[PDF] [PDF] Approaches to Representing Aircraft Fuel Efficiency - CORE

[PDF] Transatlantic airline fuel efficiency ranking, 2017 - International

9 sept 2018 · improvements are linked to the increased use of more fuel-efficient aircraft— the Boeing 787-9 for Virgin Atlantic and Boeing 777-300ER for 

[PDF] Fuel efficiency of commercial aircraft Fuel efficiency of commercial

consumption per seat-kilometre as piston-engined aircraft were replaced by jet- engined The last piston-powered airliners were at least twice as fuel-efficient as  

[PDF] Aircraft Fuel Consumption - HAW Hamburg

13 déc 2017 · method allows calculating aircraft type specific fuel consumption based on publicly available Comparison of Fuel per Kilogram Payload

[PDF] Fact Sheet More Efficient, Greener and Quieter Aircraft - Sustainable

The Airbus A380 has significantly improved fuel efficiency over some older models Shortly after receiving their first A380 Singapore Airlines CEO stated that the A380 was 20 more fuel efficient than the 747-400's they were operating at the time2

[PDF] Air Transport and Energy Efficiency - Pubdocsworldbankorg

40 percent less expensive— and more fuel-efficient—to operate than the aircraft it replaced (Airbus 2008) In fact, Airbus spends US$265 million per annum on 

[PDF] Approaches to Representing Aircraft Fuel Efficiency - CORE

A potential evaluation condition for 1/SAR is determined to be optimal speed and altitude for a representative mid-‐cruise weight defined by half of the difference 

[PDF] A380 Special edition - Airbus

Due to its size and capacity, the A380 is the most efficient way to capture traffic at the most (electricity, air, water fuel, passenger and cargo handling, towing )

[PDF] Aircraft Technology Roadmap to 2050 - IATA

Figure 4: Timeline of expected future fuel efficiency improvements compared to predecessor aircraft or engine of the same category, details are given in 

[PDF] Flying more efficiently: Joint impacts of fuel prices, capital costs and

fuel- efficient Controlling for the effect of aircraft size and age, we find that the technically achievable fleet fuel economy improves with the size of airlines and the 

[PDF] a380 fuel consumption during takeoff

[PDF] a380 fuel consumption per hour

[PDF] a380 fuel consumption per minute

[PDF] a380 fuel consumption per passenger

[PDF] a380 fuel consumption per seat

[PDF] a380 fuel consumption per second

[PDF] a380 fuel consumption taxi

[PDF] a380 fuselage height

[PDF] a380 height of tail

[PDF] a380 landing cockpit view

[PDF] a380 landing cockpit view video

[PDF] a380 length

[PDF] a380 lufthansa

[PDF] a380 minimum runway length landing

[PDF] a380 mtow lbs

APPROACHES TO REPRESENTING AIRCRAFT FUEL EFFICIENCY PERFORMANCE FOR THE PURPOSE OF A COMMERCIAL AIRCRAFT CERTIFICATION STANDARD Brian M. Yutko and R. John Hansman This report is based on

the Masters Thesis of Brian M. Yutko submitted to the Department of Aeronautics and Astronautics in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology.

Report No. ICAT-2011-05 May 2011 MIT International Center for Air Transportation (ICAT) Department of Aeronautics & Astronautics Massachusetts Institute of Technology Cambridge, MA 02139 USA

-2- [PageIntentionallyLeftBlank]

-3- ApproachestoRepresentingAircraftFuelEfficiencyPerformanceforthePurposeofaCommercialAircraftCertificationStandardbyBrianM.YutkoSubmittedtotheDepartmentofAeronauticsandAstronauticsonMay19,2011inPartialFulfillmentoftheRequirementsfortheDegreeofMasterofScienceinAeronauticsandAstronauticsAbstractIncreasingconcernoverthepotentialharmfuleffectsofgreenhousegasemissionsfromvarioussourceshasmotivatedtheconsiderationofanaircraftcertificationstandardasonewaytoreduceaircraftCO2emissionsandmitigateaviationimpactsontheclimate.Inordertodevelopacommercialaircraftcertificationstandard,afuelefficiencyperformancemetricandtheconditionatwhichitisevaluatedmustbedetermined.Thefuelefficiencymetricformofinteresttothisresearchisfuel/range,wherefuelandrangecaneitherbeevaluatedoverthecourseofareferencemissionoratasingle,instantaneouspoint.Amission-basedmetricencompassesallphasesofflightandisrobusttochangesintechnology;however,definitionofthereferencemissionrequiresmanyassumptionsandiscumbersomeforbothmanufacturersandregulators.Aninstan taneousmetr icbasedonfundamentalaircraftparametersmeasuresthefuelefficiencyperformanceoftheaircraftatasinglepoint,greatlyreducingthecomplexityofthestandardandcertificationprocess;however,asinglepointmightnotberobusttofuturechangesinaircrafttechnology.Inthis thesis,typica laircraftoperations areassessedinorde rtodevelopevaluationassumptionsforamiss ion-basedmetric,Bl ockFueldividedbyRange( BF/R),andaninstantaneousmetric,incrementalfuelburnperincrementaldistance(inverseSpecificAirRange(1/SAR)).Opera tingpatternsandfuelburnmapsareusedtodemonstratetheimportanceofmissionrangeonfleetfuelburn, andthu stheimportanceofaproperlydefinedrangeevaluationconditionforBF/R.Anevaluationconditionof40%oftherangeatMaximumStructura lPayload(MSP)limitedbyMaximumTakeof fWeight(MTOW)isdeterminedtoberepresentativeforthemi ssion-basedmetric.Apo tentialevaluationconditionfor1/SARisdeterminedtobeoptimalspeedandaltitudeforarepresentativemid-cruiseweightdefinedbyhalfofthedifferencebetweenMTOWandMaximumZeroFuelWeight(MZFW).TodemonstratesuitabilityasapotentialsurrogateforBF/R,correlationof1/SARwithBF/Risshownforthecurrentfleet,andacasestudyofpotentialfutureaircrafttechnologiesispresentedtoshowthecorrelationofimprovementsinthe1/SARmetricwithimprovementsinBF/R.ThesisSupervisor:Dr.R.JohnHansmanTitle:Professor,DepartmentofAeronauticsandAstronautics

-4- [PageIntentionallyLeftBlank]

-5- AcknowledgementsIwo uldliketothankDr .R.JohnHansmanforhisunwaveringsupportandguidancethroughoutmygraduatecareer.Thisthesiswouldnotexistwithouthim.IwouldalsoliketothankDr.PhilippeBonnefoyforhissupportandadvice.Manyoftheconceptsinthisthesisareatleastpartiallyduetohisincredibleinsight.Itwouldbedifficulttofindsomeonethatworksharderandisamoreobjectiveandcapableresearcher.ThankstomysponsorsattheFAAandEPA.Thisworkwasmadepossiblebytheirinterest,anditwasapleasuretocollaborate.Finallyandmostimportantly,toallofmyfriends,family,andespeciallymyparents:despiteallofthe challengesthroughout theyears,you'vesupportedmefr omthetime IwasgrowingupinasmallcoaltowninNortheastPennsylvaniauntilnow.Icouldn'thavedoneanyofthiswithoutyou.

-6- [PageIntentionallyLeftBlank]

-7- TableofContents Abstract...........................................................................................................................................3Acknowledgements......................................................................................................................5TableofContents..........................................................................................................................7ListofFigures..............................................................................................................................10ListofTables................................................................................................................................12AcronymsandAbbreviations...................................................................................................13Chapter1:Introduction.............................................................................................................141.1Motivation....................................................................................................................................141.2CommercialAircraftCertificationStandardasaCO2MitigationTechnique.................151.3Definitions....................................................................................................................................161.4CommercialAviationCO2Emissions......................................................................................171.5TheRoleofRepresentingAircraftPerformanceforaCertificationStandard...............181.6ApproachestoMeasuringAircraftFuelEfficiencyPerformance......................................19Chapter2:ResearchObjectiveandApproach......................................................................212.1Objective.......................................................................................................................................212.2Approach.......................................................................................................................................212.3DataSources.................................................................................................................................212.4Operationaldatabases...............................................................................................................222.4.1CommonOperationsDatabase(Global)...............................................................................222.4.2BureauofTransportationStatistics(BTS)Form41T-100(UnitedStates)......................222.5AircraftPerformanceModels...................................................................................................232.5.1Piano-5....................................................................................................................................232.5.2Piano-X....................................................................................................................................24Chapter3:Metrics,Parameters,andCategories..................................................................253.1MissionandInstantaneousPerformanceMetrics................................................................253.1.1FullMission.............................................................................................................................253.1.2SimplifiedMission..................................................................................................................263.1.3Instantaneous.........................................................................................................................273.2MeasuresofOutput.....................................................................................................................293.2.1Measureofdistancetraveled................................................................................................293.2.2MeasureofPayload(orProxy).............................................................................................303.2.3ConsiderationsforIncludingSpeedintheMetric...............................................................313.3AircraftCategoriesandAircraftList.......................................................................................33Chapter4:TypicalAircraftOperations..................................................................................354.1Payload..........................................................................................................................................354.2Range.............................................................................................................................................374.3FuelBurn......................................................................................................................................414.4TakeoffWeights..........................................................................................................................534.5Altitude..........................................................................................................................................544.6Speed.............................................................................................................................................554.7SummaryofTypicalAircraftOperations...............................................................................56Chapter5:EvaluationConditionsforaFullMissionMetric...............................................575.1FuelEfficiencyPerformanceSensitivitytoEvaluationConditions...................................575.2PrincipleforConstructingWeightedMetric.........................................................................59

