最低设备清单 Minimum Equipment List (MEL)【转】

最低设备清单（MEL）Minimum Equipment List (MEL)

1、MEL 的意义

Meaning of MEL

最低设备清单（Minimum Equipment List，MEL）也叫“最低设备放行清单”，是一份由航空公司编写，并由民航当局批准使用的文件，它规定了在符合经批准的型号合格设计，并由合格的维修人员实施了维修、预防性维修和检查工作的基础上，可以允许飞机保留故障，按照一定限制和工作程序进行有限的飞行。其中，“保留故障”是指航空器在飞行后/或维修检查中发现的故障、缺陷，因工具设备、器材短缺或停场时间不足等原因，不能在飞机起飞前排除的故障项目。“按一定的限制”是指当设备项目失效时，做出禁止使用或允许使用有关设备或系统的限制，对继续飞行的附加条件和限制，以及挂说明牌以提醒机组和维修人员注意仪表/设备所处的不合格技术情况。“按一定的工作程序”是指当设备项目失效时，需要在飞行前必须完成的某些特定的维护程序（用字母 M 表示），或需要在机上必须完成的某些特定的操作程序（用字母 O 表示），按要求执行这些程序是按照 MEL 放行的前提条件。“有限的飞行”是指考虑到带有不工作的仪表或设备继续飞行是否会遇到其他的故障/失效情况，进而飞机是否仍然能保持应有的安全水平，和/或增加机组不应有的工作负荷，因此尽早或在飞到第一个有修理能力或换件能力的航站进行修理或换件。

The minimum equipment list (MEL), also known as the “minimum equipment release list”, is a document prepared by the airline and approved by the civil aviation authority for use. It stipulates that the aircraft can be allowed to retain faults on the basis of conforming to the approved model and qualified design, and the maintenance, preventive maintenance and inspection work carried out by qualified maintenance personnel; Carry out limited flight according to certain restrictions and working procedures. Among them, “reserved fault” refers to the fault and defect found by the aircraft in the post-flight/or maintenance inspection, which cannot be eliminated before the aircraft takes off due to the shortage of tools, equipment, or parking time. “According to certain restrictions” refers to the restrictions that prohibit the use or permit the use of relevant equipment or systems, the additional conditions and restrictions on the continued flight, and the hanging of instruction boards to remind the crew and maintenance personnel of the unqualified technical conditions of the instrument/equipment when the equipment items fail. “According to certain working procedures” refers to certain specific maintenance procedures (indicated by the letter M) that must be completed before flight when the equipment item fails, or certain specific operating procedures (indicated by the letter O) that must be completed on the aircraft. The implementation of these procedures as required is the prerequisite for release according to MEL. “Limited flight” refers to whether the aircraft can still maintain its due safety level and/or increase the crew’s undue working load, taking into account whether the flight with inoperative instruments or equipment will encounter other failures/failures, so as to carry out repair or replacement as soon as possible or at the first terminal with repair or replacement capability.

2、MEL 的内容

Content of MEL

最低设备清单主要包括三部分内容：允许不工作设备项目的清单、程序文件和批准文件。

The minimum equipment list mainly includes three parts: the list of equipment items that are not allowed to work, procedure documents and approval documents.

（1）允许不工作设备项目的清单。在特定条件下，系统运行过程中部分设备可以不工作，最低设备清单明确了允许不工作的设备。最低设备清单未规定的，并且与系统使用密切关联的设备，要求系统运行时必须能够正常工作。对航空器来讲，就是最低设备放行清单未列入的、但涉及航空器适航性和飞行操作规则的项目，在航空器营运时，都必须能够正常工作。

List of items of equipment that are not allowed to work. Under certain conditions, some equipment can not work during system operation, and the minimum equipment list specifies the equipment that is allowed to not work. The equipment not specified in the minimum equipment list and closely related to the use of the system must be able to work normally when the system is running. For aircraft, items that are not included in the minimum equipment release list but involve aircraft airworthiness and flight operation rules must be able to work normally during aircraft operation.

（2）程序文件。程序文件主要包括维修程序、操作程序及其他必需的限制条件等。维修程序和操作程序都是指使不工作设备项目在特定的工作条件和限制下完全放弃其功能的特定程序。维修程序是允许不工作设备项目不工作时，系统运行前必须完成的维修程序，通常由合格的维修人员或其他经批准的人员完成。维修程序通常由营运人参照现行职能机关批准的手册、规范中的有关内容制定。操作程序是允许不工作设备项目不工作时，系统运行前或运行中必须完成的特定工作程序，通常由系统使用人员或其他经批准的合格人员完成。操作程序通常由营运人参照现行职能机关批准的手册、规范中的有关内容制定。

