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 StandardAS8019REV.AIssued1981-03Revised 1996-09AIRSPEED INSTRUMENTSFOREWORDChanges in the
4、 revision are format/editorial only.1. SCOPE:1.1 Types:This standard covers Airspeed Instruments which display airspeed of an aircraft, as follows:Type A-Air Driven, direct reading, self containedType B-Electrically operated, self containedType C-Electrically operated, input from a remote sensor1.2
5、Purpose:This standard establishes minimum performance standards for total and static pressure actuated airspeed instruments.SAE AS8019 Revision A- 2 -2. APPLICABLE DOCUMENTS:The following documents shall form a part of this specification to the extent specified herein:a. Radio Technical Commission f
6、or Aeronautics (RTCA) Document DO-160 “Environmental Conditions and Test Procedures for Airborne Electronic/Electrical Equipment and Instruments,” dated 28 February 1975. (Copies may be obtained from the RTCA Secretariat, 1717 H Street N.W., Washington, D.C. 20006).b. NASA Technical Note D-822, Tabl
7、es of Airspeed, Altitude, and Mach Number Based on International Values for Atmospheric Properties and Physical Constants, by Livingston and Gracey August 1961. 3. GENERAL REQUIREMENTS:3.1 Indicating Means:The airspeed shall be indicated by means of a pointer, dial, tape, drum, or other type of movi
8、ng element, or by a digital display. Unless otherwise specified, relative motion of the index with respect to the scale (either the index or the scale may be the moving element) must be clockwise, up, or to the right for increasing airspeed.3.2 Display:3.2.1 Graduations:The graduations shall be arra
9、nged to provide the maximum readability consistent with the accuracy of the instrument. Graduations shall be as follows:a. The first graduation shall be at the lowest usable airspeed of the instrument, as specified by the manufacturer.b. From the 10 knot, 10 mph, or 20 km/h graduation nearest to the
10、 first graduation and continuing to 250 knots, 250 mph, or 400 km/h major graduations shall be at least every 10 knots, 10 mph, or 20 km/h, with minor graduations at least every 5 knots, 5 mph, or 10 km/h.c. Over 250 knots, 250 mph, or 400 km/h, graduations shall be at least every 50 knots, 50 mph,
11、or 100 km/h.3.2.2 Numerals:The display shall include sufficient numerals positioned to permit quick and positive identification of each graduation.3.2.3 Instrument Identification:The instrument face shall be marked with “Airspeed” or “IAS” and also with the units of measure applicable to the instrum
12、ent.SAE AS8019 Revision A- 3 -3.2.4 Limits :The indicating means shall be limited in such a way that the moving element will not move more than (a) 10 degrees for circular display or (b) 0.25 in (6 mm) for linear displays beyond the greatest or least graduation in both increasing and decreasing dire
13、ctions.For circular displays, positive means must be taken so that no ambiguity will exist when the indicator is at the maximum or minimum position, including the maximum overtravel of 10. If a digital display is used a positive indication shall be provided on the display when the airspeed exceeds t
14、he instruments calibrated range.3.2.5 Visibility :The indicating means must be visible from all points within a space defined by a surface generated by lines making an angle of at least 30 degrees with the perpendicular to the display surface and diverging from the perimeter of the instrument window
15、 aperture. If integral lighting is provided, it must make all markings within the instrument easily readable, and not allow objectionable stray light to come from the instrument.3.2.6 Range :The range of operation of the instrument shall be marked on the nameplate.3.3 Fire Resistance:Except for smal
16、l 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 self-extinguishing when tested in accordance with the requirements of Federal Aviation Regulation 25.139(d) and Appendix F
17、thereto, with the exception that materials tested may be configured in accordance with paragraph (b) of Appendix F or may be configured as used.3.4 Self-Test Capability:If the equipment contains integral arrangements to permit pre-flight and/or in-flight self-test checks on the operation of the equi
18、pment in combination with other aircraft subsystems, a means shall be provided to deactivate any subsystem which might be adversely affected during the self-test cycle. In flight, self-test activating controls must provide a means to warn the pilot of this mode of operation. Self-test provisions sha