-8- 5.3FullMissionMetricWeightedbyRangeFrequency.............................................................605.4FullMissionMetricWeightedbyFuelBurn...........................................................................635.5IssuesResultingfromEvaluationConditionsWeightedbasedonOperationalData...64Chapter6:EvaluationConditionsforanInstantaneousSinglePointMetric.................656.1AtmosphericConditions............................................................................................................656.2SpeedandAltitude......................................................................................................................656.3Weight...........................................................................................................................................686.4PotentialConsiderationswithRegardtoSinglePointEvaluationSchemes...................716.5CorrelationwithBF/R................................................................................................................72Chapter7:CaseStudies-SpecificAirRangeandBF/RforFutureAircraftTechnologies................................................................................................................................737.1CaseStudyVehicle:D-8.5...........................................................................................................737.2ImpactsofMeasurementonFutureAircraftDesigns..........................................................75Chapter8:Conclusions..............................................................................................................77Chapter9:Bibliography............................................................................................................79Chapter10:Appendix................................................................................................................8110.1AppendixA:BackgroundReviewofAviationandNon-AviationCertificationStandards................................................................................................................................................8110.1.1NOx........................................................................................................................................8110.1.1.1Metric..............................................................................................................................................8110.1.1.2CorrelationParameter...................................................................................................................8210.1.1.3EvaluationConditions....................................................................................................................8210.1.2CorporateAverageFuelEconomy(CAFE).........................................................................8210.1.2.1Metric..............................................................................................................................................8210.1.2.2CorrelatingParameter...................................................................................................................8310.1.2.3EvaluationConditions....................................................................................................................8310.1.2.4ScopeofApplicability....................................................................................................................8410.2DesiredAttributesofCertificationRequirement..............................................................8410.3AppendixB:AircraftList.........................................................................................................86

-9- [PageIntentionallyLeftBlank]

-10- ListofFiguresFigure1:CO2emissions(indexedto2005)withtargetsandaspirationalgoalsfromUSCOP15andIATACO2emissionsgoalsandICAOfuelefficiencygoal(i.e.2%perannum-CO2emissionscalculationsassume2005demand).(BonnefoyY.M.,2011)..............................14Figure2:NotionalCO2CertificationStandard....................................................................................15Figure 3: Conceptual representation of aircraft level and system level inputs and outputs................17Figure4:DesignPayloadvsDesignRangeAcrosstheFleet[DataSource:Piano-X]...................18Figure5:ScreenshotofPiano5interface(Lissys,Piano-5,2010)...................................................23Figure6:ScreenshotofPiano-Xinterface.............................................................................................24Figure7:MissionandReserveAssumptionSchematic(ICCAIA,2010)..........................................26Figure8:ExamplePurchaseAgreementPerformanceGuarantee(SEC,1999).............................27Figure9:NotionalPayload-RangeDiagram.........................................................................................29Figure10:DefinitionofWeightBasedParameters(BonnefoyY.M.,2011)..................................30Figure11:HistoricalEvolutionofLaborCostsandFuelCosts(AirTransportAssociationofAmerica,2009)..................................................................................................................................32Figure12:2006Boeing737-800Operations[DataSource:BTSForm41T-100].......................35Figure13:2006USAllCarrierPayloadFrequenciesbyAircraftCategory[DataSource:BTSForm41T-100]..................................................................................................................................36Figure14:2006Boeing737-800RangeFrequency[DataSource:BTSForm41T-100]............37Figure15:2006TotalFleetUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]...............................................................................................................................................................38Figure16:2006NarrowBodyAircraftUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]............................................................................................................................................38Figure17:2006WideBodyAircraftUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]............................................................................................................................................39Figure18:April2006RegionalJetUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]..................................................................................................................................................40Figure19:2006TurboPropUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]......................................................................................................................................................40Figure20:Piano-XMissionSimulationGridonNotionalPayloadRangeChart...........................41Figure21:Bi-CubicFuelBurnInterpolation........................................................................................42Figure22:2006USAllCarrierFleetWideFuelBurn,PayloadFrequency,andRangeFrequency[DataSource:BTSForm41T-100andPiano-X].........................................................................43Figure23:WorldwideFuelBurn,Payload,andDepartures(Operations)byAircraftType[DataSource:COD].......................................................................................................................................44Figure24:2006USAllCarrierWideBodyFuelBurn,PayloadFrequency,andRangeFrequency[DataSource:BTSForm41T-100andPiano-X].....................................................44Figure25:2006USAllCarrierNarrowBodyFuelBurn,PayloadFrequency,andRangeFrequency[DataSource:BTSForm41T-100andPiano-X].....................................................45Figure26:2006USAllCarrierRegionalJetFuelBurn,PayloadFrequency,andRangeFrequency[DataSource:BTSForm41T-100andPiano-X].....................................................46Figure27:2006USAllCarrierRegionalJetFuelBurn,PayloadFrequency,andRangeFrequency[DataSource:BTSForm41T-100andPiano-X].....................................................47Figure28:April2006GlobalOperationsAboveandBelow1,000kmbyPercentDeparture(left)andPercentFuelBurn(right)[DataSource:COD]..........................................................47Figure29:April2006WorldWideOperations:%ofTotalFuelBurnedonMissions+/-1,000kmbyAircraftType[DataSource:COD]............................................................................48Figure30:April2006PercentageofFuelBurn+/-1,000kmbyAircraftType[DataSource:COD].....................................................................................................................................................51Figure31:April2006CumulativeDistributionofFuelBurn,Payload,andDepartures[DataSource:COD].......................................................................................................................................52

-11- Figure32:FuelBurnbyPhaseofFlightforEachAircraftCategory[Datasource:COD].............52Figure33:HistogramofUsefulLoadatTakeoffbyAircraftCategory[DataSource:BTSForm41T-100andPiano-X].....................................................................................................................53Figure34:HistogramofAircraftGrossWeightatTakeoffbyAircraftCategory[DataSource:BTSForm41T-100andPiano-X]..................................................................................................54Figure35:Actual(blue)andIdealFlightProfileforaBoeing757-200fromBostontoSanFrancisco(Lovegren,2011)............................................................................................................55Figure36:BF/RvsMTOWEvaluatedatTwoDifferentRangeConditions[DataSource:Piano-X]...............................................................................................................................................................57Figure37:MargintoRegressionLine[DataSource:Piano-X]..........................................................58Figure38:AircraftRankedbyResidualforTwoDifferentEvaluationConditions[DataSource:Piano-X]...............................................................................................................................................59Figure39:PrincipleforConstructingWeightedMetric.....................................................................59Figure40:FuelEfficiencyPerformanceforAircraftTypesasaFunctionofR1Range[DataSource:PIANO-X](BonnefoyY.M.,2011)....................................................................................60Figure41:WeightedMetricNormalizedbySingleEvaluationConditionMetric(R1)byAircraftType.....................................................................................................................................................61Figure42:ComparisonofRangeWeightedMetrictoSingleEvaluationConditionNon-WeightedMetric[DataSource:BTSForm41T-100andPiano-X]..........................................62Figure43:WeightedMetricNormalizedbySingleEvaluationConditionMetric(0.4*R1)byAircraftType[DataSource:BTSForm41T-100andPiano-X]................................................62Figure44:ComparisonofRangeWeightedMetrictoSingleEvaluationConditionNon-WeightedMetric[DataSource:BTSForm41T-100andPiano-X]..........................................63Figure45:1/SARpercentagechangesfromoptimumasafunctionofSpeedandAltitudeforarepresentativenarrowbodyaircraft[Datasource:PIANO-X]................................................66Figure46:SpecificAirRangeSpeedandAltitudeContoursforaRangeofRepresentativeAircraftTypes(Lovegren,2011)....................................................................................................66Figure47:Example1/SARsensitivityasafunctionofspeed(fixedaltitudeandweight)forrepresentativeaircraftforfiveaircrafttypesfromthefollowingcategories:WB,NB,RJ,TP,BJ.[Datasource:PIANO-X].......................................................................................................67Figure48:IllustrativeExampleofAircraftPerformanceDependenceonAltitudeAcrosstheFleet[Datasource:PIANO-X]..........................................................................................................68Figure49:1/SARandAircraftWeightevolutionoveranIllustrativeMission(R1,MSP)foraRepresentativeNarrowBodyAircraft[Datasource:PIANO-X]...............................................69Figure50:TakeoffWeightIso-ContoursforaRepresentativeNarrowBodyAircraft(BoeingAirportPlanningGuides)................................................................................................................69Figure51:Aircraftweightfractionsacrossaircraftcategories[Datasource:PIANO-X]............70Figure52:Designphilosophydifferences:maximumstructuralpayloadandR1rangeforaircraftinfivecategories.[Datasource:PIANO-X]....................................................................70Figure53:NotionalDepictionofAircraftRobustnesstoaFlightParameter................................71Figure54:1/SARvsMTOWforPiano5AircraftFleet[DataSource:Piano5]................................72Figure55:CorrelationofBF/Revaluatedat40%R1with1/SARevaluatedat(MTOW-MZFW)/2.............................................................................................................................................72Figure56:MITConceptAircraft-D8.5..................................................................................................73Figure57:PercentImprovementsin1/SARandBF/RforAircraftinMITD8.5MorphingStudy...............................................................................................................................................................75Figure58:PercentImprovementsfromBaselineinBF/Rvs1/SAR...............................................75Figure59:NOxperformancemetric,correlatingparameter,andregulatorylevels(BonnefoyY.M.,2011).............................................................................................................................................81Figure60:RepresentativeLTOCycleforAircraftEngineCertification..........................................82

