1、BRITISH STANDARD AEROSPACE SERIES BSG260:1996 ISO2669:1995 Environmental tests for aircraft equipment Steady-state acceleration ICS 49.020BSG260:1996 This BritishStandard, having been prepared under the directionof the Engineering SectorBoard, was published underthe authority of the Standards Board
2、and comes intoeffect on 15 June1996 BSI01-2000 The following BSI references relate to the work on this standard: Committee reference ACE/58 Draft for comment89/75587DC ISBN 0 580 25627 8 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted to Technica
3、l Committee ACE/58, Environmental and operating conditions for aircraft equipment, upon which the following bodies were represented: Civil Aviation Authority Federation of the Electronics Industry Ministry of Defence Society of British Aerospace Companies Society of Environmental Engineers Amendment
4、s issued since publication Amd. No. Date CommentsBSG260:1996 BSI 01-2000 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Normative reference 1 3 Apparatus 1 4 Equipment mounting 2 5 Classification of tests 2 6 Test sequence 3 7 Acceleration s
5、everity grades 3 8 Procedures 3 9 Information to be included in the relevant equipment specification 6 Annex A (normative) Additional accelerations 7 Figure 1 Direction of aircraft acceleration 4 Table 1 Equipment severity grades 2 Table 2 Classification of tests 3 Table 3 Equipment categories 4 Tab
6、le 4 Acceleration severity grades (functional test) 5 Table 5 Acceleration severity grades (structural test) 5 Table A.1 Additional accelerations 7 List of references Inside back coverBSG260:1996 ii BSI 01-2000 National foreword This BritishStandard has been prepared by Technical Committee ACE/58 an
7、d is identical with ISO2669:1995 Environmental tests for aircraft equipment Steady-state acceleration, published by the International Organization for Standardization (ISO). NOTEThe latest edition of an Aerospace series standard is indicated by a prefix number. A British Standard does not purport to
8、 include all the necessary 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-reference Publication referred to Corresponding BritishStandard ISO7137:1
9、995 BS4G229:1996 Schedule for environmental conditions and test procedures for airborne equipment (Identical) Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to10, an inside back cover and a back cover. This standard has been updated (see copyright
10、 date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BSG260:1996 BSI 01-2000 1 Introduction The tests specified in this International Standard aim to determine the performance characteristics and to confirm the structural integrity
11、and safety of airborne equipment and airborne equipment mountings when they are subjected to gradually changing acceleration forces generated by an aircraft, manoeuvre such as turn, pull-out, roll, etc. For example, the tests would be expected to indicate: a) any change in operating state and any va
12、riations in performance; b) any jamming occurring in moving parts and any variation in their path; c) any reduction in the free travel and change in the suspension characteristics of the anti-vibration mountings that could damage the operating state and capability of anti-vibration; d) any breakage
13、or any weakness in the fastenings mounting devices or structure of the equipment that could constitute a hazard to the aircraft or its occupants. 1 Scope This International Standard specifies two types of steady-state acceleration test and establishes five severity grades of acceleration forces used
14、 to simulate a gradually changing acceleration environment representative of that which civil aircraft equipment can encounter in operational use. The emergency landing case is not within the scope of this International Standard; reference should be made to ISO7137 for this case. 2 Normative referen
15、ce The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this International Standar
16、d are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO7137:, Aircraft Environmental conditions and test procedures for airborne equipment 1) . 3 App
17、aratus 3.1 General characteristics 3.1.1 A centrifuge should be used for producing the required acceleration forces. 3.1.2 In special cases, if stated by the relevant equipment specification, inflight testing or any other method that can produce linear acceleration may be used instead of a centrifug
18、e. 3.1.3 The apparatus shall be capable of producing the specified acceleration forces within 10% at all points in the equipment. 3.1.4 The apparatus shall be fitted with the electrical, hydraulic and/or pneumatic input and output connections needed to operate the equipment under test and to conduct
