[House Hearing, 117 Congress]
[From the U.S. Government Publishing Office]


                         EXAMINING R&D PATHWAYS
                        TO SUSTAINABLE AVIATION

=======================================================================

                                HEARING

                               BEFORE THE

                 SUBCOMMITTEE ON SPACE AND AERONAUTICS

                                 OF THE

                      COMMITTEE ON SCIENCE, SPACE,
                             AND TECHNOLOGY
                        HOUSE OF REPRESENTATIVES

                    ONE HUNDRED SEVENTEENTH CONGRESS

                             FIRST SESSION

                               __________

                             MARCH 24, 2021

                               __________

                            Serial No. 117-6

                               __________

 Printed for the use of the Committee on Science, Space, and Technology
 
[GRAPHIC NOT AVAILABLE IN TIFF FORMAT] 


       Available via the World Wide Web: http://science.house.gov
       
                               __________

                    U.S. GOVERNMENT PUBLISHING OFFICE                    
43-797PDF                 WASHINGTON : 2022                     
          
-----------------------------------------------------------------------------------         

              COMMITTEE ON SCIENCE, SPACE, AND TECHNOLOGY

             HON. EDDIE BERNICE JOHNSON, Texas, Chairwoman
ZOE LOFGREN, California              FRANK LUCAS, Oklahoma, 
SUZANNE BONAMICI, Oregon                 Ranking Member
AMI BERA, California                 MO BROOKS, Alabama
HALEY STEVENS, Michigan,             BILL POSEY, Florida
    Vice Chair                       RANDY WEBER, Texas
MIKIE SHERRILL, New Jersey           BRIAN BABIN, Texas
JAMAAL BOWMAN, New York              ANTHONY GONZALEZ, Ohio
BRAD SHERMAN, California             MICHAEL WALTZ, Florida
ED PERLMUTTER, Colorado              JAMES R. BAIRD, Indiana
JERRY McNERNEY, California           PETE SESSIONS, Texas
PAUL TONKO, New York                 DANIEL WEBSTER, Florida
BILL FOSTER, Illinois                MIKE GARCIA, California
DONALD NORCROSS, New Jersey          STEPHANIE I. BICE, Oklahoma
DON BEYER, Virginia                  YOUNG KIM, California
CHARLIE CRIST, Florida               RANDY FEENSTRA, Iowa
SEAN CASTEN, Illinois                JAKE LaTURNER, Kansas
CONOR LAMB, Pennsylvania             CARLOS A. GIMENEZ, Florida
DEBORAH ROSS, North Carolina         JAY OBERNOLTE, California
GWEN MOORE, Wisconsin                PETER MEIJER, Michigan
DAN KILDEE, Michigan                 VACANCY
SUSAN WILD, Pennsylvania
LIZZIE FLETCHER, Texas
VACANCY
                                 ------                                

                 Subcommittee on Space and Aeronautics

                   HON. DON BEYER, Virginia, Chairman
ZOE LOFGREN, California              BRIAN BABIN, Texas, 
AMI BERA, California                     Ranking Member
BRAD SHERMAN, California             MO BROOKS, Alabama
ED PERLMUTTER, Colorado              BILL POSEY, Florida
CHARLIE CRIST, Florida               DANIEL WEBSTER, Florida
DONALD NORCROSS, New Jersey          YOUNG KIM, California
                        
                        
                        C  O  N  T  E  N  T  S

                             March 24, 2021

                                                                   Page

Hearing Charter..................................................     2

                           Opening Statements

Statement by Representative Don Beyer, Chairman, Subcommittee on 
  Space and Aeronautics, Committee on Science, Space, and 
  Technology, U.S. House of Representatives......................    10
    Written Statement............................................    11

Statement by Representative Frank Lucas, Ranking Member, 
  Committee on Science, Space, and Technology, U.S. House of 
  Representatives................................................    12
    Written Statement............................................    13

Statement by Representative Brian Babin, Ranking Member, 
  Subcommittee on Space and Aeronautics, Committee on Science, 
  Space, and Technology, U.S. House of Representatives...........    14
    Written Statement............................................    15

Written statement by Representative Eddie Bernice Johnson, 
  Chairwoman, Committee on Science, Space, and Technology, U.S. 
  House of Representatives.......................................    16

                               Witnesses:

Dr. Karen A. Thole, Department Head and Distinguished Professor, 
  Department of Mechanical Engineering, Pennsylvania State 
  University
    Oral Statement...............................................    18
    Written Statement............................................    20

Dr. R. John Hansman Jr., T. Wilson Professor of Aeronautics & 
  Astronautics and Director, MIT International Center for Air 
  Transportation, Massachusetts Institute of Technology; Chair, 
  FAA Research and Development Advisory Committee (REDAC); Co-
  director, FAA Center of Excellence for Alternative Jet Fuels 
  and Environment (ASCENT)
    Oral Statement...............................................    33
    Written Statement............................................    35

Mr. Steve Csonka, Executive Director, Commercial Aviation 
  Alternative Fuels Initiative (CAAFI)
    Oral Statement...............................................    40
    Written Statement............................................    42

Discussion.......................................................    50

             Appendix I: Answers to Post-Hearing Questions

Dr. Karen A. Thole, Department Head and Distinguished Professor, 
  Department of Mechanical Engineering, Pennsylvania State 
  University.....................................................    66

Dr. R. John Hansman Jr., T. Wilson Professor of Aeronautics & 
  Astronautics and Director, MIT International Center for Air 
  Transportation, Massachusetts Institute of Technology; Chair, 
  FAA Research and Development Advisory Committee (REDAC); Co-
  director, FAA Center of Excellence for Alternative Jet Fuels 
  and Environment (ASCENT).......................................    75

Mr. Steve Csonka, Executive Director, Commercial Aviation 
  Alternative Fuels Initiative (CAAFI)...........................    79

            Appendix II: Additional Material for the Record

Letter submitted by Representative Don Beyer.....................    92

Letter submitted by Alternative Fuels & Chemicals Coalition......    97

 
                         EXAMINING R&D PATHWAYS
                        TO SUSTAINABLE AVIATION

                              ----------                              


                       WEDNESDAY, MARCH 24, 2021

                  House of Representatives,
             Subcommittee on Space and Aeronautics,
               Committee on Science, Space, and Technology,
                                                   Washington, D.C.

     The Subcommittee met, pursuant to notice, at 11:01 a.m., 
via Webex, Hon. Don Beyer [Chairman of the Subcommittee] 
presiding.
[GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

     Chairman Beyer. Great, thank you. Good morning. Welcome to 
the first meeting or hearing of our Subcommittee on Space and 
Aeronautics, ``Examining R&D Pathways to Sustainable 
Aviation.'' So good morning. Welcome to our distinguished 
witnesses. Thanks for being here. I also want to welcome our 
new and returning Subcommittee Members to this first hearing. I 
also want to say happy birthday to the Ranking Member Dr. Brian 
Babin. I think you were 63 years old, Dr. Babin, something like 
that, yesterday?
     Mr. Babin. Absolutely. Absolutely. Thank you so very much, 
Mr. Chairman.
     Chairman Beyer. OK. These are exciting times, Dr. Babin's 
birthday, humans are going back to the Moon in preparation to 
Mars for advancing scientific discovery and transforming the 
future of aviation. There's so much. And I really look forward 
to working with Ranking Member Babin and Ranking Member Lucas 
and our wonderful Chair, Chairwoman Eddie Johnson, on 
supporting a strong and bright future for America's space and 
aeronautics programs.
     One of the immediate challenges is the climate crisis, and 
today, we're considering aviation's role in how to address it. 
Typically, aviation only contributes about 2.5 percent global 
CO2 emissions, and that seems low, especially 
compared to, say, cars. However, with pre-pandemic global air 
travel growing at annual rates of three to five percent, it 
shouldn't come as a surprise that aircrafts'--aviation's global 
CO2 emissions increased from 710 million tons in 
2013 to 905 million tons in 2018, and it's supposed to triple 
by 2050.
     Now, to its credit, the aviation industry has taken 
consistent steps to improve aircraft efficiencies, in part to 
reduce fuel costs. There are 70 to 80 percent more efficient 
aircraft engines, than there were those old turbocraft jet 
aircrafts in the 1950's, and efficiencies are expected to 
continue at one or two percent annually. But while these are 
important, they're not going to be sufficient to meet 
aviation's carbon challenge.
     The good news, in 2009 the industry adopted the goal of 
reducing aviation's carbon emissions by 50 percent of 2005 
levels by 2050, but that's going to need new technologies, 
increased efficiencies, and cleaner sources of energy. And I 
think we all believe that Federal Government R&D (research and 
development) is essential for the testing, demonstrating, and 
maturing solutions.
     So today, potential approaches include electrified 
aircraft, alternative airframe designs, more efficient 
energies, and, obviously, alternative jet fuels. Some companies 
are investing in one or more of these options. Europe, for 
example, is betting on hydrogen as a cleaner aviation solution.
     So how do these approaches compare, how do they 
contribute, what are the potential impacts on noise, air 
quality, cost, infrastructure, reliability, and safety? It's 
important we get these priorities right because, unlike cars or 
cell phones, changes to aircraft and aviation require very long 
timelines to develop, test, demonstrate, certify, and scale 
throughout the system.
     A 2016 National Academies report on ``Commercial Aircraft 
Propulsion and Energy Systems Research, Reducing Global Carbon 
Emissions'' recommended priorities in aircraft-propulsion 
integration, improvements in gas turbine engines, development 
of turboelectric propulsion systems, and advances in 
sustainable alternative jet fuels. So where does that research 
stand today? What more needs to be done?
     So bottom line, today, we need the cold, hard facts on the 
strengths, limitations, feasibility, and timelines of the 
pathways to sustainable aviation. In short, we need smart and 
strategic R&D. And sustainable aviation is not only essential 
for our climate; it's a competitive advantage and a cooperative 
opportunity. And given the devastating impacts of the pandemic 
to the aircraft industry, it's more important than ever that we 
build back better.
     [The prepared statement of Chairman Beyer follows:]