-12- ListofTablesTable1:CertificationStatusofAircraftWeightParameters(BonnefoyY.M.,2011)..................31Table2:AircraftCategories.....................................................................................................................33Table3:FullMissionPiano-XAssumptions.........................................................................................42

-13- AcronymsandAbbreviationsACARSAircraftCommunicationsAddressingandReportingSystemMLWMaximumLandingWeightANCAAirportNoiseandCapacityActMRCMaximumRangeCruiseATCAirTrafficControlMSPMaximumStructuralPayloadBEWBasicEmptyWeightMTOWMaximumTakeoffWeightBFBlockFuelMTWMaximumTaxiWeightBJBusinessJetMVPMaximumVolumetricPayloadBTSBureauofTransportationStatisticsMZFWMaximumZeroFuelWeightCAEPCommitteeonAviationEnvironmentalProtectionNACENationalAverageCarbonEmissions(Australia)CAFECorporateAverageFuelEconomyNBNarrowBodyCASFECommercialAircraftSystemFuelEfficiencyNOXNitrousOxidesCOCarbonMonoxideOEWOperatingEmptyWeightCO2CarbonDioxideOPROverallPressureRatioCPCorrelationParameterPPayloadEASAEuropeanAviationSafetyAgencyPARTNERPartnershipforAiRTransportationNoiseandEmissionsReductionEDSEnvironmentalDesignSpaceRRangeEPAEnvironmentalProtectionAgencyR1Payload-RangepointatmaximumrangeatMZFWEPNdBEffectivePerceivedNoiseLevel,indecibelsR2Payload-RangepointatintersectionofMTOWandmaximumfuelvolumeFAAFederalAviationAdministrationRJRegionalJetFLFloorAreaSASingleAisleGHGGreenhouseGasSARSpecificAirRangeGIACCGrouponInternationalAviationandClimateChangeSEWStandardEmptyWeightGVWRGrossVehicleWeightRatingSOXSulfurousOxidesH20WaterSTASmallTwinAisleHCHydroCarbonSUVSportUtilityVehicleICAOInternationalCivilAviationOrganizationTCDSTypeCertificateDataSheetISAInternationalStandardAtmosphereTOGWTakeoffGrossWeightL/DLifttoDragratioTPTurbopropLQLargeQuadTSFCThrustSpecificFuelConsumptionLRCLongRangeCruiseULUsefulLoadLTALargeTwinAisleUNFCCCUnitedNationsFrameworkConventiononClimateChangeLTOLandingandTake-OffWBWideBodyMEWManufacturerEmptyWeightWG3(ICAOCAEP)WorkingGroup3

-14- Chapter1: Introduction1.1 MotivationGrowingconcernsoverclimatechangehavecreatedanimpetusforreducingGreenHouseGas(GHG)em issionsfro mallsectorsoftheglobale conomy.Despite thesubstan tialhistoricalreductionsoffuelburnandpollutantemissionsfromcommercialaviation,itisexpectedthatfurther improvementswill berequired,especiallyifthe globallong-termdemandforairtransportationcontinuestogrowandreductionsofnetGHGemissionsaretargeted.Agreenhousegasabsorbsandemitsinfraredradiation.Thecontributionofagreenhousegastoglobalclimatechangeisafunctionofthecharacteristicsofthecompoundaswellasitsabundance.Therearemanycompoundsthatfallunderthecategoryofagreenhousegas,butcarbondioxide(CO2)hasreceivedmuchattentionforitsprevalenceinadditiontoitsharmfuleffects.CO2isevenmoreimportantbecauseitsemissioncanaffecttheclimateforcenturies(Wuebbles,PARTNER-COE-2006-004,2006).Thistraitha smotivatedmanyentitiestotakestepstocurbCO2emissions.Figure1:CO2emissions(indexedto2005)withtargetsandaspirationalgoalsfromUSCOP15andIATACO2emissionsgoalsandICAOfuelefficiencygoal(i.e.2%perannum-CO2emissionscalculationsassume2005demand).(BonnefoyY.M.,2011)Figure1showsthehistoricalandprojectedtrendofaviationCO2emissionsalongwiththeproposedgoalssetbyvariousorganizations.InJune2009,theEuropeanUnion(EU-27)seta21%reductiontargetcomparedto2005tobeachievedin2020.IntheUnitedStates,theObamaAdministrationhasstatedtargetsof17%reductionsin2020(from2005levels)andan83%reductiontargetcomparedby2050.AnInternationalCivilAviationOrganization(ICAO)globalaspirationalgoalisbasedonafuelefficiencyimprovementof2%perannum.

-15- Whilecommercial aviationcontributedapproximat ely2.5%oftotalanthropo genicCO2emissionsin2005(Lee,2009),av iation'srelativecontribution toclimatechangeisestimatedtobehigher(Solomon,2007),dueinparttothetypesofemissionsproducedandthehigha ltitudeatwhichth emajorityofemissio nsare produced.Aviati on'srela tivecontributiontoclimatechangeisonlyexpectedtogrow,asothersectorsmitigatetheiremissionsproductionwhiledemandforaviationcontinuestoincrease.TheidentificationofCO2asaleadingcontributortoclimatechange,coupledwithconcernoverthepotentiallyincreasingcontributionofCO2emissionstoclimatechangebyaviation,motivatesactiontoassessmeasurestomitigateaviation'sCO2emissionsinthenear-term.1.2 CommercialAircraftCertificationStandardasaCO2MitigationTechniqueAircraftmanufacturershaveanaturalmarket-basedincentivetoreducefuelburninordertodecreasedirectoperatingcosts.Outsideofmarket-basedincentivestoimproveaircraftperformance,thereareseveralregulatorymechanismstofurtherincentivizeaircraftCO2performanceimprovements,includingemissionstradingsystems(ETS),emissionstaxes,andcertificationstandards.Thisthesisf ocusesoncertificatio nstandardsfornewaircrafttypes.AnaircraftCO2emissionsstandardisapotentialmechanismthatcouldprovi depositivein centivesforindustrystakeholderstoimproveaircraftfuelefficiencythroughtheimplementationofnewairframeandenginetechnology.Figure2:NotionalCO2CertificationStandardAspartiallyseeninFigure2,astandardcanbecomposedofthreeaspects;(1)ametric,correlatingparameter,andevaluationconditions;(2)ascopeofapplicability;and(3)aregulatorylimit.Notseenonthisnotionalcertificationstandardareevaluationconditions

