\u5bf9\u4e8e FM POSITION\uff0cA320\/A330 \u624b\u518c\u4e2d\u4e0d\u540c\u90e8\u5206\u7684\u63cf\u8ff0\u7a0d\u6709\u4e9b\u4ee4\u4eba\u7591\u60d1\u3002<\/p>\n
\u5728 AUTO FLIGHT – FLIGHT MANAGEMENT – NAVIGATION – POSITION COMPUTATION – GENERAL \u4e2d\u662f\u8fd9\u6837\u63cf\u8ff0\u7684\uff1a<\/p>\n
<\/p>\n \u4ece\u7b2c\u4e00\u53e5\u8bdd\u7406\u89e3\uff0cFM POSITION \u5e94\u8be5\u662f MIX IRS position + RADIO position \u6216\u8005 MIX IRS position + GPS position\u3002<\/p>\n \u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u6839\u636e GPS POSITION \u4e00\u8282\u4e2d\u7684\u63cf\u8ff0\uff0cGPS position \u5c31\u662f GPIRS position\uff0c\u800c\u4e0d\u662f\u5355\u7eaf\u7684 GPS \u4f4d\u7f6e\u3002<\/p>\n <\/p>\n \u7136\u800c\uff0c\u5728 FM POSITION \u4e00\u5c0f\u8282\u4e2d\u5173\u4e8e FM POSITION \u7684\u63cf\u8ff0\u4e0e GPS POSITION \u7684\u63cf\u8ff0\u975e\u5e38\u76f8\u4f3c\uff0c\u90a3\u4e2a\u62ec\u53f7\u6ce8\u91ca \u201c(GPIRS)\u201d \u5f88\u5bb9\u6613\u8ba9\u4eba\u7406\u89e3\u4e3a\u5728 FM POSITION \u4f18\u5148\u4f7f\u7528\u7684\u5c31\u662f GPIRS\u3002\u800c\u4e0d\u662f\u5728\u4e0a\u8ff0 GENERAL \u4e2d\u89e3\u91ca\u7684 MIX IRS position + RADIO position \u6216\u8005 MIX IRS position + GPIRS position\uff1a<\/p>\n <\/p>\n \u5c24\u5176\u5728 A330 \u624b\u518c\u4e2d\u8fd8\u7528\u7684\u662f \u201cmixed IRS\/GPS\u201c\uff0c\u66f4\u662f\u4e0e GPS POSITION \u7528\u8bcd\u4e00\u6a21\u4e00\u6837\uff1a<\/p>\n \u7ecf\u8fc7\u4e0e\u7a7a\u5ba2\u591a\u4e2a\u56de\u5408\u7684\u8be2\u95ee\uff0c\u9996\u5148\u786e\u8ba4\u4e86 FM POSITOIN \u662f MIX IRS + GPIRS\uff0c\u800c\u4e0d\u53ea\u662f GPIRS<\/strong>\u3002\u6211\u4e00\u76f4\u8ba4\u4e3a FM POSITION \u90e8\u5206\u7684 \u201ceach FMGC displays an FM position that is a MIX IRS\/GPS position (GPIRS)\u201d \u8fd9\u53e5\u8bdd\u4ecd\u7136\u76f8\u5f53\u5bb9\u6613\u9020\u6210\u8bef\u89e3\uff0c\u56e0\u4e3a\u90a3\u4e2a\u62ec\u53f7\u662f\u5bf9 \u201cGPS position\u201d\u7684\u6ce8\u89e3\uff0c\u800c\u4e0d\u662f\u5bf9\u6574\u4e2a\u201cMIX IRS\/GPS position\u201d\u7684\u6ce8\u89e3\u3002\u4f46\u7a7a\u5ba2\u8ba4\u4e3a\u8fd9\u4e2a\u63cf\u8ff0\u6ca1\u6709\u95ee\u9898\uff0c\u5e76\u4e0d\u6253\u7b97\u66f4\u6539\u3002<\/p>\n \u4e0d\u8fc7\uff0c\u7a7a\u5ba2\u6700\u540e\u4e5f\u627f\u8ba4\u4e86 A330 \u624b\u518c\u4e2d FM POSITION \u90e8\u5206\u7684\u201cmixed IRS\/GPS position\u201d\u7528\u8bcd\u4e0d\u6070\u5f53\uff0c\u5e94\u8be5\u6539\u6210\u548c A320 \u624b\u518c\u76f8\u540c\u7684\u201cMIX IRS\/GPS position\u201d<\/strong>\u3002\u8fd9\u4e5f\u7b97\u662f\u6d88\u9664\u4e86\u4e00\u90e8\u5206\u8bef\u89e3\u5427\u3002<\/p>\n <\/p>\n \u7591\u95ee 2\uff1aA350 \u662f\u5426\u5b58\u5728 BIAS<\/strong><\/p>\n A350 \u4f18\u5148\u4f7f\u7528\u7684\u662f consolidated GPIRS position \uff0c\u8fd9\u4e2a\u7684\u903b\u8f91\u548c A320\/330 \u7684 FM position \u4e0d\u4e00\u6837\uff0c\u90a3\u662f\u5426\u610f\u5473\u7740 A350 \u4e0d\u5b58\u5728 MIX IRS position \u548c GPIRS position \u4e4b\u95f4\u7684 BIAS \u5462\uff1f<\/p>\n \u7a7a\u5ba2\u786e\u8ba4\u4e86\uff0cA350 \u4e0d\u5b58\u5728 BIAS\u3002<\/p>\n <\/p>\n \u7591\u95ee 3\uff1aA350 \u7684 3 IRS \u662f\u4e0d\u662f\u548c A320\/A330 \u7684 MIX IRS \u4e00\u6837\uff1f<\/strong><\/p>\n A350 \u624b\u518c\u4e2d\u5bf9 3 IRS \u7684\u63cf\u8ff0\u975e\u5e38\u5c11\uff0c\u57fa\u672c\u53ea\u51fa\u73b0\u5728 DSC-34-NAV-20-10-60 C \u4e2d\u7684 NAVIGATION MODES \u8868\u683c\u4e2d\uff1a<\/p>\n <\/p>\n \u5728\u6c9f\u901a\u4e2d\uff0c\u7a7a\u5ba2\u786e\u8ba4 A350 \u7684 3 IRS \u548c A320\/A330 \u7684 MIX IRS \u662f\u57fa\u672c\u4e00\u6837\u7684\u30023 IRS \u4f4d\u7f6e\u662f FMS \u8ba1\u7b97\u7684\uff0c\u5355 IRS \u4f4d\u7f6e\u662f ADIRU \u81ea\u5df1\u63d0\u4f9b\u7684\u3002<\/p>\n \u53e6\u5916\u4e5f\u627f\u8ba4\u4e86\u5728\u4e0a\u8868\u4e2d\uff0c3 IRS \u5bf9\u5e94 Aircraft position \u4e2d\u201cIR\/radio\u201d \u7528\u8bcd\u4e0d\u5f53\uff0c\u5e94\u8be5\u6b64\u65f6\u5df2\u7ecf\u6ca1\u6709 radio \u6570\u636e\u4e86\u3002\u540e\u7eed\u624b\u518c\u4f1a\u4fee\u6539\u3002<\/p>\n <\/p>\n \u539f\u6587<\/strong><\/p>\n Q1:<\/strong><\/p>\n Regarding the computation of aircraft position, there are some differences and questions between the A320\/A330 and the A350.<\/p>\n Q1:<\/p>\n For FM POSITION, the descriptions in different parts of the A320\/A330 manuals are somewhat confusing.<\/p>\n In the AUTO FLIGHT – FLIGHT MANAGEMENT – NAVIGATION – POSITION COMPUTATION – GENERAL section, it is described as follows:<\/p>\n From the first sentence, it is understood that FM POSITION should be MIX IRS position + RADIO position or MIX IRS position + GPS position.<\/p>\n According to the description in the GPS POSITION section, the GPS position is actually the GPIRS position, not simply the GPS position.<\/p>\n Therefore, it can be concluded that FM position should be MIX IRS position + RADIO position or MIX IRS position + GPIRS position.<\/p>\n However, the description in the FM POSITION subsection can easily cause confusion:<\/p>\n Firstly, should the wording be unified between A320 and A330, for example, both using MIX instead of one using MIX and the other using mixed?<\/p>\n Secondly, the descriptions of FM POSITION and GPS POSITION are very similar, especially for A330 (using mixed):<\/p>\n This can easily lead to the understanding that the priority for FM POSITION is GPIRS, rather than as explained in the GENERAL section as MIX IRS position + RADIO position or MIX IRS position + GPIRS position.<\/p>\n So, how exactly is FM POSITION constituted?<\/p>\n Q2:<\/p>\n The A350 prioritizes the consolidated GPIRS position. This logic is different from the FM position of A320\/330. Does this mean that there is no BIAS between MIX IRS position and GPIRS position in the A350?<\/p>\n <\/p>\n A1:<\/strong><\/p>\n Airbus reviewed your queries, and we would like to provide you with the following information:<\/p>\n Q1:<\/p>\n CSC\u2019s understanding of the priority for FM position is correct. The MIX IRS plus GPS position (GPIRS)<\/strong>\u00a0is the first mode to be used for FM position. It is as described in the last paragraph of the GENERAL section:<\/p>\n \u201cGPS\/INERTIAL is the basic navigation mode, provided GPS data is valid and successfully tested. Otherwise, navaids plus inertial or inertial only are used. (Refer to FCOM\/DSC-22_20-20-10 Navigation Modes).\u201d<\/p>\n For the first paragraph of the GENERAL section that describes:<\/p>\n \u201cEach FMGC computes its own aircraft position (called the “FM position”) from a MIX IRS position and a computed radio position, or a GPS position.\u201d<\/p>\n It describes what sources FMGC uses to compute the position but not in an order<\/strong>. In fact, this content was originally from the content of aircraft without GPS<\/strong>. On the aircraft without GPS, the FMS uses the MIX IRS position and a computed radio position for FM position. When the GPS Primary function was introduced on the aircraft, the phrase \u201cor a GPS position\u201d was added to this content.