NAVY MIL-F-7872 C-1966 FIRE AND OVERHEAT WARNING SYSTEMS CONTINUOUS AIRCRAFT TEST AND INSTALLATION OF《安装及测试飞机连续消防及过热预警系统》.pdf

1、I +op a/. MIL-F-7872C (ASG) 18 NOVEMBER 1966 Superseding MIL-D-7872B(Wep) 12 June 1962 MIED-7006A(ASG) 6 January 1956 MILITARY SPECIFICATION FIRE AND OVERHEAT WARNING SYSTEMS , CONTINUOUS , AIRCRAFT: TEST AND INSTALLATION OF This specification has been approved by the Department of the Air Force and

2、 by the- Naval Air Systems Command. 1. SCOPE 1.1 Scope. This specification describes the-requirements for the design, manu- facture, testing and installation of - continuous. type fire and overheat warning systems for use in aircraft. These systems employ continuous lengths of heat- sensing elements

3、 connected to a monitoring device. 2. APPLICABLE DOCUMENTS 2.1 The following documents, of the issue in effect on date of invitation for bids or request for proposal, form a part of this specification to the extent specified herein: SPECIFICATIONS Federal TT-S-735 Standard Test Fluids; Hydrocarbon M

4、ilitary MIL-P-116 MIL-D-1000 MIL-W-5088 MIL-E5272 MIL-E-5400 MIED-6055 MIL-R-6106 1-1-6181 MIL-E-7080 MIL-L-7808 Preservation, Methods of Drawings, Engineering-and Associated Lists Wiring, Aircraft, Installation of Environmental. Testing, Aeronautical and Associated . Equipment, General Specificatio

5、n for Electronic Equipment, Aircraft, General Specificat ion for Drums, Metal, Reusable, Shipping and Storage (Cap. from 88 to 510 Cubic Inches) Relay, Electric, Aerospace, Genera1 Specification for Interference Control Requirements, Aircraft Equipment Electric Equipment , Piloted Aircraft, Installa

6、tion Lubricating Oil, Aircraft Turbine Engine, Synthetic and Selection of, General Specification for Base . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-7936 - MIL-1-8700 MIL-W-25038 . 1-26482 STANDARD3 Military MIL-STD-130 MIL-STD-143 MIL-S

7、TD-411 MIL-STD-704 W25231 Parts- and Equipment, Aeronautical, Preparation for Delivery Installation and Test of Electronic Equipment in Aircraft, General Specification for Wire, Electrical, High Temperature and Fire Resistant, Aircraft Connectors, Electric, Circular, Miniature , Quick Disconnect Ide

8、ntification Marking of US Military Property Specifications and Standards, Order of Precedence Aircrew Station Visual Signals Electric Power, Aircraft, Characteristics and Lamp , Incandescent, Single Contact , Miniature Metals , Definition of Dissimilar for the Selection of Utilization of Bayonet Bas

9、e, T-3-1/4 Bulb When requesting any of the applicable documents, refer to both title and number. All requests should be made via the cognizant Government inspector. Copies of this specification and-other unclassified specifications and drawings required by contractors in connection with specific pro

10、curement functions should be obtained upon application to the Commanding Officer, Naval Supply Depot. (Code CDS) , 5801 Tabor Avenue, Philadelphia, Pennsylvania lgl2O. All other documents should be obtained froni the procuring activity or as directed by the contracting officer. 1 3. REQUIREMENTS 3.1

11、 Preproduction testing. This specification makes provision for preproduction testing (see 4.3). 3.2 Components. The fire warning system shall consist of lengths of sensing elements, connectors, flexible connections, clamps, interconnecting wiring, relays, control unit, warning signals and test switc

12、hes, as required. 3.2.1 Nomenclature. The term “control unit“ as used in this specification shall include any device used to monitor the sensing element circuit and to actuate a warn- ing device on the instrument panel. The term “sensing element“ shall include any heat sensor used in the fire warnin

13、g system. The tem “system“ shall refer to the fire warning system. 3.3 Design objective. Items of this specification which are identified as “design objectives are intended as guides. Approval by the procuring activity is not required for deviations from such objectives. The contractor shall furnish

14、 evidence to the procuring activity or the Government inspector that due consideration has been given to meeting these objectives. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.4 Materials and parts. 3.4.1 Metals. Metals shall be of a corrosion

15、 resisting type, or shall be protected to withstand aircraft fuels, lubricating oils, salt. spray, prolonged high humidity and atmospheric conditions for the life of the equipment when in storage and in service use. Dissimilar metals, as defined in MS33586, shall not be used in intimate contact with

