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  <xsd:element id="sncy_NumberOfPurchasedAircraftsPreviouslyUnderOperatingLeases" xbrli:periodType="duration" name="NumberOfPurchasedAircraftsPreviouslyUnderOperatingLeases" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" />
  <xsd:element id="sncy_AircraftMaintenanceDepositsContraAssetsMember" xbrli:periodType="duration" abstract="true" name="AircraftMaintenanceDepositsContraAssetsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_OverMarketLeaseRatesContraAssetsIncludedInOperatingLeaseRightOfUseAssetsMember" xbrli:periodType="duration" abstract="true" name="OverMarketLeaseRatesContraAssetsIncludedInOperatingLeaseRightOfUseAssetsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_ContraAssetsOutstanding" xbrli:periodType="instant" xbrli:balance="credit" name="ContraAssetsOutstanding" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_IncreaseDecreaseInContraAssets" xbrli:periodType="duration" xbrli:balance="debit" name="IncreaseDecreaseInContraAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_DecreaseInContraAssetsRelatingToPurchaseOfAircraftsPreviouslyLeased" xbrli:periodType="duration" xbrli:balance="credit" name="DecreaseInContraAssetsRelatingToPurchaseOfAircraftsPreviouslyLeased" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_ContraAssetsAsReductionToMaintenanceExpense" xbrli:periodType="duration" xbrli:balance="credit" name="ContraAssetsAsReductionToMaintenanceExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_NumberOfAircraftsPurchased" xbrli:periodType="duration" name="NumberOfAircraftsPurchased" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" />
  <xsd:element id="sncy_StockOptionsVestingBasedOnPerformanceMember" xbrli:periodType="duration" abstract="true" name="StockOptionsVestingBasedOnPerformanceMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_PilotEmployeesMember" xbrli:periodType="duration" abstract="true" name="PilotEmployeesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_NonPilotEmployeesMember" xbrli:periodType="duration" abstract="true" name="NonPilotEmployeesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_DefinedContributionPlanEmployerNonDiscretionaryContributionAmount" xbrli:periodType="duration" xbrli:balance="debit" name="DefinedContributionPlanEmployerNonDiscretionaryContributionAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_NonDiscretionaryContributionBasedOnEarningsPercent" xbrli:periodType="duration" name="NonDiscretionaryContributionBasedOnEarningsPercent" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:percentItemType" />
  <xsd:element id="sncy_EffectiveIncomeTaxRateReconciliationEmployeeParkingPercent" xbrli:periodType="duration" name="EffectiveIncomeTaxRateReconciliationEmployeeParkingPercent" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:percentItemType" />
  <xsd:element id="sncy_EffectiveIncomeTaxRateReconciliationMealsAndPermanentPercent" xbrli:periodType="duration" name="EffectiveIncomeTaxRateReconciliationMealsAndPermanentPercent" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:percentItemType" />
  <xsd:element id="sncy_DeferredTaxAssetsOperatingLeaseObligations" xbrli:periodType="instant" xbrli:balance="debit" name="DeferredTaxAssetsOperatingLeaseObligations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_DeferredTaxAssetsFinanceLeaseObligations" xbrli:periodType="instant" xbrli:balance="debit" name="DeferredTaxAssetsFinanceLeaseObligations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_DeferredTaxAssetsAccruedMaintenance" xbrli:periodType="instant" xbrli:balance="debit" name="DeferredTaxAssetsAccruedMaintenance" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_DeferredTaxLiabilitiesFinanceLeaseAssets" xbrli:periodType="instant" xbrli:balance="credit" name="DeferredTaxLiabilitiesFinanceLeaseAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets" xbrli:periodType="instant" xbrli:balance="credit" name="DeferredTaxLiabilitiesOperatingLeaseRightOfUseAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_IntangibleAssetsNetIncludingGoodWillGross" xbrli:periodType="instant" xbrli:balance="debit" name="IntangibleAssetsNetIncludingGoodWillGross" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_NumberOfPurchasedAircraftsPreviouslyUnderFinanceLeases" xbrli:periodType="duration" name="NumberOfPurchasedAircraftsPreviouslyUnderFinanceLeases" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" />
  <xsd:element id="sncy_EquityIncentivePlanMember" xbrli:periodType="duration" abstract="true" name="EquityIncentivePlanMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_TimeBasedStockOptionsMember" xbrli:periodType="duration" abstract="true" name="TimeBasedStockOptionsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_PerformanceBasedVestingMember" xbrli:periodType="duration" abstract="true" name="PerformanceBasedVestingMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_PerformanceBasedStockOptionsMember" xbrli:periodType="duration" abstract="true" name="PerformanceBasedStockOptionsMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageGrantDateFairValue" xbrli:periodType="instant" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageGrantDateFairValue" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType" />
