1、MIL-P-70486 32 7777706 0355053 T m ,- 5-37- s3 MIL-P-704 8 6 (AR) 30 June 1983 . -c -_ - MILITARY SPECTFICATION PROCESSOR, SIGNAL, FIRE AND FLIGHT AIR DATA SUBSYSTEM, HELICOPTER ARMAMENT: M143 . This specification is approved for use by the U.S. Army Armament, Munitions and Chemical Command, and is
2、available fr -use by all Departments and Agencies of the Department of Defense. 1. SCOPE. 1.1 Scope. This specification. contains performance and environmental requirements, quality assurance provisions, and packaging for the Processor, Signal, Fire and Flight Air Data Subsystem, Helicopter Armament
3、: M143. 2. APPLICABLE DOCUMENTS. 2.1 Government documents. Unless otherwise specified, the following Specifications and Standards of the issue listed in that issue of the Department of Defense Index of Specifications and . Standards (DoDISS) specified in the solicitation, form a part of this specifi
4、cation to.the extent specified herein. SPECIFICATIONS MILITARY MIL-E-5400 Electronic Equipment, Airborne, General MIL-E-6051 Electromagnetic Compatibility Requirements, MIL-1-8500 Interchangeability and Replaceability f Specification for Systems Components Parts for Aircraft and Missiles FSC 1270 Be
5、neficial commenta (recommendationa, additions, deletioni) and any pertinent data which may be of um in improving this document ihould be addreiisd t0: Commander, US Anny Armament Reiearch rnd Development Center, At- lumC-QA, Dorer, New Je-y 07801-5001 by using the meli-addreued Sandudization Documen
6、t Improvement Proporai (DD Form 1428) apps- at the end of thir document or by letter. 1 , 1 . THIS DOCUMENT CONTAINS -i$- PAGES Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-P-704b LE 9999706 0355052 L EIL-P-70486 (AR) MIL-F-13926 MIL-M-38510
7、MIL-S-45743 MIL-S-46844 STANDARDS MILITARY DOD-STD-100 MIL- STD- 105 MIL-STD-461 MIL-STD-704 MIL-STD-781 MIL-STD-810C Fire Control Materials: General Specification Governing the Manufacture and Inspection of Microcircuits, General Specification for Soldering, Manual Type, High Reliability Electrical
8、, Electronic, Instrument, Communication and Radar for Aerospace and Control Systems, Procedure for Colder Bath, Soldering and Printed Wiring Assemblies, Automatic Machine Type Engineering Drawing Practices Sampling Procedures and Tables for Inspection by Attributes Electromagnetic Interference Chara
9、cteristics Requirements for Equipment Electric Power, Aircraft, Characteristics and Utilization of Reliability Design Qualification and Production Acceptance Tests: Exponential Distribution Environmental Test Methods 2.1.2 Other Government -u documents, drawings, and publications. The following othe
10、r Government documents, drawings, and publications form a part of this specification to theextent specified herein. DRAWINGS US ARMY ARMAMENT, RESEARCH AND DEVELOPMENT CENTER (ARDC) 11776549 Processor, Signal, Fire and Flight Air Data 11776552 Installation Drawing, Processor Signal, Fire Subsystem:
11、M143 and Flight Air Data Subsystem, Helicopter Armament: M43 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-70486 12 9779906 0355053 3 MIL-P-70486 (AR) (Copies of specifications, standards, handbooks, drawings, and publications required by man
12、ufacturers in connection with specific acquisition functions should be obtained from the contracting activity or as directed by the contracting officer.) 2.1.3 Order of precedence. In the event of a conflict of thiz specification and the references cited herein, the text of this specification shall
13、take .precedence. this specification to the extent specified herein. 2.2 Other publications, The following documents form a part of AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) ASTM-D3951 Standard Practices for Commercial Packaging 3 . REQUIREMENTS . 3.1 Materials. Materials shall be in accorda
14、nce with the applicable drawings, specifications, and standards. 3.2 Parts. All parts shall comply with applicable drawings, specifications, and standards. 3.3 Air Data System Electronic Processor (EPU) . The EPU shall comply with all the requirements specified on drawing 11776549, all associated dr
15、awings, and with all the requirements specified in applicable specification and standards. The EPU covered by this specification shall be configured for use on AH-1S series aircraft. The EPU shall process signals from the AH-1SHelicopter. processed siqnals shall be sent to the Low Airspeed Indicator
