1、.- I . ARINC 575 75 O307637 0003228 5 AERONAUTICAL RADIO, INC. 2551 Riva Road Annapolis, Maryland 21401 .- ARINC CHARACTERISTIC 595 BAROMETRIC ALTITUDE RATE COMPUTER (BARC) - Pub1 i shed : February 12, 1975 Prepared by the Ai rl i nes El ectroni c Engi neeri ng Commi ttee Characteristic 595 approved
2、 by the Ai rl i nes El ectroni c Engineering Com- mittee (by mail ballot): February 11, 1975. 0 . # ARINC 575 75 0307637 0003227 7 i. 1 a : . FOREWORD - Activities of AERONAUTICAL RADIO, INC. (ARINC) and the Purpose of ARINC Characteri s ti cs Aeronautical Radio, Inc., is a corporation in which the
3、United States scheduled ai rl i nes are the pri nci pal stockholders . Other stockholders include a variety of other air transport companies aircraft manufacturers and foreign flag airlines. Activities of ARINC include the operation of an extensive system of domestic and overseas aeronautical land r
4、adio stations, the fulfillment of systems requi rements to accompl ish ground and ai rborne compati bi 1 i ty , the al location and assignment of frequencies to meet those needs, the coordi- nation incident to standard airborne communications and electronics systems and the exchange of techni cal i
5、nforinati on, ARINC sponsors the Ai rl i nes Electroni c Engi neeri ng Committee (AEEC) , composed of ai rl i ne technical personnel. The AEEC formulates standards for electronic equipment and systems for the airlines. is a principal function of this Committee. The establishment of Equipment Charact
6、eristics An ARINC Equipment Characteristic is finalized after investigation and coordination with the airlines who have a requirement or anticipate a requirement, with other aircraft operators, with the Mi 7 i tary services having similar requirements, and with the equipment manufacturers. released
7、as an ARINC Equipment Characteristic only when the interested airline companies are in general agreement. any airline or ARINC to purchase equipment so described nor does it establish or indicate recognition of the existence of an operational requirement for such equipment, nor does it constitute en
8、dorsement of any manufacturers product designed or built to meet the Characteristic. An ARINC Characteristic has a twofold purpose, which is: It is Such a release does not commit (1 ) To i ndi cate to the prospecti ve manufacturers of ai rl i ne el ectroni c equipment the consi dered opi ni on of th
9、e ai rl i ne techni cal people, coordinated on an industry basis, concerning requisites of new equipment, and (2) To channel new equipment designs in a direction which can result in the maximum possible standardization of those physical and electrical characteristics whi ch i nf 1 uence i nterchange
10、abi 1 i ty of equipment without seriously hampering engineering initiative. ii ITEM 1 .o - 1.1 1.2 1.3 1.3.1 1.3.2 1.4 1.5 2.0 2.1 2.2 2.3 2.4 2.5 2.6 3.0 3.1 3.2 ATTACHMENTS 1 2 3 4 ARINC 595 75 O307637 0003230 3 ARINC CHARACTERISTIC 595 TABLE OF CONTENTS SUBJECT INTRODUCTION AND BACKGROUND Purpose
11、 of this Document Purpose of BARC Unit Interchangeability Interchangeabi 1 i ty (General ) BARC Interchangeabi 1 i ty Regulatory Approval Reliabi 1 i ty INTERCHANGEABILITY STANDARDS torm Factors and Connectors Pneumatic Connector Interwiring Primary AC Power Input Cool i ng . Environmental Condition
12、s STANDARD SIGNAL CHARACTER1 STI CS Altitude Rate (DC) Output Al ti tude Rate Validity PAGE - Notes Applicable to Standard Intetwi ring Standard Interwi ring Barometric Al ti tude Rate Computer (BARC) Environmental Test Categories Connector Positions Barometric Al ti tude Rate Computer 2 2 2 2 2 2 2
13、 3 3 3 ! iii - ARINC CHARACTERISTIC 595 - Page 1 1. O INTRODUCTION AND BACKGROUND 1.1 Purpose of this Document This document is intended to set forth general guidance for the design and installation of a Barometric Altitude Rate Computer (BARC) for use with a Ground Proximity Warning System (GPWS) ,
14、 This document describes the basic features needed bv the users to achieve the desired level of in- trchangeabi 1 i ty. COMMENTARY The need for this document emerged during the airlines I preparation of ARINC Character- istic 594 (“Ground Proximity Warning System“) , when it became apparent that not
15、 all aircraft on which GPWS installations were planned pro- vided a suitable source of barometric altitude rate. However, because this need was less widespread than the need for Characteristic 594, only limited amounts of time and effort were devoted to it. Thus, this Characteristic describes only t
16、he essential features of the BARC unit and installation. 1.2 Purpose of BARC Unit The Barometric Altitude Rate Computer unit should generate an electrical rate signal from pneumatic pressure supplied by the aircraft static pressure system. The BARC unit is intended primarily for use with Ground Prox
17、imity Warning equipment in aircraft that do not have a suitable electrical signal for altitude rate. 1.3 Interchangeabi 1 i ty 1.3.1 Interchangeability (General) One of the primary functions of an ARINC Equip- ment Characteristic is to designate, in addition to certain performance parameters , the i
18、nter- changeability for aircraft equipment produced by various manufacturers. Manufacturers are referred to Section 1.6 of ARINC Report No. 414 for the airline industrys definitions of interchange- ability. As explained in that Report, the degree of interchangeability consi dered necessary and attai