-16- andscopeofapplicability.Evaluationconditionsrefertotheconditionsatwhichthemetricandcorrelat ingparameteraremeasuredtodemonstratecompliance,an dscopeof applicabilityreferstothetypesofaircraftthatmustshowcompliancewiththestandard.Acorrelatingparameterisnotanecessarypartofthestandard(e.g.canconsistonlyofametricandaregulatorylevel).However,in somecasesitmightbeapp ropriate forthestandardtovarywithasafun ctionof aveh icleattribute,suchassize.Inthiscase,aregulatorylevelcanbedefinedasafunctionofthecorrelatingparameter.Ate chnologyforcingstandardapplie spressuretomanufactu rerstodevelopnewtechnologywhileatechnologyfollowingstandardsetsthelimitsuchthatallnewaircraftmustmeetthebesttechnologyavailable.Thepositionoftheregulatoryleveldeterminesifthestandardistechnologyforcingortechnologyfollowing.CurrentlyICAO,aUnitedNati ons(UN)committee,isundertakingaconsensus-basedattempttoestablishaCO2certificationstandardthatisdevelopedwiththetechnicalinputandcommitmentfromallmemberstates,regulatoryagencies,industryrepresentatives,andspecialinterests.Thisattemptlimitsthescopeofapplicabilitytonewaircrafttypes(i.e.notusedtoforceaircraftretirementintheexistingfleet).Thescopeofapplicabilityincludesnewjetaircrafttypeswithamaximumtakeoffweight(MTOW)above5700kgandnewturbopropaircrafttypeswithaMTOWabove8618kg.TheCO2TaskGroup(CO2TG)withinICAOistaskedwithdevelopingrecommendationsforthemetric,correlatingparameter,andevaluationconditions.1.3 Definitions1Metric:Themetricgenerallycapturestheperformanceparameterthatistobeinfluenced(i.e.FuelBurnorCO2).Plottedonthey-axisofgraphsCorrelatingParameter(CP):Basedonfundamentalvehicleattributes(e.g.size).Correlatingparametersreflectfundamentalphysicaltradeoffsbetweenvehiclecapabilityandtheperformanceparameterthatistobeinfluenced.EvaluationCondition:Conditionatwhichthevehicleperformanceismeasuredandreportedtoshowcomplia nce.The semeasurement conditionsareintendedtoberepresentativeofactualconditions,butmaynotpreciselypredictactualvehicleinday-to-dayoperations.RegulatoryLevel:setstheperformancegoals(y-axis)tobeachievedforaproductwithagivencapability(x-axis).ThisregulatorylevelfunctiongenerallycapturesthephysicsbasedrelationshipbetweenthemetricandtheCP.Subsequentregulatorylevelsaregenerallysetbyslidingdown. 1 Bonnefoy, Y. M. (2011). Assessment of CO2 Emission Metrics for a Commercial Aircraft Certification Requirement. PARTNER.

-17- 1.4 CommercialAviationCO2EmissionsFigure 3showsaschematicrepresentationofaircraftandsysteminputandoutput.EachaircraftintheNationalAirspaceSystem(NAS)usesfueltodeliverairtransportationoutput(movementofpersonsorcargo)whileproducingemissions(CO2,H2O,NOx,PM,etc).Fromfirstprinciples,totalfleet-wideCO2emissionsfromcommercialaviationarefunctionofthreekeyfactors:(1) FuelCO2content(2) AircraftFuelEfficiency(3) OperationalfactorsItem(1)isdefinedastheamountofCO2releasedperextractedunitofenergyfromthefuel.Item(2)isdefinedastheamountofproductivitydeliveredbytheaircraftduringtheuseofaunitoffuelenergy.Theoperationalfactorsin(3)arecomposedofmassloadfactorslessthan100%,airtrafficcontrolsysteminefficiencies,andairlineinefficiencies.Theproductofthesefactorsissummedoverthetotalactualairtransportationoutput,asseeninEquation1inordertoarriveattotalfleet-wideCO2emissions.€

CO 2

Emissions=

CO 2

Fuel_Energy

Output

Fuel_Energy

Output

1 LF ATC

Airlines

Metric=

Fuel_Energy

Output

Equation2ThemetriccaneasilybetransformedintoCO2/OutputbymultiplyingEquation2bytheFuelCO2Contentforareferencefuel.Thereasonfordecomposingthemetricinthiswayistoisolateaircraftperformanceimprovementsordegradationsfromthoseofthefuel.Figure 3: Conceptual representation of aircraft level and system level inputs and outputs.

-18- 1.5 TheRoleofRepresentingAircraftPerformanceforaCertificationStandardAirplanesmustoperatesafelyandefficientlywithinacomplexenvironmentofphysicalandregulatoryconstraints.Inaddition,themanufacturermustmeetawidevarietyofcustomerneedswithades irableproduct whiler eturningareasonableamounto fprofittothecompanyinordertosustainproduction(ICCAIA,2010).Therangeofaircraftsizesunderthescope ofacerti ficationstandard isboardandencompassesshort-rangeturbopropst olow-payload,long-rangebusinessjets towidebodytransportaircraftliketheAirbusA380with500+seats,asseeninFigure4.Figure4:DesignPayloadvsDesignRangeAcrosstheFleet[DataSource:Piano-X]Moreover,aircraftconsumevastlydifferentamountsoffueltoflytheirdesignmissions.Thisresultisduepartlytothefactthataircraftaredesignedwithdifferentlevelsoftechnology,butmostlybecauseoftheinherentdifferencesbetweenaircraftwithdifferingdesignspecificationsintendedtoservedifferentmarketneeds.Onewaytoattempttoreconcilethisdifferenceistoincludesomemeasureof"productivity"toattempttoaccountforvariationsacrossthefleet.Thiscanbeintheformofrange,ameasureof"whatistransported"(i.e.payloadorapayloadproxy),orspeed.Aircraftarealsodesignedwithanabilitytoflyadiversityofmissionspartlyduetooperatornetworkdemandsandtoprovideflexibilityforpotentialmultipleownersthroughouttheaircraft'sservicelifetime.Fuelefficiencyperformanceencompassesawiderangeofaircraftcapabilities.Whilemuchofthem arketingfoc usandavailablepublisheddatais usuallyconcerned withp eakperformance,mostoperationsdonotnormallytakeplaceatthesemaximumpoints.Itistheenormousoperationalflexibilityofmostaircraftthatmakethemsuitedforahostofoff-

-19- designmissions.Atthesametime,theperformancefiguresrealizedatoneconditionmaynotapplyat another(ICCAIA,2010).Duetothisdiversityofoperations,evenifanappropriatemetricwereavailable,thereisnoobviousevaluationpointaprioriwithregardtopayload,range,speed,altitude,etc.1.6 ApproachestoMeasuringAircraftFuelEfficiencyPerformanceConventionally,performancemeasures,themostpopularofwhichistheCorporateAverageFuelEfficiency(CAFE)standardforUSautomobiles,aremissionbased.Thatis,fuelburn(oremissions)aresummedoverthecour seofanassum edmissiondesignedtorepresenttypicaloperations.Definingblockfuel(or missionfuel)for thebasisofa naircraftl evelmanufacturercertificationstandardisquitecompli cated.A manufa cturerstudyidentifiedover150assumptionsandparameterdefinitionsrequiredtofullydefineamissionforasimulationtool(ICCAIA,2010).Th isgreatlycom plicatesthecertificati onprocedureandaddsevenmoreburdentodefiningarepresentativemeasureofaircraftperformance.Theremaybeanopportunitytogreatlysimplifycertificationburdenandcomplexitybyusingasingle,instantaneous measurementthatstillreflectsaircraftperformanceonadiversityoftypicalaircraftoperations.SpecificAirRange(SAR)isatraditionalmeasureofaircraftcruiseperformancewhichmeasuresthedistanceanaircraftcantravelforaunitoffuelmass.€

SAR= dR -dW f V

FuelFlow

measuredin km kg

Equation3SARisanalogousto'miles-per-gallon'forautomobiles,exceptinsteadofintegratingthemeasurementoverafullreferencemission,themeasurementwouldbetakenatasinglerepresentativepoint(e.g.55mph,2passengers,50%fuel,auxiliarypoweroff).Thisthesisattemptstodeterminehowtodefineevaluationconditionsformission-basedandinstant aneousmetrics.SAR isalsoevalu ateda gainstBF/Rforpo tentialfut uretechnologiestodetermineifasinglepointinstantaneousmeasureofaircraftperformanceisareasonablecertificationstandardsurrogateforamoredetailedbutcumbersomemission-basedmeasurement.