<\/p>\n Lastly, the difference in wording of \u2018MIX IRS\u201d in A320 and \u201cmixed IRS\u201d in A330, Airbus sees that there is no difference in the meaning<\/strong>\u00a0of these two wordings. Therefore, we have no plan to change them<\/strong>. However, CSC can customize your own FCOM if CSC would like to unify these wordings.<\/p>\n Q2:<\/p>\n There is no \u201cbias\u201d on A350<\/strong>. The aircraft position is a consolidated position between the 3 ADIRU positions. Each ADIRU uses the GPS and the IR source to compute the GPIRS position.<\/p>\n When the GPIRS positions from the three ADIRUs are available, the ADIRS compares the three GPIRS positions, and selects the most accurate position to be the consolidated GPIRS position.<\/p>\n <\/p>\n Q2:<\/strong><\/p>\n Thanks for the explanation, and now the confusion of GENERAL section and GPS POSITOIN section are clear.<\/p>\n However, I still think the first paragraph of FM POSITION which is too similar to GPS POSITION should be revised to the wording like GENERAL. Because they are both “FM position”, and the wording should be unified to avoid the misunderstanding to GPS position.<\/p>\n <\/p>\n A2:<\/strong><\/p>\n Airbus reviewed your query, and we would like to provide you with the following information:<\/p>\n About the FM position at flight initialization, please be clarified that:<\/p>\n On ground before takeoff thrust setting, the FM position is the following:<\/p>\n About the GPS position, please be informed that on the aircraft, the GPS position is not actually a pure GPS position but a combination of GPS and IRS position called GPIRS.<\/p>\n For this\u00a0reason,\u00a0the term\u00a0\u201cmixed\u00a0IRS\/GPS position\u201d is used in the GPS position topic.<\/p>\n We consider that the terms are\u00a0 appropriate and valid for their own topics<\/strong>, and we have no plan to update them.<\/p>\n We regret that we cannot respond to CSC\u2019s request. We remain available for any additional information and assistance.<\/p>\n <\/p>\n Q3:<\/strong><\/p>\n According to Airbus’ explanation:<\/p>\n Although I still think this explanation is far-fetched, even if this explanation is valid, the wording in the A330 manual is problematic:<\/p>\n Because in the A330 FCOM, both the FM POSITION section and the GPS POSITION section use “mixed IRS\/GPS position,” and not one as “MIX IRS\/GPS position” and the other as “mixed IRS\/GPS position” in A320 FCOM.<\/p>\n So either the A330 manual needs to be revised, or both should be revised, as this indeed can cause misunderstandings. It’s not just me, other company pilots have also expressed confusion and debated this issue. Therefore, I believe this is a common issue.<\/p>\n <\/p>\n A3:<\/strong><\/p>\n Airbus reviewed your query, and we would like to provide you with the following information:<\/p>\n After carefully reviewing the definitions of FM POSITION and GPS POSITION. We agree with CSC that the wording \u201cmixed IRS\/GPS position\u201d used in A330 FM POSITION section should be revised to \u201cMIX IRS\/GPS position\u201d<\/strong> to be the same as in A320\u00a0FM\u00a0POSITION section.<\/p>\n We will update the A330\/A340 FCOM accordingly.