    Good morning, and welcome to our distinguished witnesses. 
Thank you for being here.
    I also want to welcome our new and returning Subcommittee 
Members to our first Space and Aeronautics hearing of the 117th 
Congress.
    These are exciting times. From returning humans to the Moon 
in preparation for Mars to advancing scientific discovery and 
transforming the future of aviation, there is much that lies 
ahead of us. I look forward to working with you and Ranking 
Member Babin on supporting a strong and bright future for 
America's space and aeronautics programs.
    Today we're considering the future of aviation and how we 
can ensure that the U.S. remains the leader for next generation 
aircraft and what R&D it will take to get us there.
    With the climate crisis and as countries move to create 
parameters for permissible aircraft--like Norway determining 
that all short-haul flights will be entirely electric by 2040--
being a participant in the global marketplace of the future 
will require sustainable aviation.
    That means U.S. aviation won't have a competitive future 
without addressing climate impacts.
    Currently, aviation contributes about 2 1/2 percent to 
global CO2 emissions. In the U.S., transportation is 
the most greenhouse gas intensive sector and in 2018 aviation 
accounted for 5 percent of all U.S. emissions.
    Pre-pandemic global air travel was growing at average 
annual rates of 3-5 percent and is expected to rapidly return 
as we get the pandemic under control.
    It should come as no surprise that aviation's global 
CO2 emissions increased from 710 million tons in 
2013 to 905 million tons in 2018, with a projected tripling by 
2050.
    And that's just looking at CO2.
    According to the United Nations Intergovernmental Panel on 
Climate Change, aviation's total climate change impact could be 
from two to four times that of its past CO2 
emissions alone.
    To its credit, the aviation industry has taken consistent 
steps to improve aircraft efficiencies, in part to reduce fuel 
costs. Aircraft engines are 70-80 percent more efficient today 
than the turbojet aircraft of the 1950s, and efficiencies are 
expected to continue at 1-2 percent annually.
    But on their own, these improvements, while important, are 
not sufficient to meet aviation's future challenge.
    In 2009, the industry adopted goals to reduce aviation's 
carbon emissions by 50 percent of 2005 levels by 2050.
    Meeting even modest sustainability goals will require new 
technologies, increased efficiencies, and cleaner sources of 
energy. Federal government R&D is essential for testing, 
demonstrating, and maturing solutions.
    Today, potential approaches include electrified aircraft, 
alternative airframe designs, more efficient engines, and 
alternative jet fuels. Some companies are investing in one or 
more of these options. Europe is betting on hydrogen as a 
cleaner aviation solution.
    How do these approaches compare and how would they 
contribute to meeting aviation's climate challenge? What are 
their potential impacts on noise, air quality, cost, 
infrastructure, and reliability and safety?
    The R&D opportunities are many, but it's important we get 
the priorities right.
    Because unlike cars or cell phones, changes to aircraft and 
aviation require long timelines to develop, test, demonstrate, 
certify, and scale throughout the system.
    A 2016 National Academies report on ``Commercial Aircraft 
Propulsion and Energy Systems Research, Reducing Global Carbon 
Emissions'' recommended priorities in aircraft-propulsion 
integration; improvements in gas turbine engines; development 
of turboelectric propulsion systems; and advances in 
sustainable alternative jet fuels.
    Where does that research stand today? What more needs to be 
done?
    Bottom line: we need the cold, hard facts on the strengths, 
limitations, feasibility, and timelines of the pathways to 
sustainable aviation.
    In short, we need smart and strategic R&D.
    Sustainable aviation is not only essential for our climate, 
it's a competitive advantage and a cooperative opportunity. And 
given the devasting impacts of the pandemic to the industry, 
it's more important than ever that we build back better.
    Thank you and I look forward to our witnesses' testimony.

     Chairman Beyer. So thank you. I look forward to our 
witness testimonies. And let me--I recognize the Ranking Member 
of the Space Subcommittee, Dr. Brian Babin.
     Mr. Perlmutter. I think he decided to abandon us.
     Chairman Beyer. Well, you know, failing that, 
Representative Lucas, Ranking Member of the big Committee, I'd 
be happy to recognize you.
     Mr. Lucas. Well, I'll only pretend to be the esteemed 
doctor until he's able to return to us, but thank you, Mr. 
Chairman, for holding this hearing.
     Oklahoma is no stranger to being on the cutting edge of 
aviation. From the daring test pilots such as Tom Stafford and 
Gordo Cooper to other pioneering aviators like Jerrie Cobb, 
Oklahoma is well-represented by those who pushed the boundaries 
of flight. To this very day, Oklahoma's connection to aviation 
remains strong as the home of Tinker Air Force Base and FAA's 
(Federal Aviation Administration's) Mike Monroney Aviation 
Center.
     The aviation industry is a vital part of our Nation's 
economy. It contributes $1.8 trillion annually to the economy 
and is directly or indirectly responsible for more than 10 
million jobs.
     The Science Committee has jurisdiction over several areas 
of Federal aviation research, ranging from our drafting the 
research title of each FAA reauthorization to our oversight of 
NASA's (National Aeronautics and Space Administration's) 
aeronautics research mission directorate. The research carried 
out by NASA and FAA is then utilized by industry partners who 
integrate this knowledge into their existing fleets.
     Global air travel generates an estimated 2 to 3 percent of 
global greenhouse gas emissions. While we saw a reduction in 
the number of flights in the last year and a corresponding 
decrease in emissions, we know that these numbers will 
eventually rebound and increase. One estimate is that there 
will be roughly 10 billion passengers flying more than 12 
trillion miles annually by 2050.
     Today's hearing comes 2 weeks after we held a Full 
Committee hearing on the science of climate change. As that 
hearing made clear, we should focus on investing in research 
and development efforts, including R&D to give the aviation 
industry the tools they need to reduce emissions from flight. 
What we shouldn't do is allow ourselves to be subject to 
burdensome and unequal international mandates at the expense of 
our economic growth.
     The good news is that the aviation industry is already 
making progress in reducing emissions. Multiple domestic and 
international aircraft manufacturers have already made 
commitments to voluntarily reduce emissions. And we also will 
hear today about the research community and industry are 
teaming up to create innovative new ways to reduce emissions. 
For instance, we can help reduce emissions by researching new 
aircraft designs and the use of lighter materials to help 
reduce aircraft weight.
     Additionally, research is ongoing about the use of a 
variety of farm-produced commodities which could be blended 
into existing fuels and potentially reduce emissions.
     I thank our witnesses for being here today, and I look 
forward to a productive discussion about how we can support 
research and development efforts, which will assist our 
aviation industry in the years to come.
     Thank you, Mr. Chairman, and I yield back.
     [The prepared statement of Mr. Lucas follows:]

    Thank you for holding this hearing, Mr. Chairman.
    Oklahoma is no stranger to being on the cutting edge of 
aviation. From daring test pilots such as Tom Stafford and 
Gordo Cooper to other pioneering aviators like Jerrie Cobb, 
Oklahoma is well represented by those who pushed the boundaries 
of flight. To this very day, Oklahoma's connection to aviation 
remains strong as the home of Tinker Air Force Base and FAA's 
Michael Monroney Aeronautical Center.
    The aviation industry is a vital part of our nation's 
economy. It contributes $1.8 trillion annually to the economy 
and is directly or indirectly responsible for more than 10 
million jobs. The Science Committee has jurisdiction over 
several areas of federal aviation research, ranging from our 
drafting the research title of each FAA reauthorization to our 
oversight of NASA's aeronautics research mission directorate. 
The research carried out by NASA and FAA is then utilized by 
industry partners who integrate this knowledge into their 
existing fleets.
    Global air travel generates an estimated 2-3 percent of 
global greenhouse gas emissions. While we saw a reduction in 
the number of flights in the last year, and a corresponding 
decrease in emissions, we know that these numbers will 
eventually rebound and increase. One estimate is that there 
will be roughly 10 billion passengers flying more than 12 
trillion miles annually by 2050.
    Today's hearing comes two weeks after we held a full 
committee hearing on the science of climate change. As that 
hearing made clear, we should focus on investing in research 
and development efforts, including R&D to give the aviation 
industry the tools they need to reduce emissions from flight. 
What we shouldn't do is allow ourselves to be subject to 
burdensome and unequal international mandates at the expense of 
our economic growth.
    The good news is that the aviation industry is already 
making progress in reducing emissions. Multiple domestic and 
international aircraft manufacturers have already made 
commitments to voluntarily reducing emissions. We will also 
hear today about how the research community and industry are 
teaming up to create innovative new ways to reduce emissions.
    For instance, we can help reduce emissions by researching 
new aircraft designs and the use of lighter materials to help 
reduce aircraft weight. Additionally, research is ongoing about 
the use of a variety of farm-produced commodities which could 
be blended into existing fuels and potentially reduce 
emissions.
    I thank our witnesses for being here today and look forward 
to a productive discussion about we can support research and 
development efforts which will assist our aviation industry in 
the years to come.Thank you, Mr. Chairman, and I yield back.