Procedure documents. Procedure documents mainly include maintenance procedures, operation procedures and other necessary restrictions. Maintenance procedures and operation procedures refer to the specific procedures that make the non-working equipment items completely give up their functions under specific working conditions and restrictions. The maintenance procedure is the maintenance procedure that must be completed before the system operation when the equipment item is allowed to be out of service. It is usually completed by qualified maintenance personnel or other approved personnel. The maintenance procedure is usually formulated by the operator with reference to the relevant contents in the manuals and specifications approved by the current functional authority. Operating procedures are the specific work procedures that must be completed before or during the operation of the system when the non-working equipment items are allowed to not work. They are usually completed by the system user or other approved qualified personnel. The operating procedures are usually formulated by the operator with reference to the relevant contents in the manuals and specifications approved by the current functional authorities.

（3）批准文件。政府职能机关授权营运人按最低设备清单营运时，颁发的批准文件。

Approval documents. The approval document issued by the government functional authority authorizing the operator to operate according to the minimum equipment list.

图 1 MEL 的结构和内容

Fig.1 Structure and content of MEL

1）条目项

Item

左侧为条目（Item），记载了各种子系统、分系统、组件、部件、功能等，前面同样带有 ATA 的章节代码，一般情况下与飞机维护手册（AMM）等手册的代码Chapter-Section 部分相一致，这一部分是可以在目录（Table of Contents）中查到的。

The item on the left side records various subsystems, subsystems, components, components, functions, etc. The chapter code of ATA is also included in the front. Generally, it is consistent with the code of Chapter-Section in the aircraft maintenance manual (AMM) and other manuals. This part can be found in the table of contents.

（2）维修间隔

Repair Interval

按照要求需要维修的时间分为 A、B、C、D 四个类别。

According to the requirements, the maintenance time is divided into four categories: A, B, C and D.

A 表示不确定，但将在 Remarks or Exceptions 部分中另行指出维修的最低时限，标明的时限应开始于发现故障后一天的凌晨 00：01；

A means uncertain, but the minimum time limit for maintenance will be indicated in the Remarks or Exceptions section. The indicated time limit shall start at 00:01 a.m. the day after the fault is found;

B 表示要在故障发生后的 3 个日历日（72 小时）内进行修理，即从记录故障的当天午夜 12 点算起的 3 天以内修复。

B means to repair within 3 calendar days (72 hours) after the fault occurs, that is, within 3 days from 12:00 midnight on the day the fault is recorded.

C 表示要在 10 个日历日（240 小时）内进行修理，即从记录故障的当天午夜 12 点算起的 10 天以内修复。

C means to repair within 10 calendar days (240 hours), that is, within 10 days from 12:00 midnight on the day of recording the fault.

D 表示要在 120 个日历日（2880 小时）内进行修理，即从记录故障的当天午夜 12 点算起的 120 天以内修复。

D means to repair within 120 calendar days (2880 hours), that is, within 120 days from 12:00 midnight on the day the fault is recorded.

（3）安装数量

Number Installed

飞机在正常情况下，已安装并正常工作的组件的数量。该数量反映了飞机取证的构形要求，因此，除了执行栏目 4 和 5 中提供的要求以外，该数量是所有飞行操作所要求数量。

The number of components that have been installed and work normally in the aircraft under normal conditions. This quantity reflects the configuration 

requirements for aircraft forensics. Therefore, in addition to the requirements provided in columns 4 and 5, this quantity is required for all flight operations.

（4）放行时需要的最小数量

Number Required for Dispatch

放行时飞机所需设备项目必须工作正常的最低数量，即飞机上至少需要该组件的数量。同时还需满足其它有关的限制条件。

At the time of release, the minimum number of equipment items required by the aircraft must work normally, that is, the minimum number of components required on the aircraft. At the same time, other relevant restrictions shall be met.

（5）注释及其他

Remarks or Exceptions

在特定数量的组件不工作条件下放行所需要的飞机状态和其他附带条件。

The aircraft status and other incidental conditions required for the release of a specific number of components without operation.

（M）代表需要完成特定的维修程序才能在相应部件不工作情况下放行，这些程序一般由维修人员完成，也可以由具备相关认证和授权的个人来完成，需要特定知识或者技能，要求使用特殊工具或检测设备

(M) Representatives need to complete specific maintenance procedures to release the corresponding parts when they are not working. These procedures are generally completed by maintenance personnel, or by individuals with relevant certification and authorization. They need specific knowledge or skills, and require the use of special tools or testing equipment

（O）代表需要完成特定的操作程序才能在相应部件不工作情况下放行，这些程序一般由机组人员完成，也可以由具备相关认证和授权的个人来完成。

(O) The representative needs to complete specific operating procedures to release the corresponding parts when they are not working. These procedures are generally completed by the crew, and can also be completed by individuals with relevant certification and authorization.