GM1 MMEL.120 Format and content of MMEL

ED Decision 2014/004/R

GENERAL

(a)     The MMEL should normally be written in a ‘five-column format’. Refer to examples in GM2 MMEL.120. Other paper or electronic formats are accepted provided they are clear and unambiguous.

(b)     The MMEL should contain: cover page, revision history, detailed summary of changes at last revision, list of effective pages, and table of contents within the administrative control pages at the beginning of the MMEL, or equivalent information should be made available in the case of MMEL in other than paper format.

(c)      A model of acceptable preamble can be found in GM5 MMEL.120.

(d)     Each item listed in the MMEL should be described and identified in accordance with the Air Transport Association (ATA) specification 100 or 2200 code system. Consistency of terminology and identification means should be maintained, as far as possible, among aircraft documentation. Where appropriate, the MMEL should contain means to identify applicability of items.

(e)     Where a Message Oriented approach is used, the messages displayed may be listed in place of the item title in the relevant section, as this will be considered as a representation of the item(s) affected. Number installed and number required are not applicable for such an approach.

(f)      Rectification interval may be identified through a reference to another item.

(g)     Number installed and number required may not be listed if not practical and not relevant for dispatch determination.

(h)     Where there is a requirement for a specific maintenance procedure, then an (M) symbol should be included as part of the MMEL entry to indicate this. Where there is a requirement for a specific operational procedure, then an (O) symbol should be included as part of the MMEL entry to indicate this.

(i)      When a maintenance procedure is associated to an MMEL item, a dispatch condition, identifying the intent of the procedure (e.g. deactivation of an equipment), should be included in the associated item, as far as practicable.

(j)      References to where the content of the operational and maintenance procedures is available should be included in the MMEL.

(k)     A decision on whether the necessary procedure can be assigned as an (O) or an (M) should be based on which is the most appropriately qualified trade to carry out the procedure and which trade would normally carry out such a task in their line of duty, based on the intended types of operation normally performed by the aircraft. On this basis deactivation and securing tasks should normally be assigned an (M) while procedures based on operation of equipment should normally be assigned an (O).

(l)      The periodicity for the accomplishment of the procedures should be clarified either in a generic manner in the MMEL preamble or specifically in the associated dispatch conditions. Maintenance deactivation procedure should normally be performed once prior to the first flight under the associated item. Maintenance verification procedures periodicity may vary and should therefore be clarified in the MMEL. Operational procedures should normally be performed or acknowledged by the flight crew members before each flight, unless otherwise specified.

(m)    Placarding instructions are provided as part of the dispatch conditions or in a generic manner in the preamble to inform the crew members and maintenance personnel of the item condition, to the extent practicable.

(n)     Unless it is specifically allowed by the MMEL, an inoperative item should not be removed.