     Chairman Beyer. Thank you, Mr. Big Chair Ranking Member.
     This is the first time I've done this, so I get things out 
of order. So what we also say this hearing will come to order. 
I brought my special gavel today. And without objection, the 
Chair is authorized to declare recess at any time.
     And I also want to note that the Committee is meeting 
virtually, so please keep your video feed on as long as you're 
present in the hearing. You're responsible for your own 
microphones. That is, our wonderful staff is not going to turn 
them on and off for you. And obviously, please keep them muted 
unless you're speaking. And if you have documents you wish to 
submit for the record, please email them to the Committee 
Clerk, whose email address was circulated prior to this 
hearing.
     So now let me yield the chair to my good friend, Dr. Brian 
Babin, who is the Ranking Member of this Space Subcommittee. 
Dr. Babin?
     Mr. Babin. Thank you, Mr. Chairman. Can you hear me?
     Chairman Beyer. Yes.
     Mr. Babin. Can you hear me?
     Chairman Beyer. Yes, perfectly, Brian. Thank you, yes.
     Mr. Babin. OK, good. It still shows that I'm muted on my 
computer. That's what was confusing me a while ago, and I 
apologize.
     But I guess before my opening statement I also want to 
just say thank you for what you said a while ago, Mr. Chairman. 
You and I have worked together for a number of years on this 
great Committee, and I really want to congratulate you on your 
chairmanship, and I'm looking forward to working with you, 
continuing to do that, and getting some great things done for 
our country and our space program. So with that I'll start my 
opening statement. Thank you, Mr. Chairman.
     If I had to hazard a guess, most of our constituents fly 
budget airlines, not business class, and certainly not private 
aviation. Roughly 1/3 of the cost of a flight comes from fuel, 
and nearly half for budget airlines. The less fuel you burn, 
the less emissions you produce. Passengers want cheap tickets, 
and we all want less emissions. Both lead to the same free-
market forces that drive airlines to purchase efficient 
aircraft.
     This incentivizes aircraft manufacturers to produce more 
efficient aircraft and engines with little government intrusion 
into the market. Flights today are 50 percent more efficient 
than they were back in 1990, and each new generation of 
aircraft is 15 to 25 percent more efficient than the last. 
Separately, our Nation's airline industry already committed to 
carbon-neutral growth by 2030, and Boeing pledged to deliver 
aircraft capable of flying on 100 percent biofuels by 2030 on 
their own.
     This isn't to say that there's not a role for the 
government to play in advancing aviation sustainability. The 
FAA conducts research to certify new technologies that are 
safe, and NASA develops high-risk, high-reward technologies 
that the private sector is willing--or unwilling or unable to 
undertake.
     But we should be mindful of government intrusion into the 
market. The U.S. and Europe are embroiled in a nearly decade-
long dispute over government aircraft subsidies. And last fall, 
the World Trade Organization (WTO) allowed Europe to implement 
over $4 billion in tariffs on U.S. products over a disagreement 
about the FAA and NASA research and development grants and 
subsidies. This followed a 2019 ruling by the World Trade 
Organization that allowed the United States to impose $7.5 
billion in tariffs on Europe over European Union loans to 
Airbus. Earlier this month, those tariffs were put on hold for 
a few months pending additional negotiations. And as we look 
toward supporting our Nation's aviation sector, we should 
maintain the principles that made us the world leader in 
aviation: free enterprise and free markets.
     Another thing we must consider is the impact on safety, 
which should be everyone's highest priority. Environmental 
research and development within FAA's RE&D (research, 
engineering, and development) account increased over 190 
percent from 2008 to 2021. Over that same time, the budget for 
safety research decreased.
     Unfortunately, we may be seeing the results of these 
policy decisions. In order to compete with the new Airbus 
A320neo, Boeing designed the 737 Max to be more fuel-efficient 
and produce less emissions. The existing 737 airframe was 
modified by adding larger and more efficient engines. Because 
of the larger size, the engines had to be moved forward and 
higher on the airframe to maintain ground clearance. Doing so 
altered the aircraft's aerodynamics and required a new 
maneuvering characteristic augmentation system, or MCAS, which 
we are familiar with over in Transportation. MCAS has caused 
the aircraft to pitch downwards in certain configurations and 
was featured prominently in the National Transportation Safety 
Board's Safety Recommendation Reports.
     Similarly, the Wall Street Journal published an article 
last Friday highlighting a recent incident involving an engine 
breaking apart over Denver. The article noted several other 
incidents of engine failures and engine cover damage over the 
last 5 years, one of which led to the first U.S. airline 
passenger fatality in nearly a decade. I'm not saying these 
accidents were caused by efforts to green aviation, but we 
should be reminded of Hoover Institute economist Dr. Thomas 
Sowell, who said ``there are no solutions, only tradeoffs.''
     As we discuss the benefits of sustainable aviation today, 
we should also discuss its costs, either at the potential 
expense of safety or to other areas of our economy. Upending 
existing infrastructure, promoting land-use change and 
monocrops, raising commodity and food prices, increasing 
transportation costs, increasing taxes, and the impact of 
diluting the value of retirees' savings to pay for all of it 
should all be reviewed very carefully and very critically.
     Green aviation not only requires a whole-of-government 
approach, but it also requires a whole-of-society approach. 
Luckily, the United States is the leader in aviation and 
science. Our industry and research communities are second to 
none. With FAA, NASA, DOE (Department of Energy), and other 
agencies providing fundamental basic research and industry-
leveraging, market-based incentives, I am sure that we can meet 
any challenge presented to us.
     And with that, I'll yield back, Mr. Chairman. Thank you.
     [The prepared statement of Mr. Babin follows:]

    If I had to hazard a guess, most of our constituents fly 
budget airlines, not business class, and certainly not private 
aviation. Roughly a third of the cost of a flight comes from 
fuel, and nearly half for budget airlines. The less fuel you 
burn, the less emissions you produce. Passengers want cheaper 
tickets, and we all want less emissions. Both lead to the same 
free-market forces that drive airlines to purchase efficient 
aircraft.
    This incentivizes aircraft manufacturers to produce more 
efficient aircraft and engines with little government intrusion 
into the market. Flights today are 50 percent more efficient 
than they were in 1990, and each new generation of aircraft is 
10-25 percent more efficient than the last. Separately, our 
nation's airline industry already committed to carbon neutral 
growth by 2030, and Boeing pledged to deliver aircraft capable 
of flying on 100 percent biofuels by 2030 on their own.
    This isn't to say that there's not a role for the 
government to play in advancing aviation sustainability. The 
FAA conducts research to certify new technologies are safe and 
NASA develops high-risk, high-reward technologies, that the 
private sector is unwilling or unable to undertake.
    But we should be mindful of government intrusion into the 
market. The US and Europe are embroiled in a nearly decade-long 
dispute over government aircraft subsidies. Just last fall the 
World Trade Organization allowed Europe to implement over $4 
billion in tariffs on US products as a disagreement over FAA 
and NASA research and development grants. This followed a 2019 
ruling by the WTO that allowed the US to impose $7.5 billion in 
tariffs on Europe over EU loans to Airbus. Earlier this month 
those tariffs were put on hold for a few months pending 
additional negotiations. As we look towards supporting our 
nation's aviation sector, we should maintain the principles 
that made us the world leader in aviation--free enterprise and 
free markets.
    Another thing we must consider is the impact on safety, 
which should be everyone's highest priority. Environmental R&D 
within FAA's RE&D account increased over 190 percent from 2008 
to 2021. Over that same time the budget for safety research 
decreased.
    Unfortunately, we may be seeing the results of these policy 
decisions. In order to compete with the new Airbus A320neo, 
Boeing designed the 737 Max to be more fuel efficient and 
produce less emissions. The existing 737 airframe was modified 
by adding larger, more efficient engines. Because of the larger 
size, the engines had to be moved forward and higher on the 
airframe to maintain ground clearance. Doing so altered the 
aircraft's aerodynamics and required a new Maneuvering 
Characteristic Augmentation System, or MCAS. MCAS caused the 
aircraft to pitch downwards in certain configurations and was 
featured prominently in the NTSB's Safety Recommendation 
Reports. Similarly, the Wall Street Journal published an 
article last Friday highlighting a recent incident involving an 
engine breaking apart over Denver. The article noted several 
other incidents of engine failures and engine cover damage over 
the last five years, one of which led to the first U.S. airline 
passenger fatality in nearly a decade.
    I am not saying these accidents were caused by efforts to 
green aviation, but we should be reminded of Hoover Institute 
economist Dr. Thomas Sowell, who said ``there are no solutions, 
only trade-offs.'' As we discuss the benefits of sustainable 
aviation today, we should also discuss its costs, either at the 
potential expense of safety or to other areas of our economy. 
Upending existing infrastructure, promoting land-use change and 
monocrops, raising commodity and food prices, increasing 
transportation costs, increasing taxes, and the impact of 
diluting the value of retirees' savings to pay for all of it 
should all be reviewed critically.
    Green aviation not only requires a whole of government 
approach, it requires a whole of society approach. Luckily, the 
United States is the leader in aviation and science. Our 
industry and research communities are second-to-none. With FAA, 
NASA, DOE, and other agencies providing fundamental basic 
research, and industry leveraging market- based incentives, I 
am sure we meet any challenge presented to us.

     Chairman Beyer. All right. Thank you, Dr. Babin, very 
much.
     At this time I'd like to--well, before doing that, any 
other Member who would like to have an opening statement--
please--in the record, just please submit it in writing and we 
will include it.
     [The prepared statement of Chairwoman Johnson follows:]

    Good morning. I would like to begin by welcoming Chairman 
Beyer as the new Chairman of the Space and Aeronautics 
Subcommittee for the 117th Congress. I also want to welcome 
back Ranking Member Babin and all the Subcommittee Members. I 
am excited about the future of space and aeronautics and I look 
forward to working with you.
    The climate crisis is affecting nearly every aspect of our 
existence-weather, shelter, commerce, natural resources, 
energy, environment, and so much more.
    Research is imperative to understanding and mitigating 
climate change impacts, and addressing climate change is an 
important priority for our Committee.
    We held our first Full Committee climate hearing last week. 
And I'm pleased, Chairman Beyer, that today's hearing will 
examine aviation's role in reducing carbon emissions.
    Aviation is one of the few industries that has provided a 
positive trade balance. Pre-pandemic, U.S. civil aviation 
accounts for about 5 percent of gross domestic product, 
including both direct and catalytic sectors, $1.8 trillion in 
economic activity, and nearly 11 million jobs, including 
285,000 jobs in my own state of Texas.
    Even closer to home, Dallas is a hub for domestic and 
international air travel, and I believe that developing 
innovations to enable sustainable aviation is the industry's 
future.
    Aviation's infrastructure is immense and changes throughout 
the system take time, in part, due to the need to meet high 
safety requirements for passenger air travel.
    That's why research and development is essential for 
advancing sustainable aviation technologies.
    However, the improvements that will lead to cleaner and 
more efficient aviation can't happen on their own. The people 
and workforce that bring the ideas from the labs and into the 
engines and aircraft are instrumental. To that end, our 
investments in R&D are also investments in sustaining our human 
capital leadership in aviation going forward.
    I thank our witnesses for being here and I look forward to 
your testimony.
    Thank you, and I yield back.

     Chairman Beyer. At this time I'd like to introduce our 
witnesses. Our first witness is Dr. Karen Thole or Thole. 
Karen, you can fix it for me. Dr. Thole is the Department Head 
and Distinguished Professor of the Department of Mechanical 
Engineering at Pennsylvania State University. She co-chaired 
the 2016 National Academies' study ``Commercial Aircraft 
Propulsion and Energy Systems: Reducing Global Carbon 
Emissions.'' Her area of expertise is gas turbine heat transfer 
and using additive manufacturing to develop innovative cooling 
technologies. At Penn State she established two research 
laboratories that were both awarded the distinction of being 
Centers of Excellence in aerodynamics and heat transfer. She 
received--Dr. Thole received a bachelor of science degree and a 
master of science degree in mechanical engineering at the 
University of Illinois and her doctorate in mechanical 
engineering at the University of Texas Austin, so she's a 
Longhorn. So, Dr. Thole, welcome.
     Our second witness is Dr. John--R. John Hansman, Jr., a T. 
Wilson Professional of Aeronautics and Astronaut--Astronautics 
at the Massachusetts Institute of Technology. Dr. Hansman is 
also the Director of the MIT (Massachusetts Institute of 
Technology) International Center for Air Transportation, and he 
additionally serves as the Chair of the FAA Research and 
Development Advisory Committee and Co-Director of the FAA 
Center of Excellence for Alternative Jet Fuels and Environment, 
also known as ASCENT. Dr. Hansman's research focuses on 
applying information technology on operational aerospace 
systems. He received his bachelor of science degree in physics 
from Cornell University and a master of science and a doctorate 
in some little college in Massachusetts called MIT. So welcome, 
Dr. Hansman.
     Our third witness is Mr. Steve Csonka, the Executive 
Director of the Commercial Aviation's Alternative Fuels 
Initiative, CAAFI, a public-private partnership working on the 
development and commercialization of sustainable aviation fuels 
(SAF). Previously, Mr. Csonka had positions--held positions at 
GE Aircraft Engines, American Airlines, and GE Aviation where 
he focused on a range of aircraft lifecycle activities, 
including conceptual analysis, design, manufacture, test, and 
certification, among other areas. He received his bachelor of 
science degree in aerospace engineering from Parks College of 
St. Louis University and a master of science degree in 
aerospace engineering from the University of Cincinnati. So 
welcome, Mr. Csonka.
     So as our witnesses should know, you have five minutes 
each for your spoken testimony. Your written testimony has--
will be included in the record for the hearing, and I think 
most of us received your written testimony ahead of time, which 
I spent a long time with last night, fascinating. And when we--
you have completed all three spoken testimonies, we will begin 
with questions, so each Member will have five minutes to 
question the panel. So let's start with Dr. Thole. Dr. Thole, 
the floor and the microphone are yours.

