1、The Engineering Society For Advancing Mobility Land Sea Air and Space I N T E R N A T I O N A L400 Commonwealth Drive, Warrendale, PA 15096-0001AEROSPACESTANDARDCopyright 1996 Society of Automotive Engineers, Inc.All rights reserved.Printed in U.S.ASAE Technical Standards Board Rules provide that: “
2、This report is published by SAE to advance the state of technical andengineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use ,including any patent infringement arising therefrom, is the sole responsibility of the user.”SAE revi
3、ews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invit esyour written comments and suggestions.Submitted for recognition as an American National StandardREV.AIssued 1981-10Revised 1996-09AS8002AIR DATA COMPUTER - MINIMUM PERFORMANCE S
4、TANDARDFOREWORDChanges in the revision are format/editorial only.1. SCOPE:This SAE Aerospace Standard (AS) covers air data computer equipment (hereinafter designated the computer) which when connected to sources of aircraft electrical power, static pressure, total pressure, outside air temperature,
5、and others specified by the manufacturer (singly or in combination) provides some or all of the following computed air data output signals (in analog and/or digital form) which may supply primary flight instruments:Pressure AltitudePressure Altitude, Baro-CorrectedVertical SpeedCalibrated AirspeedMa
6、ch NumberMaximum Allowable AirspeedOverspeed WarningTotal Air TemperatureIn addition, the computer may supply one or more of the following signals:Pressure Altitude, DigitizedEquivalent AirspeedTrue AirspeedStatic Air TemperatureAltitude HoldAirspeed HoldMach HoldAngle of AttackFlight Control Gain S
7、chedulingOthersSAE AS8002 Revision A- 2 -1.1 Purpose:This Standard defines minimum performance requirements under standard and environmental conditions for Air Data Computer equipment for use in Subsonic Aircraft.2. APPLICABLE DOCUMENTS:“U.S. Standard Atmosphere, 1976”, NASA/USAF/USWB, Washington, 1
8、976. (Notes 1 and 3)“Tables of Airspeed, Altitude and Mach Number; Based on Latest International Values for Atmospheric Properties and Physical Constants” Livingston and Gracey, Technical Note D-822, NASA, Washington, 1961. (Note 1)“Environmental Conditions and Test Procedures for Airborne Equipment
9、”, Document No. RTCA/DO-160A, January, 1980. (Note 2)“Federal Aviation Regulations, Vol. III, Part 25, Airworthiness Standards:Transport Category Airplanes”, FFA, Washington. (Note 1)“The International System of Units; Physical Constants and Conversion Factors”, Mechtly, Special Publication 7012, NA
10、SA, Washington, 1964.NOTES: (1) Available from Superintendent of Documents, Government Printing Office, Washington 20402.(2) Available from Radio Technical Commission for Aeronautics, 1717 H Street, N.W., Washington 20006.(3)Identical to ICAO Standard Atmosphere for values within the scope of this A
11、S.3. GENERAL STANDARDS:3.1 Operation of Controls:The operation of controls intended for use during flight, if any, in all possible position combinations and sequences including OFF, shall not result in a condition whose presence or continuation would be detrimental to the continued performance of th
12、e computer.3.2 Accessibility of Controls:Controls which are not normally adjusted in flight shall not be readily accessible to flight personnel, when the computer is installed in accordance with the manufacturers instructions. 3.3 Compatibility of Components:If the computer consists of more than one
13、 component and these components are individually acceptable but require matching for proper operation, these individual components shall be identified on the equipment nameplate in a manner that will ensure proper matching.SAE AS8002 Revision A- 3 -3.4 Interchangeability:Instruments and components w
14、hich are identified with the same manufacturers part number shall be interchangeable.3.5 Fire Resistance:Except for small parts (such as knobs, fasteners, seals, grommets, and small electrical parts) that would not contribute significantly to the propagation of a fire, all materials used must be sel
15、f-extinguishing when tested in accordance with the requirements of Federal Aviation Regulation 25.1359 (d) and Appendix F thereto, with the exception that materials tested may be configured in accordance with paragraph (b) of Appendix F or may be configured as used.3.6 Altitude Reference:Calibration
16、 of the static air sensing mechanism for pressure altitude outputs (including baro-corrected if supplied) shall be to the geopotential altitude tables of U.S. Standard Atmosphere, 1976.3.7 Calibrated Airspeed and Mach Reference:Calibrated airspeed and mach outputs shall be calibrated per Tables in N