19、nable for each particular equipment is specified in the pertinent ARINC Equipment Char- acteristic. I Furthermore, “Generation Interchangeabi 1 i ty“ is desired by the airline industry. “Generation In- terchangeabi 1 i ty“ assures that future evolution- ary equipment improvements and the inclusion o
20、f additional functions in new equipments during the next few years do not violate the interwiring and form factor standards set forth in this document. The provisions to assure “Generation Interchangeability“ are set forth as can best be predicted in various places throughout this docu- ment to guid
21、e manufacturers in future develop- ments. 1 .3.2 BARC I nterchangeabi 1 i ty a System Interchangeabi 1 i ty of the BARC unit with respect to the standard aircraft installation and 1.3.2 BARC Interchangeability (contd) a companion ARINC 594 GPWS equipment is desired by the users. COMMENTARY It was no
22、t possible to achieve the “Unit Interchangeability“ that the users real ly desired. Thus, it may be necessary to match the manufacturering source of the BARC unit with that of the GPWS computer unit. . 1.4 Regulatory Approval The equipment should meet all applicable FAA TSO requirements. This docume
23、nt does not and cannot set forth the specific requirements which an equip- ment manufacturer must follow to be assured of FAA approval under the TSO program. Such information must be obtained from FAA. 5 ARINC 595 75 = 0307617 0003231 5 1.5 Reliability Users insist upon the utmost attention to reli-
24、 ability in all phases in the design, production, installation and operation of this equipment. i - - ARINC 595 75 0307637 0003232 7 1 ARINC CHARACTERISTIC 595 - Page 2 , 2.0 INTERCHANGEABILITY STANDARDS It is of prime importance that the Industry es- tablish specific form factors, mounting provisio
25、ns, interw“-ing, input and output interfaces and power supply characteristics for this system. standards are necessary to ensure the continued independent design of both the equipment and the - airframe instal 1 ation. Manufacturers should note that al though this ARINC document does not preclude th
26、e use of different form factors and interwiring features, the prac- tical problems of re-designing what will then be a standard installation to accommodate some special system could very well make the use of that other design prohib tively expensive for the customer. Thus, manufacturers should recog
27、nize the practical advantages of developing equipment in accordance with the form factor, interwiring and input and output interface standards set forth in this docu- ment. 2.1 Form Factors and Connectors ARINC Specification No, 404A should be followed in explicit detai 1 to assure the desi red inte
28、rchange- abi 1 i ty of the equipment of different manufacturers. Specifically, equipment manufacturers are cautioned that their units should conform to all statements concerning dimensi on tolerances, handles, projec- tions, cooling and limits on weight and center of gravity set forth in ARINC Speci
29、fication 404A. The BARC Unit should comply with the standards es- tablished in ARINC Specification No. 404A for the 1/4ATR short dwarf form factor, and and should em- ploy Type A or C racking attachments. The service connector on the rear of the unit should be a DPAMA-32-34P (or equivalent) mounted
30、in the standard location as set forth in ARINC 404A and shown in Attachment 4 in this document. The corresponding aircraft connector is DPAMA-32-33s or equivalent. These connectors consist of single shells with one 32 pin insert. These NOTE TO INSTALLATION DESIGm The standard installation should acc
31、ommodate the full height 1/4 ATR short form factor since some BARCs now in service need at least 5.11 inches of space. Future units should, however, be limited to dwarf size. 2.2 Pneumatic Connectotc The pneumatic connector provided on the BARC unit for the static pressure input should be a 9/16 18U
32、NF-2B, 5/8 DP fitting. It should be located on the BARC unit front panel. 2.3 Interwiring The aircraft interwiring should be in accordance with the “Standard Installation“ set forth in At- tachment 2. Special interwiring notes are listed in Attachment 1. 2.4 Primary AC Power Input The equipment shou
33、ld be designed to use 115 (t 5%) VAC 400 Hz single phase power from a system de- signed to MIL-STD-708 (dated 6 October 1959) as the primary input for all circuits. This primary AC power should be protected by a single circuit breaker, of the size shown in Attachment 2. The aircraft power supply cha
34、racteristics, utili- zation equipment design limitations, and general guidance material are set forth in ARINC Report No. 413, “Guidance for Aircraft Electrical Power Utilizations and Transient protecti.on“. I . _- NOTE: set forth in ARINC Report No. 413, Section 8.1.2, No DC power is provided for t
35、he reasons 2.5 Coolin2 Thermal design of the BARC unit and installation should comply with ARINC 404A for Type “B“ natural convection cool i ng , 2.6 Environmental Conditions The BARC unit should be specified environmentally in terms of the requirements of RTCA Uocument DO-138 dated June 27th, 1968.
