AVIATION & THE ENVIRONMENT
Transcript of AVIATION & THE ENVIRONMENT
AVIATION & THE ENVIRONMENT
Ian A. Waitz Professor and Deputy Head
Department of Aeronautics and Astronautics
Massachusetts Institute of Technology
© 2003 Waitz 1
LECTURE OUTLINE
• Overview of environmental effects of aircraft
• Aircraft noise
– Impacts and regulatory issues
– Technology trends
• Aircraft pollutant emissions
– Impacts and regulatory issues
– Technology and emissions trends
• Summary and references © 2003 Waitz 2
Noise
None applicable
Compatibility with nearbyland uses
Air quality
Most serious problem currently
Most serious problem in the future
Wetlands
29AIRPORT Noise22RANKING OF
ENVIRONMENTAL 12
Water quality
ISSUESWater Quality
6
6
Air QualityCurrent and Future 16
2Compatibility with Land-use limitations 4
1
None Applicable 0
0
Wetlands2
0 5 10 15 20 25 30 35
Number of airports
Most serious problem currently Most serious problem in future
Source: GAO’s survey of the nation’s 50 busiest commercial service airports. © 2003 Waitz (GAO, 2000) 3
CHARACTERISTICS OF NOISE AND EMISSIONS ISSUES
• Noise
– Local
– Persistence = minutes
– Well-established metrics
– Impacts: annoyance, sleep disturbance, domestic animals?, endangered species?, health impacts?
• Emissions
– Local, regional, global
– Effluents: CO2, H2O, NOx, CO, VOC’s, soot, others
– Persistence = 1 day -1000 years
– Drastic change in public/scientific perception and regulatory frameworks
– Impacts: human health, ecosystem health© 2003 Waitz 4
AVIATION ENVIRONMENTAL IMPACTS
• “EXTERNALITIES”
– A large fraction of current aviation health and welfare impacts are real costs to society but are not accounted for by the providers or users of the service
“The government’s objectives for aviation are that…the polluter should pay and aviation, like other industries, should meet its external costs, including environmental costs.”
(From UK Department of Transport, Aviation and the Environment, Using Economic Instruments, March 2003)
© 2003 Waitz 5
EXTERNAL COSTS OF AVIATION
VALUATION SOCIAL INSTITUTIONAL BASIS (industry + affected public) (regulatory policy)
Impact Area (objective)
Total $ $ / capita Total $ $ / capita % of Total $
addressed by regulation
Noise $ 26B $ 2100 $ 2.9B $ 6000 11% (quiet environs)
Air Quality $ 11B $ 140 $ 2.5B $ 30 22%(safe air)
Climate Change ~$100B $ 345 $ 0.0B $ 0 0% (stable climate)
TOTAL ~$137B $ 5.4B 5%
• Regulatory framework currently accommodates ~ 5% potential
internalization of external costs
• Noise cost per capita greater than emissions aligns with public
opinion and institutional attention
– Most vociferous opposition to noise, but air quality becoming
more of an issue (GAO 2000) >>PRELIMINARY ESTIMATES ONLY<<
Lukachko, 2003 © 2003 Waitz 6
GROWTH IN MOBILITY PROVIDED BY U.S. AVIATION INDUSTRY (DOT Form 41 data)
Fastest Growing Mode of Transportation (4-6%/yr)
Revenue Passenger Miles Performed by All Airlines Operating Aircraft with >60 Seats
8E+11
7E+11
6E+11
5E+11
4E+11
3E+11
2E+11
1E+11
01965 1970 1975 1980 1985 1990 1995 2000 2005
Year
© 2003 Waitz 7
AIR TRAVEL PROJECTED TO BE FASTEST GROWING MODE OF TRANSPORTATION (4-6%/yr)
- DRIVEN BY POPULATION AND GDP GROWTH, AND AVAILABLE DAILY TRAVEL TIME -
AutomobilesBuses
RailwaysAircraft
1960 1990 2020 2050
5.5×1012 RPK 23 ×1012 RPK 54 ×1012 RPK 105 ×1012 RPK
Source: Schafer et al. (1998), GDP/cap growth rates from IPCC IS92a Scenario © 2003 Waitz 8
MOBILITY AND THE ENVIRONMENT
“ Environmental issues are likely to impose the fundamental limitation on air transportation growth in the 21st century. ” U.S. National Science and Technology Council, 1995
72%
28% 25%
75%
Expansion Projects Delayed due to Environmental Issues
Source: GAO (2000) survey of 50 busiest commercial airports. N=33 for this question, 1 airport did not respond.
