{"id":4103,"date":"2023-05-10T11:37:34","date_gmt":"2023-05-10T03:37:34","guid":{"rendered":"https:\/\/caucanimax.com\/blog\/?p=4103"},"modified":"2023-05-10T11:37:34","modified_gmt":"2023-05-10T03:37:34","slug":"why-the-minimum-tat-and-oat-are-different-on-ground","status":"publish","type":"post","link":"https:\/\/caucanimax.com\/blog\/why-the-minimum-tat-and-oat-are-different-on-ground\/","title":{"rendered":"\u4e3a\u4ec0\u4e48\u5728\u5730\u9762\u6700\u5c0f TAT \u548c OAT \u4e0d\u4e00\u6837"},"content":{"rendered":"<p>\u7406\u8bba\u4e0a\u6765\u8bf4\uff0c\u5728\u98de\u673a\u9759\u6b62\u7684\u65f6\u5019\uff0cTAT \u5e94\u8be5\u7b49\u4e8e OAT\u3002<\/p>\n<p>\u53c2\u8003 A350 FCOM LIM-AG-OPS A ENVIRONMENTAL ENVELOPE \u90e8\u5206\uff0c\u6700\u5c0f TAT \u662f-52 \u2103\u3002\u800c\u6c14\u538b\u9ad8\u5ea6\u4e3a 0 \u7684\u6700\u5c0f OAT \u662f\u7565\u5c0f\u4e8e-54\u2103\u7684\u3002\u4e3a\u4ec0\u4e48\u4e24\u8005\u4e0d\u4e00\u81f4\u5462\uff1f<\/p>\n<p><a href=\"https:\/\/caucanimax.com\/blog\/why-the-minimum-tat-and-oat-are-different-on-ground\/why-the-minimum-tat-and-oat-are-different-on-ground_image_1\/\" rel=\"attachment wp-att-4105\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone  wp-image-4105\" src=\"http:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2023\/05\/Why-the-minimum-TAT-and-OAT-are-different-on-ground_image_1.png\" alt=\"\" width=\"512\" height=\"437\" srcset=\"https:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2023\/05\/Why-the-minimum-TAT-and-OAT-are-different-on-ground_image_1.png 1266w, https:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2023\/05\/Why-the-minimum-TAT-and-OAT-are-different-on-ground_image_1-300x256.png 300w, https:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2023\/05\/Why-the-minimum-TAT-and-OAT-are-different-on-ground_image_1-1024x875.png 1024w, https:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2023\/05\/Why-the-minimum-TAT-and-OAT-are-different-on-ground_image_1-768x656.png 768w, https:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2023\/05\/Why-the-minimum-TAT-and-OAT-are-different-on-ground_image_1-150x128.png 150w, https:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2023\/05\/Why-the-minimum-TAT-and-OAT-are-different-on-ground_image_1-400x342.png 400w\" sizes=\"auto, (max-width: 512px) 100vw, 512px\" \/><\/a><\/p>\n<p><!--more--><\/p>\n<p>\u7a7a\u5ba2\u89e3\u91ca\uff1a<\/p>\n<ul>\n<li>\u4ece\u76ee\u7684\u6765\u8bf4\uff0c\u6700\u5c0f TAT \u662f\u4e3a\u4e86\u4fdd\u8bc1\u98de\u673a\u5728\u957f\u65f6\u95f4\u66b4\u9732\u5728\u4f4e\u6e29\u60c5\u51b5\u4e0b\uff0c\u7ed3\u6784\u8fd8\u80fd\u6062\u590d\u7684\u6e29\u5ea6\u9650\u5236\u3002\u800c\u6700\u5c0f OAT \u662f\u4e3a\u4e86\u4fdd\u8bc1\u98de\u673a\u7684\u5404\u79cd\u7cfb\u7edf\u80fd\u6b63\u5e38\u8fd0\u884c\u7684\u6e29\u5ea6\u9650\u5236\u3002<\/li>\n<li>\u4ece\u6d4b\u91cf\u6765\u8bf4\uff0cOAT \u662f\u673a\u573a\u6c14\u8c61\u90e8\u95e8\u62a5\u544a\u7684\uff0cTAT \u662f\u98de\u673a\u63a2\u5934\u6d4b\u91cf\u7684\uff0c\u6d4b\u91cf\u4f4d\u7f6e\u4e0d\u540c\u3002<\/li>\n<\/ul>\n<p>\u6240\u4ee5\uff0c\u4e24\u79cd\u6e29\u5ea6\u7684\u76ee\u7684\u3001\u6d4b\u91cf\u65b9\u5f0f\u548c\u4f4d\u7f6e\uff0c\u4ee5\u53ca\u8ba4\u8bc1\u6807\u51c6\u90fd\u4e0d\u540c\uff0c\u6240\u4ee5\u9650\u5236\u4f1a\u6709\u6240\u4e0d\u540c\u3002<\/p>\n<p>&nbsp;<\/p>\n<hr \/>\n<p>&nbsp;<\/p>\n<p><strong>TechRequest \u539f\u6587\uff1a<\/strong><\/p>\n<p><strong>Q:<\/strong><\/p>\n<p>In FCOM LIM-AG-OPS A ENVIRONMENTAL ENVELOPE, minimum TAT is -52\u2103. And in the chart above, the minimum OAT on 0 pressure altitude is even below -54\u2103\u3002If aircraft stay still on ground without wind, TAT should be same with OAT. So why the minimum values are different?<\/p>\n<p><strong>A:<\/strong><\/p>\n<p>The purpose of the minimum TAT limitation is to ensure that the recovery temperature (approximating the structure temperature in cruise) is high enough to avoid a prolonged exposure of the aircraft equipment below their qualification temperature. The limitation on the TAT ensure that the recovery temperature remains within its limits.<\/p>\n<p>The minimum OAT is related to the ensure that the aircraft and its system can be operated at this minimum OAT.<\/p>\n<p>On ground, the OAT is provided by the weather station of the airport, whereas the TAT is measured by the aircraft probes. As the location of these sensors are different, the TAT and the OAT measurement may be different, even without aircraft speed.<\/p>\n<p>To conclude, the OAT and TAT limitations are needed for different certifications criteria and are checked on ground against different means of measurement. CSC must comply with both.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u7406\u8bba\u4e0a\u6765\u8bf4\uff0c\u5728\u98de\u673a\u9759\u6b62\u7684\u65f6\u5019\uff0cTAT \u5e94\u8be5\u7b49\u4e8e OAT\u3002 \u53c2\u8003 A350 FCOM LIM-AG-OPS A  &#8230; <a title=\"\u4e3a\u4ec0\u4e48\u5728\u5730\u9762\u6700\u5c0f TAT \u548c OAT \u4e0d\u4e00\u6837\" class=\"read-more\" href=\"https:\/\/caucanimax.com\/blog\/why-the-minimum-tat-and-oat-are-different-on-ground\/\" aria-label=\"\u9605\u8bfb \u4e3a\u4ec0\u4e48\u5728\u5730\u9762\u6700\u5c0f TAT \u548c OAT \u4e0d\u4e00\u6837\">\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-4103","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\/4103","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=4103"}],"version-history":[{"count":2,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/4103\/revisions"}],"predecessor-version":[{"id":4108,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/4103\/revisions\/4108"}],"wp:attachment":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/media?parent=4103"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/categories?post=4103"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/tags?post=4103"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/ppma_author?post=4103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}