Appendix III — Definitions and explanatory notes

(a)     The systems in the MMEL are described and identified in accordance with the numbering system used in the aircraft manufacturer’s documentation.

(b)     The MMEL item list provides the list of pieces of equipment/system/function which may be inoperative prior to dispatch. Items are gathered by relevant chapter and provided under a table format. The structure of the MMEL item list table is as follows:

(1)     System and sequence numbers item — column No 1 — details equipment, system, component or function listed.

The applicability for each item may vary based on the type of operation, and is given, when needed, as follows:

(CAT): for Commercial Air Transport, regulated by Part-CAT;

(SPO): for Specialised Operations, regulated by Part-SPO;

(NCO): for Non-Commercial Operations, regulated by Part-NCO; and

(ALL): for all above types of operations.

(2)     Rectification interval — column No 2 — Inoperative items or components, deferred in accordance with the MEL, must be rectified at or prior to the rectification intervals established by the following letter designators:

Category A

No standard interval is specified, however, items in this category shall be rectified in accordance with the conditions stated in the MMEL.

Where a time period is specified in days, the interval excludes the day of discovery.

Where a time period is specified in other than days, it shall start at the point when the defect is deferred in accordance with the operator’s approved MEL.

Category B

Items in this category shall be rectified within three (3) calendar days, excluding the day of discovery.

Category C

Items in this category shall be rectified within ten (10) calendar days, excluding the day of discovery.

Category D

Items in this category shall be rectified within one hundred and twenty (120) calendar days, excluding the day of discovery.

(3)     Number installed — column No 3 — is the number (quantity) of items normally installed in the aircraft. This number represents the aircraft configuration that was considered in developing this MMEL. Should the number be a variable or not applicable, a number is not required; a ‘–’ is then inserted.

Where the MMEL shows that a variable number may be installed, the MEL should reflect the actual number installed, if applicable.

(4)     Number required for dispatch — column No 4 — is the minimum number (quantity) of items required for operation provided the conditions specified are met. Should the number be a variable or not applicable, a number is not required; a ‘–’ is then inserted.

Where the MMEL shows a variable number required for dispatch, the MEL should reflect the actual number required for dispatch, as applicable, or an alternate means of configuration control approved by the competent authority.

(5)     Remarks or exceptions — column No 5 — include statements either prohibiting or permitting operation with a specific number of items inoperative, provisos (conditions and limitations), notes, (M) and/or (O) symbols, as appropriate for such operation.

‘(M)’ indicates a requirement for a specific maintenance procedure which must be accomplished prior to operation with the listed item inoperative. Normally, these procedures are accomplished by maintenance personnel, however, other personnel may be qualified and authorised to perform certain functions. The satisfactory accomplishment of all maintenance procedures, regardless of who performs them, is the responsibility of the operator. Appropriate procedures are required to be published as part of the operator’s MEL or other documentation, endorsed by the operator and made available to the person(s) authorised to perform the task(s).

‘(O)’ indicates a requirement for a specific operations procedure which must be accomplished in planning for and/or operating with the listed item inoperative. Normally, these procedures are accomplished by the flight crew, however, other personnel may be qualified and authorised to perform certain functions. The satisfactory accomplishment of all procedures, regardless of who performs them, is the responsibility of the operator. Appropriate procedures are required to be published as a part of the operator’s MEL or other documentation, endorsed by the operator and made available to the person(s) authorised to perform the task(s).

‘Notes’ provide additional information for flight crew or maintenance consideration. Notes are used to identify applicable material which is intended to assist with compliance, but do not relieve the operator of the responsibility for compliance with all applicable requirements. Notes are not a part of the dispatch conditions.

Placarding: each inoperative item must be placarded, as applicable, to inform and remind crew members and maintenance personnel of the items’ condition. To the extent practical, placards should be located adjacent to the control or indicator for the item affected, however, unless otherwise specified, placard wording and location will be determined by the operator. These placards do not relieve the operator from the obligation of writing an inoperative item entry into the appropriate document, such as a logbook.

(c)      A vertical bar (change bar) in the margin indicates a modification in the adjacent text for the current revision of that section only. The change bar is dropped at the next revision of that page.

