注意，更换主轮这个螺杆力矩变了！

jlhuang_05 · 发表于 2021-8-12 10:23:30

安监检查真细，发现了不少问题。最近安监检查发现更换主轮APS项目（一种拆装总结）存在与手册不一致的地方，在风险提示中提到主轮大螺帽固定螺杆力矩为为65±2in-lb，手册更新后已对该螺杆力矩进行了明确标注为80±2in-lb。安监建议对该APS项目进行相应修订。

072版的手册

注意，更换主轮这个螺杆力矩变了！-1.jpg

074版的手册

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这就有点尴尬了，因为之前我编写的一份标准力矩查找教案，该螺杆的力矩就是按波音提供的力矩值反查的，详细可以查阅《波音紧固件标准力矩查找方法》。它这一改我得打脸了，不过还得怪自己业务不精呀。

知之为知之，不知为不知。还是向波音求证下怎么回事！

1，首先，螺杆在内侧，螺帽在外侧，用螺杆打力矩实在不方便甚至行不通，能不能打螺帽力矩呢？

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波音答复：图纸要求打的螺杆力矩，这锅就甩的干净了。

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SR4-4649468392

QUERY ON SUBTASK 32-45-11-420-001

DESCRIPTION:In Ref /A/ message customer has noticed that there is a change about the step (2).(l).3) SUBTASK 32-45-11-420-001 , in the new version of AMM. It gives the specified torque value about the bolts[10], while the reference in the former version. It may be difficult to tighten the bolt[10] to the specified torque value because it locates in the inner side.Q1. Is it appropriate to torque the NUT [8]? If so, please review the steps and torque values.RESPONSE:Boeing has reviewed your inquiry and provides the following response:Q1. Is it appropriate to torque the NUT [8]? If so, please review the steps and torque values.A1. Please note that according to PSDL_277A6000 (MAIN AND NOSE LANDING GEAR - WHEELS/BRAKES/EQUIP INSTL), FL 5, there is requirement to "install the axle nut locking bolt and tighten per BAC5009". Therefore, the torque value has to be applied for bolts [10]

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2，这个螺杆力矩值图纸可没有给，波音怎么查的力矩，最开始手册没写，按标准力矩；后来明确写是65±2in-lb，现在更新为80±2in-lb，能给个说明吗？

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波音答复：波音经过进一步评估，还是使用65±2in-lb这个力矩值。并且打的是螺帽力矩（螺杆螺帽都可以打力矩），波音计划在6月份修订手册。

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其实这个也是查标准力矩得来的。螺杆属于干安装，按AMM20-51-11查找螺帽力矩为65±2in-lb，螺杆力矩为80±2in-lb，螺杆螺帽那个力矩低就选哪个！

SR #4-5063487415

SUBJECT: QUERY ON THE CHANGE TORQUE OF THE BOLTS [10] ON THE AMM SUBTASK 32-45-11-420-001DESCRIPTION: =====================China Southern has noticed that there is a change about the step (2).(l).3) SUBTASK 32-45-11-420-001, in the new version of AMM. The torque value about the bolts [10] was changed from 65 ±2 in-lb to 80 ±2 in-lb in the AMM version 074. Could Boeing please provide the steps on how to determine the torque value about the bolts [10] (PN:BACB30NR4K14)?DESIRED ACTION:======================Q1:Could Boeing please provide the steps on how to determine the torque value for the bolts [10] (PN:BACB30NR4K14)? undefined RESPONSE:Boeing has reviewed China Southern Airlines' inquiry and offers the following response: After further evaluation, the statement and torque value for the step should read: "Tighten the nuts [8] to 65 ±2 in-lb (7.3 ±0.2 N·m)."

In this case, both the nut and bolt can be tightened. The AMM TASK 20-50-11-910-801, A. General, (1) states the following: "If the fastener torque value and the nut torque value are different, use the torque range that has the lowest maximum value." This step gives the instructions to use the lowest maximum value when there are conflicting torque requirements for a joint.

In Table 205 of AMM TASK 20-50-11-910-801, China Southern Airlines would refer to the "Dry Fastener" column at the nominal thread size of "0.2500-28" and, lastly, to a torque value of 63 in-lb (7 N·m) - 65 in-lb (8 N·m) for the nut.Boeing has updated AMM TASK 32-45-11-400-801 step F.(2).(l).(4) to tighten the nuts [8] to 65 ±2 in-lb (7.3 ±0.2 N·m). This change will be in the 15-Jun-2021 revision of the 737NG AMM.

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