19、 operational checks. The loss of the connections shall not exceed the limit specified in the relevant specification. 3.1.5 The test apparatus shall be equipped with an adjustable acceleration system, and any additional vibration due to the test apparatus shall be maintained within the tolerance spec
20、ified in the relevant specifications. 3.1.6 The centrifuge shall be equipped with an adjustable mass balance system to compensate for any out-of-balance forces due to the mass of the test item. 3.2 Special cases 3.2.1 If, because of the excessive size of the equipment, it is not possible to maintain
21、 the tolerance specified in3.1.3 at all points in the equipment, the relevant equipment specification may relax requirements on those parts not considered to be sensitive to specified acceleration forces. 3.2.2 During functional tests in vertical directions carried out with equipment sensitive to gr
22、avity or inversion and which could cause malfunctions, a special centrifuge, inflight test bed or other apparatus which reproduces the required acceleration shall be used. 3.2.3 Care should be taken when interpreting results of functional performance tests carried out on equipment subjected to accel
23、eration tests using a centrifuge, if the equipment contains rotating parts with appreciable moments of inertia (e.g.a rate gyro). The relevant equipment specification shall state if the equipment may be tested on a centrifuge, if it is necessary to use other apparatus, or if special requirements for
24、 the tests need specifying. 1) To be published. (Revision of ISO7137:1992)BSG260:1996 2 BSI 01-2000 3.2.4 Acceleration grade0 is defined as a gradually changing acceleration which causes equipment to become weightless. For equipment sensitive to zero gravity, a special test procedure may be required
25、 and should be detailed in the relevant equipment specification. 3.3 Monitor system 3.3.1 An acceleration pickup, an angular velocity pickup or other method may be used to measure acceleration forces directly or indirectly. The accuracy of the acceleration measuring device shall be one-third of the
26、tolerance specified in the relevant equipment specification or better. In some cases, several accelerometers may be located on the equipment under test to determine the acceleration at various places on the equipment. 3.3.2 When the acceleration is measured with an angular velocity pickup, the angul
27、ar velocity may be defined by using the following equation: 3.3.3 When the acceleration is measured using an acceleration pickup, it may be located, in accordance with practice, at the geometric centre, the centre of mass, or the rotary surface, depending on the position of sensitive parts of the eq
28、uipment under test. 4 Equipment mounting 4.1 Orientation The equipment under test shall be mounted on the apparatus in such a way that it can be successively orientated in the six directions of acceleration defined by an orthogonal reference system. The relevant equipment specification shall define
29、the reference system. 4.2 Mounting method The orientation may be set by using an adjustable table which is integral with the apparatus or with a special fixture attached to the apparatus. The equipment shall be attached to the adjustable table or fixture by its fastenings or mounting devices, as def
30、ined in the installation manual for the equipment. If equipment fitted with an absorber is to be tested, the relevant equipment specification shall define whether the equipment should be installed together with the absorber on the centrifuge. 4.3 Supply connections The connection and orientation to
31、the equipment of any electrical, hydraulic or pneumatic supplies shall simulate as closely as possible those used in practice. 5 Classification of tests 5.1 Severity The equipment shall be classified in accordance with the appropriate severity grade given in Table 1 as a function of environmental an
32、d operational conditions. For light and transport aircraft, grade1or2, as applicable, shall be stated in the relevant equipment specification. Table 1 Equipment severity grades 5.2 Types of test Two types of steady-state acceleration test are specified in Table 2. The relevant equipment specificatio
33、n shall state which type of test is to be carried out. 5.3 Categories of equipment The equipment under the imposed acceleration forces shall be classified in accordance with requirements of function, structural integrity and safety as shown in Table 3. The relevant equipment specification shall stat
34、e the category of the equipment. where n is the rotational frequency of the arm, in revolutions per minute; a is the acceleration value required by the test, in numbers of g (standard acceleration of free fall: g n =9,80665m/s 2 ); d is the distance, in metres, from the rotary shaft of the centrifug