16、 (LAI), The drawing 11776301, the Fire Control Doppler Navigation System. 3.3.1 Major components list. Nomenclature Pressure Transducer Unit Analog Interface Unit Central Processor Unit Power Supply Unit Front Panel Assembly Chassis Rear Cover Computer: M22, and Major components of Drawing 11776576
17、1177666 3 11776653 11776551 11776673 11776666 11776670 the AN/ASN-128 the EPU are: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-P-70LiBb i2 W 9999906 0355054 5 MIL-P-70486 (AR) 3.4 - Characteristicsl 3.4.1 Electrical. 3.4.1.1 Signal interface
18、. The EPU signal interface with the AH-1 series helicopter and with the LAI and AADS shall be as defined in Appendix A to this specification and Figure 1, _I_ 3.4.1.1.1 Detail characteristics, The ADS communicates with the Fire Control Computer, Digital: M22 (FCC). Data transmission to the FCC is by
19、 means of a dedicated serial-data bus. 3.4.1.2.2 Fire control computer interface. The ADS transmits data to the FCC by means of a dedicated serial data bus.- consists of a data line-pair which carries the data and its logical . complement, a clock line-pair which carries the associated data clock an
20、d its complement, and additional wires which carry the discrete signals required for protocol., The wiring configuration is shown in . Figure 2. A timing diagram, illustrating typical signal timing, is shown in Figure 3. 3.4.1.1.3 Bus characteristics, The data Pine-pair between the ADS and the PCC c
21、onsists of a twisted shieided wire pair with a characteristic impedance of 7 ohms, 4-10 percent, The shield on this pair is grounded in accordance with god EM1 suppression practices. Data shall be transmitted and received by differential 3-state logic transmitters and receivers. The signal levels us
22、ed shall be TTL compatibIe. The bus 3.4.1.1-4 - Data clock characteristics. This signai 5s a square wave with a 50-percent duty cycle such that the 0-1 transition defines the beginning of a data bit interval It is sent on a twisted shielded wire pair with the same electrical. characteristics as thos
23、e of the data ine. The data clock signai levels shall be TTL compatible. The data clock shall have a nominal pulse rate of 19 Khz. 3.4.1.1.5 Discrete line characteristics. Discrete signals used for protocol shall be transmitted on shielded wire pairs. shall be received differentially, Dkcrete signal
24、s no Data bus wir-fnq eonfiquration Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I - - MIL-P-70486 12 m 7777706 0355057 O m MIL-P-70486 (AR) a c 1 FIGURE 3. Data bus timinq diagram 7 Provided by IHSNot for ResaleNo reproduction or networking permi
25、tted without license from IHS-,-,-MIL-P-70486 (AR) 3.4.1.1.6 Data format. The data shall be sent as serial 8-bit words in binary non-return-to-zero (NRZ) -L code. Each data bit shall begin coincident with the rising edge of the data clock signal supplied by the FCC. transmission period consisting of
26、 six 8-bit words and a trailing parity bit. the first bit transmitted for each word. Transmitted parity of the 49-bits shall be odd. Each data word shall form a part of a 49-bit The least significant bit. of each 8-bit word shall be 3.4.1.1.7 Siqnal protocol. Transmission of data along the bus is un
27、der control of the FCC. The FCC initiates data transfer from ADS to FCC by supplying a logic 1 to the data transmit request line. After a time, tl (minimum =.l usec, maximum = 250 usec), the ADS responds by-supplying a logic 1 to the data ready line. After delay, t2 (minimum = 1 usec, max-imum = 20
28、msec), the FCC begins sending the data clrock signal. The ADS then transmits the data as described in 3.2.1.18. At the conclusion of the 49th bit (parity), the FCC returns the data transmit request Iine to logic O and interrupts the data clock. After time delay t3, not to exceed 1.0 usec, the ADS re
29、turns theredy data line to logic O, and data transfer is complete. 3.4.1.1.8 Data word format. The information sent in the data The ADS shall send all six woras each fime a data transmit words shall be in the sequence Vu, V I Vw, P , Tair, and vdw. request is received. 3.4.1.2 Electrical power. 3.4.