36、 Attachment 3 to this document tabu1 ates the relevant envi ronmental cateciories. I ARINC CHARACTERISTIC 595 - Page 3 3.0 STANDARD SIGNAL CHARACTERISTICS 3.1 Altitude Rate (DC) Output Range Accuracy Threshold Sensi tivi ty Reference Voltage Scale Factor Index Reference Approx. Gradient Source Imped
37、ance Min. Update Sate Load Capabi 1 i ty O to 5 20,000 feet per mi nu te 5% or 30 feet per min- ute to 2 6,000 feet per minute 0.025 inches of mercury per minute Positive + 12 5 1.2VDC Negative - 12 f 1.2VDC 20 millivolts (t ViU3F) - VREF) VREFI - I - VREFG Alt. Rate ft/min 48,000 Positive for incre
38、asing al ti tudes 500 millivolts per 1000 feet/mi n . 20 ohms or less 16 times per second Signal: 2,000 ohms to in- finity Reference : 900 ohms to infi ni ty COMMENTARY Al though ARINC-specified air data computers supply alti tude rate with the accuracies and over the ranges specified in Sections 4.
39、1.3 and 4.1.4 of ARINC 594, these ranges and the accuracies over them are not required for the GPWS application. BARC altitude rate need only supply the accuracy specified over a range of O to 57000 feet per minute up to an altitude of 20,000 feet. Note also that the performance parameters of these
40、air data computers are specified for given loads on each output, The GPWS load specified in ARINC 594 is intended to be high enough to not degrade BARC performance if it is used for other put-poses. - 3.2 Altitude Rate Validity Signal Status t 18.5 to t 30VDC for valid data. Less than t 3.5VDC for i
41、nvalid data. 20 rnilliarnps. Load Capabi 1 i ty ! ARINC 595 75 0307617 0003234 O W I 1. 2. 3. 4. 5. 6. ARINC CHARACTERISTIC 595 - Page 4 ATTACHMENT 1 NOTES APPLICABLE TO STANDARD INTERWIRING SHIELDS Wires should be shielded or twisted and shielded as indicated with an insulating cover over the shiel
42、d. are to be grounded at one end only and to the same ground stud. PINS RESERVED BY VIRTUE OF PRIOR USE Some equipment and installations designed prior to publication of this document used pin assignments which are NOT preferred for future use. These pin assignments are identified by Note 2 and shou
43、ld NOT be used in future installations or equiptient. All Shi-elds for analog circuits JUMPER TO “PRIOR USE“ PIN ASSIGNMENTS New designs of BARC equipment should contain a jumper within the unit from pins 27 to 11 and from pin 14 to signal ground -to accommodate installations designed prior to publi
44、cation of this document. RESERVED PINS FOR AIR DATA INPUT Pins have been reserved on the BARC Unit for possible use by some manufacturers of an electrical input of altitude data (signal format not specified) in place of the pneumatic input considered standard for the BARC. RESERVED PINS FOR POWER IN
45、PUT FROM GPWS Pins 19 and 20 on the BARC have been reserved for possible use by some manufacturers as an input of power, taken from the GPWS power supply, in place of the 115VAC primary power. In such cases the installation de- signer will need to add wires from pins TP-30 and TP-31 on the GPWS to p
46、ins 19 and 20 respectively on the BARC, These wires should be of the proper size to accommodate 2 Amps with a resistance of not more than 2 Ohms per wire. RESERVED PINS FOR AC ALTITUDE RATE OUTPUT Pins have been reserved on the BARC Unit for possible use by some manu- facturers of an AC signal forma
47、t for the Altitude Rate output. In such cases the signal should conform to the AC Altitude Rate input signal standards set forth in Section 4.1.3 of the ARINC 594 GPWS Spec. ARINC CHARACTERISTIC 595 - Page 5 FUNCTION BARC GPWS RESERVED - H 1 2 . ATTACHMENT 2 STANDARD INTERWI RI NG BAROMETRIC ALTITUD
48、E RATE COMPUTER (BARC) 2AMP 115 VAC Hot -3 BP-3 0% 1 1 5VAC IX I Altitude 4 GPWS CKT. BKR. (J) RESERVEDIY Input 5 IZ I Synchro 6 RESERVED - Air Data Validity 7 ATE (Altitude Output) 8 9 ATE (Test Input) 10 Altitude Rate Output (t DC) 11 115VAC Cold 12 - IIIAC Ground Chassis 13 - IilGround Altitude R
49、ate Output (- UC) 14 BARC Validity Output 15 BP-27 DC Ground 16 IIiDC Ground 17 ATE (Test Input) 18 RESERVED + INPUT 19 20 RESERVED - t POWER 0 Q ATE ( + ATE ( - RESERVED Power Supply) 21 Test 1 22 H Altitude Rate 23 RESERVED - C t Output Signal (AC) 24 25 Output Ref. Voltage (+) I 26 BP-29 BP-28 BP-30 Al ti tude Rate Output (DC) Output Ref. Voltage (-) - - RESERVED - H 26VAC 29 30 31 RESERVED - C Reference I 32 IMPORTANT NOTE All pins which do not have assigned functions are reserved for future Industr use. desiririg function assignments should contac
