SAE AS 439A-2001 Stall Warning Instrument (Turbine Powered Subsonic Aircraft)《失速警告仪器(由涡轮机提供动力的亚音速飞机)》.pdf

1、AEROSPACE STANDARDAS439 REV.AIssued 1967-01Reaffirmed 2008-02Revised 2001-10Stall Warning Instrument(Turbine Powered Subsonic Aircraft)FOREWORDChanges in this Revision are format/editorial only.1. SCOPE:This standard covers stall warning instruments to provide positive warning to the pilot of an imp

2、ending stall. Stall, as defined for the purpose of this standard, is the minimum steady flight speed at which the airplane is controllable.1.1 Purpose:This Aerospace Standard establishes the essential minimum safe performance standards for stall warning instruments primarily for use with turbine pow

3、ered subsonic transport aircraft, the operation of which may subject the instruments to the environmental conditions specified in paragraph 3.4.2. REFERENCES:There are no referenced publications specified herein.3. GENERAL REQUIREMENTS:3.1 Materials and Workmanship:3.1.1 Materials: Materials shall b

4、e of a quality which experience and/or tests have demonstrated to be suitable and dependable for use in aircraft instruments.3.1.2 Workmanship: Workmanship shall be consistent with high-grade aircraft instrument manufacturing practice.SAE Technical Standards Board Rules provide that: “This report is

5、 published by SAE to advance the state of technical and engineering 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 reviews each tec

6、hnical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2008 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in a

7、ny form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: h

8、ttp:/www.sae.org SAE AS439 Revision A- 2 -3.2 Identification:The following information shall be legible and permanently marked on the instrument or nameplate attached thereto:a. Name of instrument.b. SAE AS439A.c. Manufacturers part number.d. Manufacturers serial number or date of manufacture.e. Man

9、ufacturers name and/or trademark.f. Rating (electrical, pressure, etc.).g. Explosion category (if applicable).h. Aircraft type and model.3.3 Compatibility of Components:If components are individually acceptable, but require matching for proper operation, they shall be specified accordingly.3.4 Envir

10、onmental Conditions:The following conditions have been established as minimum design requirements. Tests shall be conducted as specified in paragraphs 5, 6 and 7.3.4.1 Temperature: When installed in accordance with the instrument manufacturers instructions, the instrument shall function over the ran

11、ge of ambient temperature shown in Column A below and shall not be adversely affected by exposure to the range of temperature shown in Column B below:TABLE 1SAE AS439 Revision A- 3 -3.4.2 Altitude: When installed in accordance with the instrument manufacturers instructions, the instrument shall func

12、tion from sea level up to the altitudes and temperatures listed below:TABLE 2Altitude pressure values are per NACA Report 1235. The instrument shall not be adversely affected following exposure to extremes in ambient pressure of 50 and 3 inches of mercury absolute, respectively.3.4.3 Vibration (Turb

13、ine Powered Subsonic Aircraft): When installed in accordance with the instrument manufacturers instructions, the instrument shall function and shall not be adversely affected when subjected to vibrations of the following characteristics:TABLE 33.4.4 Humidity: The instrument shall function and shall

14、not be adversely affected following exposure to any relative humidity in the range from 0 to 95% at a temperature of approximately 70 C.SAE AS439 Revision A- 4 -3.5 Explosion Category:The instrument component, when intended for installation either in uninhabited areas of non-pressurized aircraft or

15、innon-pressurized areas of pressurized aircraft, shall not cause an explosion when operated in an explosive atmosphere. The component shall meet the requirements applicable to the explosion category below. Specifically, any instrument component which can be an ignition source and is intended for ins

16、tallation in an area in which combustible fluid or vapor may result from abnormal conditions (e.g., fuel line leakage) shall meet the requirements of Category I. If the intended location is an area where combustible fluid or vapor can occur during normal operation (e.g., fuel tank) the instrument co

17、mponent shall meet the requirements of Category II, listed below:TABLE 43.6 Fire Hazard:The instrument shall be designed to safeguard against hazards to the aircraft in the event of malfunction or failure, and the maximum operating temperature of surfaces of any instrument component contacted by com

18、bustible fuel or vapor shall not exceed 200 C due to self-heating. All materials shall be non-combustible and shall not liberate gases or fumes which will result in such corrosion as to cause malfunction of equipment or discoloration of dial or indicia, nor shall toxic gases or fumes that are detrim