28% (9 airports) with no impact
projects delayed at 72% (23 airports)
Expansion Projects Cancelled or Indefinitely Postponed due to Environmental Issues
25% (12 airports) with at least 1 project affected
no impact at 75% (36 airports)
Source: GAO (2000) survey of 50 busiest commercial airports. N=50 for this question, 2 airports with no projects planned.
© 2003 Waitz 9
AIRPORTS ARE REACHING CAPACITY LIMIT Figure 2: Anticipated Date for Airports to Reach Capacity
Number of airports
14
13
11
5
2
8
7
4
0
1
2
3
4
5
6
7
8
9
10
11
12
13
Already 1-2 years 3-4 years 5-6 years 7-9 years 10 or Otherat or moreabove yearscapacity
Estimated time to reach capacity
Source: GAO’s survey of the nation’s 50 busiest commercial service airports. © 2003 Waitz 10
DOD ENCROACHMENT
• External factors such as urbanization, increasing environmental restrictions, and competition with civilian demands on airspace, land, seaspace, and radio frequencies
“The overall trends are adverse because the number of external inputs is increasing, and the readiness impacts are growing. Future testing and training needs will only further exacerbate these issues, as the speed and range of test articles and training scenarios increase…” (DOD Sustainable Ranges Outreach Plan, SROC)
Examples: JSF basing, Oceana operations, Navy in Japan
• Senior Readiness Oversight Council (SROC) action plans: – Endangered species, ordnance, frequency encroachment, the
maritime sustainability, airspace restrictions, air quality, airborne noise and urban growth
• House of Representatives proposal (2002): National Security Impact Statement with all Environmental Impact Statements
© 2003 Waitz 11
REGULATIONS: BALANCING PUBLIC GOALS
• Economy and Mobility vs. National Security vs. Environment • State vs. National interests and control
• Federal Noise Control Act + local noise restrictions – Commercial yes– Military no (Nat. Sec. Exemption, but NEPA EIS)
• Federal Clean Air Act + State Implementation Plans – Military yes (General Conformity Rule) – Commercial “no” (Interstate Commerce & Trade exemption)
• Endangered Species and Marine Mammal Protection Acts – Military “yes” (Nat. Sec. Exemption, but never used) – Commercial yes
© 2003 Waitz 12
GROWTH OF ENVIRONMENTAL REGULATION
Reflects increasing environmental impacts and increasing valuation of the environment
Materiel Developer’s Guide for Pollution Prevention,
Cumulative Number of Federal Environmental Laws
World-wide Civil Aircraft Noise Restrictions
NAP
Charges
QuotasBudgetsCH2 PO CH2 Rest. CH3 Rest.
19700
50
100
150
200
250
300
350
400
1980 1990Year
Nu
mb
er o
f R
estr
icti
on
s
2000
Curfews
Levels
Army Acquisition Support Office, 1994 www.boeing.com
© 2003 Waitz 13
AIRCRAFT REGULATIONS - Local , National, International -
• Noise
– Certification standards
– Phase-outs
– Curfews
– Flight control
– Landing fees
– Ticket taxes
• Emissions
– Certification standards
– Phase-outs
– Limited local rules in place
© 2003 Waitz 14
LECTURE OUTLINE
• Overview of environmental effects of aircraft
• Aircraft noise
– Impacts and regulatory issues
– Technology trends
• Aircraft pollutant emissions
– Impacts and regulatory issues
– Technology and emissions trends
• Summary and references © 2003 Waitz 15
AIRCRAFT NOISE GENERATION
AIRFRAMENOISE
ENGINENOISE
SONICBOOM?
