1、BRITISH STANDARD BS M 88:1996 ISO 11242:1996 Air cargo equipment Pressure equalization requirements for cargo containers ICS 49.120BSM88:1996 This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the authority of the Standards Board and
2、comes into effect on 15 September 1996 BSI 11-1998 The following BSI references relate to the work on this standard: Committee reference ACE/57 Draft for comment 94/704030 DC ISBN 0 580 26056 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted to
3、 Technical Committee ACE/57, Aircraft cargo systems and ground equipment, upon which the following bodies were represented: Association of Webbing Load Restraint Equipment Manufacturers British Airways British Narrow Fabrics Association Civil Aviation Authority (Airworthiness Division) Health and Sa
4、fety Executive Ministry of Defence Society of British Aerospace Companies Ltd. Society of Motor Manufacturers and Traders Ltd. Amendments issued since publication Amd. No. Date CommentsBSM88:1996 BSI 11-1998 i Contents Page Committees responsible Inside front cover National foreword ii Introduction
5、1 1 Scope 1 2 Normative references 1 3 Definitions 2 4 Environment 2 5 Aircraft containers requirements (general cargo) 2 6 Requirments for temperature-controlled aircraft containers 3 7 Requirements for airtight shipping containers (with pressure equalization) 3 8 Requirements for volumetric expans
6、ion type airtight shipping containers 4 9 Requirements for pressurized type airtight shipping containers 5 Annex A (informative) Standard atmosphere 7 Annex B (informative) Example of typical pressure equalization valve for airtight shipping containers 8 Annex C (informative) Bibliography 9 Figure B
7、.1 Example of valve 8 Figure B.2 Typical valve characteristics airflow as a function of differentialpressure 8 Table 1 (Untitled) 2 Table A.1 Standard atmosphere 7 Table B.1 (Untitled) 8 List of references Inside back coverBSM88:1996 ii BSI 11-1998 National foreword This British Standard has been pr
8、epared by the Technical Committee ACE/57 and is identical with ISO11242:1996 Aircraft Pressure equalization requirements for cargo containers, published by the International Organization for Standardization (ISO). The Technical Committee has reviewed the provisions of ISO8058:1985, the ICAO Technica
9、l instruction for the safe transport of dangerous goods by air and the IATA Dangerous goods regulations to which normative reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A British Standard does not purport to include all the necessa
10、ry provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred to Corresponding British Standard ISO 4118:1996 BS M 86:1990 Air
11、cargo equipment. Non-certified lower-deck containers for air transport. Specification and testing (Identical) ISO 6517:1992 BS M 70:1993 Air cargo equipment. Base-restrained certified containers exclusively for the lower deck of high-capacity aircraft (Identical) ISO 8097:1995 BS 2M 72:1996 Air carg
12、o equipment. Minimum airworthiness requirements and test conditions for certified air cargo unit load devices (Identical) ISO 8323:1985 BS ISO 8323:1985 Freight containers. Air-surface (intermodal) general purpose containers. Specification and tests (Identical) ISO 10327:1995 BS M 84:1995 Air cargo
13、equipment. Certified aircraft container for air cargo. Specification and testing (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may
14、 have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BSM88:1996 BSI 11-1998 1 Introduction The decrease in ambient pressure with altitude creates a pressure differential between the inside of a cargo container and the outside environment. When th
15、e internal volume and/or area of a container are significant, this may, if not properly controlled, result in tremendous forces exerted on the container panels, thus becoming a major flight safety hazard. Incidents were recorded during flight in which overly airtight containers broke down or nearly
16、exploded during climb. In order to avoid such potentially hazardous situations, it is essential that this problem be clearly identified and taken into account when designing any type of container to be moved regularly or occasionally by air cargo. 1 Scope Since most modern civil transport aircraft c
17、apable of carrying air cargo unit load devices or large-size shipping containers have pressurized cabins and cargo compartments, two different cases must be considered: a) normal (low airflow) pressure equalization during climb and descent from the departure airport pressure down to the cruise fligh