                TESTIMONY OF DR. KAREN A. THOLE,

          DEPARTMENT HEAD AND DISTINGUISHED PROFESSOR,

             DEPARTMENT OF MECHANICAL ENGINEERING,

                 PENNSYLVANIA STATE UNIVERSITY

     Dr. Thole. Chairman Beyer, Ranking Member Babin, and 
distinguished Members of the Subcommittee, thank you for this 
opportunity to testify. As was stated, my name is Karen Thole, 
and the opinions expressed in my testimony today are that of my 
own and do not represent views of the Pennsylvania State 
University.
     Throughout my testimony, I will use information from the 
2016 National Academies' low carbon aviation study, which was 
commissioned by NASA and which I cochaired. Resulting from the 
2016 Academies report, the Chief Technology Officers of seven 
of the world's major aviation manufacturers jointly signed an 
agreement on a unified commitment to reduce commercial aviation 
emissions by half in 2050 relative to the levels in 2005.
     As Chairman Beyer has already mentioned, commercial 
aviation is responsible for between 2 and 2.5 percent of the 
total global CO2 emissions, of which 90 percent 
comes from large single-aisle and twin-aisle aircraft. 
Resulting from the 2016 Academy report, four research 
approaches for sustainable aviation were recommended: 1, 
advances in aircraft propulsion integration; 2, improvements in 
gas turbine engines; 3, development of turboelectric propulsion 
systems; and 4, advances in sustainable alternative jet fuels.
     This past year, hydrogen has entered into the discussion 
for aviation and is being explored by U.S. industries and 
aggressively by the European Union. In my opinion, with strong 
support we can develop solutions starting with the use of 
sustainable alternative jet fuels progressing to turboelectric 
and hybrid electric propulsion systems followed by the use of 
hydrogen either for fuel cells or for producing synthetic 
fuels.
     In the near term, we should promote sustainable 
alternative jet fuels. These fuels already exist as a drop-in 
option certified for use in jet engines at up to 50 percent 
blend with kerosene, and with further development it may be 
possible to achieve 100 percent. Given our third panelist has 
expertise in this area, he can further elaborate.
     In agreement with the 2016 study, I believe the United 
States needs to invest in the development of new aircraft 
architectures that take full advantage and the potential 
benefits of turboelectrics and of hybrid electric propulsion 
systems. The Committee strongly recommended the development of 
turboelectric systems, which differ from all-electric and 
hybrid concepts because no additional batteries or fuel cells 
are required, both of which can add significant weight.
     Turboelectric propulsion systems do require high power 
generators, cabling, and power electronics. Unlike other 
propulsion systems--electric propulsion systems, they do make 
beneficial concepts such as distributed propulsion more 
feasible. Some hybrid electric propulsion systems may also be 
feasible in my opinion.
     Key to improvements, however, for both turboelectrics and 
hybrid electrics are continued improvements in both propulsive 
efficiency and in thermal efficiency of gas turbine engines, 
which is likely to produce the power by--the power for both. 
Many efficiency improvements can also be synergistic with the 
needs of our military's propulsion needs.
     Today's engines have propulsive efficiencies of up to 70 
percent and thermal efficiencies of up to 55 percent, both of 
which still have the potential to increase, which dramatically 
reduce fuel requirements. To improve propulsive efficiency, 
research is needed to make both evolutionary improvements, as--
such as reducing fan pressure ratios and revolutionary 
improvements such as going beyond the traditional tube-and-wing 
platform.
     To support improved thermal efficiencies, we need to 
shrink engine cores while meeting or even increasing thermal 
efficiencies. Added to those recommendations in 2016, research 
is needed on developing high-temperature materials and 
coatings, as well as for 3-D metal printing. We need to be able 
to integrate reliable sensors to support high-fidelity 
simulation tools to reduce both development, time, and risks.
     Despite the ongoing discussions related to hydrogen as an 
aviation fuel, there are significant techno-economic and safety 
concerns. However, the United States needs to develop a long-
term strategy on hydrogen for aviation to make sure we do not 
lag our foreign competitors. In that regard, Mr. Chairman, 
please make no mistake we are in a race particularly with China 
in the aviation industry, and whoever wins will have an 
economic and possibly military advantage that will result from 
a talented workforce. We need to invest now to make sure the 
United States is well-positioned to develop sustainable 
solutions and maintain our leadership in the aviation industry 
through strong partnerships between Federal agencies, 
industries, and universities.
     Thank you.
     [The prepared statement of Dr. Thole follows:]
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     Chairman Beyer. Thank you. Thank you, Dr. Thole, very 
much. It will provoke many questions, which is good.
     I now recommend--or recognize MIT's Dr. John Hansman.

             TESTIMONY OF DR. R. JOHN HANSMAN JR.,

       T. WILSON PROFESSOR OF AERONAUTICS & ASTRONAUTICS

             AND DIRECTOR, MIT INTERNATIONAL CENTER

                    FOR AIR TRANSPORTATION,

             MASSACHUSETTS INSTITUTE OF TECHNOLOGY;

              CHAIR, FAA RESEARCH AND DEVELOPMENT

                  ADVISORY COMMITTEE (REDAC);

             CO-DIRECTOR, FAA CENTER OF EXCELLENCE

       FOR ALTERNATIVE JET FUELS AND ENVIRONMENT (ASCENT)

     Dr. Hansman. Chairman Beyer, Ranking Member Babin, and 
Members of the Committee, thanks for the opportunity to talk 
about this important topic today.
     As you guys have already noted, the impact of aviation on 
the environment is an increasing concern worldwide in that the 
aviation community is really highly motivated both in market 
reasons and international strategic reasons to improve its 
sustainability. There's lots of things we can talk about. I'm 
going to briefly discuss a few key areas today.
     First, you know, the first thing that motivates 
understanding how we mitigate aviation environmental impacts is 
understanding the mechanisms of impact, and modeling the 
impacts is sort of a full system level. So you mentioned 
greenhouse gas emissions. There was other impacts that we need 
to understand, for example, contrails. But we have to look at 
it in terms of the system level. You have to think about all--
how we fly the airplanes, where we fly them. As you mentioned, 
aviation contributes about 2 to 3 percent of the greenhouse gas 
emissions, but they are injected high in the atmosphere where 
they have a higher impact, so you have to think about where you 
fly, what the markets are around the world. These things are 
not necessarily symmetric. And you have to think about it in 
terms of the lifecycle. So, you know, it may make sense to use, 
for example, hydrogen as a fuel but only if you get it from a 
sustainable source.
     The other thing I just mentioned as a fundamentalist that 
we need to think about aviation as a potential platform to 
monitor climate change mechanisms and risks both in terms of 
how we operate the airplanes but also as aviation platforms. 
And when you think about mitigations, I'm just going to 
separate them into three sort of timeframes. In the near term 
in the next 5 to 10 years we're going to have to figure out how 
to use the airplanes we have today more efficiently. You can't 
quickly--you know, even if you had a new technology, airplane 
technology, it's going to take 20 or 30 years to migrate into 
the fleet.
     So given that you have to use the existing airplanes, 
there's two sort of approaches that--one of them has already 
been mentioned. So drop-in sustainable aviation fuels are 
clearly important and can be used in our existing airplanes. 
Right now, we're limited to blends of less than 50 percent 
sustainable aviation fuels, so there's a need to get to 100 
percent so we can fully use that. The other thing you need to 
think about--again, this is a lifecycle and a system-level 
impact--is where do those fuels come from and do you have 
sustainable aviation fuel pathways that make sense from an 
overall societal standpoint?
     The second thing you can do in the near term is to fly the 
airplanes more efficiently. From a greenhouse gas emissions 
standpoint, most of the fuel is burned [inaudible] altitude 
improves or oceanic flight, so there are things that we can do 
to operate the airplanes more efficiently at altitude in terms 
of improving air traffic control, using the technologies of, 
for example, space-based surveillance to allow more direct 
routings to allow airplanes to be at their optimal speeds and 
altitudes.
     We can also slow down a little bit. It turns out we burn 
probably a little bit more fuel than we need to from the 
speeds. In the terminal area, arriving and departing, the main 
opportunity for efficiency is going to be not only efficiency 
but local air quality and noise.
     In the midterm we can think about new airplanes. And 
again, this is going to be 10 to 20 years out there. And the 
main thing we can do in R&D is to enable and de-risk new 
technologies and new configurations. NASA has shown in some 
other studies, the N+3 studies, for example, that there are 
potential for 50 to 70 percent improvement in fuel efficiency 
from new configurations, but these are too risky for industry 
to take on by themselves. [inaudible] been mentioned, I would 
say that the battery-based systems are going to be probably 
limited for short-range operations, but either hybrid systems 
or fuel cells may have some potential.
     Also in the midterm we need to think about how we scale up 
the sustainable aviation fuels to the full level. In the far 
term hydrogen might be an option. It's appealing because you 
don't have to basically put the carbon back into the fuel to 
make a synthetic electro fuel, but it's a tough problem. It's 
got a couple key areas. One is really the safety issue, so, you 
know, as we know from the images of the Hindenburg that, you 
know, hydrogen is explosive. You have to think about how do you 
protect a hydrogen airplane from, for example, a lightning 
strike and how do you inert the fuel? [inaudible] 
infrastructure of hydrogen. We have--there are design issues 
because of the way hydrogen is held and stored. And we also 
have to think about the indirect impacts of something like 
hydrogen. Hydrogen puts out more water vapor, so does that 
create, for example, more contrails where the contrails may 
actually have a knock-on effect.
     So there's a lot we can do, and I'm looking forward to the 
discussion.
     [The prepared statement of Dr. Hansman follows:]
[GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]
    
     Chairman Beyer. Dr. Hansman, thank you very much.
     And I now recognize Mr. Steve Csonka for your five minute 
testimony.