ATMOSPHERIC PROPAGATION
SPECTRUM, MAGNITUDE, DIRECTIVITY, DURATION FREQUENCY OF OCCURENCE, TIME OF DAY, LOCATION
HUMAN ANNOYANCE
© 2003 Waitz 16
NOISE EFFECTS ON PEOPLE
(FICON, 1992)
© 2003 Waitz 18
Effects Hearing Loss Annoyance
Day-Night
AverageSound
Level in Decibels
QualitativeDescription
% of Population
HighlyAnnoyed
AverageCommunity
Reaction
General Community Attitude Towards Area
75 and above
May begin tooccur 37% Very Severe
Noise is likely to be mostimportant of all adverse aspects of
the community environment
70 Will not likelyoccur 22% Severe
Noise is one of the most adverseaspects of the community
environment
65 Will not occur 12% Significant Noise is one of the adverse aspectsof the community environment
60 Will not occur 7% Moderate to slight
Noise may be considered an adverse aspects of the community
environment
55 and below Will not occur 3% Moderate to
slight
Noise considered no moreimportant than various other
environmental factors
COMMERICAL AIRPORT NOISE EXPOSURE MAP (DNL levels)
(INM, 1999)
© 2003 Waitz 19
NOISE IMPACT TRENDS •Phase-out
–55% of U.S. fleet
–94% reduction in impact
–During 6X mobility growth
–$10B US cost
–
–TECHNOLOGY foundation
•$1B/yr in US for sound abatement
–
–Low cost effectiveness
$43/person/DNLdB
$960/person/DNLdB
© 2003 Waitz 20
COMMERCIAL AND MILITARY NOISE IMPACTS
Norfolk Intl. Airport
210 TO/day
Oceana121 TO/day 7 FCLP/day
Fentress20 TO/day
354 FCLP/day
http://www.norfolkairport.com, http://www.nasoceana.navy.mil/aicuz
© 2003 Waitz 21
AIRCRAFT NOISE TECHNOLOGY TRENDS
© 2003 Waitz 22
AIRCRAFT NOISE SUMMARY
• Difficult connection between human annoyance and physics
– Public becoming more sensitive to aviation noise
– Relatively mature regulatory history
• Step changes in fleet unlikely
• Increased commercial certification stringency likely but probably within current technological capabilities
• Growing problem for the military
• Local restrictions make noise a product differentiator
– For GE-90 powered B-777 (-6EPNdB cumulative relative to other engines) twice as many t/o and landings allowed at Heathrow
– Manufacturers willing to trade 2% fuel burn for 2 dB (A380)
© 2003 Waitz 23
LECTURE OUTLINE
• Overview of environmental effects of aircraft
• Aircraft noise
– Impacts and regulatory issues
– Technology trends
• Aircraft pollutant emissions
– Impacts and regulatory issues
– Technology and emissions trends
• Summary and references © 2003 Waitz 24
EMISSIONS IMPACTS
• Local air quality (NOx, CO, UHC, PM)
– Focus of current regulations
• Regional/global atmospheric effects
1) Stratospheric ozone depletion (time-scale=10 years)
– Largely a concern for supersonic aircraft (NOx)
2) Climate change (time-scale = 100-1000 years)
– Subsonic and supersonic aircraft
– CO2 and H2O
– NOx through ozone production
– Particulates (SOx and soot) through heterogeneous chemistry and cloud nucleation
© 2003 Waitz 25
AIRCRAFT ENGINE EXHAUST
• Composition
– Reservoir and primary combustion products
CO2, H2O, N2, O2: O(10000-100000) ppmv
– Secondary products and pollutant emissions
CO, NOx, HC, soot: O(1-100) ppmv
– Trace species constituents
NOy, SOx, HOx: O(0.0001-0.1) ppmv
• Most constituents play some role in atmospheric processes
– e.g. If 100% of SO2 in engine oxidizes to SO3 it may double stratospheric ozone depletion
– Primary and secondary species relatively well-understood
– Relative magnitudes and engine/operations effects on trace species poorly characterized
© 2003 Waitz 26
LOCAL AIR QUALITY
• Approx. 1% of US mobile source NOx emissions are from aircraft
• NOx, particulate matter, VOCs, CO -- ozone
– Lung function, cardiovascular disease, respiratory infection
© 2003 Waitz 27
28© 2003 Waitz
PM-10
LeadCO
Ozone
SO2
Notes: Incomplete data, not classified, and Section 185(a) areas are not shown. Ozone nonattainment areas on map based on pre-existing ozone standard. Nonattainment designations based on revised 8-hour ozone standard will not be designated until 2000. PM-10 nonattainment areas on map are based on pre-existing PM-10 standards. Nonattainment designations based on revised PM-10 standards have not yet been made. Source: U.S. EPA, National Air Quality and Emissions Trends Report, 1997 .
