Development of an MCC Aircraft Defect Control Procedure
Sofema Online (SOL) www.sofemaonline.com considers the basic process involved with implementation of a Defect Control process within the Maintenance Control Centre (MCC).
Introduction
The complexity of the MCC Systems used to manage defects, including the organisation of rectification downtime and deferral using MEL procedures, as well as identifying and handling recurring defects will vary according to the type of aircraft operated and the size and nature of the operation.
The system may also include additional policies and procedures for the use of an approved Minimum Equipment List (MEL).
Defect Analysis Activities
Defect Control Engineers (DCE) will:
» Analyse defects and failures, with specific focus on any defects that could seriously impact any safety related aircraft systems.
» DCE shall discuss any defects which require additional consideration with either the Aircraft Maintenance Provider or the Type Certificate Holder / OEM in conjunction with CAMO Engineering.
» The analysis should be performed as soon as possible after the occurrence.
» DCE shall distinguish between occurrences which are considered random and those where there is clear evidence of repetition. (Engineering Judgement Required)
» DCE may propose any of the following:
o Component Change / Modification
o Temporary repair
o Other maintenance action
» It is the responsibility of the PART 145 AMO to report all defects and other occurrences to DCE.
» DCE is responsible to ensure that when applicable occurrences are reported to aircraft manufacturer and competent authority within 72 hours.
o The occurrence report should always provide details concerning the functional behaviour of any underlying systems (In particular where such an event involves a system or component that is monitored or protected by a warning system (critical to safety).
Deferred Defect Policy
Deferment of any defect found during maintenance that is not addressed by the MEL or CDL may be required, (structural deterioration or other damage) in which case DCE may investigate, in consultation with the PART-145 AMO, to confirm the defect or damage is within the limits described in the manufacturer’s publications (e.g. structural repair manual, repair drawings, etc.) in order to support deferment.
If the found defect is outside of the proscribed limits it is necessary for the TCH to be contacted for disposition (temporary repair).
Concerning Pilot Reports (PIREPS) - MCC Reliability and Defect Control Considers
» MCC DCE considers specific issues/defects which re-appear over a given period on each individual aircraft.
» Such repeated defects could be an identification of any number of issues and should be subjected to a thorough root cause analysis process.
Development of a Defect Control Procedure – Example
» A description of the defect rectification and control procedures, including details of:
o The methods used to detect and report recurring defects;
o The procedures for scheduling the rectification of defects whose repair has been deferred;
o Procedures for recording and rectification of defects, including the identification of recurring defects.
» Note 1: The pilot in command must know the status of the aircraft in order to make an informed decision on its serviceability for the intended flight. (The final authority to reject an unsafe aircraft rest with the pilot.)
» Note 2: Additional crew workload must be taken into consideration if defects are deferred.
Example Definition of a Recurring Defect
» A recurring defect is one that is repeated 3 times on a particular aircraft within 15 flight segments.
» The purpose of specific procedures for identifying recurring defects is to avoid ineffective methods of repair and to ensure the defect will not reoccur.
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