Chapter2: ResearchObjectiveandApproach2.1 ObjectiveTheobjectiveofthisresearchisto:1) Assesstypi calcommercialaircraftop erationsinordertoinfo rmtheevaluationofmissionandinstantaneousperformancemetrics.2) Definerepresentativeevaluationconditionsformission-basedmetrics.3) Definerepresentativeevaluationconditionsforinstantaneouspointmetrics.4) Determineifaninstantaneouspointmetriccouldbeareasonablesurrogateformission fuelmetricdespiteit sinherentsimplicity,andidentifyanydifferences.Theendre sultof thiseffortisapotentialevaluationconditionformis sionandinstantaneouspointmetricsbasedontyp icalaircraftoper ations,anassessmentofthecorrelationbetweenthetwometricsattheirevaluationconditions,andanassessmentofmissionandinstantaneousmetriccorrelationforfutureaircraftdesigns.2.2 ApproachFirst,alistmetricsandcorrelatingparametersweredefined.Operationaldatawasthenusedtoassesstypicalaircraftoperationsinordertoinformtheevaluationofmissionandinstantaneousperformancemetrics.Missionmetricswerewe ightedbyoperation parameterstodetermineifare presentati vesingleevaluationconditionsuffi cientlyrepresentstypicalaircraftoperations.Assumptionsrequiredtodefineinstantaneouspointmetricevaluationc onditionsweremadebasedonfirs tprinciplesandtypicalaircraf toperations.Finally,afutureaircraftdesignwasevaluatedtodetermineiftheinstantaneouspointmetricimprovementscorrelatewithmissionmetricimprovements.2.3 DataSourcesSeveralanalysistools anddatasourceswere usedinthe evaluationof current fleetperformance.Theassumptions,fields,andaggregationtechniquesinherenttoeachsourceareimportanttounderstandinganyresultlimitations.

2.4 Operationaldatabases2.4.1 CommonOperationsDatabase(Global)TheCommonOperationsDatabase(COD)2isaglobalflight-by-flightoperationaldatabase.Eachlineinthedatabaserepresentsasingleaircraftflightandcontainsaircraftidentifiers(aircrafttype,enginetype);origin/destinationinformation(airport,country);andpayload,range,andfuelburnbyphaseofflight.3TheCODis constructed fromEuroco ntrol's(EC)EnhancedTrafficFligh tManagementSystem(ETFMS),FAA'sEnhancedTrafficManagementSystem(ETMS),andInternationalOfficialAirlineGuide(I OAG)data.ETFMSandETMSaccountforupto~75%ofglobalcommercialoperations,whileETMSalonecovers~55%,andtheremainderofworldwideoperationsarecoveredbyIOAGyear2006schedule.Payloadisnotdirectlyreportedonaflight-by-flightbasis,thereforeassumptionswereusedtocalculatepayloadintheCOD.Equation4describestheassumptionsusedtopopulatetheCODpayloaddata.Passengerpayloadiscomputedbymultiplyingthepassengerpayloadfactorbythenumberofseatsandaveragepassengerweight.Cargopayloadiscomputedbymultiplyingthecargoloadfactorbytheavailablecargocapacity.Specifically,IorDspecifiesinternationalordomestic;Wpistheaveragepassengerweight(91kg);PLFisthepassengerloadfactor;CLF(BEL)isthecargoloadfactoronpassengerflights;andCLF(FRT)isthecargoloadfactoronfreightflights.Equation4Foraspe cif icaircrafttype,Wp,me dianseats,andmedia nmaxstructural payloadare constant.PLFandCLFvarybyregionandcategory(IorD).Becausethereare6regions,2categories,and2loadfactors(PLFandCLF),payloadisaggregatedinto24binsforeachaircraft(MODTFRapporteurs,2008).2.4.2 BureauofTransportationStatistics(BTS)Form41T-100(UnitedStates)BecauseofthehighlevelofpayloadaggregationintheCOD,asecondoperationaldatabasewasobtain ed,butislimitedtoUnited Statesoperations.TheBureauo fTransportationStatistics(BTS)Form41Schedul eT-100U. S.all-carrier(internationa landdomestic) 2 InternationalCivilAviationOrganization,CommitteeonAviationEnvironmentalProtection,ModellingandDatabasesGroup's2006CommonOperationsDatabase;JointlymaintainedbyU.S.DOT'sVolpeCenter,onbehalfoftheFederalAviationAdministration,andEUROCONTROL'sExperimentalCenter;CAEP/9Version. 3 Columns: DATE;DEP_APT_CODE;ARR_APT_CODE;DEP_CNTRY_CODE;ARR_CNTRY_CODE;AIRCRAFT_TYPE;ENGINE_TYPE;AIRCRAFT_ROLE;TRAJECTORY_TYPE;DE P_BELOW10K_DISTANCE;ABOVE10K_DISTANCE;ARR_BELOW10K_DISTANCE;TO TAL_DISTANCE;DEP_BELOW10K_FUELBURN;ABOVE10K_ FUELBURN;ARR_BELOW10K_FUELBURN;TOTAL_FUELBURN;PAYLOAD;SEATS_MEDIAN;OEW_MEDIAN;MTOW_MEDIAN;FUEL_CAPACITY_MEDIAN;MSP_MEDIAN !

Payload

I/D (PAX)=[PLF I/D *Median_Seats*W P ]+[CLF(BEL) I/D P

Payload

I/D (Cargo)=CLF(FRT) I/D *Median_Max_Structure_Payload

-23- segmentdataforthefullyear20064providedbaseyearoperationaldata.Datawasfilteredtoexcludecargoservice,militaryflights,repositioningflights(i.e.departuresperformedwithzeropassengersreported),andsightseeing(i.e.departuresperformedwhoseoriginanddestinationwerethesameairport).Eachentryinthedatabaseisamonthlyaggregationofauniqueaircrafttype,operator,andorigin-destination(OD)pair.2.5 AircraftPerformanceModels2.5.1 Piano-5Piano-5isanintegratedtoolforanalyzingandcomparingexistingorprojectedcommercialaircraft.Itconsistsofa250+aircraftdatabase,aflightsimulationmodule,andanaircraftredesigntool.Piano'saircraftdatabase(AppendixB:AircraftList)containsexistingtypesaswellasprojecteddevelopments.Eachaircrafthasbeencalibratedaccordingtothebestdataavailablefrombothpri vateandp ublicsou rces.Piano'smodelsarec onstructedindependentlyonthebasisofgenerally available, non-confidentialinformat ionanddescriptions,andarenotin anywayendor sedbythe manufac turers orbyanyotherorganization(Lissys,Piano-5,2010).Figure5:ScreenshotofPiano5interface(Lissys,Piano-5,2010)Piano5allowsrealisticmanipulationofmostdesignparameters(Figure5)byredesigningtheaircraftusinguserspecifiedcriteria.Forexample,theusercouldopttore-enginetheaircraftwithanupdatedTSFCandnochangetotheairframe,ortheusercouldupdateengineTSFCandreoptimizetheaircraft(i.e.designanewaircraft)forthesameoranewmission.Thiscapabilitywillallowrealisticevaluationofperformancemetricsundertheinfluenceofnewtechnology.WhilePiano'smo delsandredesigncapab ilitieshavenotbee nvalidatedbyanymanufacturer,itisthebestavailablesecondarydatasource. 4 http://www.transtats.bts.gov/DL_SelectFields.asp?Table_ID=309&DB_Short_Name=Air%20Carriers

-24- 2.5.2 Piano-XPiano-XissimilartoPiano5withouttheaircraftredesigntool.Piano-Xcontainsanaircraftdatabase(AppendixB:AircraftList)andflightsimulationmodule.Figure6:ScreenshotofPiano-XinterfacePiano-Xallowstheinputofspeedpreference,altitudeconstraints,reserve,diversion,andtaxiin/outtimesinordertoprovidearealisticsimulation.Multipleoutputformatsarepossible,includingblockfuel summaries(fuel,time, CO2,NOx,et c)anddetailed flightprofiles(time,altitude, andfuelburnatstepsal ongthemission).

Chapter3: Metrics,Parameters,andCategoriesTherearetwoa pproachestoq uantifyingaircraftfuelefficiencyperformance:(1)fullmissionmetricsand(2)instantaneousmetrics.Fullmissionmetricsencompassallflightphasesandrequirealargesetofassumptionstodefineinthecontextofacertificationstandard.Asubsetofthefullmissionapproachistosimplifymeasurementsbyexcludingcertainphasesoffli ght.Theinstantaneou sapproa chcaneithermeasurefuelefficiencyperformanceatonepointormultiplepoints.Usingtheformi dentifiedi nEquation2,f uelefficiencymetricsare definedasFuel_Energy/Output.Anymeasureoftransportationoutputmustincludesomemeasureofdistancetraveled.Therefore,forthepurposeofthisresearch,outputisdefinedasrange.Becausethereisnoma thematicaldiffer encebetw eendefininganoutputterminthedenominatorofthemetricor onthec orrelating parameter,otherformsof output(e.g.payloadorpayloadproxy)areincludedinthecorrelatingparameter.Inthis chapter,ful lmissionandinstantaneou sfuelefficiencymetricsaredefined.Inaddition,rangeparameters,a ndpayloadproxiesaredetailed.Sp eedisexaminedfo rinclusioninametricorCP,andalistofaircraftandcategoriesarepresented.3.1 MissionandInstantaneousPerformanceMetrics3.1.1 FullMissionTheperformanceoftheaircraftismeasuredfortheentiremission.Thefullmission(FM)metricisdefinedinEquation5asBlockFueldividedbymissionrange.€