LOCATION OF “NON-ATTAINMENT” AREAS FOR CRITERIAPOLLUTANTS AS OF SEPTEMBER, 1998
(Chang, 1999)
% r
eg m
obile
sou
rce
emis
s AIRCRAFT CONTRIBUTION TO REGIONAL MOBILE SOURCE NOX
EMISSIONS AT SELECTED US CITIES IS ESTIMATED TO INCREASE
Estimated commercial aircraft contribution to regional mobile source emissions of NOx
12
10
8
6
4
2
0
LA DC
Atlanta
Boston
Charlotte
ChicagoHousto
n NY
Phila.
Phoenix
1990 2010
Source: Table 4-2, EPA 420-R -99-013, "Evaluation of Air Pollutant Emissions from Subsonic Commercial Jet Aircraf t," April, 1999
(Chang, 1999)
© 2003 Waitz 29
30© 2003 Waitz
AIRCRAFT AND OZONE
(NOAA, NASA, UNEP, WMO, “ScientificAssessment of Ozone Depletion: 1994”)
• Aircraft: NEGATIVEEFFECT AT ALLALTITUDES
– Subsonics: +0.9% totalcolumn ozone (globalwarming)
– Supersonics (1000, <5% of fleet): -1.3% totalcolumn ozone
– Combined fleet: -0.4%total column ozone
(IPCC, 1999)
SCIENTIFIC UNDERSTANDING IN 2003 vs. 1999
Green bars are updated values, with arrows updateduncertainty.
© 2003 Waitz 32
NOTES ON CLIMATE CHANGE IMPACTS
• Burning a gallon of fuel at 11km has about double the radiative impact of burning a gallon of fuel at sea-level
• Burning a gallon of fuel at 19km has about 5 times the impact at sea-level
• CO2 is not the biggest global concern (potential impacts from contrails and cirrus clouds are greater).
• Large imbalance between northern and southern hemisphere
• Improving engine efficiency tends to make NOx and contrails worse
• High uncertainty
© 2003 Waitz 36
THE ROLE OF TECHNOLOGY: CHARACTERISTICS OF AVIATION SYSTEMS
• Safety critical
• Weight and volume limited
• Complex
• 10-20 year development times
• $30M to $1B per unit capital costs
• 25 to 100 year usage in fleet
• Slow technology development and uptake
© 2003 Waitz 37
TECHNOLOGY CHOICES: BOEING
“Boeing is focusing its product development efforts on a super efficient airplane. This is the airplane that airline customers around the globe agree will bring the best value to an industry in need of improved performance. The advanced technologies that allowed the Sonic Cruiser configuration to provide 15 to 20 percent faster flight at today’s efficiencies now will be used to bring 15 to 20 percent lower fuel usage at the top end of today’s commercial jet speeds. Boeing believes that in the future airlines will again be interested in faster flight and we will be ready with a concept and technologies to meet this need.” (www.boeing.com, March, 2003)
© 2003 Waitz 38
COMMERCIAL vs. MILITARY FLEET TRENDS
• Demand growth for civil aviation (3.8%/year in US)
• Military fleet contraction
• Ops tempo (4.3/day commercial, 0.35/day military)
Number of Aircraft Flights/day
© 2003 Waitz 40
FUEL CONSUMPTION TRENDS
Aircraft responsible for 2%-3% of U.S fossil fuel use
© 2003 Waitz 41
COMMERCIAL AIRCRAFT EFFICIENCY
Average Age = 13 yrs
© 2003 Waitz 42
MILITARY AIRCRAFT FUEL BURN
Average Age 21 yrs
© 2003 Waitz 43
ENERGY EFFICIENCY
• Function of performance of entire system
– Aircraft technology (structures, aerodynamics, engines)
– Aircraft operations (stage length, fuel load, taxi/take-off/landing time, flight altitude, delays, etc.)