30、1.2.1 Steady state. The electrical service conditions will be in accordance with MIL-STD-704, Category %“ utilization equipment, except that the transient frequency limit of Figure 5, Lirnkk 4 in MIL-STD-304 shall be 240 Hz. The equipment shall meet all I specified requirements of MIL-STD-704 for th
31、e types of power specified herein, and shall give specified performance when suppied with electrical power having these characteristics and limits. The power required shall not exceed 28V dc, 34 Watts. 3.4.1.2.2 Electrical power interruptions. Momentary power interruptions to the equipment will be e
32、xperienced when external primary power is switched to helicopter power or when switching from one helicopter power bus to another. performance requirements of this specification after such momentary power interruptions have been experienced. The EPU shall return automatically to specifi-ed performan
33、ce within 5 seconds after any power interruption. The EPU shall meet the 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NIL-P-?Oqb 12 7777706 0355057 q M MIL-P-70 4 8 6 (AR) 3.4.1.2.3 Polarity ?reversal?. Components that receive 28 Volt dc helicop
34、ter power shall not be damaged when subjected to a polarity reversal due to inadvertant reversal of the helicopter, 28V dc power. Component operation shall be normal when normal polarity is res tored. 3.4.1.2.4 Bondinq resistance. The resistance -between any of the four bonding points and any expose
35、d metal surfaces of the EPU shall be less than 0.1 ohms. 3.4.1.2.5 Insulation resistance. The insulation resistance shall be greater than 20M ohms at least 10 seconds after 50V dc is applied between all pins of the connector linked together and the EPU bonding point. The insulation resistance shall
36、be greater than 20M ohms at least 10 seconds after 50V dc is applied between pins 17, 25, 26, 34, 35, 43, 51, and 63 connected together and all other pins of the connector linked together. 3.4.2 Performance. 3.4.2.1 Operation. The EPU is used to process data received from the AH-1 Helicopter and the
37、 Air Speed and Direction Sensor (AADS). The processed data is used to compute armament aiming and . flight information, 3.4.2.2 Input parameter. The EPU shall accept data in 3.4.2.3 Output parameter. The EPU shall provide the air data parameters over the ranges and within the error tolerance in Tabl
38、e II. accordance with Table I, TABLE I. Input parameters Par ame t e r * Sin Alpha Cos Alpha Sin Alpha-Beta Cos Alpha-Beta A ir Temper at ur e Radar Alti tude Pc Pd Par ame ter Voltage Type Ranqe Ranqe Equiv Analog Analog Analog Analog Resistance Analog Pnuematic Pnuematic +I to -1 +1 to -1 +1 to -1
39、 +1 to -1 374.4 ohm to 609.9 ohm O to 1500 ft 9.625 to 16 psia 9.625 to 16 psia 9.6V P-P +20 9.6V P-P +20 9.6V P-P - T20 9.6V P-P +20 - N/A 0.6 ohm 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-70L18b 12 777770b 0355060 O Par amet e vu vv v
40、w PABS R VDW VIU VIV NOTES : MIL-P-70486 (AR) TABLE II. Parameter ranqe of measurement Required Accuracy - +4kn - +3 kn - +3kn - +O ,Opsi +O.2psi - - - +3kn - +3kn - +3kn Vu = Fore-aft true airspeed vv = Lateral true airspeed VI, = Vertical true airspeed P-S = Ahsolute (static) air pressure TArR = F
41、ree-stream temperature VIV = Lateral indicated airspeed VIU = Fore-aft indicated airspeed VDw. = Rawnwash velocity Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-704b 12 7777706 0355061 2 W MIL-P-70486 (AR) 3.4.2.4 Fault detection/location. -1
42、 - The EPU shall have a Built-In Test (BIT) capability to check the operational status of the Air Data Subsystem (ADS). equipment for the performance of pre-flight or in-flight testing. The EPU shall provide detection/identification of a fault to the defective ADS LRU (EPU, LAI, AADS). Bit shall obv
43、iate the need for any external test O 3.4.2.5 BITE Output. The BIT circuitry shall also provide a -_. go/no-go output signal to drive a remote indicator. This output shall be as specified in Appendix A. 3.4.2.6 Malfunction indication. A status indicator shall be provided for each LRU. The status ind
44、icator shall be a go/no-go device and shall be such as to hold the last result if power is interrupted or removed, and shall be on the surface of the EPU, visible to the maintenance personnel when the equipment is installed in the aircraft. 3.4.2.7 Accuracy. The EPU accuracy values shown in Table II
45、 shall be defined as 95 percent confidence values. EPU measured accuracy shall be within the specified accuracies in at least 19 out of each 20 separate measurements to achieve the EPU performance envelope. 3.4.2.8 System turn-on time. The EPU response time from power-on actuation to ready state sha
46、ll not exceed 5 seconds. 3.4.2.9 Air leakage. Air leakage from the pitot and static lines within the EPU shall not cause an equivalent error greater than 0.5 knot in the dynamic pressure sensed by the AADS. This shall apply for any point within the performance envelope of the EPU, and for the enviro
47、nmental conditions specified herein. O 3.4.3 Physical characteristics. -3.4.3.1 Dimensions. Dimensional requirements applicable to envelope size, mounting, and mating shall be in accordance with drawing 11776552. 11 Provided by IHSNot for ResaleNo reproduction or networking permitted without license
48、 from IHS-,-,-MIL-P-704Bb 12 W 7797706 0355062 4 W MIL-P-70486 (AR) I 3.4.3-.2 Weight., EPU weight shall be 7 pounds 8 ounces maximum, 34.4 Preconditioninq (burn-in) . Each EP procured under this specification shaX1 be subjected to a burwin test as defined irr Figure 4. 3.4.5 Envkronmental condition
49、s (first article testinq onLy). The EPU shall operate and meet the perEormance requirements of 3.4.2 under any a the environmental. conditions, or a reasonable combination of these condftions, as specified herein. 3.4.5.1 Natard environment, The EPU shall apeKate and withstand storage in the environments specified herrein, 3.4.5.1,L Altitude. Operating: O-ZO,BO feet