16、 each other. 3.4.1.1 Magnesium. The use of magnesilun and its alloys shall be avoided if practic- able, and its use where necessary shall be subject to approval by the procuring activity. 3.4.2 Nonmetals. All nonmetals shall be moisture- andflame-resistant to the extent, practicable commensurate wit

17、h other aircraft design requirements, shall not support fungus growth, and shall. not be adversely affected by weathering, aircraft fluids and temperature extremes encountered during operation or storage of the aircraft. 3.b.3 Select.ion of materials and parts. Specifications and standards for neces

18、sary materials and parts, processes and equipment which are not specifically designated herein shall be selected in accordance with the order of precedence set forth in MIL-STD-143. AN or MIL standard parts shall be used wherever they are suitable fc.r t.he purpose. 3.4.3.1 Materials. Materials shal

19、l conform to the applicable specifications as set forth in MIL-E-5400. 3.k.4 Interchangeability. All parts having the same manufacturers part number sha.11 be directly and completely interchangeable with each other with respect. to installation and performance. Changes in manufacturers part numbers

20、shall be gov- erned by the drawing number requirements of MIL-D-1000, t 3.4.5 Weight. Weight shall be kept to a minimi consistent with other requiremects of tns specif-ication. 3.5 System design requirements. 3.5.1 Fire response. The system shall indicate a fire within. 5 seconds after any 6-inch po

21、rtion of the entire sensing element arrangement is exposed to a 2,000 F flame of the flame test burner illustrated on figure 1. The systems shall maintain . the fire signal for the duration of the fire and shall automatically clear the signal in not more than 30 seconds following extinguishment of t

22、he fire. As-a design objec-. tive, the system should also be capable of indicating a fire within 5 seconds after any 6-inch portion of the entire sensing element arrangement is exposed to a 1,500 F flame. 3.5.1.1 Automatic repeatability. The system shall be capable of signalling three consecutive fi

23、res without requiring manual resetting. 3.5.2 Loop circuit. Detachable sensing. elements -shall be connected to the control unit in a- continuous loop circuit such that a single break in the sensing element. loop will not cause the system to become inoperative. If one or more breaks occur, those por

24、tions of the sensing element circuit that remain connected-to the control unit shall retain the ability to detect and signal a fire. 3 v Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-UBES ISGATED AT INTERSECTION F SOLID LINES DOTS LOCATE SECONDARY

25、AIR HOLES SEGONDARV AIR. OR TUBES ONLY SEAL (TIHT FIT, WELD OR 6RA2,E. ETC.) FOUR 1/8- IN. PIPE TAPS, LOCATED DIRECTLY IN LINE WITH CENTER ROW OF THE QUADRANTS OF Ih-lN. COPPER TUBES IN EACH BURNER BASE 4 1. - _. Provided by IHSNot for ResaleNo reproduction or networking permitted without license fr

26、om IHS-,-,-I I I 3.5.3 Abnormal flight conditions. The system shall be capable of continuing operation during abnormal flight attitudes, rapidly changing altitudes, extremes of-temperature, contaminating atmospheres, accelerations and other conditions which may be encountered during take-off, flight

27、, landing or servicing the aircraft. As a design objective, the system should also be capable of detecting and signalling a fire when a fault such as a ground or short occurs in the sensing element circuit. 3.5.4 Prevention of fa.lse warnings. The design and installation of the system shall be such

28、as to prevent the occurrence of false warnings resulting from flight operations, damage to %he components of the system, loose connections or inadequate maintenance. 3.5 .h .1 Flight conditions c A false warning shall not occur as a result of abnorma.1 flight conditions as described in 3.5.3, nor fr

29、om any bending or mechanical abuse of of the sensing elenenta. 3.5.4.2 Break in sensing element. A false warning shall not occur as a result of one or more brsaks in the sensing element circuit. 3.5.h.3 Short or groundcondition. A false warning shall not. occur as a result, of any normally ungrcunde

30、d conductor accidently making a cofitinuous or intermittent contact with any other conductor or with agrowdedportion of the airplane, 3.5.b.4 Moisture -accumulation. A false warning shall not occur as a result- of an accumulat.ion of saline nioisture in any connector of the sensing element, circuit.