FM=

Block_Fuel

Range

-26- Figure7:MissionandReserveAssumptionSchematic(ICCAIA,2010)Fullmissiondefinitionrequiresmanyassumptionswithregardtopayload,range,climbschedules,etc.Asi nglephaseofthebl ockfuelmissionc ontains manysub-phases.Forexample,taxiconsistsofstart-up,enginewarm-up,overcomingstiction,accelerationtotaxispeeds,turns,stops,andre-starts(ICCAIA,Sept2010).Eachtaxiphasevariesbygroundcongestionandairportgeography(weatherandterrain).Calculationofblockfuelalsorequiresthedefinitionofreserves(Figure7),whichtypicallyvarybyoperatorandcrew.Whilereservefuelisnotcountedas"fuelburned"duringthecalculationofblockfuel,itisimportanttoincludeduetotheextraweightcarriedduringthemission.Reservefuelisdefinedbyoperationalrequirements(FAR121orEU-OPS1.255)andismandatedtocopewithdeviationsbetweenpredictedflightplanandactualflight.Byit'snature,blockfuelisdrivenheavilybyoperationalconstraints(noiseontakeoff,taxitimes,missionrulesbyODpair,overwaterroutes,etc).Whileblockfuelispredictablebasedonmanuf acturermodels,itsaccuracyisafunct ionoftheappropriateoperation alassumptionsofhowtheaircraftwil lbef lown(ICCAIA,Sept2010).To beused inacertificationstandard,theseassumptionswouldneedtobefullydefined.3.1.2 SimplifiedMissionSimplifiedmissionsareasubsetoffullmissions,andexcludesomephasesofflight.Forexample,inFigure7"StillAirRange"isasimplifiedmissionbecauseitexcludesthetaxi,takeoff,approach,andlandphases.Simplifiedmissionmeasurementsattempttolimitthenumberofassumptionsrequiredtodefinetheevaluationconditionforthecertificationrequirement.Simplifiedmissionmetricsalsoattempttolimittheinfluenceofoperationallydrivenphasesofflight.CAEP9_WG3_CO2-2_WPXX

Page 2 of 11

200 nmi

Climb

Cruise* @ LRC

Approach and land

30 Min. hold @ 1,500 ft

Mission

Reserves

Defined by operational rule jurisdiction

e.g. FAR International Mission Rules

Still air range

Flight time & fuelBlock time & fuel

Numerous assumptions/definitions required to sufficiently describe a "mission" for the purposes of calculating performance:

Aircraft definition, performance level, payload level, route (ordistance) definition, airport definition, operational rule jurisdiction, operational techniques, environmental factors, fuel quality, etc.

Fig 1. Mission Profile Descriptor -illustration of the mission elements typically used for the calculation of aircraft performance (fuel

burn, payload capability, range capability)

Accelerate to climb speed

Climb to 10,000 ft at 250kts

Climboutand acceler ate

to 1,500 ft & 250kts

Taxi out (xx min.)

Takeoff to 35 ft

Climb

Descend and decelerate

to 10,000 ft and 250 kts

Approach and land

Taxi in (yymin. from reserves)

Fuel for 10% flight time @

LRC Mach, final alt. and wt.

Missed approach

Descend

Descend to 1,500 ft at 250kts

Mission Profile & Fuel Requirements Descriptor

Cruise (w/Steps)

* e.g. defined as >zz% of Alternate Distance

-27- 3.1.3 Instantaneous5SpecificAirRange(SAR)6,is anins tantaneousmetricthatmeasurestheaircraftfuelefficiencyperformanceatasinglepointintime.Analogoustoinstantaneous'miles-per-gallon'forautomobiles,SARrepresentstheincrementalairdistanceanaircraftcantravelforaunitamountoffuelataparticularflightcondition.Equation6Thisinstantaneo usmeasureofaircraftfueleffi ciencyisawell -knownandwidelyusedperformanceindicatorinindustrytoday.Forinstance,apurchaseagreementbetweentheAirbusIndustryand USAirways,publiclyavailablefromtheSecurityExchangeandCommission'sdatabase(SEC,1999),specifiesSARvaluesguaranteedbythemanufacturer.Figure8:ExamplePurchaseAgreementPerformanceGuarantee(SEC,1999)SARcanbederivedfromfirstprinciples.Aircraftrange(R)isitsvelocitymultipliedbythetimealoft.Timealoftisequaltothecarriedfueldividedbytherateoffuelburn,whichisalsoequaltothrustrequired(Treq)multipliedbyspecificfuelconsumption(TSFC).Asfuelisburnedtheaircraftweightchanges,thuschangingdragandTreq,timealoft,andR(Raymer,2006).Thiscanbeexpressedinequationform,€

dR dW V -T(TSFC) V

D(TSFC)

VLD -W(TSFC) SAR= V TSFC L D 1 W

Equation8whereVistrueairspeed,TSFCisthrustspecificfuelconsumption,Lislift,Disdrag,andWistotalaircraftweightatthetimeofcalculation.Duetoitssimpledefinition,SARcanbecalculated(Equation6)bydividingtrueairspeed(measuredinkm/s)byfuelflow 5 Section partially appe ars in: FAA/PARTNER. (September 2010). Project 30 Metric Recom mendation . Geneva: International Civil Aviation Organization. 6 Specific Air Range is actually -dR/dW; the negative sign in the derivation indicates fuel burn (lost weight) !

SAR= dR "dW f V

FuelFlow

measuredin km kg

The nautical miles per pound of fuel at an A320 Aircraft gross weight of 145,000 lb at a pressure altitude of 37,000 ft in ISA+10(degree)C conditions at a true Mach number of 0.78 will be not less than a guaranteed value of 0.0839 nm/lb. !

-28- (measuredinkg/s).L/Dand,t oalesser extent, TSF Car efunctions ofaltitudeandatmosphericconditions.Thus,whenmeasuredinsteady-levelconditions,SARdependsonlyonaircr aftweight,altitude,airspeed,ambienttemperatureandsomeoperationalassumptionssuchaselectricalpowerextraction,operationoftheairconditioningsystem,andaircraftcenterofgravitylocationintermsofthemeanaerodynamicchord.ThismakesSARrelativelysimpleincomparisontofull-missionmetricsin3.1.1FullMission.Inaddition,SARencapsulatesfundamentalparametersthatdirectlyinfluenceairplanefuelefficiencyincluding:propulsionsystemefficiency(V/TSFC),aerodynamicefficiency(L/D),andairplane weight(1/W).Thefirstterm(V/TSFC)ofEquation8isequivalentto(T*V)/(FuelFlow*HeatingValue)foragivenfueltype,whichdenotestheratioofthetimerateofworkdonetothetimerateofchemicalenergyinput,alsoknownastheoverallefficiencyofapropulsionsystem.Thesecondterm(L/D)ofEquation8isthelift-to-dragratio,awell-knownparameterthatrepresentsaerodynamicefficiencyofanairplane.Thelasttermisairplaneweightattheevaluationcondition,whichincludesairframeweight.Therefore,SARisabletocapturetheprogressionofCO2reductiontech nologiese ncompassingth eareasofaerodynamics, propulsionsystem,andairframeweightreduction.WhilethesefundamentalparametersareincludedinEquation8,theequivalentdefinitionofSARasV/FuelFlow(Equation6)isanticipatedtoallowtheevaluationofSAReitherbydemonstrationthroughflighttestsornumericanalysis.Numericalanalysisistypicallydoneusinganairplaneperformancemodelcalibratedandvalidatedthroughanalysesandflighttests.Althoughnotrequiredbyairworthinessauthorities,manufacturersconductanumberofflighttestsd uringthecertificatio nprocesstovalidatecruiseperfor manceforthedevelopmentofflightmanualsthataresuppliedtotheoperators.Duetothiscommonuse,itisexpectedthatSARwouldberelativelyeasytocertifycomparedtomission-basedmetrics,whichrequiren umerousparameterstob edefinedandagreedupon,byaregulatoryauthorityaswellascomplexmethodologytoimplementwithinthecertificationprocess.AlthoughSARisapoint-basedmetricmeasuredforasingleaircraft,thefleetfuelburnperformancecommunicatedtothepubliccouldbecalculatedbasedoncertificationdata.AlthoughSARiswidelyusedintheaeronauticalengineeringcommunity,thereciprocalofSAR(1/SAR)isusedinthisresearchfortworeasons.First,thereisageneralconsensusamongstregulatorybod iesthataCO2metricshouldbe inaform ofCO2e missions normalizedbyaparameteroraproductofparameters.ThereciprocalofSARrepresentstheamountoffuelrequiredperaunitairdistance,andthusisconsistentwiththisgeneralmetricform(i.e.fuelburnperunitofairtransportationoutput).Secondly,byusing1/SARalongwiththeappropriateCP,areductioninthemetricindicatesanimprovement,whichisconsistentwiththenatureofmission-basedmetrics.Thisconsistentprinciplemetricformfacilitatesthecommonassessmentof1/SARandblockfuel metric s,sinceboth canbeinvestigatedforimprovementtrendsinthesamedirection.

