{"id":5455,"date":"2026-06-04T20:04:46","date_gmt":"2026-06-04T12:04:46","guid":{"rendered":"https:\/\/caucanimax.com\/blog\/?p=5455"},"modified":"2026-06-04T20:16:42","modified_gmt":"2026-06-04T12:16:42","slug":"question-about-rat-auto-extension-logic","status":"publish","type":"post","link":"https:\/\/caucanimax.com\/blog\/question-about-rat-auto-extension-logic\/","title":{"rendered":"RAT \u81ea\u52a8\u653e\u51fa\u903b\u8f91\u7684\u4fee\u6539"},"content":{"rendered":"<p><!-- obsidian --><\/p>\n<p>\u611f\u8c22\u540c\u4e8b\u53d1\u73b0\u7684\u95ee\u9898\u3002<\/p>\n<p>A350 FCOM \u4e2d\u6709\u4e24\u5904\u5bf9 RAT \u81ea\u52a8\u653e\u51fa\u6709\u8bf4\u660e\uff1a<\/p>\n<ol>\n<li>FCOM DSC-24-10-20 A APU GENERATOR<\/li>\n<li>FCOM DSC-24-10-40 A RAM AIR TURBINE (RAT)<\/li>\n<\/ol>\n<p>2024 \u5e74 10 \u6708\u4e4b\u524d\u7684\u7248\u672c\u4e2d\uff0c\u4e24\u5904\u7684\u903b\u8f91\u662f\u4e00\u81f4\u7684\uff1a\u6240\u6709 <mark>AC BUS \u4e22\u5931\u540e<\/mark> RAT \u4f1a\u81ea\u52a8\u653e\u51fa\u3002\u4f46\u4e4b\u540e\u7684\u7248\u672c\u4e2d\uff0cDSC-24-10-40 A RAM AIR TURBINE (RAT) \u5904\u7684\u63cf\u8ff0\u5c31\u53d8\u6210\u4e86\uff1a<\/p>\n<p>If both AC 1A and AC 2A or both AC 1B and AC 2B busbars are lost in flight, the RAT extends automatically<\/p>\n<p>\u800c DSC-24-10-20 A APU GENERATOR \u4f9d\u7136\u662f\u6240\u6709 AC BUS \u4e22\u5931\u540e\u624d\u4f1a\u653e\u51fa\uff1a<\/p>\n<p>In flight, if the entire normal AC network (AC 1A, AC 1B, AC 2B, and AC 2A busbars) is lost, the RAT will be deployed<\/p>\n<p>&nbsp;<\/p>\n<p>\u7a7a\u5ba2\u56de\u590d\u8bf4 APU GENERATOR \u90e8\u5206\u786e\u5b9e\u6ca1\u6709\u66f4\u65b0\uff0c\u540e\u7eed\u4f1a\u66f4\u65b0\u3002<\/p>\n<p>\u4e0d\u8fc7\u5947\u602a\u7684\u662f\uff0c\u8fd9\u4e48\u5927\u7684\u4fee\u6539\u4e00\u822c\u6765\u8bf4\u4f1a\u6709\u76f8\u5173\u6587\u4ef6\u8fdb\u884c\u8bf4\u660e\uff0c\u6bd4\u5982 MOD, ISI, TFU \u7b49\u7b49\uff0c\u4f46\u5728 airbusworld \u4e0a\u5b8c\u5168\u627e\u4e0d\u5230\u3002\u7a7a\u5ba2\u56de\u590d\u4e5f\u8bf4\u5e76\u6ca1\u6709\u76f8\u5173\u6587\u4ef6\uff0c\u53ea\u63d0\u5230 AMM \u4e0a\u5c31\u662f\u8fd9\u4e2a\u903b\u8f91\u3002\u4f46\u7531\u4e8e A350 \u7684 AMM \u662f\u7ebf\u4e0a\u7248\uff0c\u4e5f\u770b\u4e0d\u51fa AMM \u662f\u4ec0\u4e48\u65f6\u5019\u4fee\u6539\u7684\u3002<\/p>\n<p><!--more--><\/p>\n<p><strong>TR-81739841 \u539f\u6587<\/strong><\/p>\n<p><strong>Q1<\/strong><\/p>\n<p><!-- obsidian --><\/p>\n<p>There are two references to automatic RAT extension in the manual:<\/p>\n<ol>\n<li>FCOM DSC-24-10-20 A APU GENERATOR<\/li>\n<li>FCOM DSC-24-10-40 A RAM AIR TURBINE (RAT)<\/li>\n<\/ol>\n<p>In versions prior to October 2024, the logic was consistent in both sections: the RAT automatically extends if all AC buses are lost.<\/p>\n<p>However, in later versions, the description in DSC-24-10-40 A RAM AIR TURBINE (RAT) was changed to:<\/p>\n<blockquote><p>If both AC 1A and AC 2A or both AC 1B and AC 2B busbars are lost in flight, the RAT extends automatically<\/p><\/blockquote>\n<p>while the text in DSC-24-10-20 A APU GENERATOR still states:<\/p>\n<blockquote><p>In flight, if the entire normal AC network (AC 1A, AC 1B, AC 2B, and AC 2A busbars) is lost, the RAT will be deployed<\/p><\/blockquote>\n<p>The two descriptions are not consistent. Could you please clarify the reason for this discrepancy?<\/p>\n<p>&nbsp;<\/p>\n<p><strong>A1<\/strong><\/p>\n<p><!