(d)     Applicability: when a variant of a page is required for certain aircraft, the special applicability is indicated in the lower part of the relevant page as well as in the list of effective pages.

(e)     Definitions for the purpose of this MMEL:

‘Aircraft Flight Manual (AFM)’ is the document required for type certification and approved by EASA.

‘Alternate procedures are established and used’ or similar statement, shall be taken to mean that alternate procedures (if applicable) to the affected process must be drawn up by the operator as part of the MEL approval process, so that they have been established before the MEL document has been approved. Such alternate procedures are normally included in the associated operations (O) procedure.

‘Any in excess of those required by regulations’ means that the item required by applicable legislation (e.g. Regulation Air Operations, Single European Sky legislation or applicable airspace requirements) must be operative, and only excess equipment may be inoperative. When the item is not required, it may be inoperative for the time specified by its rectification interval category. Whenever this condition is used in the MMEL, the applicable regulations for the intended flight routes and the resulting dispatching restrictions need to be clarified at operator’s MEL level.

‘As required by (operational) regulations’ means that the listed item is subject to certain provisions (restrictive or permissive) expressed in the applicable legislation (Regulation Air Operations, Single European Sky legislation or applicable airspace requirements). When the item is not required, it may be inoperative for the time specified by its rectification interval category.

‘Calendar day’: a 24-hour period from midnight to midnight based on either UTC or local time, as selected by the operator. All calendar days are considered to run consecutively.

‘Commencement of flight’ is the point when an aeroplane begins to move under its own power for the purpose of preparing for take-off, or the point when the rotors of a helicopter start to turn for the purpose of taking off.

‘Considered inoperative’, as used in the dispatch conditions, means that the item must be treated for dispatch, taxi and flight purposes as though it were inoperative. The item shall not be used or operated until the original deferred item is repaired. Additional actions include: documenting the item on the dispatch release (if applicable), placarding, and complying with all remarks, exceptions, and related MMEL provisions, including any (M) and (O) procedures, and observing the rectification interval.

‘Daylight’ corresponds to the period between the beginning of morning civil twilight and the end of evening civil twilight relevant to the local aeronautical airspace; or such other period, as may be prescribed by the appropriate authority.

‘Day of discovery’ means the calendar day when a malfunction was recorded in the aircraft maintenance record/logbook.

‘Flight’ (for the purposes of this MMEL): a flight is the period of time between the moment when an aircraft begins to move by its own means, for the purpose of preparing for take-off, until the moment the aircraft comes to complete stop on its parking area, after the first landing.

‘Icing conditions’ means an atmospheric environment that may cause ice to form on the aircraft or in the engine(s) as defined in the AFM.

‘If installed’ means that the item is either optional or is not required to be installed on all aircraft covered by the MMEL.

‘Inoperative’ means that the item does not accomplish its intended purpose or does not consistently function within its approved operating limits or tolerances.

‘Intended flight route’ corresponds to any point on the route, including diversions to reach alternate aerodromes required to be selected by the operational rules.

‘Is not used’ in the dispatch conditions, remarks or exceptions for an MMEL item may specify that another item relieved in the MMEL ‘is not used’. In such cases, crew members should not activate, actuate, or otherwise utilise that item under normal operations. It is not necessary for the operators to accomplish the (M) procedures associated with the item. However, operations-related provisions, (O) procedures and rectification interval must be complied with. An additional placard must be affixed, to the extent practical, adjacent to the control or indicator for the item that is not used to inform crew members that an item is not to be used under normal operations.

‘Item’ means component, instrument, equipment, system, or function.

‘Master Minimum Equipment List (MMEL)’ means a document approved by EASA that establishes the aircraft items that are allowed to be inoperative under the conditions specified in the document for a specific type of aircraft.

‘Minimum Equipment List (MEL)’ means a document approved by or declared to the competent authority, as applicable, that authorises an operator to dispatch an aircraft with aircraft items that are inoperative under the conditions specified in the document.

‘Visible moisture’ means an atmospheric environment containing water in any form that can be seen in natural or artificial light; for example, clouds, fog, mist, rain, sleet, hail, or snow.

[Issue No: GEN-MMEL/2]