommittee that the work on Sustainable 

Aviation Fuels (SAF) is critical to the U.S. industry, and the FAA should maintain a global 

leadership role in the development of SAF. Since the maturation of the Sustainable Aviation 

Fuel program will be a major environmental benefit for the public, will create a new industry 

within the U.S. that benefits rural America, and will benefit the U.S. aviation industry, we 

strongly recommend that the FAA AEE continues to allocate funds for the continuation of 

research on SAFs. This includes finding ways to use SAF as blending percentages above 50% 

and work towards the use of 100% SAF in today's aircraft. The partnerships with the 

Department of Energy and the U.S. Department of Agriculture must also be reinforced.

FAA Response: The FAA concurs with the Committee's finding and recommendation and 

is undertaking the following actions to address it - The FAA wholeheartedly agrees with the 

importance of Sustainable Aviation Fuels (SAF). As captured in the fact sheet from President 

Biden's Leaders Summit on Climate, "the United States is committed to working with other 

countries on a vision toward reducing the aviation sector's emissions in a manner consistent with 

the goal of net-zero emissions for our economy by 2050, as well as, on robust standards that 

integrate climate protection and safety. The United States intends to advance the development 

and deployment of high integrity sustainable aviation fuels and other clean technologies that 

meet rigorous international standards, building on existing partnerships, such as through 

ASCENT– the Aviation Sustainability Center – and pursue policies to increase the supply and 

demand of sustainable aviation fuels." SAF are the most effective near-term opportunity to 

reduce aviation carbon dioxide emissions and will be critical to achieving the Administration's 

goals for economy-wide carbon dioxide reductions. The new Aviation Climate Research budget 

line item will augment our longstanding efforts by supporting the development of SAF that could 

be used in jet engines without blending with conventional petroleum-based jet fuel and by 

evaluating aviation fuel supply chains to reduce the cost to produce SAF and maximize their 

environmental benefits. We also continue to work closely with others agencies, and in particular 

with the Department of Energy, the U.S. Department of Agriculture, and NASA, to work in a 

coordinated manner to accelerate the development and deployment of SAF.

Finding: Global Leadership - It is evident that the FAA AEE currently maintains a leadership 

role in ICAO CAEP and has been the driving force behind the push for data-driven rulemaking. 

Because of the impacts of COVID 19 on aviation globally and the continuing importance being 

placed on environmental issues around the globe, other governments have made commitments to 

their own research and environmental agenda. As a result, the Subcommittee firmly believes that 

maintaining the U.S. global leadership position at ICAO CAEP is not an option. It is essential 

and advantageous to the U.S. aviation industry. Work that has been done with ASCENT and the 

Volpe Center has clearly allowed the FAA to maintain a scientifically supported position at the

International Civil Aviation Organization/Committee on Aviation Environmental Protection 
15

(ICAO CAEP). The close collaboration with NASA at ICAO CAEP is also clearly supporting 

global leadership. Anything that jeopardizes ongoing research at AEE will impact the FAA/U.S. 

global leadership position at ICAO CAEP.

Recommendation (4): The Subcommittee recommends the continuing strong support of all 

research efforts/programs that will allow the FAA and the U.S. to maintain its global leadership 

position at ICAO CAEP. It is the belief of the Subcommittee that if the FAA/U.S. does not 

maintain its leadership position at ICAO CAEP, it will not be able to influence 

policy/rulemaking, and this could have a significant negative impact on the U.S. aviation 

industry.

FAA Response: The FAA concurs with the Committee's recommendation and is 

undertaking the following actions to address it - The FAA appreciates the support of the 

Subcommittee for our ICAO CAEP activities and the importance of continued U.S. leadership 

therein. We concur that it is critical for FAA to have robust participation in the ICAO CAEP 

process, and we have allocated resources such that we can provide leadership in many of the 

working groups of CAEP, as FAA leadership is critical to securing overall U.S. objectives at 

ICAO. FAA prioritized research efforts include developing the modeling capabilities and 

generating the data to support the decision-making process within ICAO CAEP. Under the 

direction of the FAA, much of this work is being done by ASCENT COE universities and the 

Volpe Center, in close collaboration with NASA and industry. Over the past few years, we have 

been working with U.S. stakeholders and the international community to develop noise standards 

for supersonic aircraft with a focus on landing and takeoff noise. As AEDT is the primary tool 

for supporting decision-making related to noise at ICAO CAEP, this has included working with 

the Volpe Center to enhance its capabilities to include supersonic aircraft. In addition to this 

broad effort related to supersonic aircraft, FAA is also utilizing the broad research portfolio of 

ASCENT and expertise at NASA and DOE to ensure that the evaluation of any long-term 

aspirational goal is based on robust scientific analyses that quantify the economic costs and 

potential benefits of any specific goal. We continue to advance work in ICAO to ensure that 

sustainable aviation fuels from biomass and wastes, as well as lower carbon aviation fuels from 

fossil resources, are appropriately credited within the ICAO Carbon Offsetting and Reduction 

System for International Aviation (CORSIA). Finally, we are examining what additional 

research efforts may be needed to support efforts that could come out of the CAEP/12 meeting in 

February 2022.