– Airline operations (load factor)
• Each component of system can be examined independently for reduced fuel burn and impacts on local air quality and regional/global atmospheric effects
© 2003 Waitz 44
⋅⋅
⋅⋅
RANGE EQUATION Technology and Operations
Stage Length V L D
g SFC W
W W W fuel
payload structure reserve
= ( ) ⋅
+ + +
ln 1
= Technology = Operations
EfficiencyW StageLength
W
ASKkg
Stagelength seats
payload
fuel
fuelW
gf
∝∝
==
,
#
Use data to separate effects and understand influences of technology
© 2003 Waitz 45
TRENDS IN LOAD FACTOR
Lo
ad F
acto
r 0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Regional Jets
Turboprops
Large Aircraft
1965 1970 1975 1980 1985 1990 1995 2000 Year
Babikian, Raffi, The Historical Fuel Efficiency Characteristics of Regional Aircraft From Technological, Operational, and Cost Perspectives, SM Thesis, Massachusetts Institute of Technology, June 2001
© 2003 Waitz 46
FLIGHT AND GROUND DELAYS R
atio
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Airborne to Block Hours Minimum Flight to Airborne Hours Mininum Flight to Block Hours
1965 1970 1975 1980 1985 1990 1995 2000
Year
© 2003 Waitz 47
HISTORICAL TRENDS Aerodynamic Efficiency
L/D
max
25
20
15
10
5
01955 1960 1965 1970 1975 1980 1985 1990 1995 2000
abikian et al. (2002) Data Unavailable For: EMB-145 FH-227
BAE RJ85 SA-226
CV-600 DHC-7
Turboprops CV-880 Nihon YS-11
Regional Jets Beech 1900 DHC-8-100Large Aircraft CV-580 L-188
DHC8-300
D328
J41
ATR42 BAE-ATP
ATR72F27 BAC111-200/400 B767-200/ER
S360
J31
SA227
S340A
F28-1000 F28-4000/6000
BAE146-100/200/RJ70B727-200/231A BAE-146-300
B757-200 F100 B747-400RJ200/ER B777
B707-100B/300 B707-300BB737-100/200 L1011-1/100/200
A300-600
DC9-30 B737-300
DC10-40
MD11
B737-400
A320-100/200A310-300
DC10-30 L1011-500 B767-300/ER
B747-100/200/300
DC10-10 MD80 & DC9-80 EMB120 B737-500/600
B
Year© 2003 Waitz 48
HISTORICAL TRENDS Engine Efficiency
TS
FC
(m
g/N
s)
30
25
20
15
10
5
0
B707-300
B720-000
B727-200/231A
F28-4000/6000BAC111-400 DC9-40BAE146-100/200/RJ70
CV880 F28-1000
BAE-146-300
F100RJ85
B737-100/200DC9-30
DC9-10DC9-50
MD80 & DC9-80
B737-300
D328 EM170
RJ200/ERF27
CV600
DC10-30
DC10-40
L1011-500
B767-200/ER MD11B747-400
B737-400 B737-500/600
A300-600
B767-300/ERB757-200
L1011-1/100/200B747-100
B747-200/300
DC10-10
EMB145
EMB135RJ700
J31L188A-08/188C A320-100/200A310-300 B777
D328
J41
ATR72
DHC7S360
B1900
CV580
SA226 SA227
EMB120ATR42
DHC8-300BAE-ATPDHC8-100
DHC8-400
Turboprops
S340A
bikian et al. (2002)Ba
Regional Jets Large Jets New Regional Jet Engines New Turboprop Engines
1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Year
© 2003 Waitz 49