-- obsidian --><\/p>\n<p>In Oct 24, the RAT extension logic condition described in FCOM DSC-24-10-40-10-00013541.0003001 has been updated to reflect the logic applicable on the aircraft.<\/p>\n<ul>\n<li>Before Oct 24: &#8220;If the AC 1A, AC 1B, AC 2B, and AC 2A busbars are lost in flight, the RAT extends automatically.&#8221;<\/li>\n<li>After oct 24: &#8220;If both AC 1A and AC 2A or both AC 1B and AC 2B busbars are lost in flight, the RAT extends automatically&#8221;.<\/li>\n<\/ul>\n<p>On the other hand, the FCOM DSC-24-10-20-10-00001786.0001001 <mark>APU GENERATOR has not been updated<\/mark> (dated Dec 2015).<br \/>\nWe agree this may generate confusion and needs to be clarified.<br \/>\nWe take this point into consideration for <mark>future FCOM modification<\/mark>.<\/p>\n<p>We thank you for your input. We remain available should you require any additional information or assistance.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Q2<\/strong><\/p>\n<p>Do you have any other relevant materials (such as ISI, TFU, etc.) that detail the modifications to this RAT logic?<\/p>\n<p>&nbsp;<\/p>\n<p><strong>A2<\/strong><\/p>\n<p><!-- obsidian --><\/p>\n<p>We confirm there is <mark>no RAT modification logic<\/mark> associated with the update of FCOM DSC-24-10-40-10-00013541.0003001.<br \/>\nAs stated in the previous answer, this is to reflect the logic applicable on the aircraft.<\/p>\n<p>This logic is described in CSC AMM A350-A-24-24-XX-01001-04CA-A AC Emergency Generation:<br \/>\n&#8220;\u00a75 (2) For the automatic mode, two logics control the extension of the RAT module:<\/p>\n<ul>\n<li>230VAC main busbars 1A and 2A not available<\/li>\n<li>230VAC main busbars 1B and 2B not available.&#8221;<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u611f\u8c22\u540c\u4e8b\u53d1\u73b0\u7684\u95ee\u9898\u3002 A350 FCOM \u4e2d\u6709\u4e24\u5904\u5bf9 RAT \u81ea\u52a8\u653e\u51fa\u6709\u8bf4\u660e\uff1a FCOM DSC-24-10- &#8230; <a title=\"RAT \u81ea\u52a8\u653e\u51fa\u903b\u8f91\u7684\u4fee\u6539\" class=\"read-more\" href=\"https:\/\/caucanimax.com\/blog\/question-about-rat-auto-extension-logic\/\" aria-label=\"\u9605\u8bfb RAT \u81ea\u52a8\u653e\u51fa\u903b\u8f91\u7684\u4fee\u6539\">\u9605\u8bfb\u66f4\u591a<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[113],"tags":[],"ppma_author":[5],"class_list":["post-5455","post","type-post","status-publish","format-standard","hentry","category-fly"],"authors":[{"term_id":5,"user_id":2,"is_guest":0,"slug":"yaoguai","display_name":"\u5996\u602a","avatar_url":"https:\/\/secure.gravatar.com\/avatar\/dfe71d09a1a83f49a02a4400c69ef2c361c2d967eae2ffeeb6318b73a0da763f?s=96&r=g","0":null,"1":"","2":"","3":"","4":"","5":"","6":"","7":"","8":""}],"_links":{"self":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/5455","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/comments?post=5455"}],"version-history":[{"count":2,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/5455\/revisions"}],"predecessor-version":[{"id":5457,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/5455\/revisions\/5457"}],"wp:attachment":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/media?parent=5455"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/categories?post=5455"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/tags?post=5455"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/ppma_author?post=5455"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}