1、AEROSPACE AIR 1076 c- - issued: 1963 (See Preface) I N FO R M AT1 O N a) SPACE Society TWO PENNSYLVANIA of Automotive PLAZA NEW Engineers, YORK N Y 10001 Inc. R E p 0 RT Reissued: 5 -1-70 GAS TURBINE ENGINE INSTALLATIONS , PREFACE. 1 PURPOSE . 1 SCOPE 1 INTRODUCTION . 1 1. FIRE PROTECTION FOR RECIPR
2、OCATING ENGINE INSTALLATIONS 2 1.1 Fire Terms and Zone Definitions . 2 1.2 Prevention of Occurrence of Fire 3 1.3 Prevention of Spread of Fire . 5 1.4 Fire Detection . 6 1.5 Fixed Fire Extinguishing Systems 8 1.6 Ventilation and Smoke Evacuation 15 1.7 Summary 15 1.8 References 15 2. FIRE PROTECTION
3、 FOR GAS TURBINE ENGINE INSTALLATIONS 16 2.1 General Discussion and Terms . 16 2.2 Prevention of Occurrence of Fire . 18 2.3 Prevention of Spread of Fire . 25 2.4 Fire Detection . 26 2.5 Fixed Fire Extinguishing Systems 28 2.6 Ventilation and Smoke Evacuation 35 2.7 Summary 35 8 2.8 References . 35
4、APPENDIX I I il) - Printed in U.S.A. SAE AIR*LO?h 70 m 8357340 0003330 9 m -1 PREFACE This document was issued in 1963 by the Powerplant Installation Committee of the Aerospace Industries Associa- tion (A. I. A.) as a design manual for all. types of aircraft. Since then the originating Committee was
5、 dissolved and the manual became unavailable. In this period, advancements in aircraft fire protection methods have been produced by both governmental and private agencies that are not re- flected in the manual. Recognizing this, but nevertheless feeling that there is much of present-day value in th
6、e man- ual, the SAE S- 12 Helicopter Powerplant Committee be- lieves it is performing a useful service to the helicopter in- dustry in again making it available. Hence, the Committee herewith reissues without change, as an AIR, the entire orig- inal manual except for deletion of Acknowledgements. A
7、future revision to this AIR to bring it up to date and to em- phasize helicopter powerplant fire protection is under con- sideration by the s-12 Committee. PURPOSE The Aerospace Industries Association has published this design manual, containing fire-prevention information accumulated on civil and m
8、ilitary aircraft, as a service to all organizatiohs, government agencies, and individuals interested in aviation as well as to the aircraft designer, at whom the information is specifically directed. This mate- rial has been presented in concise indexed form to serve as generalized reference materia
9、l and to provide background data for the designer. It is not intended that this be con- sidered as proposed regulatory or specification material be- cause it borders on maximum rather than minimum required airworthiness. The Manual was first published 1 August 1949. It was previously revised on 15 A
10、pril 1954 and 1 December 1957 and, in that time, has been used widely as a guide by many government and civil organizations of both domestic and foreign countries in the manufacturing, operating, and edu- cational fields f aircraft. SCOPE This document is reissued for application to helicop- ters. I
11、NTRODUCTION The work done in the initial stages of design will de- termine the final degree of fire protection inherent in a new helicopter; therefore, considerable foresight as to the eventual installation details is necessary. A lack of per- ception as to the relationship between a source of ignit
12、ion and combustible fluids or materials may result in a com- bination which no amount of subsequent detailed design struggling can ever completely remedy. The inevitable design conflicts which arise on any new helicopter and the resultant compromises, should always tonsider the fire po- tential in o
13、rder to obtain a sensible balance. For this rea- son, emphasis to keep the thought of fire protection promi- nent in preliminary design work is well worth the effort. The following design points are intended to give a number of general rules for the fire protection features of preliminary design. If
14、 fire protection is considered in the preliminary design, the work of the detail designer trying to protect any particular section of the helicopter from the hazards of fire can be greatly simplified. Each helicopter is an individual problem and it is realized that many fac- tors will affect the dec
15、isions in its design, However, the nearer the design can be to basic safety principles, the less will be the chance of trouble caused by detail design errors, maintenance in the field, or failures of equipment. It is strongly felt that the basic safety responsibility for a helicopter lies on the dra