18、t cabin pressure, up to the landing airport pressure; b) emergency (rapid decompression) pressure equalization in the event of a sudden (possibly “explosive”) depressurization of the aircraft fuselage occurring at cruise altitude: this case requires very fast (high airflow) pressure equalization bet
19、ween cruise flight cabin pressure and outer ambient pressure. This International Standard defines the minimum safety requirements to be met by containers used to transport cargo by civil transport aircraft in either case a) or b) above. The flight safety requirements specified in this International
20、Standard are applicable to the design of aircraft containers for general cargo, as covered by ISO 4118 for non-certified lower deck containers, ISO 6517 for base-restrained certified containers exclusively for the lower deck of high-capacity aircraft, ISO 8323 for air/surface intermodal containers,
21、ISO 10327 for certified containers for air cargo; air mode insulated containers, as covered by ISO8058; any airtight shipping containers with an internal volume of 1 m 3(35ft 3 ) or more. NOTE 1Most shipping containers/packagings used for air cargo are made of sufficiently low-strength material (e.g
22、.fibreboard) or provide sufficient air leakage (e.g. wooden crates) that they cannot be considered airtight and do not present any significant hazard as a result of pressure equalization. There are however a number of special containers, notably for the carriage of satellites/space hardware, aircraf
23、t spares, sensitive scientific or technical equipment, etc., which are airtight per design (in order to protect the contents against atmospheric pollution) or per construction (because of the quality of sealing and materials used). 2 Normative references The following standards contain provisions wh
24、ich, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibilit
25、y of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 4118:1996, Non-certified lower-deck containers for air transport Specification and testing. ISO 6517:1992, Air cargo equipment Base-restr
26、ained certified containers exclusively for the lower deck of high-capacity aircraft. ISO 8058:1985, Air cargo equipment Air mode insulated containers Thermal efficiency requirements. ISO 8097:1995, Aircraft Minimum airworthiness requirements and test conditions for certified air cargo unit load devi
27、ces (Endorsement of NAS3610,10th edition). ISO 8323:1985, Freight containers Air/surface (intermodal) general purpose containers Specification and tests. ISO 10327:1995, Aircraft Certified aircraft container for air cargo Specification and testing. ICAO, Technical instruction for the safe transport
28、of dangerous goods by air 1) . IATA, Dangerous Goods Regulations 2) . 1) Available from the International Civil Aviation Organization, 1 000 Sherbrooke Street West, Suite 400, Montreal, Quebec H3A2R2, Canada. 2) Available from IATA Publications Dept., 2 000 Peel Street, Montral, Qubec H3A 2R4, Canad
29、a or IATA Publications Dept., Route de lAroport 33, PO Box 672, CH-1215 Genve 15 Aroport, Switzerland.BSM88:1996 2 BSI 11-1998 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 airtight shipping container any container, unless constructed of low-stre
30、ngth materials (fibreboard or equivalent), where the cumulated cross-sectional area of all apertures allowing a flow of air between the inside and the outside of the container is less than 5cm 2per cubic metre (0,02in 2per cubic foot) of internal container volume 3.2 pressurized shipping container a
31、irtight container which is entirely sealed and does not include either means of pressure equalization as described in clause7 or an expandable volume as described in clause8 3.3 normal flight conditions flight conditions with cabin/cargo compartment pressure decreasing from standard sea level101,3kP
32、a (14,4lbf/in 2 ) to minimum cruise flight cabin altitude pressure 75kPa (10,7lbf/in 2 ) during climb, and increasing back to standard sea level during descent, at the maximum rates given in Table 1 3.4 emergency (rapid decompression) conditions cabin/cargo compartment atmosphere dropping linearly f
33、rom a minimum normal equivalent altitude of 1830m (6 000ft), i.e. a maximum normal pressure of 81kPa (11,8lbf/in 2 ) in cruise flight, to the standard ambient pressure at13715m(45 000 ft) altitude of 15 kPa (2,14lbf/in 2 ) in a duration of 1 s 4 Environment 4.1 General The decrease of ambient atmosp
34、heric pressure with altitude is described by the international standard atmosphere as shown in annex A. The maximum operating altitude for modern civil transport aircraft (with the exception of supersonic aircraft which do not carry air cargo containers) is13715m (45000ft), corresponding to an ambie