17、ASA Technical Note D-822 dated August 1961.3.8 Alarm Signal:A means shall be provided to activate a warning device when electrical power (voltage and/or current) is not supplied to the computer. If the equipment has a self-test capability, a malfunction in the self-test system which affects output a
18、ccuracy of the computer shall be indicated in a positive manner.3.9 Self-Test Capability:If the computer contains integral arrangements to permit preflight and/or in-flight self-test checks on the operation of the equipment and/or in combination with other aircraft subsystems, a means shall be provi
19、ded to permit deactivating a using subsystem which might be adversely affected during the self-test cycle. In-flight self-test activating controls shall provide a means to warn the pilot of this mode of operation and which subsystems, if any, are deactivated. The self test feature shall be spring lo
20、aded or otherwise arranged to return automatically to the normal operating mode.SAE AS8002 Revision A- 4 -3.10 Applied Pressures:The computer shall meet the accuracy requirements herein and shall not be damaged after having applied to its pressure fittings, (energized and unenergized):Static Pressur
21、e Fitting - Approximately 1.4 inch (35.6 mm) Hg abs to 32 inch (813 mm) Hg abs.Total Pressure Fitting - The computer shall withstand (a) a Total Pressure of 125% of the differential pressure corresponding to the maximum airspeed range plus 32 inch (813 mm) Hg abs when static pressure is 32 inch (813
22、 mm), and (b) an excess of Static over Total Pressure of 2 inch (50.8) Hg.4. MINIMUM PERFORMANCE UNDER STANDARD CONDITIONS:4.1 Accuracy:Within the ranges specified by the manufacturer, the computer outputs shall meet the performance requirements of Tables 1 through 7 and other portions of this secti
23、on, as applicable during room ambient operation. The tolerances include threshold, friction, hysteresis, and repeatability. Tolerances for intermediate values are a straight line interpolation.4.2 Static Source Error Correction (if Applicable):Unless otherwise noted, outputs may be corrected for sta
24、tic source errors of the specific aircraft model in which the instrument is intended to be used. The tolerances for the outputs as corrected may be increased by the sum of: 10% of the tolerance, plus the product of the allowed tolerances of the correcting parameter and the slope of the certified cor
25、rection curve.Input pressures shall be adjusted from the values obtained using the references listed in paragraphs 3.6 and 3.7 by an amount corresponding to the static source error for each test point. Test points shall be selected by the vendor by combining test points shown in Tables 1, 3, and 4 i
26、n such a manner as to reflect minimum, zero, and maximum static source error correction and to reflect an intermediate value of static source error correction. Test points may be added to Tables 1, 3, and 4 to meet this requirement. If a parameter not shown in Tables 1, 3, and 4 is used for static s
27、ource error correction, the input signal for the parameter shall be applied to the computer at appropriate test points to meet the requirements of this specification.SAE AS8002 Revision A- 5 -TABLE 1 - AltitudeAltitudeFeetAltitudeMetersTolerance FeetTolerance Meters0.1000.2000.3000.4000.5000.8000.11
28、000.14000.17000.20000.30000.40000.50000.0.305.610.914.1219.1524.2438.3353.4267.5182.6096.9144.12192.15240.25.25.25.25.25.25.30.35.40.45.50.75.100.125.8.8.8.8.8.8.9.11.12.14.15.23.30.38.SAE AS8002 Revision A- 6 -TABLE 2 - Barometric Corrected AltitudeBarometricSettingScaleinch HgBarometricSettingScal
29、eMBCorrectionAppliedFeetCorrectionAppliedMetersBaroCorrectionTolerance FeetBaroCorrectionTolerance Meters22.0023.2723.9224.9825.9826.9927.5528.2028.5828.9429.9130.1530.7730.987457888108468809149339559689801013102110421049-8266-6794-6065-4907-3850-2825-2265-1630-1264- 920- 10211776965-2519-2071-1849-
30、1496-1173- 861- 690- 497- 385- 280- 36423729440353530302525252525252525251211119.09.07.57.57.57.57.57.57.57.57.5SAE AS8002 Revision A- 7 -TABLE 3 - Calibrated AirspeedAirspeedKnotsAirspeedkm/hourTolerance KnotsTolerance km/hour5080100120150200250300350400450901501802202803704605606507408305.03.02.02
31、.02.02.02.42.83.23.64.09.36.53.73.73.73.74.45.25.96.77.4SAE AS8002 Revision A- 8 -TABLE 4 - Mach NumberAltitudeFeetAltitudeMeters MachTolerance Mach010,00020,00030,00040,00050,00003,0486,0969,14412,19215,240.3.4.5.6.4.5.6.7.4.5.6.7.6.7.80.90.95.70.80.90.95.75.90.951.00.012.012.010.0075.012.010.0075.