3.2 MeasuresofOutputAmajorconsiderationinthedefinitionofcandidatefuelefficiencymetricsishowtodefine"Output"inEquation1.Thepurposeofairtransportationistotransportpeopleandgoodsoversomedis tanceinsome amountoftime.Thus,air transportat ionoutputcan beconstructedusingoneoracombinationofthefollowinghigh-levelparameters:(1) Measureofdistancetraveled(2) Measure(orproxy)ofwhatistransported(3) Measureofspeed(ortime)3.2.1 MeasureofdistancetraveledAnymeasureoftransportationproductivitymustincludesomemeasure ofdistancetraveled.Therearetwowaystoreferencedistance:first,absolutedistanceintermsofmilesorkilometers;orsecond,arelativedistancethatisdefinedasafractionofsomemeasureofaircraftrangecapability.Figure9:NotionalPayload-RangeDiagramFigure9depictsanotionalpayload-rangediagram.Theboundaryofthediagramislimitedbycha racteristicsoftheaircraft(e.g.MaximumStruct uralPayloa d(MSP),max landingweight,MTOW,andfuelcapacity).Theregioninsideoftheboundaryrepresentsfeasiblecombinationsofpayloadandr ange(miss ions).Acontourinsideofthe boundaryandparallelwiththeMTOWli mitedboundaryrepresentslinesofconstanttakeoffweight(TOW)(i.e.allcombinationsofpayloadandrangeonagivenlinecanbeachievedbyasingleTOW).InordertoachieveadifferentmissionatthesameTOW,theproportionofpayloadandfuelmustbechanged.

?"781$+",*-".$ &'()*#+,#-+(*.$(.##/$0)+1#2)'34.#

-30- R1isacommonlyusedreferencedistance.ItistheintersectionoftheMSPlimitedlineandtheMTOW(o rmaxlandingweight)limitedline.R1representsthemaximumrangeanaircraftcanflytheMSP.Forthisreason,R1servesinthisresearchasaproxyforaircraftdesignrange.R1aisdepictedhereforcompleteness.Notallaircraftaremaxlandingweightlimitedontheirpayload-rangeboundaryasthisonlyhappenswhenthereservefuelforlong-rangemissionsisverylarge.Inthis research,r elativedistancemea surementsarepreferredoverabsolutedistancemeasurementsduetodesigndifferencesinherenttotheaircraftfleet.Thereisafactorof15differencebetweentheshortestandlongestR1rangeamongstaircraftinthisstudy(Piano-X).Thus,fractionsofR1rangeareused,asitisconvenienttocompareaircraftonasimilarrelativebasis.3.2.2 MeasureofPayload(orProxy)EachaircraftcanbedecomposedintoafewweightcategoriesasshowninFigure10.Figure10:DefinitionofWeightBasedParameters(BonnefoyY.M.,2011)TheManufact uringEmptyWeight(MEW)istheai rcraftweig htasitleavesthemanufacturingfacility.Th isincludesstructuralweight,avionics, electricalsystems,pneumatics,hydrologicsystems,andothers.MEWisnotcertifiedandisnotstandardacrossaircraftmanufacturers. Oncetheaircraftisdeliveredtoanoperatoritisoutfittedwithoperationalequipmentsuchasseats,servicecarts,etc.TheOperatorEmptyWeight(OEW)isnotcertifiedanddoesnothaveastandarddefinitionacrossoperators.ThisfullyoutfittedaircraftcanthenflyapayloaduptoMaximumStructuralPayload(MSP).Theoperatingaircraftweigh twithMSPonboard isMaximumZeroFuelWeight(MZFW),whichisacertifiedparameter.Ultimately,MaximumTakeoffWeight(MTOW)limitsthetotalaircraftweight,andthisparameterlimitstheamountoffuelwithMSPonboard.

Table1:CertificationStatusofAircraftWeightParameters(BonnefoyY.M.,2011)AvailabilityofCertifiedMetricsAcronymMetricAircraftManufacturerCertificationOperatorCertificationMTWMaximumtaxiweightCertifiedN/AMTOWMaximumtakeoffweightCertifiedN/AMLWMaximumlandingweightCertifiedN/AMZFWMaximumzerofuelweightCertifiedN/AOEWOperatingemptyweightNotCertifiedCertified(inAirplaneFlightManual)Max.PayloadMaximumPayloadNotCertifiedCertified(inAirplaneFlightManual)MEWManufacturer'semptyweightNotCertifiedN/AWhilesomeweightparametersarenotcertified(Table1)atthemanufacturerstage,theyarecertifiedbytheoperatorintheaircraftflightmanualinordertoinformpilotsduringflightplanning. Parametersthatarenot certifiedbythemanufacturerdono thaveconsistentdefinitionsacrossmanufacturersoroperators.Thereisnocertifiedpayloadparameter.ThedefinitionofMSPisMZFW-OEW,whichisnotcertifiedasOEWvariesacrossmanufacturersandoperators.Othermeasuresof'WhatisTransported'includefloorarea,volume,numberofseats,orsomecombinationofthese.Floorareawaseliminatedfromconsiderationduetothelackofastandarddefinitionacrossmanufacturersandthepotentialgamingofastandardbasedonfloorarea(i.e .increasesin" non-productive"floorareainorder tobeatthestandard).Volumewaseliminatedfromconsiderationforthissamereason.Numberofseatsisahighlydependantonoperationalconsiderations.Forexample,aB737-700canbeoutfittedwithastandard~126-seatconfiguration,oritcanbeoutfittedwithanallbusinessclassconfiguration.Themanufacturerhasnocontroloverthenumberofseatsthatareoutfittedbytheoperator;thus,inthisexamplethereisalargedifferencebetweenthecertificationvalueofthemetricandthe"day-to-day"valueofthemetric.Forthesereasons,theparametersofinteresttothisresearchareMTOW,MZFW,andOEW(whilenotcertified, istheon lyavailableparametertobeu sedasa proxytoca lculatepayload).3.2.3 ConsiderationsforIncludingSpeedintheMetricThereareconsequencesforincludingspeedinaproposedmetric,andtherearepotentialimplicationsfornotincludinganymeasureofspeed.First,BlockFuelandSpeedarecoupledattheoperationallevelanddesignlevel.Thecruisespeedatwhichairlineschoosetoflytheaircraft(operational)infl uencesfuelburn.Fromadesigns tandpoint,aircraft

-32- manufacturerschooseacruisespeedbas edonthevehiclemiss ions pecifications(influencingfuelburn).Blockfuelenergycanbereducedbyasignificantamountincurrentaircraftbyusingaspeedlessthancurrentoperationalspeeds(BonnefoyP.A.,2010).Further,researchhasshownthattherearesignificantfuelburnbenefitsfromdesigningaircraftwithslightlylowerdesignspeeds(MITN+3ResearchTeam,April2010).Ifspeedwereincludeddirectlyinthemetricdenominator,aircraftdesignssimilartocurrentvehicleswouldbedriventohigherspeedsinordertoachievebettermetricscores,potentiallyatthecostofincreasedactualfuelburn.ThissuggeststhatincludingspeedinaCO2metricmayresultinnegativeunintendedconsequences.Theinclusionofthespeedinthemetricalsoimplicitlyassumesarelativeweightbetween"timerelatedcosts"drivenbyspeedvs."fuelrelatedcosts"drivenbyfuelburn.ThisrelativeweightissimilartotheCostIndexusedbyairlines,onanoperationalbasis,toadjustcruisespeedbasedontherelativecostoffuelandlabor.Whilethisworkswellforoperationaladjustments(basedonreal-timechangesoffuelvs.laborcosts),theinclusionofaspeedparameterintheaircraftcer tific ationmetric wouldrequireforecastingac ostindex.However,theratiooffueltolaborcosts(i.e.costindex)hasnotbeenconstantovertimeasshowinFigure11.Figure11:HistoricalEvolutionofLaborCostsandFuelCosts(AirTransportAssociationofAmerica,2009)Clearly,speedisafac torthat significantlyinfluencesaircraftfuelburn.Becauseofitssignificance,speedisaparameterthatcannotbeignoredintheprocessofdeterminingacertificationrequirementregulatingaircraftCO2emissions.However,itislikelythatspeedismostappropriatelydealtwithasameasurementconditioninthecertificationprocess.