35、nt pressure of approximately 15kPa (2,14lbf/in 2 ) as compared to the standard sea level atmospheric pressure of approximately 101,3kPa (14,4lbf/in 2 ). Table 1 4.2 Normal flight conditions The pressurization systems of modern civil aircraft maintain, during cruise flight at the maximum operating al
36、titude, the cabin and cargo compartment pressure at a maximum equivalent altitude of approximately 2600m (8500ft), i.e. a minimum pressure of approximately75kPa(10,7lbf/in 2 ). 5 Aircraft containers requirements (general cargo) 5.1 Normal flight conditions 5.1.1 Unless constructed of low-strength (f
37、ibreboard or equivalent) material, certified and non-certified aircraft containers for general cargo in accordance with ISO4118, ISO6517, ISO8323 or ISO10327 shall be designed with a built-in vent area sufficient to cope with normal (low airflow) pressure equalization. 5.1.2 The minimum vent area sh
38、all be 5cm 2per cubic metre (0,02in 2per cubic foot) of container internal volume. 5.1.3 The container door seals area may be considered as part or all of the required minimum vent area, provided any seals occupying the apertures so considered are sufficiently flexible to deflect fully in either dir
39、ection (in or out) under a pressure differential of between 3,5kPa and7kPa(0,5lbf/in 2to 1lbf/in 2 ). 5.1.4 The vent area shall be located so that it cannot be inadvertently blocked by cargo, and shall be adequately protected from cargo load shift to ensure this minimum area is maintained in all cir
40、cumstances. 5.2 Emergency (rapid decompression) conditions 5.2.1 Certified and noncertified aircraft containers for general cargo in accordance with ISO4118, ISO6517, ISO8323 or ISO10327 shall be designed to be able to ensure high flow pressure equalization in the event of a rapid decompression at c
41、ruise altitude, as defined in3.4, without creating a hazard to the cargo compartment or aircraft structure. Cabin altitude rate Cabin pressure rate m/s ft/min Pa/s (lbf/in 2 )/min Maximum climb rate + 12,7 + 2 500 150 1,3 Maximum descent rate 7,6 1 500 + 90 + 0,78BSM88:1996 BSI 11-1998 3 5.2.2 Full-
42、scale tests have indicated that the design and construction of typical aircraft containers meet the above requirement since, when submitted to rapid decompression, the panel joints and notably the door frames immediately deform to the extent of creating sufficient space for the high airflow required
43、, without breaking or projecting parts which could become a hazard to the surrounding structure. 5.2.3 However, it remains necessary, in compliance with ISO8097 (endorsement of NAS3610), to verify this requirement by analysis or testing when designing any new type of container, particularly if the n
44、ew design is intended to be built in a stronger manner than is current industry practice. 6 Requirements for temperature-controlled aircraft containers 6.1 General It can be required for temperature-controlled aircraft containers, certified or non-certified, in accordance with ISO8058, that the poss
45、ibility of a flow of air into/out of the container is minimized in order to improve temperature control efficiency. Consequently, unless they are designed in accordance with the full requirements of clause5, temperature-controlled aircraft containers shall be designed with: a) a built-in vent area o
46、r pressure equalization device capable of meeting the normal flight conditions; and b) a built-in blow-out panel or equivalent device capable of meeting the emergency (rapid decompression) conditions. 6.2 Normal flight conditions 6.2.1 If a built-in vent area is provided, it shall comply with the re
47、quirements of 5.1. 6.2.2 If the container is designed to be airtight, a pressure equalization device (valve or equivalent) meeting the requirements of 7.2 shall be provided. 6.3 Emergency (rapid decompression) conditions 6.3.1 Unless the container is designed to the requirements of 5.2.1, it shall b
48、e equipped with a blow-out panel or equivalent device in order to cope with the rapid decompression situation in a nonhazardous manner. 6.3.2 The blow-out panel or equivalent device, when fully open, shall provide a minimum cross-sectional area of 100cm 2per cubic metre (0,45in 2per cubic foot) of c
49、ontainer internal volume. 6.3.3 The blow-out panel or equivalent device shall fully open in less than 0,2s when submitted to a maximum pressure differential from inside of14kPa (2lbf/in 2 ). 6.3.4 The blow-out panel or equivalent device shall meet the requirements of 5.1.4. 6.3.5 The container door(s) may be used as a blowout panel, provided its (their) attachment to the container structure meets the requirements of 6.3.3, and, in the case of a certified container, can withstand the ultimate side load required by airwort