35、e to the position on the equipment under test at which the acceleration value a is to be applied. n 2 a 0,0012d - = Equipment severity grade Intended for installation in 0 Equipment subject to zero gravity (e.g.spacecraft) 1 Transport aircraft Light aircraft 2 3 Helicopters 4 High-performance aircra
36、ft Aerobatic aircraft BSG260:1996 BSI 01-2000 3 Table 2 Classification of tests 6 Test sequence 6.1 General case For category A and category B equipment, the functional and structural integrity tests shall be carried out in the following order: a) one functional test with performance check in accord
37、ance with8.1 once in each of the six attitudes; b) one structural integrity test with performance check in accordance with8.2 once in each of the six attitudes. For category C equipment, the functional and structural tests are identical. 6.2 Special cases In order to reduce the number of operations
38、necessary for re-orientating the equipment on the test apparatus, the structural integrity test may immediately follow the functional test unless prohibited by the relevant equipment specification. 7 Acceleration severity grades Functional testing shall be carried out in accordance with Table 4. Str
39、uctural testing shall be carried out in accordance with Table 5. Directions of the aircraft acceleration are shown in Figure 1. 8 Procedures 8.1 Functional test procedure (all categories) The procedures specified in8.1.1 to8.1.4 shall be repeated in each of the six attitudes, unless the equipment un
40、der test is symmetrical in both structure and performance. In this case, it may be tested in only one of the six attitudes, provided the acceleration is that for the most severe mounting attitude. The relevant equipment specification may waive the test requirement for any of the six attitudes in whi
41、ch the equipment is known to be insensitive to acceleration. 8.1.1 Initial measurements Mount the equipment on the test apparatus. Carry out a visual check of the appearance and mounting attitudes of the equipment. Operate the equipment and check the electrical and mechanical performance parameters
42、as stated in the relevant specification. 8.1.2 Acceleration test Operate the equipment in accordance with the functional test given in the relevant equipment specification for a minimum period of5min. With the equipment still operating, progressively increase the acceleration to the severity grade s
43、pecified for the equipment category over a minimum period of15s. Maintain this acceleration for a minimum of60s during which time functional performance measurements should be made. Progressively decrease the acceleration to zero taking at least15s. Repeat the procedure for all attitudes specified b
44、y the relevant equipment specification. 8.1.3 Intermediate measurements During the period of increasing or decreasing acceleration, the equipment operating state shall be monitored. During the period of constant acceleration, the performance parameters shall be checked for compliance with the requir
45、ements stated in the relevant specification. Type of test Purpose and requirement of test 1 Functional 1) To check the good running order of the equipment under the imposed acceleration forces. 2) The equipment shall be in operation during the acceleration phase and the performance shall be monitore
46、d (see8.1.2). 2 Structural 1) To check equipment for structural integrity under the imposed acceleration forces, i.e.for structural strength or stiffness of the equipment. 2) To check the equipment and its mounting for safety, i.e.for any structural damage that would constitute a hazard to the aircr
47、aft or its occupants. 3) Normally, the equipment shall not be in operation during the acceleration phase. Where it is essential for equipment to operate correctly in emergency situations (e.g.crash recorder) the performance of the equipment shall be monitored (see Table 3, category C).BSG260:1996 4
48、BSI 01-2000 Table 3 Equipment categories Equipment category Operational requirements Test requirements Functional test Structural test A Equipment not required to function in manuvre state. Equipment required to operate before and after, but not during the acceleration phase. Equipment not required
49、to function during and after the acceleration phase, but which must remain free from structural damage that would cause hazard to aircraft or its occupants. B Equipment required to function reliably in manuvre state. Equipment required to function before, during and after the acceleration phase. Equipment required to function before and after, but not during the acceleration phase. After the test, the structural integrity shall remain unimpaired. C Equipment required to function normally in emergency situations (for example cra