16、wing board. Each engineer concerned with the design of a system or component should realize its potential relation to all other affiliated and ad- jacent items and to the helicopter as a whole. Because the most important phase of fire protection is the prevention of occurrence of fire, each engineer
17、 responsible for the design 9 of a component of a helicopter can contribute most satis- factorily to the basic safety of the helicopter if he has a thorough knowledge of the aircraft fire protection problem. Therefore, this Aerospace Information Keport is built around a general discussion of fire pr
18、otection. Mention of specific systems is made only where the general discussion does not apply, or where exceptions to the general discussion must be pointed out. Kegardless of the original fire protection design fea- tures built into the helicopter, it is necessary to maintain the helicopter proper
19、ly to avoid increasing fire hazards; various means and procedures for accomplishing this can also be found in this AIR. For purposes of discussion, fire protection consists of Prevention of Occurrence of Fire Prevention of Spread of Fire Fire Detection Fire Extinguishment Ventilation and Smoke Bracu
20、ation five basic divisions: - - - . SAE AIR*3076 70 83573i.10 0003333 O S I -2- AIR 1076 I 1. FIRE PROTECTION FOR RECIPROCATING ENGINE INSTALLATIONS 1.1 Fire Terms and Sone Definitions 1.11 Terms - Terms which must be definedta clarify their usage herein are the following: 3,111 Fireproof: A materia
21、l which will withstand heat as well as or better than steel which will withstand 2000 F for 3.5 minutes and still fulfill its design purpose. When applied to materials and parts used to confine fires within designated fire zona, 11 ireproof“ means that the material or part will perform this function
22、 under the most severe conditions of fire, and duration of fire, likely to occur in such zona, An example: Nacelle firewall, whch resists 2000 E flame for 15 min. 1.112 Fire Resistant: When applied to sheet or structural members, I fire resistant“ describes a material which will withstand heat as we
23、ll as or better than alu- minum alloy in dimensions appropriate or the purpose When applied to fluid-carrying lines, other flammable fluid system crnponents, wiring, air ducts, fittings and power plant controls, fire resis- tant refers to a line and fitting assembly, component, wiring, duct, or cont
24、rols which will perform the ntended functions under the heat and other conditions likely to pcur at the particular location. An example: Fire re- sistant hose which will resist 2000 F flame for 5 min. . for which it is used, 1.113 Flame Resistant: Materials which will not support combustion to the p
25、oint of propagating a flame beyond safe limits after removal of the ignition source. A test procedure to determine the minimum safe limits is presented in CAA Safety Regulation Release No. 259 dated August 25, -1947 (Reference 6). 1.114 Flash Resistant: Materials which will not .burn violently when
26、ignited, 1.115 Flammable: Solids, fluids, or gases which will Ignite readily or explode, Methods for determining the relative flammabilities of fluids are being developed. A per cent nonflammable method applicable to fluids (aviation gasoline, .kerosene, standard hydraulic fluid, lubricating ils, et
27、c, ) that are miscible with nexachloro- butadiene is pksented in CAA Technical Development Report No. 142. - Determination of Ignition Character- istics of Hydraulic Fluids Pari II Flammability Reference . Scale, May 1951 (Reference 8). 1.116 Compartmentation: The process of isolat- ing components f
28、rom other items with which they would normally be hazardous in combination. 1.117 Ventilation Stop: An isolating bulkhead, at least fire resistant, which is substantially vapor and liquid tight, for the purpose of controlling ventilation and liquid paths, 1.12 Zones and Zone Classifications 1.121 Co
29、mbustible Zone: An airplane compart - ment containing equipment from which leakage of com - bustibie fluids or vapors is not abnormal. An example: fuel cell bay. 1.522 Ignition Zone: An airplane compartment containing equipment which is normally an ignition source. An example: Inverter compartment.