                 TESTIMONY OF MR. STEVE CSONKA,

             EXECUTIVE DIRECTOR, COMMERCIAL AVIATION

              ALTERNATIVE FUELS INITIATIVE (CAAFI)

     Mr. Csonka. Thank you, Mr. Chairman. Esteemed Members of 
the Committee and Subcommittee, thank you for your general 
interest in aviation sustainability and your specific interest 
in sustainable aviation fuels, or SAF, and that's the 
nomenclature I'll use for the rest of this discussion with SAF 
being the sole focus of my remarks today.
     I'm going to dive right into the three themes that are 
representative of questions extended to me by Committee staff 
with respect to SAF.
     First, big question, how does SAF fit into the larger 
landscape of approaches and pathways to enable more sustainable 
aviation? I believe SAF represents the only viable approach for 
achieving any near-term, substantive, in-sector net carbon 
reduction. Further out in time, we might see more radical tech 
incorporated at rates that offset traffic growth driven by the 
aviation value paradigm. In the meantime, SAF scaling and usage 
can deliver a direct and proportional reduction in net carbon. 
SAF incorporation has no impact on any other parallel 
approaches to enable or improve sustainability via advancements 
in technology, operations, or infrastructure.
     Second question, what are the opportunities and challenges 
of SAF for reducing the aviation sector's carbon emissions? The 
opportunities include the fact that SAF is a drop-in fuel. It 
obviates the need for significant investments outside of the 
fuel production itself. Two, SAF are not hypothetical. We 
started using them commercially 5 years ago. Three, SAF are 
proven to lower net carbon emissions. Four, SAF will be free of 
sulfur and likely have lower levels of certain hydrocarbons 
responsible for tailpipe soot and criteria pollutants that 
affect air quality. Five, SAF can be produced from a very wide 
range of processes and feedstocks which recycle carbon from our 
biosphere or feedstocks from 24/7 waste streams of various 
human and circular economy industrial activities.
     On the other side of the spectrum, the challenges include 
SAF being a very nascent industry. We're just getting started, 
and every new facility is high on the cost curve. Given the 
nascent state, SAF production generally cannot compete with the 
cost of PETROJET at the current range of oil prices. The carbon 
reduction afforded by SAF is not yet broadly monetizable, and 
as a result of the inability of free-market economics to change 
this paradigm, policy is likely needed to affect change.
     Industrial system cost reductions are typically achieved 
through the continued introduction of new technology, 
utilization of lower-cost inputs, and via learning curve 
improvements and tech and supply chain scaleup. However, none 
of these can be achieved without initiating the first steps of 
expansion, again, likely only available through policy support 
and regulation.
     Third and finally, what research could be undertaken or 
accelerated by NASA and FAA to support SAF development and 
utilization to further reduce aviation environmental impacts? 
NASA has expertise in measurement analysis and characterization 
of the atmosphere and atmospheric impacts of aviation emissions 
constituents. Questions associated with SAF in these areas 
include, one, quantifying the impact of different hydrocarbon 
molecules in jet fuel, the resulting combustion constituents, 
and their contribution to greenhouse gas agents. Two, further 
work can be done on physical emissions measurements both on 
ground test and flying aloft using different formulations of 
SAF with varying chemistry. Three, work can be done to address 
the impacts and benefits of elimination of certain hydrocarbon 
compounds known to have difficulty in achieving full combustion 
and responsible for soot, PM (particulate matter), HAPS 
(hazardous air pollutants), and other things we care about.
     On the FAA side, they've been using several impactful 
programs to advance the modeling and understanding of ways to 
expedite SAF development and use, including the programs of 
ASCENT, CLEEN (Continuous Lower Energy, Emissions and Noise), 
and CAAFI. R&D associated with SAF in these areas includes, 
one, continuing to make progress on the modeling, referee test 
models, small-quantity fuel screening, clearinghouse assistance 
to continue to reduce the cost and time associated with 
industry qualification of additional SAF pathways. Using such 
models and knowledge development will help us move more quickly 
in the direction of higher allowable SAF blends or 100 percent 
SAF formulations that have been brought up a couple of times.
     Second, removing supply chain barriers through analysis, 
tool development, and facilitating broader industry engagement 
and collaboration. All of these efforts by NASA and FAA should 
foster more interest on the part of commercialization entities 
to consider SAF production by creating a better realizable 
value proposition than exists today.
     In summary, the opportunity for SAF is great. While the 
challenges for scaling remain abundant, the research 
capabilities of NASA and FAA and other agency partners are 
critical to enabling SAF maturation and improving aviation 
sustainability. Thank you for your attention, and I look 
forward to addressing your questions.
     [The prepared statement of Mr. Csonka follows:]
[GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]
    