HISTORICAL TRENDS Structural Efficiency
OE
W/M
TO
W
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
DC9-40
B737-100/200
B727-200/231A
DC9-10 DC10-10
BAC111-200F28-1000
BAC111-400
F27FH227
CV600
L188A-08/188C DC10-40
DC9-50
MD80 & DC9-80
B767-200/ER
B777B747-400
B737-400
B737-500/600
A320-100/200
A300-600A310-300
B767-300/ER
B737-300B757-200
L1011-1/100/200
B747-200/300
F28-4000/6000
BAE146-100/RJ70
BAE146-200
BAE-146-300F100
RJ85
RJ200/ER
EMB145
DHC8-300D328
J41BAE-ATP
ATR72DHC7 S360
B1900
J31
DHC8-100
SA226
SA227 EMB120 S340A
ATR42
DC9-30CV880 L1011-500DC10-30 MD11
B747-100
Turboprops
B707-300B
bikian et al. (2002)Ba
Regional Jets Large Aircraft
1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 Year
© 2003 Waitz 50
EFFICIENCY Regional Jets Versus Turboprops
6E
ner
gy
Usa
ge
(MJ/
AS
K)
5Regional
BAC111-400 Jet Fleet Regional
4 CV880 Aircraft Fleet
BAC111-200
CV600
3 RJ200/ERB1900F28-1000L188A-08/188C
BAE146-100 RJ85F28-4000/6000
F27 J31DHC7
SA226S360 SA227 BAE-146-300
F100 EMB1452 J41 D328Turboprop BAE146-200DHC8-300Fleet
DHC8-100ATR72S340ABabikian et al. (2002)
EMB120
1 ATR42 BAE-ATP
TurbopropsRegional Jets
01955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Year© 2003 Waitz 51
ENERGY USAGE Total Versus Cruise
0
1
2
3
4
5M
J/A
SK
EU,CR Large Aircraft Total EU Large Aircraft EU,CR Regional Aircraft Total EU Regional Aircraft
Babikian (2001)
1955 1960 1965 1970 1975 1980 1985 1990 1995 2000
Year 52 © 2003 Waitz
COMMERCIAL AIRCRAFT ENERGY INTENSITY TRENDS
• New technology energy intensity has been reduced 60% over last 40 years (jet age)
– 57% due to increases in engine efficiency
– 22% due to increases aerodynamic performance
– 17% due to load factor
– 4% due to other (structures, flight time efficiency, etc.)
– Structural efficiency constant (but traded for aero, passenger comfort, noise and SFC)
– Flight time efficiency constant (balance of capacity constraints and improved ATM)
• Fleet average energy intensity has been reduced 60% since 1968
– Lags new technology by 10-15 years
© 2003 Waitz 53
SHORT HAUL AIRCRAFT Facing Increasing Scrutiny
EU
(M
J/A
SK
)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
JetsTurboprops
Aircraft introduced during or after 1980 only
(Babikian, 2002)
0 1000 2000 3000 4000 5000 6000 7000 8000 9000
Stage Length (km)
Royal Commission on the Environment (2002)
the prospect of continuing rapid increases in air transport, particularly an increase in short haul flights…”
government should divert resources...encouragingand facilitating a modal shift from air to high-
“…deeply concerned at
“It is essential that the
speed rail.”