32、005.012.010.0075.005.0075.005.005.005.0075.005.005.005.0075.005.005.0075.015SAE AS8002 Revision A- 9 -TABLE 5 - Vertical SpeedVertical SpeedFPMVertical SpeedM/MTolerance FPMTolerance M/M20000.6000.4000.2000.1000.500.200.100.50.0.-50.-100.-200.-500.-1000.-2000.-4000.-6000.-20000.6096.1829.1219.610.30
33、5.152.61.30.15.0.-15.-30.-61.-152.-305.-610.-1219.-1829.-6096.1000.300.200.100.50.45.45.45.45.45.45.45.45.45.50.100.200.300.1000.305.91.61.30.15.14.14.14.14.14.14.14.14.14.15.30.61.91.305.SAE AS8002 Revision A- 10 -TABLE 6 - Maximum Allowable Airspeed/Overspeed WarningAltitudeFeetAltitudeMetersVmo/M
34、moSpeedMaximumAllowableAirspeedToleranceKnotsMaximumAllowableAirspeedTolerancekm/hourOverspeedWarning1ToleranceKnotsOverspeedWarning1ToLerancekm/hour05,00010,00015,00020,00025,00030,00035,00040,00045,00050,00001,5003,0004,5006,0007,5009,00010,50012,00013,50015,000As specified byairframe builderAs sp
35、ecified byairframe builderAs specified byairframe builderAs specified byairframe builderAs specified byairframe builderAs specified byairframe builderAs specified byairframe builderAs specified byairframe builderAs specified byairframe builderAs specified byairframe builderAs specified byairframe bu
36、ilder-4,+0-4,+0-4,+0-4,+0-4,+0-4,+0-4,+0-4,+0-4,+0-4,+0-4,+0-7.5,+0-7.5,+0-7.5,+0-7.5,+0-7.5,+0-7.5,+0-7.5,+0-7.5,+0-7.5,+0-7.5,+0-7.5,+0-0,+4-0,+4-0,+4-0,+4-0,+4-0,+4-0,+4-0,+4-0,+4-0,+4-0,+4-0+7.5-0+7.5-0+7.5-0+7.5-0+7.5-0+7.5-0+7.5-0+7.5-0+7.5-0+7.5-0+7.51If an overspeed warning switch is provide
37、d in the computer, the switch shall be “off” for values below the overspeed value and “on” above the overspeed value.SAE AS8002 Revision A- 11 -TABLE 7 - Total Air TemperatureTemperatureCTolerance C50403020100-10-20-30-40-50-60-701.51.51.51.51.51.51.51.51.51.51.51.51.5SAE AS8002 Revision A- 12 -4.3
38、Barometric Corrected Altitude (if Applicable):The computer may contain an altitude output(s) which is corrected for barometric pressure. This particular output(s) shall differ from Table 1 values by the amount shown in Table 2 for the barometric settings shown in Table 2. The tolerances shown in Tab
39、le 2 are to be added to the Table 1 tolerances. If a remote device is used for the barometric setting, Table 2 tolerances shall be divided between the remote device and the computer as specified by the manufacturer. The barometric altitude feature shall not change other output parameters including t
40、he normal uncorrected altitude output(s).4.4 Additional Outputs:Additional outputs that are normally used for scheduling purposes or performing minor functions in subsystems are not required to meet the accuracy requirements of this specification. The manufacturers installation instructions shall cl
41、early identify these additional outputs and shall specify the accuracy of these outputs.4.5 Threshold:The flight instrument outputs shall provide a signal change of discernible magnitude upon an interface readout device of the proper phase when the input is varied incrementally or in alternate direc
42、tions by the following values:Altitude: 0.003 inches (0.08 mm) of mercuryAirspeed:0.003 inches (0.08 mm) of mercury or 25% of tolerance shown in Table 3, whichever is greater4.6 Leakage:The Leakage of the computer with static and pitot ports connected together shall not exceed 0.010 inches (0.25 mm)
43、 of mercury per minute with a pressure equivalent to 40,000 feet (5.54 inches or 140 mm of Hg abs) applied. With a pressure equivalent to 15,000 feet 1 (16.88 inches or 429 mm of Hg abs) applied to the static port and pitot port open to the atmosphere, the leakage shall not exceed 0.010 inches (0.25
44、 mm) of mercury per minute. These leak rates shall be measured with total volume of both Ps and Pt pressure (trapped gas) in the computer and test equipment equal to 100 10 cubic inches (1639 164cm 3 ). Thermal equilibrium shall be maintained while performing this test.1 If the applied pressure will
45、 exceed the total pressure fitting requirement of paragraph 3.10, the pressure for this portion of the test shall be increased to provide the differential pressure defined in paragraph 3.10.SAE AS8002 Revision A- 13 -4.7 Attitude Tolerance:The additional error in the output from the computer in the
46、following positions, without a change in the inputs, shall not exceed 25% of the tolerances for the normal position, except that a 50% tolerance increase is allowed for sub-paragraph (b).a.Computers rotated clockwise around its longitudinal axis, 90 from its normal position.b.Computers rotated aroun
47、d its longitudinal axis, 180 from its normal position.c.Computers rotated counterclockwise around its longitudinal axis, 90 from its normal position.d.Computers rotated about its lateral axis, 90 from its normal position so that the front end is up.e.Computers rotated about its lateral axis, 90 from
48、 its normal position so that the front end is down.5.MINIMUM PERFORMANCE UNDER ENVIRONMENTAL CONDITIONS:5.1 Test Procedures:Unless otherwise specified herein, the procedures applicable to a determination of the performance of air data computers under environmental conditions are set forth in Radio T
49、echnical Commission for Aeronautics, RTCA, document number DO-160A, entitled “Environmental Conditions and Test Procedures for Airborne Electronic/Electrical Equipment and Instruments”, dated January, 1980. Performance tests specified after subjection to test environments may be made after exposure to several environmental conditions. The order of tests shall be in accordance with paragraph 3.2, page 4, of DO-160A.The test procedures specified or referenced are satisfactory for use in determining the performance of air data computers under standard and extrem