19、ll automatically return to the normal operation mode following self testing.3.5 Compatibility of Components:If instrument system components are individually acceptable but require matching for proper operation, they shall be identified on the equipment nameplate in a manner that will ensure proper m
20、atching.3.6 Reflectance, Cover Glass:The total reflectance of the instrument cover glass including the integral lighting wedge, if applicable, shall not exceed 10 percent of the incident light. This reflectance applies over the visible light spectrum from 450 milli-microns to 600 milli-microns, and
21、over an incident solid angle of 60 perpendicular to the viewing plane.SAE AS8019 Revision A- 4 -3.7 Accessibility of Controls:Controls not normally adjusted in flight must not be readily accessible to flight personnel.3.8 Case Markings (Types A and B):The back of the case, adjacent to the connection
22、s shall be permanently marked as follows:P-for pitot pressure connectionS-for static pressure connection3.9 Interchangeability:Instruments which are identified with the same manufacturers part number shall be interchangeable. When an instrument is characterized for a particular type aircraft it shal
23、l be so marked on the instrument nameplate.3.10 Effects of Tests:Unless otherwise stated, the application of the specified tests shall not produce a condition which would be detrimental to the continued performance of the instrument.3.11 Mounting Attitude:Should the capability of an instrument to me
24、et its stated performance be limited to a specific relationship of its axes to the axes of the aircraft, this limitation must be stated.3.12 Accuracy:Accuracy requirements for this standard are related to the instrument output for a specified sensor input. For Type A and B instruments, the accuracy
25、relates output to pressure input to the instruments, since they are self contained. For Type C instruments, the accuracy relates output to the input at the remote sensor; if matching of the instrument to the remote sensor is necessary to maintain the required overall accuracy, this must be so stated
26、 on the instrument nameplate.3.13 Power Malfunction Indication:For Type B and C instruments, means must be incorporated in the instrument to indicate the loss of adequate electrical power or loss of signal to the instrument. The indicating means must indicate a failure or malfunction in a positive m
27、anner.SAE AS8019 Revision A- 5 -4. MINIMUM PERFORMANCE REQUIREMENTS UNDER STANDARD TEST CONDITIONS:The test conditions applicable to a determination of the performance of airspeed instruments are set forth in Appendix A of this Standard. All instruments shall be tested in accordance with the manufac
28、turers recommendations. The manufacturer shall conduct sufficient tests to prove compliance with these Minimum Performance Standards.4.1 Scale Error:The airspeed instruments shall be tested for scale error at the proper pressure to produce all the differential pressure test points shown on Table 1,
29、Table 2, or Table 3 (knots, mph, or km/h), within the instrument range, first with pressure differential increasing, and then with pressure differential decreasing. With the differential pressure increasing it shall be brought up to, but shall not exceed, the specified differential pressure; with th
30、e differential pressure decreasing, it shall be brought down to, but shall not go below, the specified differential pressure. The errors at the test points shall not exceed the tolerances specified in Table 1, Table 2, or Table 3 as applicable.4.2 Friction:Type A.The instrument shall be tested for f
31、riction at four approximately equal scale intervals appropriate to the total range. The differential pressure shall be brought up to the desired test point and be held constant while two instrument readings are taken:the first reading shall be taken before the instrument is vibrated, and the second
32、reading after the instrument is vibrated. The difference between any pair of readings shall not exceed the tolerance shown in Table 4. The vibration applied shall be sufficient to remove all the friction from the instrument, and may be more than that given in Appendix A.Types B and C.The instrument
33、operation and indication shall be smooth and free from irregular motion as the differential pressure or its electrical equivalent is increased and decreased smoothly. Irregular motion shall be defined to be compatible with the type of display used.4.3 Balance Error:A pressure equivalent to one quart
34、er, one half, and three quarters of full scale deflection shall be applied to the instrument successively as test points. The difference in readings at each test point between that with the instrument in its normal operating position and that with the instrument in any other position, while being vi
