1、 AEROSPACERECOMMENDEDPRACTICESubmitted for recognition as an American National StandardDESIGN AND INSTALLATION OF PITOT-STATIC SYSTEMSFORTRANSPORT AIRCRAFTSAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. Th
2、euse of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is thesole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised
3、, or cancelled. SAE invites your writtencomments and suggestions.Copyright 1996 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.Land Sea Air and SpaceFor Advancing MobilityThe Engineering SocietyINTERNATIONAL400 Commonwealth Drive, Warrendale, PA 15096-0001Issued 1968-10Re
4、vised 1996-10REV.ARP920 AFOREWORDChanges in the revision are format/editorial only.1. SCOPE:This SAE Aerospace Recommended Practice (ARP) covers the design and installationrequirements for pitot-static systems.1.1 Purpose:The purpose of this Aerospace Recommended Practice is to present recommendatio
5、ns for thedesign and installation of pitot and static systems for transport type aircraft. This document alsomakes recommendations for several system configurations and sets forth the acceptable qualitycontrol requirements and the means by which they are to be controlled.2. REGULATORY DOCUMENTS:2.1
6、Federal Aviation Administration Documents:The following document, of the issue in effect on date of application for certification, forms a partof this Aerospace Recommended Practice to the extent noted herein: Federal AviationRegulation: Part 25 - Airworthiness.Standards: Transport Category Airplane
7、s. In the event of conflict between this document andFAR, Part 25, the regulatory document should apply.SAE ARP920 Revision A- 2 -2.2 Applicable Documents:The following documents, of the issue in effect on the date of application for certification, form apart of this Aerospace Recommended Practice t
8、o the extent noted herein:2.2.1 SAE Publications: Available from SAE, 400 Commonwealth Drive, Warrendale,PA 15096-0001.AS390 Pitot or Pitot-Static Pressure Tubes, Electrically Heated (Turbine PoweredSub-Sonic Aircraft)AS393 Airspeed Tubes - Electrically HeatedARP921 Flight Test Procedures for Subson
9、ic Transport Pitot-Static SystemsARP975 Maintenance Procedures for Pitot-Static Systems for Transport Aircraft2.2.2 Federal Aviation Administration Publications: Available from FAA, 800 Independence Avenue,SW, Washington, DC 20591.Part 25 Airworthiness Standards: Transport Category AirplanesAC 43-20
10、3 Advisory Circular - Altimeter and Static System Tests and Inspections2.2.3 Radio Technical Commission for Aeronautics Publications: Available from RTCA, 1140Connecticut Ave., NW, Suite 1020, Washington, DC 20036.120-61/00-108 Environmental Test Procedures for Airborne Electronic Equipment2.2.4 U.S
11、. Government Publications: Available from DODSSP, Subscription Services Desk, Building4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094.MIL-STD-1247 Identification of Pipe, Hose, and Tube Lines for Aircraft, Missile, and SpaceSystems3. GENERAL REQUIREMENTS:3.1 Materials and Workmanship:3.1.1 Mater
12、ials: Materials should be of a quality which experience and/or tests have demonstrated tobe suitable and dependable for use in aircraft.3.1.2 Workmanship: Workmanship should be consistent with high grade aircraft manufacturingpractice.3.2 Compatibility of Components:If individual components of the p
13、itot-static systems recommended herein are individuallyacceptable, but require matching for proper operation, they should be identified in a manner thatwill assure proper matching.SAE ARP920 Revision A- 3 -3.3 Environmental Conditions:The following environmental conditions have been established as d
14、esign requirements unlessmore severe requirements are specified by the airframe manufacturer. The means of maintainingand testing to the following criteria are not covered in this recommended practice.3.3.1 Temperature: When installed in accordance with the manufacturers instructions, the individual
15、components of the pitot-static system (i.e., sump valves, normal-to-alternate switching valves,etc.) should function over the range of ambient temperature shown in Column A below andshould not be adversely affected following exposure to the range of temperature shown inColumn B below.TABLE 1TABLE 1A
16、 - Reciprocating Engine Powered AircraftInstrument Location A BHeated Areas(Temperature Controlled) 0 to 55 C -50 to 71 CUnheated Areas 0 to 55 C -50 to 71 CNon-Pressurized -46 to 71 C -50 to 71 CTABLE 1B - Turbine Powered Aircraft (Subsonic)Instrument Location A BPressurized Areas(Temperature Contr
17、olled) 0 to 60 C -50 to 71 CNon-Pressurized -54 to 71 C -62 to 71 CTABLE 1C - Turbine Powered Aircraft (Supersonic)Instrument Location A BPressurized Areas(Temperature Controlled) 0 to 60 C -50 to 71 CNon-Pressurized Areas - -54 to 260 C -62 to 260 CNo Temperature ControlSAE ARP920 Revision A- 4 -3.