  <xsd:element id="sncy_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestWeightedAverageGrantDateFairValue" xbrli:periodType="duration" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestWeightedAverageGrantDateFairValue" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType" />
  <xsd:element id="sncy_LongTermDebtGrossMaturityYearFive" xbrli:periodType="instant" xbrli:balance="credit" name="LongTermDebtGrossMaturityYearFive" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_DebtIssuanceCostsFutureAmortizationYearFive" xbrli:periodType="instant" xbrli:balance="debit" name="DebtIssuanceCostsFutureAmortizationYearFive" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_PropertyPlantAndEquipmentAcquiredThroughFinanceLeases" xbrli:periodType="duration" xbrli:balance="credit" name="PropertyPlantAndEquipmentAcquiredThroughFinanceLeases" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_LessorMaintenanceDepositsPolicyTextBlock" xbrli:periodType="duration" name="LessorMaintenanceDepositsPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" />
  <xsd:element id="sncy_CobrandedCreditCardProgramPolicyTextBlock" xbrli:periodType="duration" name="CobrandedCreditCardProgramPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" />
  <xsd:element id="sncy_ConcentrationRiskPolicyTextBlock" xbrli:periodType="duration" name="ConcentrationRiskPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" />
  <xsd:element id="sncy_PropertyPlantAndEquipmentUsefulLifeTableTextBlock" xbrli:periodType="duration" name="PropertyPlantAndEquipmentUsefulLifeTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" />
  <xsd:element id="sncy_AirlineEmployeeUnionGroupsTableTextBlock" xbrli:periodType="duration" name="AirlineEmployeeUnionGroupsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" />
  <xsd:element id="sncy_PartsRelatedToFlightEquipmentMember" xbrli:periodType="duration" abstract="true" name="PartsRelatedToFlightEquipmentMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_InventoryResidualValuePercent" xbrli:periodType="instant" name="InventoryResidualValuePercent" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:percentItemType" />
  <xsd:element id="sncy_AirTransportationEquipmentAirframesMember" xbrli:periodType="duration" abstract="true" name="AirTransportationEquipmentAirframesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_AirTransportationEquipmentCoreEnginesMember" xbrli:periodType="duration" abstract="true" name="AirTransportationEquipmentCoreEnginesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_AmazonMember" xbrli:periodType="duration" abstract="true" name="AmazonMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_ContractWithCustomerNumberOfPerformanceObligations" xbrli:periodType="instant" name="ContractWithCustomerNumberOfPerformanceObligations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" />
  <xsd:element id="sncy_CustomerMember" xbrli:periodType="duration" abstract="true" name="CustomerMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_AirLinePilotsAssociationMember" xbrli:periodType="duration" abstract="true" name="AirLinePilotsAssociationMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_InternationalBrotherhoodOfTeamstersMember" xbrli:periodType="duration" abstract="true" name="InternationalBrotherhoodOfTeamstersMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_TransportWorkersUnionMember" xbrli:periodType="duration" abstract="true" name="TransportWorkersUnionMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_LeaseDisclosureTextBlock" xbrli:periodType="duration" name="LeaseDisclosureTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" />
  <xsd:element id="sncy_LesseeBalanceSheetInformationTableTextBlock" xbrli:periodType="duration" name="LesseeBalanceSheetInformationTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" />
  <xsd:element id="sncy_LesseeSupplementalCashFlowInformationTableTextBlock" xbrli:periodType="duration" name="LesseeSupplementalCashFlowInformationTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" />
  <xsd:element id="sncy_LesseeTermsAndDiscountRatesTableTextBlock" xbrli:periodType="duration" name="LesseeTermsAndDiscountRatesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType" />
  <xsd:element id="sncy_AircraftMember" xbrli:periodType="duration" abstract="true" name="AircraftMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_OtherOperatingLeasesMember" xbrli:periodType="duration" abstract="true" name="OtherOperatingLeasesMember" nillable="true" substitutionGroup="xbrli:item" type="dtr-types:domainItemType" />
  <xsd:element id="sncy_NumberOfCategoriesInOperatingLeases" xbrli:periodType="duration" name="NumberOfCategoriesInOperatingLeases" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" />
  <xsd:element id="sncy_NumberOfLeasesForAircraft" xbrli:periodType="duration" name="NumberOfLeasesForAircraft" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" />
