1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
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4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AIR6160 AEROSPACE INFORMATION REPORT AIR6160 Issued 2014-05 Magnesium Alloys in A
5、ircraft Seats - Developments in Magnesium Alloy Flammability Testing RATIONALE This SAE Aerospace Information Report (AIR) is offered to support the use of magnesium alloys in aircraft seat applications by removal of the restrictive paragraph in AS8049B, paragraph 3.3.3, magnesium alloys shall not b
6、e used. INTRODUCTION In the interest of reducing the weight of civil and commercial aircraft for fuel economy and environmental reasons, aircraft seat producers would like to take advantage of the potential weight reduction benefits of magnesium alloys in seat structures. Current SAE standards and r
7、elated FAA requirements do not allow magnesium for use in aircraft seat construction. This restriction of magnesium is presumed to be related to flammability and the possibility of an increased hazard level in an inflight or post-crash fire situation. Flammability testing by the FAA and others has d
8、emonstrated that the hazard level is not increased when magnesium alloys with certain chemistries are employed in this application. In order to consider the removal of the restrictions contained in AS8049, this report is offered as documentation of these evaluations and conclusions. SAE INTERNATIONA
9、L AIR6160 Page 2 of 9 TABLE OF CONTENTS 1. SCOPE 3 2. APPLICABLE DOCUMENTS 3 2.1 SAE Publications . 3 2.2 Code of Federal Regulations (CFR) Publications . 3 2.3 Department of Transportation, Technical Standard Order (TSO) 3 2.4 FAA Publications . 4 2.5 The Mineral, Metals however, magnesium remains
10、a material that, once ignited, is very challenging to cope with using fire extinguishers currently available on aircraft. The use of magnesium is currently the subject of a task group of the International Aircraft Materials Fire Test Working Group. Depending on the outcome of the task groups work, t
11、he FAA may support additional research in this area to the extent industry can supply materials. This would likely include full-scale testing should the initial assessments suggest there is some potential for acceptable installations. Both the post-crash, as well as in-flight, fire scenarios need to
12、 be addressed. Following the full-scale testing performed and initial development of a laboratory scale test the FAA position statement was updated in August 2012 to read: Use of Magnesium in Airplane CabinsUpdated 8/12 Based on requests from industry, and considering the absence of recent research
13、data, the FAA has worked extensively with industry to evaluate the potential use of magnesium alloys in airplane cabins. Specifically, magnesium alloys have been evaluated as seat structure. The FAAs central concern regarding the use of magnesium in the cabin is flammability. The current regulations
14、 do not address the potential for a flammable metal to be used in large quantities in the cabin. Therefore, the FAA and industry research has focused on identifying the large scale performance of different magnesium alloys under realistic fire threats, and characterizing that behavior in a laborator
15、y scale test method. The work has progressed to the point where it appears that certain magnesium alloys may have flammability properties acceptable to be used in aircraft seat structure. Special conditions will likely be required to establish appropriate criteria. The development of a laboratory-sc
16、ale test method is progressing and could be defined near the end of the year. The use of magnesium is still the subject of a task group of the International Aircraft Materials Fire Test Working Group. Depending on the outcome of the task groups work, the FAA may entertain requests for approval using
17、 the special condition process. SAE INTERNATIONAL AIR6160 Page 8 of 9 In the minutes of the IAMFTWG Meeting of June 2013 the FAA indicated that with the information at hand they were now prepared to entertain requests for use of magnesium in aircraft seat structure. The FAA indicated that in order t
18、o obtain certification for magnesium the use of Special Condition provisions would be necessary. The European Aviation Safety Agency (EASA) was also present. Possible Process for Certifying the Use of Magnesium in Seat Frame Construction (i.e., Application for Special Conditions). Special Conditions
19、 are used for situations when a novel or unusual design feature is proposed to be used on an aircraft for which there is no current Rule for certification. Those requesting Special Condition consideration must demonstrate that the novel or unusual design feature does not compromise safety levels. Sp