-33- 3.3 AircraftCategoriesandAircraftListAnobjectiveofthisresearchistoidentifyperformanceforawidevarietyofaircraft.Aircraftinthisstudyspansizesfrom4,500kgto600,000kgand6seatsto800seats.AnaircraftlistisincludedinAppendixB:AircraftList.Broadclassificationschemeswereusedtoplacetheaircraftmodelsintogeneralcategoriesbasedongeneraltypeandcapability.Groupingaircraftintobinsfacilitatedobservationofhowmetricstreateddifferentclassesofaircraft.SeveraldifferentcategorizationswereusedinthisresearchandarelistedinTable2alongwiththeassociatedabbreviations.Table2:AircraftCategoriesCategorization1Categorization2Turboprop(TP)Turboprop(TP)BusinessJet(BJ)BusinessJet(BJ)RegionalJet(RJ)RegionalJet(RJ)SingleAisle(SA)SmallTwinAisle(STA)NarrowBody(NB)LargeTwinAisle(LTA)LargeQuad(LQ)WideBody(WB)

Chapter4: TypicalAircraftOperationsInordertodefineastandardthatisrepresentativeofthewayaircraftareoperated,thestandardshouldbebasedonevaluationconditionsthatarerepresentativeoftypicalaircraftoperations.Thedefinitionoftypic alaircraft operationscanbeinformedbyeval uatingoperationaldatabasestounderstandthewaysinwhichaircraftareoperatedtoday.Aircraftaredesignedwiththeabilitytoflyadiversityofmissionspartlyduetooperatornetworkdemandsandtoa lsotoprovidefl exibili tyforpo tentialmultipleo wnersthroughouttheaircraft'sservicelifetime.Figure12:2006Boeing737-800Operations[DataSource:BTSForm41T-100]Whilemostofthemarketingfocusandavailablepublisheddataisusuallyconcernedwithpeakperformance,mostoperationsdonotnormallytakeplaceatthesemaximumpoints(Figure12).Itistheoperationalflexibilityofaircraftthatmakethemsuitedforahostofoff-designmissions.Atthesametime,theperformancefiguresrealizedatoneconditionmaynotapplyatanother(ICCAIA,2010).Forthisreason,typicalaircraftoperationswillbeassessedinordertoinformthedefinitionofmissionandinstantaneousevaluationconditions.4.1 PayloadTheBTSdatabaseisusedtoexaminedetailedpayloadfrequenciesforallflightsoriginatingorterminatingintheUnitedStates.Asstatedin2.3,BTSForm41T-100databaseincludesdomesticandinternationalcarrierswithoriginsordeparturesintheUnitedStates.BTSpayloadincludespassengerweight,bellyfreight,andmail.Thedataisaggregatedinentriesaccordingto:oneentrypermonthforauniqueaircrafttype,carrier,O-Dpair.Thisisthehighestfidelitypayloaddataavailablefordetailedexamination.Duetothefactthatitisslightlyaggregatedthereissomeregressiontothemeanascomparedwithatruepayloaddistribution.

-36- Figure13:2006USAllCarrierPayloadFrequenciesbyAircraftCategory[DataSource:BTSForm41T-100]

-37- Asseen inFigure13,al lpayloadfreq uenciesarehaveasinglemode,withanaveragefrequencybetween49%to55 %of MSP.The chartisorde redfromtop tobottomby(generally)shorter-rangeaircrafttolonger-rangeaircraft.4.2 RangeTheBTSdatabasewasusedtoassessrangefrequenciesbyaircrafttypeandcategory.AnexamplerangefrequencyisdepictedinFigure14foraBoeing737-800.Figure14:2006Boeing737-800RangeFrequency[DataSource:BTSForm41T-100]TheBoeing737-800(withwinglets)hasanR1rangeat4,009km(Piano-X).AscanbeseeninFigure14,approximately97%ofoperationsoccurbelowR1range.Thedistributionhasapeaknear40%ofR1range.AbsoluterangefrequencyforthetotalfleetisshowninFigure15.

-38- Figure15:2006TotalFleetUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]Mostfleetmissionsoccurbelow5,000kmmissionrange.Thisisduetothefactthatallintra-USmissionsarelessthanthisdistance.Trans-AtlanticflightsfromtheNortheasternUnitedStatestoWesternEuropeareapproximately5,000km(BOStoLHR,5,230km).Theslightincreaseinfrequencyonmissionsofapproximately 6,000km+ isduetotrans-AtlanticflightsfromSoutheasternandMid/Mid-WesternUnitedStatestoWesternEurope,allofUStoMid/EasternEurope,andtrans-Pacificflights.Rangefrequenciesbyaircraftcategorywerecomputedandtheresultswereaggregatedinto500binsbasedo nfractionofR1rangeforeachaircrafttype.Thechartswithrelativedistances(i.e.percentofR1)presentedinthissectionincludedistancesuptoR1range.Onafleet-widebasis,1.7%ofoperationsoccurpastR1range(BTS,Piano-X).Figure16:2006NarrowBodyAircraftUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]

!"##"$%&'(%)*&+,-.&/0-1*2&$3&45*2(6$%#&

-39- AsseeninFigure16,narrowbodyaircraftoperateamajorityoftheirflightsatrangesbelow50%ofR1range.Therangefrequencyhasameanof41%ofR1range.Figure17:2006WideBodyAircraftUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]Asseen inFigure17,widebodya ircrafthaveameanof 0.61,withmoreoperationsoccurringneartheR1rangethanthenarrowbodies.Widebodyaircrafttendtoflylonger-rangemissions(i.e.mostlyservethemajorintercontinentalmarkets),thusunlikeanarrowbodyaircraftsuchastheBoeing737-800(Figure14)whichservesmainlyintra-continentalmarkets,thewidebodiesoperatemoreoftheirmissionsatamuchhigherpercentageofR1range.Thisdifferen cecanbesee nmoreexplicitlybycomparing Figure17withthecorrespondingnarrowbodyrangefrequencychart(Figure16).Regionaljets,whichgenerallydescribe50-100seatshort-haulaircraft,becamemuchmorewidelyusedafterairlinederegulationin1978.Onceairtravelbecamemoreaffordableforawiderrangeofpopulation,shortroutesfeedingmajormarketsbecamemorecrucialtoservice.Theshorthaulregionaljetsupplantedthetubro-propontheseroutesduetotheirlongerrangeandfastercruisespeeds(andperceivedsafetybenefitsbyconsumers).TheBAeSystems146wasdesignedtofillthisgapinthemarketshortlyafterderegulation,butwasdesignedwithoutthedesigndiversityinherentinmostcommercialaircraft.Becauseofthis,competitorssuchasBombardier(e.g.CRJ)andEmbraer(e.g.ERJ145)designedlonger-rangeregionaljetscapableofpoint-to-pointservice(ratherthanoperatinginthehubandspokenetwork),whicheventuallycapturedthemarket.

-40- Figure18:April2006RegionalJetUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]Duetothesedesignco nsiderationsandthema rketthattheyserve,regionaljetsareoperatedwithameanfrequencyof39%ofR1(Figure18).Currently,amidcompetitionfromlowcostc arriersonmids izecitypairs,regionalje tsarefacingd ecliningnumber ofdepartures.Figure19:2006TurboPropUSAllCarrierRangeFrequency[DataSource:BTSForm41T-100]Turbopropaircraftcompetewithregionaljetsbyofferinglowerfuelconsumption(buthighermaintenancecosts)andanabilitytotakeofffromshorterrunways.However,theemergenceofregionaljetshaspushedtheturbopropintoveryshort-rangemarkets,asexhibitedbythemeanrangefrequencyat30%ofR1rangeinFigure19.

-41- 4.3 FuelBurnInordertocompleteadetailedexaminationofwherefuelisburnedbypayloadandrange,acombinationofBTSoperationaldataandPiano-Xperformancedatawereused.BTSdatadoesnotcontainfuelburn.However,itdoesincludepayloadandrange(4.2and4.3).FuelconsumptionforeachaircraftflyingaspecificO-DpairiscomputedfromPiano-Xmissionsimulations.Foreachaircrafttype,missionsweresimulatedatfractionsofmaximumstructuralpayload(MSP)andfractionsofR1range(i.e.rangeatthefirstbreakpointinapayloadrangecurve,whichdepictsthepointatwhichthesumofpayloadandfuelarelimitedbyMTOW,andafterwhichpayloadistradedformorerange).Figure20:Piano-XMissionSimulationGridonNotionalPayloadRangeChartInFigure20,acombinationofmissionsweresimulatedat1.0*MSP,0.8*MSP,...0*MSP,and1.0*R1,0.quotesdbs_dbs21.pdfusesText_27