     Chairman Beyer. Thank you, Mr. Csonka, very much.
     At this point I'd like to ask unanimous consent to include 
Congresswoman Julia Brownley of California on our Space 
Subcommittee for the purposes of this hearing. If there's no 
objection, Ms.--Julia, yesterday, by the way, gave a very 
passionate argument for SAF at a Ways and Means Committee 
Member hearing, so great to have you with us, Julia.
     Ms. Brownley. Thank you.
     Chairman Beyer. Let me begin by asking Dr. Thole. You--in 
fact, all three of you have talked about hydrogen and the 
difficulty with it, the safety, problems to be overcome. Why 
has Europe chosen hydrogen and charged forward with that when 
we've been so reluctant?
     Dr. Thole. That's a great question, Chairman Beyer. You 
know, I mean, I think that they are being pushed by Airbus, 
which is one of their manufacturers, and they have made a 
decision to go that direction. There are a lot of advantages of 
hydrogen. You know, the fuel--or the energy density content of 
hydrogen is superior, and it can be made using green 
electricity, although currently it's not, so there are a lot of 
advantages there. And I think Europe sees the advantages, and 
they are putting a lot of money into it.
     And so I can't really explain their rationale for doing 
this, but, you know, as I see it, I think there are a lot of 
challenges. There are a lot of challenges just from considering 
that the amount of space that hydrogen would require on an 
aircraft is three times larger than what we would--what we 
currently have. We have to store liquid hydrogen at minus 450 
degrees Fahrenheit, which is a challenge in itself. And----
     Chairman Beyer. And I guess all the opponents would have 
to do is say ``Hindenburg.''
     Dr. Thole. And Hindenburg, correct.
     Chairman Beyer. Dr. Thole, you--let me pivot because you 
talked a lot about design disruption. You know, the larger 
picture, moving away from SAF, and you totally confused me by 
talking about fan pressure ratio and nacelles and revolutionary 
improvements in traditional tube-and-wing platform and boundary 
layer ingestion configurations. Can you simplify that for us 
humble Members of Congress----
     Dr. Thole. Yes, so----
     Chairman Beyer. And the potential there?
     Dr. Thole. So if we want to improve the efficiency of our 
power generation on our aircraft, there's a big advantage to 
reducing fan pressure ratio and to have high bypass ratio 
engines. And so, you know, when you fly on an aircraft, right, 
and you look at the really big engines, you--they're huge. And 
right now, we're limited with the traditional tube-and-wing and 
landing gear constraints such that the nacelle can't grow any 
larger. And as the nacelle grows, in addition, you have 
additional weight and you have additional drag. So really our 
bypass ratios of our engines are somewhat limited at this 
point.
     The other alternative is to shrink the core engine, right, 
so we can shrink the core of the turbine, which allows more 
flow area, or perhaps we can develop a new overall aircraft 
propulsion integration system such that we could have 
distributed propulsion. And that's another way to do it. And 
that's what--and a disruption would be required for that.
     Chairman Beyer. Thank you. You know, I've long had an 
interest in this, and Senator Cardin and I have introduced 
legislation in the last Congress and will again, the Cleaner, 
Quieter Airplanes Act, to bolster the R&D we need for 
competitive future aviation sector. And this testimony is 
exactly what we need. And this is not accidental because I live 
about two miles from a national airport, so it's our number-one 
constituent complaint.
     Dr. Hansman, Norway is on track for full electrification 
for short-haul stuff by 2040. Do you see that electrification 
being--can we do that for short-haul? Should we be--where are 
we on electrification perspective?
     Dr. Hansman. So if you say--if by electrification you mean 
full battery, it's really going to be short-haul, but the 
problem that we have with airplanes is that airplanes have to 
carry the battery, so the figure of merit that we think about 
is something we call specific energy, the amount of energy you 
can get per unit pound. And basically the battery technology 
has been improving, driven by the automobile interest, but, you 
know, we're sort of getting to the point where it's much 
harder, and once we get to the point that it's really not an 
issue for cars, it's going to be hard to get that specific 
energy up high enough that it really makes big airplanes 
practical, particularly on even medium hauls. So I think it's a 
desirable goal, but I think it's going to be tough to do 
anything practical, right, other than relatively very short-
range airplanes at a sort of limited scale.
     Chairman Beyer. OK, great. Thank you. My time is almost 
up, so let me yield now to our Ranking Member Dr. Babin if 
Brian is here.
     Mr. Babin. I am here. Can you hear me?
     Chairman Beyer. Yes, good, good. I can hear you, and 
charge. The floor is yours.
     Mr. Babin. OK. All right. Thank you very, very much.
     First off, I really appreciate the witnesses being here 
today. Dr. Hansman, the WTO recently ruled that Europe was 
allowed to implement $4 billion in tariffs against the United 
States, including aircraft tractors, ag products, and according 
to the World Trade Organization and the European complaint, 
this is based on NASA and FAA research and development 
subsidies, as well as tax breaks provided by the State of 
Washington. The U.S. has stated that it is now in compliance 
with the WTO order.
     Similarly, Europe claims that they are now fully compliant 
with the WTO ruling that allowed the U.S. to impose $7.5 
billion on European products despite the U.S. Trade 
Representative (USTR) arguing that they are not. NASA and FAA 
subsidies are small compared to the significant loan guarantees 
provided by European nations to Airbus.
     Given the fact that U.S. industry funds most of the $15 
billion annually spent on aviation research and development and 
that aviation is one of the largest sources of U.S. exports 
accounting for $148 billion in 2019 alone, is the small funding 
from NASA and the FAA worth the headache that it creates in 
terms of international trade and overall economic health of the 
U.S., Dr. Hansman?
     Chairman Beyer. Dr. Hansman, you're muted for the moment.
     Dr. Hansman. Sorry about that. Yes, I think there are some 
things that need to be funded by the either FAA or NASA. On the 
FAA side--and Steve talked about this a little bit--there's a 
need to fund those things that allow us to determine whether we 
can, for example, use synthetic or sustainable aviation fuels 
safely, so we have to think about the certification processes, 
so there's clearly a role there.
     There's a general role for NASA to be doing fundamental 
research that enables the knowledge and understanding of the 
mechanism, so there's clearly benefit to us. If we want to move 
the system to a more sustainable system, it won't be done by 
the industry alone.
     One of the things we did a few years ago, one of my 
students did a game theory analysis of, you know, what would 
incentivize improving the efficiency of airplanes? And it turns 
out it's very hard to take the risk and development time to do 
an airplane which would be fundamentally better. We know we can 
get 50 percent, 70 percent improvement in efficiency, OK, but 
this is too big a risk for an individual company to take on its 
own, so you need to do the underlying research to de-risk 
[inaudible] validation.
     Mr. Babin. OK. Well, thank you. Thank you very much.
     And, Dr. Thole, the market has already responded to 
sustainable aviation challenges, and companies continue to 
pivot operations. Flights today produce 50 percent less 
CO2 as the same flight did in 1990, and each new 
generation of aircraft leads to a 15 to 25 percent improvement 
in efficiency per passenger mile. The vast preponderance of the 
$15 billion a year spent on aviation efficiency research and 
development is funded by the private sector.
     In January of 2021 the Boeing Company, a leading 
manufacturer of commercial jets, announced that they will begin 
delivering commercial airplanes capable of flying on 100 
percent biofuel by the end of the decade. Airlines for America, 
the U.S. airline trade group, pledged to improve fuel economy 
by 1.5 percent a year, have carbon-neutral growth by 2020, and 
reduce CO2 emissions by 2050 relative to 2005 
levels.
     In August of 2020, the energy company Phillips 66 
announced plans to convert a facility in Rodeo, California, 
into the world's largest renewable fuels plant to support 
growing demands for these types of fuels. These impressive 
steps were taken by the U.S. private sector on their very own.
     How can we maintain this positive momentum and focus 
academia and industry efforts to solve this challenge? What 
high-risk, high-reward research should NASA support that 
industry is unable or uninterested in conducting? And what are 
the highest-priority safety research areas tied to sustainable 
aviation that the FAA should focus on?
     Dr. Thole. I think during my talk I actually outlined some 
of those, so, for example, if we focus particularly on thermal 
efficiencies and improving thermal efficiencies, I think there 
are a lot of areas that we can work on in particular looking at 
high-temperature materials. The other thing I'd want to point 
out is--Mr. Babin is that----
     Mr. Babin. Yes, ma'am.
     Dr. Thole [continuing]. The amount of time to develop 
these new solutions is too long right now. It is--it takes a 
long time to develop new solutions. Part of that is because of 
our manufacturing requirements. The United States is one of the 
few countries in the world that can actually cast turbine 
blades, but those turbine blades come at a cost in terms of 
time and in terms of money. And I think that we need to develop 
better ways to do faster manufacturing and evaluate innovative 
solutions faster.
     I think academia has a large role to play. We usually 
generally focus on lower technology readiness levels. We--for 
successful universities to work in this field, we work closely 
with industry. This is not a field that you fund through the 
FAA or NASA without a partnership between the Federal agency, 
the university, and industry. If you want to be successful in 
this field, you have to work with industry. And many of our 
universities do. So the dollars you spend in research are not 
going into esoteric studies. They're going into real studies.
     Chairman Beyer. Thank you, Dr. Thole. And thank you, Dr. 
Babin.
     Mr. Babin. Thank you. My time is up, and I yield back. 
Yes, sir, Mr. Chairman. My connectivity and my video have gone 
down the tubes here, and I don't know how much time I've spent 
or have any left at all, so I apologize.
     Chairman Beyer. That's all right. Thank you. Thank you, 
Dr. Babin.
     Let me now recognize Dr. Bera from California.
     Mr. Bera. Great. Great, thanks, Mr. Chairman. I may have--
I've got poor internet connection right now as well, so let me 
know if my audio is not great.
     A question for Dr. Thole. You talked a little bit about 
turbo-electric. If you can kind of expand on that compared to, 
you know, the battery-charged electric and then also the role 
of maybe hybrid technologies as, you know, I think about the 
car I bought 15 years ago, it was a hybrid vehicle, and the 
next car I'll buy will be all electric and, you know, what role 
hybrid technology may play. So, Dr. Thole.
     Dr. Thole. Yes, that's a great question. So there's a 
spectrum, right? There's the conventional gas turbines that 
operate today that--the next phase off of that is what I would 
call turbo-electrics. Turbo electrics do not require batteries 
or fuel cells, but they do require motor generators and all of 
the auxiliary equipment along with that, and what they enable 
is a concept that I talked about earlier which is distributed 
propulsion, and that can have significant benefits or at least 
we believe that it will have significant benefits in overall 
reducing the amount of fuel needs. So that's the turbo-electric 
class.
     Then if you go to the next class, you have the hybrid 
electric class of engines or potential solutions. There are 
also a range of those. Generally, those still require a gas 
turbine as the power plant most likely, but perhaps a battery 
would be also put into the overall propulsion system to provide 
some power maybe during takeoff when more power is needed and 
so forth. So there are a lot of different hybrid electric 
architectures that are feasible, and companies are looking at a 
range of different architectures right now to see the 
tradeoffs.
     And then finally, you go to the last step, and the last 
step is maybe addressing your next car needs, and that's fully 
electric. And as already was mentioned I think by some of the 
other Committee Members, fully electric is a big challenge for 
large aircraft. And if you remember, 90 percent of the CO2 
emissions is coming from the large aircraft. To scale batteries 
and fuel cells to large aircraft, we do not see a path for that 
right now because if you look at the current energy density of 
batteries and what it would take to get there to implement 
solutions by 2050, there--it would require a major--you know, a 
major discovery, and we don't project that right now.
     Mr. Bera. Maybe for----
     Dr. Thole. I hope that answers your question.
     Mr. Bera. It does. And maybe for all the witnesses, then 
how should we be thinking about this as Congress? What are the 
investments we should be making if we're looking at turbo-
electric as, you know, kind of the next step in reducing 
emissions and then, you know, the investments we might be 
thinking about making in hybrid electric if those are the more 
feasible paths and which of you----
     Dr. Thole. So the good news here is that both for turbo-
electrics and hybrid electrics, considering that the gas 
turbine is still going to be the power plant, any investments 
that can be made in that area to increase the thermal 
efficiency is going to be--is going to impact both, the success 
of both.
     In addition, the research that is needed to do the 
