Table of Contents
1.0INTRODUCTION
1.1PurposeofThisDocument
1.2SummaryofOperationalCharacteristics
1.3BriefDescriptionoftheSystem
1.4Interchangeability
1.4.1General
1.4.2InterchangeabilityDesiredforthe
ARINC706AirDataSystem
1.4.3"GenerationInterchangeability"
Considerations
1.5RegulatoryApproval
1.6Reliability
1.7IndustryViewsonDualADS
2.0INTERCHANGEABILITYSTANDARDS
2.1Introduction
2.2FormFactor,ConnectorandIndexPinCoding
2.3StandardInterwiring
2.4PowerCircuitry
2.4.1PrimaryPowerInput
2.4.226VoltACReferenceInput
2.4.3TheCommonGround
2.4.4TheACCommonCold
2.5SystemFunctionsandSignalCharacteristics
2.6Airframe-UniqueFunctions
2.7EnvironmentalConditions
2.8Cooling
2.9GroundingandBonding
3.0SYSTEMDESIGN
3.1PitotandStaticAirSystem
3.2TemperatureSensor
3.3AltitudeBaro-CorrectionSources
3.4IndicatedAngleofAttackSensors
3.5DigitalSignalStandards
3.6IndicatorStandards
4.0COMPUTERUNITDESIGN
4.1Introduction
4.2PressureLimits
4.3ComputerLeakRate
4.4Computer"Pressure"Volume
4.5Airframe-UniqueFunctions
4.5.1StaticSourceErrorCorrection(SSEC)
4.5.2VMO/MMOandOverspeedWarning
4.5.3CorrectedAngleofAttack
4.5.4AngleofAttackComparisonMonitor
4.6MonitoringandFailureWarning
4.7FunctionalTestProvisions
4.8StandardTemperatureSensorCharacteristics
4.9GeneralCharacteristicsofADSComputer
Outputs
4.9.1AccuracyandOperatingRanges
4.9.2FunctionThresholdSensitivity
4.9.3StandardizedOutputSignals
4.9.4FunctionFrequencyResponse
4.9.4.1Altitude
4.9.4.2Mach
4.9.4.3Airspeed
4.9.4.4AltitudeRate
4.9.4.5IndicatedandComputedAngleofAttack
4.9.5FunctionSlewingSpeeds
4.10SpecificCharacteristicsofADSComputer
Outputs
4.10.1Altitude(1013.25mb)
4.10.2BaroCorrectedAltitudeNo.1
4.10.3BaroCorrectedAltitudeNo.2
4.10.4AltitudeRate
4.10.5ComputedAirspeed
4.10.6Mach
4.10.7TrueAirspeed
4.10.8StaticAirTemperature
4.10.9TotalAirTemperature
4.10.10ImpactPressure
4.10.11TotalPressure
4.10.12Baro-CorrectionOutputNo.1
4.10.13Baro-CorrectionOutputNo.2
4.10.14IndicatedAngleofAttack
4.10.15CorrectedAngleofAttack
4.10.16MaximumAllowableAirspeed(VMO)
4.10.17DiscreteOutputs
4.10.17.1DigitalDiscreteWords
4.10.17.2OverspeedWarningOutput
4.11ADSComputerInputs
4.11.1Baro-Correction(Analog)
4.11.2Baro-Correction(Digital)
4.11.3IndicatedAngleofAttackInput
4.11.3.1IndicatedAngleofAttackInputMonitoring
4.11.4DiscreteInputs
4.11.4.1InputsforDiscreteOutputWords
4.11.4.2SSECSelectionDiscrete
4.11.4.3VMO/MMODiscretes
4.11.4.4AngleofAttackCorrectionSelection
Discrete
4.11.4.5PrimaryAngleofAttackSensorMonitor
Discrete
4.11.5ExternalProgramFunctions
4.11.5.1Baro-CorrectionAnalog/DigitalProgram
4.11.5.2AngleofAttackAverage/UniqueProgram
4.11.5.3Baro-CorrectionInputDiscrete
4.11.5.4ZeroMachSSECProgram
4.11.5.5ZeroAngleofAttackSSECProgram
4.12SpecialEnvironmentalTesting
Considerations
4.12.1CabinDecompression
4.12.2Temperature
5.0ADSAPPLICATIONSNOTES
5.1Introduction
5.2ADSOutputSignalsforOtherAccessory
UsersversusSeparatelyGenerated
SignalsinthoseAccessories
6.0PROVISIONSFORAUTOMATICTESTEQUIPMENT
6.1General
6.2UnitIdentification
6.2.1PinAllocation
6.3UseofATLASLanguage
7.0BUILT-INTESTEQUIPMENT(BITE)
7.1Built-InTestEquipment(BITE)
7.2Display
7.3FaultMonitor
7.4Self-TestInitiation
7.5MonitorMemoryOutput
ATTACHMENTS
1ADSComputerConnectorandPneumatic
FittingLocations
2StandardInterwiring
NotesApplicabletotheInterwiring
3AccommodationofAirframe-UniqueFunctions
4EnvironmentalTestCategories
5Table5-1ResistanceVsTemperature(CDEG)
for500OhmPCIPlatinumSensingElements
6ADSPerformanceEnvelope
7DigitalDataStandards-Table7-1
OutputDataStandards
Table7-2BNRDataEncodingExamples
Table7-3BCDEncodingExamples
Table7-4.1ADSDiscreteWordNo.1Format
Table7-4.2ADSDiscreteWordNo.2Format
Table7-5DataBusLoading
8IndicatorDesignGuidance
APPENDICES
1Symbols,DefinitionsandEquations
2ChronologyandBibliography Abstract
Describes the characteristics of a digital ADS intended for installation in subsonic commercial transport aircraft. Provides essential air data information for display to pilots and for use by other aircraft systems. Consists of a computer unit located in the aircraft electronics rack and suitable indicators located in the cockpit.