19、ental to performance of aircraft or health of personnel be liberated under the operating conditions specified herein.SAE AS439 Revision A- 5 -3.7 Radio Interference:The instrument shall not be the source of objectionable interference under operating conditions at any frequencies used on aircraft, ei

20、ther by radiation, conduction or feedback in any electronic equipment installed in the same aircraft as the instruments, in accordance with MIL-I-6181, latest revision.3.8 Magnetic Effect:The magnetic effect of the instruments shall not adversely effect the performance of other instruments installed

21、 in the same aircraft.3.9 De-Compression:When installed in accordance with the instrument manufacturers instructions, the instrument shall function and not be adversely affected following exposure to a pressure decrease from 22 to 2 inches of mercury in 2 seconds.3.10 Interchangeability:Instruments

22、and components which are identified in accordance with paragraph 3.2 shall be directly and completely interchangeable.3.11 Precipitation and Ice:The instrument shall be designed so that it will continue to function properly and provide reliable stall warning during flight through rain and moderate i

23、cing conditions, per paragraph 7.10.4. DETAIL REQUIREMENTS:4.1 Indication:The signal to the pilot must be positive and command his attention through hearing and/or feeling and must be a continuous warning during conditions under which warning is required. There shall be no means whereby the stall wa

24、rning instrument may remain disconnected when unattended during flight.SAE AS439 Revision A- 6 -4.2 Operating Range:Figure 1 shall be supplied by the aircraft manufacturer for each aircraft configuration (combination of flaps, speed brakes, power, gear, etc.) for which stall warning is required. The

25、 warning point shall be adjustable within the shaded area. The instrument shall operate within a tolerance of 5% of the set point.NOTE: The shaded area lying between 95% T.L.F. and 75% T.L.F. represents the region in which the warning signal shall first commence in the approach toward the stall and

26、cease upon retreat from the stall. The stall warning shall commence at no less than 5% of Vs1, above Vs1.EXAMPLE: At speed “D“ the aircraft stalls at a T.L.F. of “A“. Point “B“ is 95% of “A“ and point “C“ is 75% of “A“. The warning shall occur between points “C“ and “B“.FIGURE 1 - T. L. F.4.2.1 Side

27、slip or Yaw: When installed in accordance with the instrument manufacturers instructions, the stall warning margins shown in Figure 1 shall also apply under conditions of 5% degrees sideslip or yaw.SAE AS439 Revision A- 7 -4.3 Power Variation:The instrument shall properly function with 15% variation

28、 in DC voltage and 5% variation in frequency, or hydraulic pressure limits of 30% of rated value.4.4 Power Malfunction Indication:Means shall be incorporated in the instrument to provide a fail safe signal when adequate power (voltage and/or current) is not being made available to all phases require

29、d for the proper operation of the instrument. The indicating means shall indicate a failure or a malfunction in a positive manner.4.5 Synchro Requirements:The synchro requirements should be in accordance with the conditions specified in ARP461B.4.6 Altitude and Differential Pressures:Altitude pressu

30、re values shall be in accordance with those specified in NACA Report 1235, “Standard Atmosphere - Tables and Data for Altitudes to 65,800 Feet.“5. TEST CONDITIONS:5.1 Atmospheric Conditions:Unless otherwise specified herein, all tests required by this standard shall be made at an atmospheric pressur

31、e of approximately 29.92 inches of mercury, an ambient temperature of approximately 25 C and a relative humidity of not greater than 85%. When tests are conducted with the atmospheric pressure or temperature substantially different from these values, allowance shall be made for the variation from th

32、e specified conditions.5.2 Vibration to Minimize Friction:Unless otherwise specified herein, all tests for performance may be conducted with the instrument subjected to a maximum vibration of 0.001 inch double amplitude at a frequency of 10 to 60 cycles per second. The term double amplitude, as used

33、 herein, indicates the total displacement from positive maximum to negative maximum.5.3 Vibration Equipment:Vibration equipment shall be such as to allow vibration to be applied along each of three mutually perpendicular axes of the instrument at frequencies and amplitudes consistent with the requir

34、ements of paragraph 3.4.3.5.4 Power Conditions:Unless otherwise specified herein, all tests shall be conducted at the power rating recommended by the manufacturer.SAE AS439 Revision A- 8 -5.5 Position:Unless otherwise specified herein, all tests shall be conducted with the instrument in its normal o

