Managing Aircraft Minimum Equipment List (MEL) Defects

Sofema Online (SOL) www.sofemaonline.com considers the Maintenance Control Centre (MCC) – Defect Control Procedure related to the treatment of MEL applicable defects.

Terminology 

DCE - Defect Control Engineer

Introduction - For aircraft operated with an MEL the following procedures apply:

» Any defect identified prior to departure will be recorded in the Aircraft Technical Log (ATL) / Journey Immediately.

» The CS will determine if a defect can be deferred or if it must be rectified prior to flight. If the CS is unable to make the determination, he will consult with the MCC DCE for support and guidance.

» In the event that a defect cannot be rectified at any line station the Certifying staff (CS) will notify MCC

o If the item can be deferred, as identified in the MEL, the CS will ensure that the "O", "M" & "M#" procedures in the MEL are followed and ensure the appropriate entries are made in the ATL / Journey Log;

» In the event of a deferment IAW with MEL Procedures CS will ensure placards installed, Circuit Breakers pulled & tagged, unserviceable equipment isolated and all action(s) entered in the ATL as required.

» The CS will record the deferred defect on the Deferred Defect Sheet (within the ATL) The sheet will include the MEL categorization and the date the defect must be rectified by. In addition, reference to the granted extension if the MEL overrun procedure is employed.

Defects Arising During Flight Operations

» For any defect occurring in flight the defect will be recorded in the ATL / Journey Log as soon as practical but before deplaning on arrival.

Defects arising during a “Transit” at an unmanned station

» The pilot in command (holding MEL deferment approval) shall consult the MEL and defer the item, if permitted, following the appropriate MEL procedures. The PIC will notify MCC as soon as possible;

» The MCC Defect Control Engineers (DCE) will enter the defect into Maintenance Planning and Control Program and include the date and time by which the MEL'd item must be rectified;

» The DCE will make the necessary arrangements to have all defects rectified;

Following the Rectification of an MEL Defect

» Once a defect is rectified, an appropriate logbook entry shall be made.

» Following rectification any placards and/or circuit breaker collars will be removed and the item will be deleted from the Maintenance Planning and Control Program.

Recurring Defects

DCE - Will review the last 15 flight segments in the Journey Log for any signs of a recurring defect.

A recurring defect is one that reoccurs 3 times in 15 flight segments.

» Once a defect has been identified as a recurring defect the MCC DCE will flag the aircraft for removal from service in order to conduct an investigation into the root cause of the defect.

» The aircraft will remain off-line until MCC is satisfied that a positive action has been taken regarding the identification of the source of the defect with the stated aim being a permanently fix.

Sofema Aviation Services (www.sassofia.com) and Sofema Online (www.sofemaonline.com) offer EASA Regulatory Compliant and Vocational Training across a range of Aviation Areas including the following course. For additional details please see our Websites or email team@sassofia.com