18、3.2 Altitude: When installed in accordance with the manufacturers instructions, the componentshould function and should not be adversely affected following exposure to a pressure andtemperature range equivalent to -1000 to the maximum certificated altitude for the aircraft. Thecomponent should not b
19、e adversely affected when subjected to an ambient pressure of50 inches (1280 mm) and 0.8 inch (20.51 mm) of mercury absolute.3.3.3 Vibration (Reciprocating Engine Powered Aircraft): When installed in accordance with themanufacturers instructions, the component should function and should not be adver
20、selyaffected when subjected to vibrations of the following characteristics.TABLE 2Instrument Location Cycles Maximum Double Maximumin Airframe Per Second Amplitude (Inch) AccelerationWings and Empennage 5-2000 0.010 .25 gFuselage 5-55 0.020 3.0 gPanel (Vibration Isolated) 5-55 0.010 1.5 g3.3.3.1 Vib
21、ration (Turbine Powered Subsonic Aircraft): When installed in accordance with themanufacturers instructions, the component should function and should not be adverselyaffected when subjected to vibrations of the following characteristics:TABLE 3Frequency (Peak)Cycles Maximum Double MaximumInstrument
22、Location Per Second Amplitude (Inch) AccelerationWings, Empennage 5-2000 .030 5.0 gFuselage 5-2000 .020 3.0 gFlight Deck Area 5-2000 .010 .25 g3.3.4 Humidity: The component should function and should not be adversely affected followingexposure to any relative humidity in the range from 0 to 95% at a
23、 temperature of approximately70 C.3.3.5 Explosion Category: The system component, when intended for installation either inuninhabited areas of non-pressurized aircraft or in non-pressurized areas of pressurizedaircraft, should not cause an explosion when operated in an explosive atmosphere. Thecompo
24、nent should meet the requirements applicable to the explosion category below. Specifically, any component which can be an ignition source and is intended for installation inan area in which combustible fluid or vapor may result from abnormal conditions, e.g. fuel lineleakage, should meet the require
25、ments of Category I. If the intended location is an area wherecombustible fluid or vapor can occur during normal operation, e.g. fuel tank, the instrumentcomponent should meet the requirements of Category II listed below:SAE ARP920 Revision A- 5 -TABLE 4Category DefinitionI Explosion proofed: case n
26、ot designedto preclude flame or explosionpropagation.II Explosion proofed: case designed topreclude flame or explosionpropagation.III Hermetically sealed.IV Instrument not capable of causing anexplosion.3.3.6 Fire Hazard: The system should be so designed as to safeguard against hazards to the aircra
27、ftin the event of malfunction or failure and the maximum operating temperature of surfaces ofany instrument component contacted by combustible fuel or vapor should not exceed 200 Cdue to self heating.All materials should be non-combustible and should not liberate gases or fumes which will resultin s
28、uch corrosion as to cause malfunction of equipment, nor should toxic gases or fumes thatare detrimental to performance of the aircraft or health of personnel be liberated under theoperating conditions specified herein.3.3.7 Radio Interference: The system should not be a source of objectionable inter
29、ference underoperating conditions at any frequencies used on the aircraft, either by radiation, conduction orfeedback in any electronic equipment installed in the same aircraft as the instruments inaccordance with RTCA Report 120-61/DO-108, latest revision.3.3.8 Magnetic Effect: The magnetic effect
30、of the system components should not adversely affectthe performance of other instruments installed in the same aircraft.3.4 General System Design and Installation:Each aircraft should be fitted with a minimum of two pitot and three static systems. Static ports orsystems should be provided in manifol
31、d pairs and so designed and installed as to minimize theeffects of aircraft sideslip (YAW). Figures 1, 2 and 3 show system configurations which havebeen approved for use in specific aircraft and which may be used as a guide to the systemdesigned.SAE ARP920 Revision A- 6 -SAE ARP920 Revision A- 7 -SA
32、E ARP920 Revision A- 8 -FIGURE 3 - Drain Hole Cross Section3.4.1 Pitot (Total Pressure) System: Each aircraft should be equipped with a minimum of two pitotsystems. These systems should be identified as:a. Pitot System (Pilots)b. Pitot System (First Officers)c. Auxiliary Pitot System (if required by
33、 paragraph 3.4.1.3)3.4.1.1 Captains Pitot System: The captains pitot system should be connected to his airspeedindicator. In aircraft equipped with machmeters, air data computers and/or altitude encoders,the captains equipment should be connected to his pitot system. In aircraft equipped withonly on
34、e air data computer and/or altitude encoder, it should be connected to the captainspitot system.SAE ARP920 Revision A- 9 -3.4.1.2 First Officers Pitot System: The first officers pitot system should be connected to hisairspeed indicator. In aircraft equipped with machmeters, maximum allowable speed s
35、witch,air data computers and/or altitude encoders, the first officers equipment should be connectedto his pitot system.In aircraft equipped with automatic flight control systems (autopilots), flight data recorders andpitch trim compensators, etc. such equipment may be connected to the first officers
36、 pitotsystem. However, means must be provided to permit either manual or automatic disconnectof such auxiliary equipment from the basic system supplying pitot pressures to the firstofficers airspeed and Mach indicators in the event of a failure in any of the auxiliaryequipment or a leak in the assoc
37、iated plumbing.3.4.1.3 Auxiliary System(s): Should an additional independent auxiliary pitot system(s) be installed,such auxiliary system should be connected to the automatic flight control system, flight datarecorder, pitch-trim compensators and any other equipment that may require pitot pressure.