20、ecial Condition requirements are written by the FAA (or other governing authority for other countries) and are posted in the Federal Register for public comment. If satisfied, the Final Special Condition becomes the Rule. In the case of magnesium, the laboratory scale test method being developed, wh
21、en completed will be inserted in the current Aircraft Materials Fire Test Handbook. This does not make it Rule and to use magnesium in aircraft seats will still require Special Conditions being granted. The inclusion of the laboratory scale flammability test method for magnesium in the Handbook will
22、 make the Special Conditions process go more smoothly. With the results of the Magnesium Full Scale Testing and the progress demonstrated in the development of the lab scale test method the FAA would now allow magnesium in aircraft seats, providing the requirements and conditions as set out in the S
23、pecial Conditions are satisfied. 3.4 Magnesium Flammability Studies 3.4.1 Flammability Testing of Magnesium Alloys at FAATC At the request of the FAA Transport Airplane Directorate the FAA Fire Safety Branch at the FAA Tech Center conducted preliminary flammability testing on a range of magnesium al
24、loys currently employed in various vehicle applications to determine a baseline of flammability characteristics and establish a hierarchy of ignition properties if possible. The testing was performed in May of 2007. The FAA published a report on all of the activities related to the testing of magnes
25、ium alloys, in addition to the numerous presentations made to the IAMFTWG on this subject. In addition, a report was issued by Magnesium Elektron on the tests containing sample descriptions, test conditions and observed results that did establish differences between alloy systems relative to their s
26、usceptibility to burning. Magnesium alloy WE43 was the most resistant to ignition and alloy AZ31 was the least resistant. The Magnesium Elektron report MR10/DATA/475 is available as described in reference documents above 3.4.2 Ignition Resistance of Various Magnesium Alloys A study performed by the
27、Institut National Polytechnique Grenoble and EADS Centre Commun de Recherches, Ignition Resistance of Various Magnesium Alloys, examined the ignition characteristics of magnesium and two magnesium alloy systems. The study was presented at the Magnesium Technology 2004 section of the TMS Annual meeti
28、ng in 2004 and subsequently published. The results corroborate the test results from the FAATC testing. Copies can be obtained from the TMS. 3.4.3 Full Sale Testing of Magnesium Alloy Seats Following the observations of the preliminary flammability testing of magnesium bars using the oil burner appa
29、ratus, the FAA conducted a series of full scale tests comparing magnesium framed seats to aluminum framed seats. The results showed that there was no appreciable increase in the hazard level during the critical first 5 minutes of the test when compared to the aluminum seats. Incapacitation of passen
30、gers was in the same approximate time period for both the magnesium containing seats and the baseline aluminum seats. Further, there was no propagation of fire in the test aircraft as a result of the presence of magnesium. There were some differences observed in the time to extinguish the fires insi
31、de the aircraft when comparing the more ignition resistant alloy WE43 and the more ignitable alloy AZ31. The AZ31 alloy proved to be difficult to extinguish following extinguishment of the external fuel fire, representing an unacceptable condition. FAA report DOT/FAA/AR-11/3 was issued in January 20
32、13 and is available to the public. SAE INTERNATIONAL AIR6160 Page 9 of 9 3.4.4 Laboratory Scale Testing of Magnesium Alloys for Aircraft Seats. The results of the full scale testing led to the FAA developing a laboratory scale test to differentiate between suitable and not suitable magnesium alloys
33、for use in Aircraft Seat Structure. More than 520 tests were performed by the FAATC to analyze and determine the burning characteristics of various magnesium alloys, the best sample configuration, apparatus and procedures. Work commenced in June 2010 and was completed by June 2013. The resulting rep
34、ort, DOT/FAA/TC-13/52, Development of a Laboratory-Scale Flammability Test for Magnesium Alloys Used in Aircraft Seat Construction was released March 2014. The report contains the test method details and specification as an appendix and is available to the public. 4. NOTES 4.1 A change bar (l) locat
35、ed in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY SAE AIRCRAFT SEAT COMMITTEE