propulsion aircraft integration will also impact both areas, so 
I think that is a key area to invest in.
     Dr. Hansman. Yes, I think the--one way to think of it is 
that these new hybrid electric or turbo-electric have to buy 
their way onto the airplane, so they either have to bring in 
[inaudible] efficiencies. So when we think about efficiency, 
there's something called the Breguet range equation, so you 
either have to improve the aerodynamics or you improve the 
energy consumption of the engines. So one of the nice things 
about particularly hybrid is you don't have to have a big 
engine for takeoff. Today, we [inaudible] because they have to 
be [inaudible] get away with a smaller engine so it might be 
more efficient. So we need to think about all of those pathways 
from the entire airplane system and how does the propulsion 
system improve the entire [inaudible].
     Mr. Bera. Right. And, Mr. Csonka, if you want to add 
something?
     Chairman Beyer. Mr. Csonka, you're muted for the moment.
     Mr. Csonka. My apologies. I would say the hybrid 
propulsion actually is the--a good first step that puts us on a 
pathway to expanding opportunities for other technologies down 
the road. So when you start the development of the hardware 
required to handle more electric power on the aircraft, you 
open the door up to the potential hybrid, and you potentially 
open the door up to further--more fully electric aircraft that 
don't appear to be on the horizon right now. So that's clearly 
where it has been a focus of NASA work over the last couple 
years, and that clearly would suggest continued effort because 
it's a good first step for the--for pathways that lie in our 
future but still remain somewhat uncertain.
     Mr. Bera. Great. And I see I'm out of time. Mr. Chairman, 
I'll yield back.
     Chairman Beyer. OK. Thank you, Dr. Bera.
     I now recognize the--Mr. Posey from Florida, who will be 
followed by Mr. Perlmutter. Mr. Posey, the floor is yours. And 
you are muted.
     Mr. Posey. All right. Thank you very much, Mr. Chairman, 
for holding this hearing.
     I fully support the use of technologies to reduce 
emissions but have concerns for using feedstocks from crops and 
for the use of sustainable aviation fuels. My concern is that 
here we have, as in other parts of the world, we're devoting an 
increasing amount of land and resources to nonfood crops such 
as ethanol and now sustainable aviation fuels. You know, simply 
put, I think we should be growing crops for food and not for 
fuel.
     I recently was shown a white paper on sustainable aviation 
fuels from the International Council on Clean Transportation 
(ICCT) March of 2021, and the paper contained the following 
statement that I'd like to share with you. ``Increased demand 
for biofuels made from crops grown on dedicated cropland such 
as wheat or palm may displace commodity used for food and feed 
and increase the total agricultural area needed to meet the 
demand. The conversion of high-carbon stock forest, natural 
lands, and pastures to agriculture to meet the increased demand 
would release carbon from distributed biomass in soil and 
thereby would generate indirect emissions attributable to those 
biofuels.'' Those type of things often get forgotten and 
overlooked in the process.
     Mr. Csonka, in your testimony you state, ``Sustainable 
aviation fuels is not yet broadly monetizable and as a result 
of the inability of the free-market economics to change this 
paradigm, policy is likely needed to affect the change.'' Would 
one policy include a new renewable fuel standard (RFS) that 
would mandate volume production levels for sustainable aviation 
fuels, as happened with the ethanol fuels?
     Mr. Csonka. So let me address the first part of your 
question first. Yes, I understand ICC's position. I would 
suggest that that's somewhat of an alarmist position for an 
entity that's interested in other solutions for aviation. And 
what I would also say to you is that there are no crops being 
grown today for the production of SAF. It's fairly limited in 
supply.
     But I think the more interesting perspective, Mr. Posey, 
is that we--the aviation industry is very attuned to the 
criticisms associated with things that have happen in the past 
with respect to sustainability of feedstocks, and so it may 
surprise you that, as we look at the use of waste streams 
alone, municipal solid waste, forestry waste residues, wood 
processing waste, ag waste, waste food production oils, 
industrial off gases, and some amount of oil coming from crops 
that actually don't contribute to indirect land-use change can 
supply the full amount of fuel that we need for aviation. 
That's without dedicated energy crops. And the aviation 
industry is clearly focused where we need to be with respect to 
dedicated energy crops on ones that address sustainability.
     Secondly, with respect to the issue of policy, there are a 
lot of policy elements. Jet fuel actually does--is able to take 
advantage of RFS policy at it exists today, as well as tax 
treatment from a blenders tax credit perspective and things 
like the California low-carbon fuel standard (LCFS) and other 
mechanisms in other parts of the world. So the policy does 
exist.
     Would the production of SAF benefit from refinements to 
those policies? Absolutely, and there is a clear effort right 
now in Congress to address perhaps the first challenge that the 
industry sees as trying to level the playing field between the 
production of sustainable aviation fuel and the production of 
renewable diesel. I just added up the statistics this morning. 
There are 6.9 billion gallons of renewable diesel capacity 
being planned today. That technology is completely applicable 
to the production of SAF. The issue for--the reason why that 
production is targeted to diesel is that diesel enjoys benefits 
from that policy that SAF doesn't, and so a blenders tax credit 
specific to aviation fuel is being proposed for renewable 
diesel to level that playing field and see some of that 7 
billion gallons of fuel production come in the direction of 
sustainable aviation fuel.
     Mr. Posey. I see my time is expired, so I yield back. 
Thank you very much.
     Chairman Beyer. Thank you, Mr. Posey. And, Mr. Csonka, 
thank you for that very clear description of where those 
biofuels are coming from. It was a fairly effective response to 
Dr. Babin's opening statement, so thank you.
     I'd now like to recognize Mr. Perlmutter, who will be 
followed by Congresswoman Young Kim from California. So, Mr. 
Perlmutter, the floor is yours.
     Mr. Perlmutter. Thanks, Mr. Chair.
     And this is to Dr. Hansman and Mr. Csonka. And it's--I'm 
coming at it a little different angle here. I'll give you some 
background. I've been working on helicopter fuel systems for 
the last few years. We've seen in--there's--the fuel systems 
have been very fragile. If there have been accidents, the 
helicopter blows up, burns everybody. And we recognized this 
back during the Vietnam War, and the military changed their 
fuel systems. But commercially, we haven't really done much 
until just now. There have been some very well-known high-
publicity kinds of accidents where people were killed, and I 
guess what I'm saying is I just--it's hard--and, Dr. Thole, you 
were talking about this. How long, given the fleets that are 
out there, will it take to retool and revamp our engine systems 
for sustainability? I'm just trying to get new fuel systems in 
helicopters for safety purposes.
     So, Dr. Hansman, you started off talking about how long it 
will take to retool the entire fleet, so can you and Mr. Csonka 
and Dr. Thole expand on that for me, please?
     Dr. Hansman. Sure. So if--one way to think of it is if a 
brand-new technology came in, so if you go back and look 
historically at the jet engine, when the jet engine came in, it 
took 20 to 25 years for most of the airplanes flying to be jet 
aircraft. So in--another way to think of it is a commercial 
transport airplane is like a factory, so you're not going to 
throw away that factory. In fact, we don't have the capability 
to reproduce it. So even if you had the airplane ready to go 
and certified, it would take 20 years to propagate into the 
system.
     Now, let's step back and look at what it would take to get 
that airplane available. You need to design the airplane 
[inaudible] certification. One of the reasons--pardon me--why 
we are hesitant to go to new technologies is there's a huge 
risk in certification. If you go to a totally new technology, 
you don't necessarily know what will be--we need to do to make 
it fully safe, so it's easier to go to an existing--what Karen 
mentioned as a tube-and-wind configuration. We know how to do 
that. We know how to do the structures. We certainly know how 
to do the engines. So in order to stimulate a kind of 
revolution in--there are things we know we can do to make the 
airplanes much better, but nobody's going to take the risk. So 
this is really where we have to, as a collective, sort of go 
into that.
     So, now, the sustainable aviation fuels or the alternative 
fuels are a little bit easier because they can be used, as 
Steve said, as a drop-in, but you need to make sure that 
they're safe, so one of the challenges to go to 100 percent 
today is to make sure you haven't introduced a problem like 
leaking C-fuels or whatever that come due to the chemistry of 
the fuels. So we need, you know, to look at it as sort of a 
long-term process, all of the steps. We need to do what we can 
in the short term, but we need to invest to get the risk down 
so we can make the changes in the long term.
     Mr. Perlmutter. All right. So let me turn to Mr. Csonka 
for a second. So in my helicopter example, the military made 
changes 50 years ago. Commercially, we haven't made any 
changes, but now we're changing the fuel systems in new 
helicopters, but we still need to go retool the current fleets. 
So how would your drop-in fuels--I mean, what kinds of things 
do we have to worry about with your approach? And you're muted.
     Mr. Csonka. Yes. Yes, thanks. Thanks for the question. So 
the short answer is you have to take no changes with respect to 
the current or legacy or future fleet. The thing we have to 
keep in mind is that jet fuel is an extremely efficient, 
extremely safe fuel system. It's an energy system. And it's 
actually quite unparalleled. We've talked about hydrogen and 
other things, and there are tradeoffs associated with those. So 
jet fuel works.
     I think a lot of the changes that you're talking about are 
actually changes to the infrastructure of the vehicle itself, 
to delivery systems, fuel protection systems, et cetera. The 
beauty of a SAF approach is that all of that stuff can happen 
in parallel with the continued introduction of sustainable 
aviation fuel. And the reason that that can happen in parallel 
is because these molecules that we're producing synthetically, 
they are identical to the molecules that you find in jet fuel. 
There are no differences. We're not introducing something new. 
We're not introducing an ethanol molecule to a gasoline pool or 
a fatty acid methyl ester to a diesel pool. These are jet fuel 
molecules. So drop in, no change is required, it continues to 
enable the safety and efficiency in the system that we've come 
to know and love.
     Dr. Thole. If I could also say something unless the time 
is up.
     Chairman Beyer. Dr. Thole, go ahead, please.
     Dr. Thole. I--you know, I appreciate what Dr. Hansman said 
and, you know, he gave your timescale, but I also want to point 
to a counterexample. In 2016, Pratt & Whitney offered the gear 
turbofan. The gear turbofan reduces the amount of fuel needed 
by aircraft by about 100 gallons of fuel per hour, which is 
significant. Since 2016, there are already 10,000 engine orders 
for that engine. I can point to an equally successful program, 
the LEAP (Leading Edge Aviation Propulsion) program on the GE 
side, so the market is very hungry for this.
     While it will take some time to infiltrate the entire 
market, there are some success stories out there that are 
recent success stories that aircraft, as Chairman Beyer pointed 
out, you know, airlines are spending a lot of money on fuel, 
and so with fuel savings, they're going to buy these new 
engines, for example. Thank you.
     Mr. Perlmutter. Thank you very much. Thanks to our 
witnesses. I yield back.
     Chairman Beyer. Thank you, Mr. Perlmutter.
     I now recognize and welcome to the Science Committee and 
the Space Subcommittee Congresswoman Kim. The floor is yours.
     Ms. Kim. Thank you, Chairman Beyer. I'd like to go 
directly to the questions and to all our witnesses. I want to 
thank you for joining us. This is a very enlightening session 
for me.
     You know, NASA Aeronautics in southern California has 
played a leading role in the new X-Plane flight demonstrators, 
including electric propulsion and low boom supersonic flight 
demonstrators. As NASA prepares to launch a new transonic 
truss-braced wing flight demonstrator, how can a national 
subsonic demonstrator support and accelerate adoption of 
innovative new structures, composites, and propulsion systems 
for commercial aviation that can help increase efficiency and 
reduce emissions?
     Dr. Hansman. So let me start on that. I think that the 
role of the X-Planes is to demonstrate the technology and 
provide a basis to de-risk it, to allow the industry to 
actually move forward on that. So the--the X-Planes, for 
example, the transonic truss-braced wing, it's not just that 
transonic wing, it's the set of tests that would be done on the 
airplane that would provide the basis. It would allow you to 
both design and certify airplanes in the future. So, again, 
it's--NASA is not a manufacturer. They're not trying to push an 
idea. They should be trying to do the knowledge discovery, the 
engineering that would support us in actually investing and 
making a new airplane configuration going forward.
     So I think it's an important role because there is--you 
know, these things take a long time and they're expensive to do 
these big test airplanes and to do the engineering right and 
get the information.
     Dr. Thole. Yes, I think the only thing I would add is I 
think the role of NASA is really critical in making sure that 
this industry take risks and can demonstrate risky 