30、1.123 Possible Fire Zone: A region in which an ignition source, together with combustibles, combus- tible fluid line leakage, or combustible mixtures, may exist at some time during airplane operation, The pos- sible ignition source or combustibles might be contained within the region, or might enter
31、 the region from an external location during an emergency. The following should be consideted to determine their possible hazard: A. Nacelle Zones: Reciprocating engine nacelles are normally referred to as divided into the follow - ing three zones from a geographical stahdpoint (these are nacelle zo
32、nes, as distinguished from fire zones). Zone 1: The section within the front of the engine nacelle ahead of the fire seal or inner cowl seal (engine power section). Zone 2: The nacelle section between the fire seal and the Tirewall (the accessory section), Zone 3: The section within the nacelle and
33、be- hind the firewall (wheel well space or rear nacelle skate), B. All baggage compartments C. Auxiliary power plant installation sections D. Combustion heater installation sections E. Other regions equally hazardous from the stand- point of fire possibilities, 1.124 Fire Zone: A “possible fire zone
34、“ which has been recognized and treated as a region which re- quires fire detecting and/or fire extinguishing equipment and a high degree of inherent fire resistance. I _ SAE AIR*1076 70 m 8357340 0003332 2 . - . -3- 1.125 Designated Fire Zone: The CAA has recog- nized certain regions as fire hazard
35、s, and has called them “designated fire zones“. For non-military air- craft, the CAA has declared the zones listed below to be in this category: A. Engine power sections B. Engine accessory sections C. Sections where no isolation is provided be- tween engine and accessory Compartment D. Auxiliary po
36、wer installations E. Fuel burning heater installations 1.2 Prevention of Occurrence of Fire 1.21 General Rules 1.211 Desien u A. Compartmentation: Separate and isolate com - bustibles from sources of ignition, In defining the application of this rule, any single potential fail- ure of any equipment
37、item (such as a leak in a fuel line connection, or burning out an electric motor) should be considered as a realistic basis under which the isolation principle should be met. B. Drainage: Prevent combustible mixtures and fluids-from accumulating by providing adequate drain holes and/or drain lines i
38、n all compartments where combustibles are encountered. Care should be taken to assure drainage throughout the normal range of flight and ground attitudes. C. Re-entry Seals: Drain lines should extend be- low the exterir surfaces when practical and be sealed at the surface to prevent a return of vapo
39、r and liquid flow into the compartment. R. Drain Location: Drain lines should lead to low pressure skin areas, and should be sufficiently large to quickly discharge large quantitities of fluid under conditions of serious fluid line leak- age, Drain line discharge should not come in contact with flui
40、d line leakage. Drain line dis- charge should not come in contact with exhaust gases under any conditions of airplane maneuver - ing. Drainage paths should be examined to de- termine that fluids are not carried into openings or compartments where ignition hazards exist. E. Leakage: Fuel and oil tank
41、 locations, and sump and vent locations, should be analyzed with the point of view in mind that leakage will some- time occur, and fire must not result, If it is nec- essary to locate a fuel tank immediately behind a fire wall, a ventilated air space of at lease 1 in. should be allowed between the t
42、ank and the fire- wall, Drainage paths should be included to pro- vide for clearance from exhaust. Re-entry of drained fluids should be avoided, P. Component Location: Combustible fluids tend to collect-in the bottoms of compartments, so it is AIR 1 O76 desirable to keep exhaust lines and other igni
43、tion sources as high within each compartment as practical. G. Exhaust Location: Avoid, where possible, running the exhaust system through zones contain - ing combustible fluid lines, such as the accessory section, Exhaust gases should be discharged clear of the nacelle surface, so that they do not p
44、ass over access doors, drain outlets, or other places where combustible fluids may be present, H. Exhaust vs. Combustibles: In general, com- bustible fluid carrying lines should be located on the opposite side of the nacelle from the exhaust system and from electrical wiring, I. Exhaust Leakage: Par
45、ticular care should be exercised to prevent exhaust system leakage. Leakage points produce flame, which is a greater hazard from the standpoint of ignition than bare exhaust pipe. Special attention should be given to locking all nuts on disconnect flanges, etc, Failure to exhaust clamp bolts has bee
46、n generally chronic. In some installations the use of double bolts has provided a desirable safety factor, Ex- haust systems should be supported in a manner which will preclude displacement of a portion of the collector in the event of a bolt or nut failure. This avoids the condition where a large a
47、mount of exhaust impinges on shrouding, cowling, etc. J. Exhaust Shrouds! Exhaust systems should be completely separated from the accessory section and Zone 3 by substantially vapor-tight fireproof shrouds. If the exhaust system passes through the lower part of Zone 2 or 3, it may fie desirable to U
48、SE: a double shroud with ventilating air flowing between the inner and outer shroud. The tempera- ture of the accessory section surface of the shroud should be kept below 500 F, for all operating conditions. K. Fuel Vent Configuration: Fuel vent systems mus; be designed so thatfluids will not spill
49、out during maneuvering. Actual ground tests should be conducted under conditions of maximum accel- eration, deceleration, and 360 deg turns on a sharp radius, Flight test and analysis should in- clude consideration of maximum roll, climb and glide angle, and yaw. L, Feel Vent Outlets: Fuel vent outlets should be so located-and designed that solid fuel exiting from them cannot impinge on any airplane surface, Malfunction or misuse of fuel transfer systems should not cause a high rate of fuel flow to be pumped out the vent. M, Fuel Dump System: Fuel dumping systems must-be inert