38、Should equipment connected to auxiliary static systems require pitot (dynamic pressure)inputs, such auxiliary pitot systems should be installed.3.4.2 Static System: Each aircraft should be equipped with a minimum of three static systems. These systems should be identified as: captains, first officer
39、s and alternate. Should additionalstatic systems beyond the ones specified be used, they should be identified as auxiliarysystems in terms of the use to which they are put (e.g., “Autopilot Static System”, etc.).Caution should be exercised, however, to avoid connecting too many systems to each stati
40、csystem. The number of transducers which can be connected to each system is dependentupon their volume and the resultant effect upon lag (see paragraph 3.6.4) when connectedthereto.3.4.2.1 Captains Static System: The captains static system should be connected to his altimeter,airspeed indicator, and
41、 rate of climb indicator if installed. The captains static system shouldalso be equipped with a selector valve permitting transfer of the captains instruments to thealternate static system. In aircraft equipped with machmeters, air data computers and/oraltitude reporting systems, the captains equipm
42、ent should be connected to his static system.In aircraft equipped with only one air data computer and/or altitude reporting system, it shouldbe connected to the captains static system.3.4.2.2 First Officers Static System: The first officers system should be connected to his altimeter,airspeed indica
43、tor and rate of climb indicator. The first officers static system should also beequipped with a selector valve permitting transfer of the first officers instruments to thealternate static system. In aircraft equipped with machmeters, maximum allowable speedswitch, air data computers and/or altitude
44、reporting systems, the first officers equipmentshould be connected to his static system.SAE ARP920 Revision A- 10 -3.4.2.3 Alternate Static System: For purposes of reliability, an alternate static system should beinstalled in each aircraft. The alternate system should be provided with independent ca
45、ptainand first officers selector valves to permit the system to be independently or simultaneouslyconnected to the captain and first officers flight instruments in lieu of their primary system(see paragraph 3.4.2.1 and 3.4.2.2).3.4.2.4 Auxiliary Static System(s): Auxiliary static systems are identif
46、ied as any static systeminstalled in the aircraft other than those previously identified as the captains, first officers andalternate systems. As many auxiliary static systems as deemed absolutely necessary toinsure aircraft safety should be used in the aircraft. The auxiliary static system(s) may b
47、eused to provide static pressure to the autopilot, flight data recorder, pitch-trim compensator,cabin pressure controller1, cabin differential pressure gauge, etc. or any combination thereof. Each auxiliary static system should be identified.3.5 Specific System Design:3.5.1 Pitot (Total Pressure) Sy
48、stems:3.5.1.1 Accuracy: The total pressure as measured by either the captain or first officers and/orauxiliary pitot systems should not differ from the true pitot (total) pressure by more than 1.0%at any speed, altitude, angle of attack, angle of sideslip or aircraft configuration within theapproved
49、 operating envelope of the aircraft. In addition, the first officers or auxiliary pitotsystems should not differ from the captains system by more than 0.5% when the aircraft isflying so as to exhibit no detectable sideslip.3.5.1.2 Pitot Tubes: Pitot (total) pressure should be obtained either from a pitot or pitot-staticpressure tube or probe. In addition to the requirements specified herein, their basic designshould meet the requirements of AS393 or AS390.a. Pitot Tube Total Pressure Entry: The shape of the tubes entry should be s