technologies. And I think that's where NASA, again, working 
with the industries and universities, can play a major role.
     Ms. Kim. All right. I'll go to next question, actually, 
Dr. Thole, since you talked in your testimony, you remind us 
that China and the E.U. are also racing to develop sustainable 
aviation solutions. So what actions are currently taking place 
to ensure that the U.S. is a leader in sustainable aviation 
technologies, and where are further investments needed to 
remain competitive?
     Dr. Thole. Yes, so I will start off by telling you a 
little story, and I put this in my testimonial. You know, I 
have been approached on numerous occasions by colleagues in 
China working at very highly respected universities asking for 
me to work with them directly. And I was opened and--you know, 
given an opportunity to have an open spigot of money on any 
research I wanted to do. And so, you know, I didn't take that 
money and--because I am fortunate to be--you know, be well-
funded by the--by industry as well as by FAA, NASA, and the 
Department of Energy. And so what's very key and what's 
important for us to develop a competitive workforce in this 
area and for us to keep that--to keep universities working in 
the space is to make sure that NASA Aeronautics is funded at a 
heavy rate, the FAA, the ASCENT program, which I also am a part 
of, you know, is funded at a high rate and particularly also 
the U.S. Department of Energy. So those--you know, those 
Federal funding agencies play a key role in making sure that, 
you know, we do maintain some--you know, some--we maintain 
leadership in the aviation industry.
     Ms. Kim. Thank you.
     Dr. Hansman. Yes, I think--sorry.
     Ms. Kim. Go ahead.
     Dr. Hansman. No, I was going to say I think we need to 
think about this strategically, so as Karen indicates, we need 
to make this as a strategic investment. [inaudible].
     Ms. Kim. Well, thank you. I wanted to put in the last 
thoughts and maybe if there was time I would like to hear your 
thoughts as well. You know, regarding the former U.S. Trade 
Representative Robert Lighthizer, he recently stated in an 
interview with Reuters that the U.S. and Europe should agree to 
cooperate in opposing any future hurtful subsidies used by 
China to buildup its commercial aircraft industry. And Mr. 
Lighthizer expressed frustration that current WTO rules would 
not prevent future subsidies by the European Union or China. So 
can you explain what can the U.S. do domestically to prevent 
predatory trade practices by other nations? Anyone can answer.
     Dr. Hansman. I think we're not experts on WTO policies.
     Dr. Thole. I would agree. We're not--I'm not an expert in 
this, so I----
     Ms. Kim. OK.
     Chairman Beyer. Congresswoman Kim, that may be a better 
question for the record, but----
     Ms. Kim. Yes.
     Chairman Beyer [continuing]. We'll get you to ask it as a 
Ways and Means Committee.
     Ms. Kim. I know my time is up, so if I can get an answer 
at a later time, that would be greatly appreciated. Thank you. 
I yield back.
     Chairman Beyer. Thank you very much.
     I now recognize Congresswoman Lofgren, Chairman of the 
House Administration Committee and many other things.
     Ms. Lofgren. Well, thanks very much, Mr. Chairman. This 
has been an interesting hearing.
     And as everyone probably knows, I represent San Jose, 
California, and the San Francisco Bay area is very much on 
board with sustainable aviation fuel. In fact, I believe or 
have been told that two California airports, San Francisco and 
LAX, actually dispense most of the sustainable aviation fuel in 
use today.
     Now, I think part of the reason for that is the California 
Air Resources Board addition of sustainable aviation fuels as 
an eligible credit generator to the carbon--low-carbon fuel 
standard program, but there are still, I think, a few other 
barriers. And I'm interested--I probably--Mr. Csonka, you might 
be best to answer this but maybe others have comments, too. 
What can be done to reduce the price of SAF's as it compares to 
conventional jet fuel? And would Federal policy creating 
something like the California credit be part of that price 
reduction?
     Mr. Csonka. Thank you very much. And yes, absolutely. 
First, I concur with your belief and statement that the 
introduction of fuel to California airports of SAF is directly 
attributable to the policy associated with low-carbon fuel 
standard. And so in the comments that I made earlier about the 
need for policy to change the paradigm that exists in the 
marketplace today with carbon reduction not being recognized or 
monetizable, the California low-carbon fuel standard clearly 
does that, and it's--it has absolutely been responsible for the 
introduction of that fuel.
     There are other likely policy mechanisms that can come 
into play. Those--and there have been several think tanks and 
other folks who have looked at additional mechanisms for 
different kinds of policy support that could be brought into 
play. I'll refer you to the Atlantic Council's look at policy 
applicable to sustainable aviation fuel. But yes, a national 
LCFS system could address issues associated with potential 
shortfalls to the existing RFS policy. It can do some other 
things like level the playing field between all airlines with 
respect to whether one airline wants to be more progressive 
with SAF usage and another doesn't and helps create a level 
playing field there. So yes, there clearly are opportunities 
for mechanisms.
     The reason that the industry is clearly behind the 
blenders tax credit at present is to address this disparity 
with respect to existing policy between diesel and jet fuel but 
also because it's near term. We understand economics associated 
with producing fuel in California under the LCFS and with the 
existing non-level playing field, and the blenders tax credit 
proposal addresses that issue specifically.
     What becomes harder is something like what Congresswoman 
Brownley has proposed is a longer-term strategy for what 
actually moves us further in the direction of long term 
addressing these issues, and that's where it becomes very gray 
because we don't know, as an industry, what happens if RFS gets 
redone in some fashion. You know, what might happen at the 
Federal level to bring in new policy elements? And will 
significant regulation that requires multiple years be required 
to introduce that kind of legislation? So it's one of those 
things of, you know, a bird in the hand is worth two in the 
bush. That's why we have the focus on BTC today, and tomorrow, 
it becomes much less clear to us what appropriate policy 
mechanisms might be.
     Ms. Lofgren. I wonder if--you know, this has been a useful 
hearing for me to hear that, you know, a molecule is a molecule 
is the same as the other jet fuel, so what's the reason behind 
the current 50 percent blend limit?
     Mr. Csonka. So I said that all of the molecules in SAF are 
molecules that are currently found in jet fuel but not 
necessarily all of the molecules that are found in jet fuel. 
That's the difference. So we established initially a blending 
limitation to ensure that the full suite of molecules that 
we've been operating off of for the last six, seven decades 
still remains in jet fuel while we continue to learn more in 
this sector.
     The good news is or the bad news is the first couple 
pathways were limited in how much--how identical they were to 
the jet fuel they were replacing. We've got a couple pathways 
now. One's already approved and a couple or more on the way 
that now are producing a nearly identical replication of the 
full suite of molecules that we find in petroleum jet fuel, so 
those create the basis for us over the next couple of years to 
increase the SAF blending limit from its 50 percent maximum 
level today to perhaps fully drop-in 100 percent synthetic 
fuels tomorrow. And we're working diligently on the foundation 
of that strategy.
     Ms. Lofgren. Well, my time is expired, but let me just say 
I think that is exciting news given the role that aviation 
plays in climate change.
     So, Mr. Chairman, I yield back. Thank you very much.
     Chairman Beyer. And thank you, Chairman Lofgren.
     And now one of our greatest enthusiasts of SAFs, 
Congresswoman Brownley from California.
     Ms. Brownley. Thank you, Mr. Chairman, and I thank the 
Ranking Member also for allowing me to participate in today's 
hearing.
     You know, I have been working on this issue and have 
reintroduced a bill that has a number of different policy 
mechanisms, including grants, tax credits, standards, as well 
as R&D funding.
     And I'm grateful for Mr. Csonka here today. Full 
disclosure, he has been extraordinarily helpful to my office in 
crafting legislation, so I'm greatly, greatly appreciative.
     And so, Mr. Csonka, my first question is to you. You know, 
as you know, my bill would fund a number of research priorities 
that industry experts have told me are important issues in need 
of more study. So one of these priorities is developing SAF 
that can be used without blending with fossil jet fuel. Another 
is studying the climate impacts of non-CO2 
greenhouse gas emissions from jet fuels like water vapor or 
contrails. What are these--why are these important research 
priorities for the industry?
     Mr. Csonka. So the first one is I personally answered that 
in the last question which is if we know that we need to count 
on sustainable aviation fuels to deliver carbon reductions that 
the industry has signed up for, that policymakers might be 
interested in, we need to remove artificial barriers long term, 
right? So external fans or foes of what we're doing [inaudible] 
look at the 50 percent blending limit as a hurdle, a limitation 
on how much benefit we can actually get from SAF. And so we're 
interested in removing those kinds of carriers and hurdles, 
letting the world know that, yes, we can go beyond the 50 
percent blend level.
     And so if we produce a fuel that delivers an 80 percent 
net lifecycle carbon reduction and we're able to use it at a 50 
percent level to get a 40 percent reduction, if we're able to 
use it at a 100 percent as a full drop-in, we get that full 80 
percent reduction. So that's why we're focused on that. And 
there is some more research and development activity that needs 
to occur that builds on work of the last five years through the 
National Jet Fuel Combustion Program and other work of NASA and 
FAA to continue to ensure that we move from the paradigm that 
we're in today, 50 percent maximum levels to 100 percent max 
levels.
     Ms. Brownley. I've got a couple more questions 
[inaudible].
     Chairman Beyer. Go ahead.
     Ms. Brownley. So, you know, to all the panelists, I just 
wanted to ask a very quick question and that in your opinion do 
we need more research before SAF is ready to be deployed at 
scale? Just yes or no.
     Dr. Hansman. Yes.
     Mr. Csonka. Yes.
     Dr. Thole. Yes. Yes.
     Mr. Csonka. Yes.
     Ms. Brownley. OK. And, you know, I guess I would like to 
delve into that deeper by your answers, but I don't think I 
have enough time, so I'll talk to you later about it.
     And the last question before I run out of time here is, 
Dr. Thole, you talked about China and the European Union. I was 
just wondering if you could tell me, you know, where is--we 
sort of--I think in this hearing sort of disclosed and 
uncovered where the United States is with SAF at this 
particular point and where it might be going in the nearest 
future, so where is exactly China and the European Union on SAF 
production?
     Dr. Thole. Yes, I think I will have to defer to Steve on 
this one. He probably is more aware of that than I am in terms 
of----
     Ms. Brownley. So you have talked more about hydrogen and 
other technologies, where they are ahead?
     Dr. Thole. They--oh, yes, that's right. They have made a 
committed effort to hydrogen right now, a significant financial 
commitment, and they are plowing ahead.
     Ms. Brownley. OK. So----
     Dr. Thole. And China on the--you know, what China is doing 
is they are developing an aviation ecosystem, right? Everything 
from airframers to engine companies and everything in between, 
so----
     Ms. Brownley. Very good. So, Mr. Csonka, is China doing 
SAF production as part of their portfolio here? No, none?
     Mr. Csonka. They are not.
     Ms. Brownley. OK.
     Mr. Csonka. They've done some demonstration work only. 
Europe produces about half, America produces about half of 
what's being produced today.
     Ms. Brownley. Very good. Well, it looks like my time is 
up. Again, thank you, Mr. Chairman, for allowing me--this has 
been a great hearing, and I yield back.
     Chairman Beyer. Thank you, Congresswoman Brownley, very 
much. And I'd really like to thank all of you.
     Dr. Thole, we heard your name pronounced six different 
ways today, which is fun, but----
     Dr. Thole. That's OK. I think I've answered to all of 
them, so I hope it's OK. It's Thole. It's Thole, but that's 
fine.
     Chairman Beyer. And I for one have been really impressed 
by the incredible range of knowledge that all three of you have 
brought to this, so I'm very, very grateful.
     I would like to ask for unanimous consent to introduce a 
letter from BIO that was sent and has been reviewed by 
Republican staff, so if no concerns, it will be part of the 
record.
     There--I think Members have two weeks to submit other 
additional statements, and we will try to get Congresswoman Kim 
an answer on USTR Lighthizer's concerns about China and its 
progress.
     So with that, I want to thank you very much again for 
being part of this, and I bring this meeting to a close. Thank 
you all for your testimony. Have a good, good spring and 
goodbye.
     [Whereupon, at 12:24 p.m., the Subcommittee was 
adjourned.]

                               Appendix I

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                   Answers to Post-Hearing Questions
[GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

                              Appendix II

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                   Additional Material for the Record
[GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]

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