\u00a0The update will be available in the next suitable A330\/A340 FCOM revision.<\/p>\n <\/p>\n Q4:<\/strong><\/p>\n Additional questions.<\/p>\n In FCOM DSC-34-NAV-20-10-60 C NAVIGATION MODES:<\/p>\n <\/p>\n Q1:<\/p>\n In the table above, should “IR\/radio” be “3 IRS”? Because “no radio navaids available”.<\/p>\n Q2:<\/p>\n Is “3 IR” for A350 the same with “MIX IRS” for A320?<\/p>\n Q3:<\/p>\n Confirm 3 IRS is from FMS, and 1 IRS only from ADIRU itself?<\/p>\n <\/p>\n A4:<\/strong><\/p>\n Airbus reviewed your query, and we would like to provide you with the following information:<\/p>\n Q1 and Q2:<\/p>\n Refer to the A350\u00a0FCOM-DSC-34-NAV-20-10-60-Position Computation, ADIRU provides the aircraft systems with the most accurate position that is available, using the following priority:<\/p>\n – The consolidated GPIRS position (computed inside ADIRU<\/strong>) When the IR\/radio position has no radio navaids available, The FMS uses the MIX IRS position for position computation. The MIX IRS is a center of gravity of the pure inertial position (IR position) elaborated by each IR (IR1, IR2 and IR3). It is similar to the MIX IRS position of A320<\/strong>.<\/p>\n <\/p>\n We agree that the content of \u201c3 IRS\u201d mode should be improved to be clearer.<\/strong><\/p>\n Please be informed that we are considering an update of the Aircraft Position section of A350 FCOM, we will take this opportunity to improve this content in the next suitable opportunity.<\/p>\n Q3:<\/p>\n As described above, the 3 IRS mode is a MIX IRS position computed inside the FMS<\/strong>, and the 1 IRS mode is a pure IR position from the ADIRU<\/strong>.<\/p>\n","protected":false},"excerpt":{"rendered":" \u5173\u4e8e\u98de\u673a\u4f4d\u7f6e\u7684\u8ba1\u7b97\uff0cA320\/A330 \u4e0e A350 \u6709\u4e00\u4e9b\u4e0d\u540c\uff0c\u4e5f\u5b58\u5728\u4e00\u4e9b\u7591\u95ee\u3002\u672c\u6587\u4f1a\u6d89\u53ca\u4e09\u4e2a\u7591\u95ee\uff0c\u5e76\u5728\u4e0e\u7a7a … \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-4968","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\/4968","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=4968"}],"version-history":[{"count":6,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/4968\/revisions"}],"predecessor-version":[{"id":4987,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/posts\/4968\/revisions\/4987"}],"wp:attachment":[{"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/media?parent=4968"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/categories?post=4968"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/tags?post=4968"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/caucanimax.com\/blog\/wp-json\/wp\/v2\/ppma_author?post=4968"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"http:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2024\/08\/A320-A330-A350-\u4f4d\u7f6e\u8ba1\u7b97\u7684\u4e09\u4e2a\u95ee\u9898_image_1.png\")
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<\/a><\/p>\n\n
\n
<\/a><\/p>\n
\n– Its own GPIRS position\u00a0(computed inside ADIRU)
\n– The IR\/radio position (computed inside FMS<\/strong>, then sent to ADIRU)
\n– Its own IR position\u00a0(pure IR position, from ADIRU).<\/p>\n![\"\"](\"http:\/\/caucanimax.com\/blog\/wordpress\/wp-content\/uploads\/2024\/08\/A320-A330-A350-\u4f4d\u7f6e\u8ba1\u7b97\u7684\u4e09\u4e2a\u95ee\u9898_image_8.png\")
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