35、perating position.6. INDIVIDUAL PERFORMANCE REQUIREMENTS:All instruments shall be subjected to tests by the instrument manufacturer to demonstrate specific compliance with this standard, including the following requirements where applicable:6.1 Operating Range Test:The instrument shall be tested at

36、appropriate air speeds in accordance with curves similar to Figure 1. These curves shall be supplied by the aircraft manufacturer for each aircraft configuration (combination of flap position, speed brake position, gear position, power, etc.) for which stall warning is required. The instrument shall

37、 initiate the warning signal within a tolerance of 5% of the set point.6.2 Lag:No more than a one-half (1/2) second lag shall exist shall exist between the time the stall sensitive unit is actuated and the corresponding warning is indicated.6.3 Dielectric:Each instrument shall be tested by the metho

38、d of inspection listed in paragraphs 6.3.1 and 6.3.2.6.3.1 Insulation Resistance: The insulation resistance measured at 200 V DC for 5 seconds between all electrical circuits connected together and the metallic case shall not be less than 5 megohms. Insulation resistance measurements shall not be ma

39、de to circuits where the potential will appear across elements such as windings, resistors, capacitors, etc., since this measurement is intended only to determine adequacy of insulation.6.3.2 Overpotential Tests: The instruments shall not be damaged by the application of a test potential between ele

40、ctrical circuits and between electrical circuits and the metallic case. The test potential shall be a sinusoidal voltage of a commercial frequency with an R.M.S. value of five times the maximum circuit voltage, or per paragraph 6.3.2.1 or 6.3.2.2, whichever applies. The potential shall start from ze

41、ro and be increased at a uniform rate to its test value. It shall be maintained at this value for 5 seconds, and then reduced at a uniform rate to zero.Since these tests are intended to insure proper electrical isolation of the circuit components in question, these tests shall not be applied to circ

42、uits where the potential will appear across elements such as windings, resistors, capacitors, etc.6.3.2.1 Hermetically sealed instruments shall be tested at five times the maximum circuit voltage up to a maximum of 200 V R.M.S.6.3.2.2 Circuits that operate at potential below 15 V are not to be subje

43、cted to overpotential tests.SAE AS439 Revision A- 9 -6.4 Sealing:Hermetically sealed components shall be tested for leaks by means of a mass spectrometer type of helium leak detector or equivalent. The leak rate shall not exceed 0.0434 micron cubic feet per hour per cubic inch of filling gas at a pr

44、essure differential of one atmosphere.NOTE: A micron cubic foot per hour leak rate is defined as that gas leakage which would change the pressure of a one cubic foot volume by the amount of one micron (one millionth of a meter of mercury) in one hour.7. QUALIFICATION TESTS:As many instruments of com

45、ponents deemed necessary by the manufacturer to demonstrate that all instruments will comply with the requirements of this section shall be tested in accordance with his recommendation.7.1 Temperature Characteristics:7.1.1 Low Temperature Operation: The instrument shall be subjected to the applicabl

46、e low ambient temperature listed in Column A of paragraph 3.4.1 for a period of 5 hours without operating. The instrument shall meet, at that temperature, the applicable individual performance tests.17.1.2 High Temperature Operation: The instrument shall be subjected to the applicable high ambient t

47、emperature listed in Column A of paragraph 3.4.1 for a period of 5 hours without operating. (Electrical equipment shall be energized.) At that temperature, the instrument shall meet the applicable individual performance tests.17.1.3 Extreme Temperature Exposure: The instrument shall be exposed to th

48、e applicable low and high temperatures listed in Column B of paragraph 3.4.1 for a period of 24 hours at each extreme temperature, without operating. After a delay of 3 hours at room temperature, the instrument shall meet the applicable individual performance tests1 at room temperature. There shall

49、be no evidence of damage as a result of exposure to the extreme temperatures specified.7.1.4 Altitude: The instrument shall be subjected to the ambient temperature and pressure listed in paragraph 3.4.2 for a period of 3 hours while operating. The instrument shall then meet, at the conditions specified, the applicable individual performance tests.1The instrument shall be exposed alternately to 50 inch Hg absolute and 3 inch Hg absolute, non-operating. The ins