31、 As a design objective, the range of sensing element circ.uit resistance in which a fire alam may be signaled should not include resistance values that could be produced by any concentration f moisture in the end connectors. 3.5 .h, 5 Voltage varlat ions. A false warning shall not result from transi

32、ent voltage condltions, as specifled in MIL*-STD-704, or from any intermittent voltage between O and 124 volts for the rate of tempera- ture rise required to signal a fire alarm shall be at least 100 percent greater than. the maximum rate of temperature rise occurring during normal engine starting a

33、nd ecceleration. 3.5.5.1 Response limits. Unless otherwise approved by the procuring activity,the system shall be adjusted not to signal a fire alarm at temperatures under 500 F in engine spaces. The temperature required to alarm the system, when applied to any 4- inch section of sensing element, sh

34、all not exceed 1,000 F. For overheat systems, trigger temperatures lower Chan 500 F may be used. 3.5.6 Alzrm adjustment. Alarm temperature adjustments shall be secured with a locking device Gd sealed with tamper-proof seals. Externally mounted adjusting “inits shall be protected aga:inst mechanical

35、damage. 3.5J Fire warnin(r signal. The system, when actuating,.shail display a legend-type warning signal :jhowirlg the wore “FIRE“ in bold red lettering at least- one-half inch il? height. The signal shall conform to MIL-STD-411 and shall be located in the direct view of the pilot and copilot. 5 c

36、- “, a I* - : i. L 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-F-7872C (ASG) 3.5.7.1 Additional warning signal In those aircraft where a crew member other than %he pilot or copilot is responsible for the .fire -emergency procedure, the fire

37、 warning signal shall be located in the direct view of that crew member, and a master warning signal shall be provided for the pilot-and copilot. 3.5.7.2 Lamps. Where light signals are used for fire warning, each signal shall include two MS25231-313 lamps or two other MS or AN lamps. of equivalent w

38、attage. During the fire indication, the lamps shall be operated- at rated current. 3.5.7.3 Zone indlcation. Wnere more than one fire warning signal is provided, each signal shall indicate the specific engine or compartment in which the fire occurs, and shall be marked in accordance with table I of M

39、IL-STD-411. The fire warning signals shall differentiate between fires in different zones of the same power plant when the crews emergency procedure differs depending upon the zone inTolved, Warn- ing signals marked to indicat-e an engine fire shall not. be used $3 signal unrelated conditions, such

40、as rocket pack fires , generator overheat. cr bearing overheat , which could produce misinterpretation of the actual emergency that exists. 3.5.8 Overheat actuation Where overheat warning is provided and the emergency Drocedure for overheat differs from that for a fire condition, the warning system

41、shall provide a distinct overheat signal. This signal shall be in -accord without being damaged, and shall automatically resume operation when the input voltage returns within operating limits. If transistors are used.in the system,-protection shall be incorporated to prevent damage by 200 volts rms

42、 voltage transients.of-50 milliseconds duration, aid by 56 volts dc voltage transients- of 50 milliseconds duration. 3.5.15 Electromagnetic interference. The system shall comply with the electro- magnetic interference requirements of MIEI-6181. 3.5.16 Design operating life. !The system shall have a

43、reliable operating life of at least 1,000 hours without requiring removal for bench servicing. A8.a reliability objective, less than five failures per 100 service installations shall occur per year. 3.5.16.1 . Total operating life. The system shall have- a minimum. total operating life of 10,000 hou

44、rs with reasonable servicing and replacement of parts. 3.6 Component design. 3.6.1 Control unit design. The control unit shall be a leakproof metal coneainer and shall be hermetically sealed. The cover shall be securely attached by mechanical means other than solder. Internal wiring shall be in acco

45、rdance. with MIL-E-5400. 3.6.2 Sensing element. Sensing elements shall be enclosed- in a fireproof metallic covering. Detachable sensing elements shall be provided with suitab1e.end fitsings to permit connection into continuous lengths. Sensing elements shaU be hermetically sealed or shall be made.

46、environment-proof by other suitable means. 3.6.2.1 Sensing element lengths. Detachable sensing elements- shall be furnished only in 36, 60, 120 and 180 inch lengths, with a tolerance of plus or minus one-half inch. Not more than two different lengths of sensing elements shall be used in an installat

47、ion. 3.6.3 Fire-resistance. Sensing elements and other- components installed in fire zones shall be capable of withstanding a temperature of 2;000 F for a period of 5 minutes without impairing the fire detection capability. External finishes on the sensing element surface need not be capable of with

48、standing this fire-resistancetest, 3.6.4 Bend radius. The sensing element shall be capable of being bent completely around a one-inch radius without becoming mechanically or functionally damaged. 3.6.5 Connectors. Connectors used to connect sensing elements may be of a non- standard type provided th

49、ey meet the performance requirements of-this specification. Connectors not in the sensing element circuit shall conform to the applicable per- formance requirements of MIL-C-26482. 3.6.6 Support clamps. The sensors shall be securely .supported by clamps in a manner that permits removal or loosening of the sensing elements without requiring removal or loosening of the clamps from the mounting surface Mounting provisions shall be such as to prevent inadvertent