  <xsd:element id="sncy_NumberOfLeasesUnderFinanceLeases" xbrli:periodType="duration" name="NumberOfLeasesUnderFinanceLeases" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" />
  <xsd:element id="sncy_NumberOfLeasesUnderRightOfUseOperatingLeases" xbrli:periodType="duration" name="NumberOfLeasesUnderRightOfUseOperatingLeases" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" />
  <xsd:element id="sncy_AssetsLesseeAbstract" xbrli:periodType="duration" abstract="true" name="AssetsLesseeAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" />
  <xsd:element id="sncy_FinanceAndOperatingLeaseRightOfUseAsset" xbrli:periodType="instant" xbrli:balance="debit" name="FinanceAndOperatingLeaseRightOfUseAsset" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_LiabilitiesLesseeAbstract" xbrli:periodType="duration" abstract="true" name="LiabilitiesLesseeAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" />
  <xsd:element id="sncy_FinanceAndOperatingLeaseLiability" xbrli:periodType="instant" xbrli:balance="credit" name="FinanceAndOperatingLeaseLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_FinanceLeasesCostAbstract" xbrli:periodType="duration" abstract="true" name="FinanceLeasesCostAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" />
  <xsd:element id="sncy_OperatingLeasesCostAbstract" xbrli:periodType="duration" abstract="true" name="OperatingLeasesCostAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" />
  <xsd:element id="sncy_CashFlowLesseeAbstract" xbrli:periodType="duration" abstract="true" name="CashFlowLesseeAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" />
  <xsd:element id="sncy_MaintenanceReservePaymentsExpensed" xbrli:periodType="duration" xbrli:balance="debit" name="MaintenanceReservePaymentsExpensed" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_ContractualObligationForRetiredTechnologyCharges" xbrli:periodType="duration" xbrli:balance="debit" name="ContractualObligationForRetiredTechnologyCharges" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_GainOnSaleOfAirportSlotRights" xbrli:periodType="duration" xbrli:balance="credit" name="GainOnSaleOfAirportSlotRights" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" />
  <xsd:element id="sncy_NumberOfFreightersSubleasedDirectly" xbrli:periodType="duration" name="NumberOfFreightersSubleasedDirectly" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" />
  <xsd:element id="sncy_AmortizationOfMaintenanceReserveOverMarketLiabilities" name="AmortizationOfMaintenanceReserveOverMarketLiabilities" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" />
  <xsd:element id="sncy_CaresActGrantsRecognized" name="CaresActGrantsRecognized" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" />
  <xsd:element id="sncy_CaresActEmployeeRetentionCredit" name="CaresActEmployeeRetentionCredit" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="credit" />
  <xsd:element id="sncy_CaresActLoanMember" name="CaresActLoanMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="sncy_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentageVestingEachYearOverFourYearPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentageVestingEachYearOverFourYearPeriod" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="sncy_TwoVendorsMember" name="TwoVendorsMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="sncy_ScheduleOfPropertyPlantAndEquipmentDepreciationAmortizationAndRentExpensesTableTextBlock" name="ScheduleOfPropertyPlantAndEquipmentDepreciationAmortizationAndRentExpensesTableTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="sncy_ScaHorusHoldingsLlcMember" name="ScaHorusHoldingsLlcMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="sncy_PRInvestmentPartnersL.pMember" name="PRInvestmentPartnersL.pMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="sncy_CertainFundsOrAccountsManagedByInvestmentAdviserSubsidiaryOfBlackrockIncMember" name="CertainFundsOrAccountsManagedByInvestmentAdviserSubsidiaryOfBlackrockIncMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="sncy_AggregatePurchasePriceOfSharesIssued" name="AggregatePurchasePriceOfSharesIssued" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="sncy_SharePriceAsPercentageOfIPOSharePrice" name="SharePriceAsPercentageOfIPOSharePrice" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="sncy_CaresActGrantsUnderTreasuryUnderPayrollSupportProgramExtensionMember" name="CaresActGrantsUnderTreasuryUnderPayrollSupportProgramExtensionMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="sncy_NumberOfPurchasedAircraftsUnderFinanceLeases" name="NumberOfPurchasedAircraftsUnderFinanceLeases" nillable="true" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="sncy_LeaseTermForDeterminingMonthlyLeasePayments" name="LeaseTermForDeterminingMonthlyLeasePayments" nillable="true" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="sncy_DepreciationAmortizationAndRentalExpenses" name="DepreciationAmortizationAndRentalExpenses" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="sncy_OverMarketLiabilities" name="OverMarketLiabilities" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="sncy_IncreaseDecreaseInOverMarketMaintenanceReserveLiabilities" name="IncreaseDecreaseInOverMarketMaintenanceReserveLiabilities" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="sncy_NumberOfAircrafts" name="NumberOfAircrafts" nillable="true" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="sncy_NotesPayableToWilmingtonTrustCompanyMember" name="NotesPayableToWilmingtonTrustCompanyMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="sncy_PercentageOfCashSavingsInFederalAndStateIncomeTaxesThatPreIPOStockholdersRightToReceive" name="PercentageOfCashSavingsInFederalAndStateIncomeTaxesThatPreIPOStockholdersRightToReceive" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="sncy_TaxReceivableAgreementPercentageOfBenefitOnCashSavingsRetainedByCompany" name="TaxReceivableAgreementPercentageOfBenefitOnCashSavingsRetainedByCompany" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="sncy_NumberOfAircraftsIntendedToBePurchased" name="NumberOfAircraftsIntendedToBePurchased" nillable="true" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" />
  <xsd:element name="TaxReceivableAgreementAdjustment" id="sncy_TaxReceivableAgreementAdjustment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ProceedsFromStockOptionAndWarrantExercises" id="sncy_ProceedsFromStockOptionAndWarrantExercises" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="AdjustmentsToOperatingLeaseRightOfUseAssets" id="sncy_AdjustmentsToOperatingLeaseRightOfUseAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="NumberOfUnions" id="sncy_NumberOfUnions" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="EffectiveIncomeTaxRateReconciliationTaxReceivableAgreement" id="sncy_EffectiveIncomeTaxRateReconciliationTaxReceivableAgreement" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="EffectiveIncomeTaxRateReconciliationExecutiveCompensation" id="sncy_EffectiveIncomeTaxRateReconciliationExecutiveCompensation" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="TaxReceivableAgreementLiabilityNoncurrent" id="sncy_TaxReceivableAgreementLiabilityNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="IncreaseDecreaseInTaxReceivableAgreementLiability" id="sncy_IncreaseDecreaseInTaxReceivableAgreementLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ApolloGlobalManagementInc.AndItsSubsidiariesMember" id="sncy_ApolloGlobalManagementInc.AndItsSubsidiariesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="NumberOfStockholders" id="sncy_NumberOfStockholders" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonvestedOptionsExercisedWeightedAverageGrantDateFairValue" id="sncy_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNonvestedOptionsExercisedWeightedAverageGrantDateFairValue" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="DefinedContributionPlanEmployerNonDiscretionaryContributionYearOne" id="sncy_DefinedContributionPlanEmployerNonDiscretionaryContributionYearOne" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="DefinedContributionPlanEmployerNonDiscretionaryContributionYearTwo" id="sncy_DefinedContributionPlanEmployerNonDiscretionaryContributionYearTwo" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="DefinedContributionPlanEmployerNonDiscretionaryContributionYearThree" id="sncy_DefinedContributionPlanEmployerNonDiscretionaryContributionYearThree" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="NumberOfAircraftsInPowerByHourPeriod" id="sncy_NumberOfAircraftsInPowerByHourPeriod" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="LongTermDebtGrossMaturityAfterYearFive" id="sncy_LongTermDebtGrossMaturityAfterYearFive" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="DebtIssuanceCostsFutureAmortizationAfterYearFive" id="sncy_DebtIssuanceCostsFutureAmortizationAfterYearFive" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="ValuationOfTraLiabilityPolicyTextBlock" id="sncy_ValuationOfTraLiabilityPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="LeasesPolicyTextBlock" id="sncy_LeasesPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="NumberOfVendors" id="sncy_NumberOfVendors" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="NumberOfFinancialInstitutions" id="sncy_NumberOfFinancialInstitutions" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="CostIncurredToGetCargoAircraftsReadyForServiceNumberAmortizationPeriod" id="sncy_CostIncurredToGetCargoAircraftsReadyForServiceNumberAmortizationPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="NumberOfEnginesForDepositRecovered" id="sncy_NumberOfEnginesForDepositRecovered" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="NumberOfAircraftsExpectedToBeDelivered" id="sncy_NumberOfAircraftsExpectedToBeDelivered" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="LesseeOperatingLeasePaymentsCommittedPerYear" id="sncy_LesseeOperatingLeasePaymentsCommittedPerYear" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardInitialVestingPeriodFromGrantDate" id="sncy_ShareBasedCompensationArrangementByShareBasedPaymentAwardInitialVestingPeriodFromGrantDate" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="AdditionalIncreaseDecreaseInContraAssets" id="sncy_AdditionalIncreaseDecreaseInContraAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
</xsd:schema>