35、brated, shall not exceed the tolerance of Table 4.SAE AS8019 Revision A- 6 -TABLE 1 - Scale Error KnotsIndicated AirspeedknotsDifferential Pressurein HgDifferential PressurekPaTolerance knots2030405060708090100120140160180200220250300350400450500550600650700.0192.0431.0767.120.173.235.308.390.481.69
36、5.9491.241.581.962.383.104.536.298.3910.8713.7817.1621.0825.6330.76.065.15.26.41.59.761.041.321.632.353.214.205.356.648.0610.5015.3421.3028.4136.8146.6658.1171.3986.80104.175555544433335555558888101010For differential pressure equivalent to the test points, but given in pounds per square inch (psi)
37、or inches of water (in H2O) see NASA Technical Note D822.SAE AS8019 Revision A- 7 -TABLE 2 - Scale Error Tolerance Miles Per Hour (mph)Indicated AirspeedmphDifferential Pressurein HgDifferential PressurekPaTolerance mph2030405060708090100120140160180200220250300350400450500550600650700.0145.0325.057
38、9.0905.130.178.232.294.363.524.715.9361.191.471.792.323.384.676.207.9810.0512.4415.1618.2621.78.05.11.20.31.44.60.791.001.231.772.423.174.034.986.067.8611.4515.8121.0027.0234.0342.1351.3461.8473.7655555444333336666669999912For differential pressure equivalent to the test points, but given in pounds
39、per square inch (psi) or inches of water (in H2O) see NASA Technical Note D822.SAE AS8019 Revision A- 8 -TABLE 3 - Kilometers Per Hour (km/hour)Indicated Airspeedkm/hourDifferential Pressureinches of HgDifferential PressurekPaTolerance km/hour406080100120140160180200250300350400450500600700800900100
40、0110012001300.022.047.089.140.202.277.356.453.562.8811.2751.7452.2932.9233.6375.3337.4169.92712.91516.44120.57425.39630.984.074.159.301.474.684.9381.2051.5341.9032.9834.3175.9097.7659.89812.31618.05925.11333.61643.73555.67569.67186.001104.92488886655555101010101015151515202020TABLE 4 - Friction and
41、Position Error ToleranceAir SpeedknotsAir SpeedmphAir Speedkm/hTolerance knotsTolerance mphTolerance km/h40-180190-70040-200210-80064-320336-12803546610SAE AS8019 Revision A- 9 -4.4 Leak:With both the pitot pressure and static pressure connections simultaneously evacuated to 15 inches Hg (50.7 kPa)
42、and properly sealed off, the leakage shall not cause more than 0.05 inch Hg (0.17 kPa) pressure drop during a 1 minute period. With the static pressure connection open and pressure equivalent to full scale pointer deflection applied to the pitot pressure connection and properly sealed off, the leaka
43、ge shall not cause more than 1 mph (1.6 km/h) or 1 knot decrease in indication during a 1-minute period. This test shall be made with test apparatus having a total volume of 100 10 in 3 (1.6L .16L), including the instrument and the test equipment. For types A and B only.4.5 Insulation Resistance:The
44、 insulation resistance between all electrical circuits connected together and the metallic case, measured at 200 VDC for 5 seconds, shall not be less than 5 megohms. Insulation resistance measurements shall not be made to circuits where the potential will appear across elements such as windings, res
45、istors, capacitors, etc., since this measurement is intended only to insure adequacy of insulation.5. MINIMUM PERFORMANCE STANDARDS UNDER ENVIRONMENTAL CONDITIONS:Unless otherwise specified herein, the measurement procedures applicable to a determination of performance of airspeed instruments under
46、environmental conditions are set forth in Radio Technical Commission for Aeronautics (RTCA) Document No. DO-160 entitled “Environmental Conditions and Test Procedures for Airborne Electronic/Electrical Equipment and Instruments,” dated 28 February 1975. Performance tests which must be made after sub
47、jection to test environments may be made after exposure to several environmental conditions. The order of tests must be in accordance with paragraph 3.2 of DO-160. The test procedures specified or referenced are satisfactory for use in determining the performance of airspeed instruments under normal
48、 and extreme environmental conditions; equipment category is to be as specified by the manufacturer. Alternate approved test procedures that provide equivalent results may be used.5.1 Magnetic Effect:When subjected to the test of DO-160, paragraph 15.0, the instrument must meet the requirements of C
49、lass A or Z.SAE AS8019 Revision A- 10 -5.2 Temperature:a. Low Temperature:When subjected to the tests of DO-160, paragraph 4.4, the instrument must operate electrically and mechanically, and the requirements of paragraph 4.1 of this standard must be met, except that the tolerance for all points shall be increased by 3 knots (3.5 mph - 6 km/h). After subjection to this test, the requirements of paragraphs 4.1 and 4.2 of this standard shall be met.