© 2003 Waitz 55
IMPACT OF NASA TECHNOLOGY SCENARIOS G
lob
al C
O2
Em
itte
d p
er Y
ear
Billion Kg Effect of Proposed Environmental CO2 Goals2000
1750
1500
1250
1000
750
500
250
0
1990 2000 2010 2020 2030 2040 2050
No Improvement Beyond 1997 Technology 25% Reduction Introduced in 2007 50% Reduction Introduced in 2022 Zero CO2 Emission A/C Introduced in 2027 Zero CO2 Emission A/C Introduced in 2037
+340%
+140%
+230%
+40%
Change Relative to 1990:
Emission inventories
U.S. DOE reported fuel use
1990-5% Level
-20%
( - GA and Military Emissions based on Boeing forecast
- IPCC IS92a based ICAO demand model - No retrofit of technologies)
Kyoto Protocol Timing For Reductions
Year
J. E. Rohde, NASA 1999© 2003 Waitz 56
IMPACTS OF MISSION REQUIREMENTS (NOx & Noise)
• Range/payload ~ fuel efficiency (commercial and military) High pressures and– Thermal efficiency temperatures High NOx
– Propulsive efficiency velocity change Large mass flow with small
Low Noise
• Maneuverability (military) High energy conversion per
– High thrust-per-weight, unit volume (high small compact engine temperatures and
pressures)High NOx
• Supersonic flight (military) velocity change– Low drag, small compact
engine
Small mass flow with large
High Noise
© 2003 Waitz 57
NOx EMISSIONS TECHNOLOGY TRENDS
© 2003 Waitz 58
NOx EMISSIONS TRENDS
© 2003 Waitz 59
HISTORICAL FLEET CRUISE EMISSIONS PER PASSENGER PER KILOMETER
1.0
Rel
ativ
e E
mis
sio
n /
Pas
s-km
0.5
0
1975 1980 1985 1990 1995
NOx
CO2,H2O
CO
HC
Year (DuBois, Boeing)
© 2003 Waitz 60
TECHNOLOGY AND EMISSIONS
• Improvements will not keep up with growth
• Aircraft typically have greater impact per unit of fuel burned
• “Solutions” for global climate will require unprecedented action (demand management/regulations, electric vehicles, contrail avoidance, etc.)
• Current understanding is that hydrogen makes problem worse
• High uncertainty relative to global impacts
• Engine efficiency improvements exacerbate NOx and contrails
• Significant improvements in structural efficiency, aero and operations are possible
– Improvements in these areas do not exacerbate other problems
© 2003 Waitz 61
SUMMARY
• Broad range of environmental impacts from aircraft
– Social costs of same order as industry profits
– Currently not internalized
– Current technology path and regulations not aligned with social costs
• Strong growth in demand
• Increasing public concern/regulatory stringency
• High uncertainty
• Many competing trades
– Environmental impacts
– Design, operations © 2003 Waitz 62
SELECTED REFERENCES
• Babikian, R., Lukachko, S. P. and Waitz, I. A. "Historical Fuel Efficiency Characteristics of Regional Aircraft from Technological, Operational, and Cost Perspectives,” Journal of Air Transport Management, Volume 8, No. 6, pp. 389-400, Nov. 2002
• Lee, J. J., Lukachko, S. P., Waitz, I. A., and Schafer, A., “Historical and Future Trends in Aircraft Performance, Cost and Emissions,” Annual Review of Energy and the Environment, Volume 26, 2001. (Available on Waitz web page)
• Waitz, I. A., Lukachko, S. P., and J. J. Lee, "Military Aviation and the Environment: Historical Trends and Comparison to Civil Aviation," AIAA-2003-2620, invited contribution to AIAA/ICAS International Air and Space Symposium and Exposition, Dayton, Ohio, July 14-17, 2003.
• Marks, D. H., et al., "Mobility 2001", World Business Council for Sustainable Development, Switzerland, 2001. (Available on Waitz web page)
• Miake-Lye, R.C., Waitz, I.A., Fahey, D.W., Kolb, C.E., Wesoky, H.L., and Wey, C.C., “Aviationand Climate Change,” Aerospace America, September, 2000. (Available on Waitz web page)
• Penner et al., United Nations Environment Programme, Intergovernmental Panel on Climate Change (IPCC), Special Report on Aviation and the Global Atmosphere, 1999. (Summary for Policy Makers available on Waitz web page)
• RCEP, “The Environmental Effects of Civil Aircraft In Flight,” Royal Commission on Environmental Pollution (RCEP), England, December, 2003
• Waitz web page: http://web.mit.edu/aeroastro/www/people/iaw/bio.html
© 2003 Waitz 63