3.12 MEL Item Repair Interval Self Extension Program


Under certain conditions, such as a shortage of parts from manufacturers, or other unforeseen situations, air operators may be unable to comply with specified repair intervals. This may result in the grounding of aircraft. To preclude that from happening, a MEL Item Repair Interval Extension Program has been instituted that will allow operators, under controlled conditions, to grant extensions to MEL repair interval categories. The following paragraphs give instructions to Principal Maintenance Inspectors (PMIs) and to Principal Operations Inspectors (POIs) to administer an operator's MEL Item Repair Interval Extension programs.


  1. Each operator seeking this alleviation shall revise their MEL to include the following statements: “(Air Operator) _____________may self-extend the repair interval for Category A,B,C,and D items contained within the MEL, but shall notify the Transport Canada Principal Maintenance Inspector (PMI) or Principal Operations Inspector (POI) responsible for the operator within one working day when this action is taken and the reason it was required.
  2. Furthermore, the Transport Canada Principal Maintenance Inspector (PMI) or Principal Operations Inspector (POI) responsible for the air operator shall be notified within one working day, any time it becomes necessary to continue or extend the item repair interval period beyond the expiry date of the original extension. When advised of any extension, the TC Inspector receiving such notification shall ensure that his/her counterpart is fully informed as soon as possible. (See Section 3.12.4)”
  3. For all extensions, the air operator shall complete Schedule 1 (See Appendix B), or provide the information to Transport Canada in an equivalent and acceptable format. A copy of the completed schedule must accompany the journey log entry as follows:
    1. “This aircraft is operating on a MEL item repair interval extension as specified in the attached Schedule”;
    2. A copy of the completed Schedule 1 (or the equivalent document) shall be retained on file by the air operator for a period of thirty-six months, for auditing purposes. The period of the self-extension shall be subject to Transport Canada review upon notification by the air operator. This review may result in changes to the period of the extension, or may be used to determine abuse of the process;
    3. Prior to the approval or amendment of the air operator's MEL to include this policy, TC personnel must ensure that the provisions of this section have been fully addressed.

Note: Certain items qualify for time-limited dispatch as specified in the Type Certificate Data Sheets. The notation “And no extensions are authorized” will appear in the MMEL or TC Supplement for such items.

3.12.3Program Procedures

Maintenance Control Manual

To ensure that air operators extend MEL repair intervals only when necessary, the following elements must be adequately addressed in the MCM. Some of the elements listed below are already required as part of an operator's maintenance program. They are restated here to emphasize their importance with respect to the MEL Interval Extension Program. This list is not all inclusive and Airworthiness personnel should take any other appropriate factors into account as necessary:

  1. Authority

    The operator must assign authority to the appropriate level of the maintenance department for the approval of interval extensions. Procedures must be established and implemented to ensure that extensions are not granted without approval from the assigned maintenance management level. The authorized maintenance manager will indicate his/her approval of the extension in writing.
  2. Communications

    Operator's maintenance and operations divisions must establish clear lines of communication to show that a MEL item repair extension will not be granted unless both parties agree that the extension is clearly warranted.
  3. Parts/Equipment Control

    The air operator must establish and implement procedures that will ensure where parts and/or equipment are needed to rectify a MEL defect, and that these established procedures are acted upon in the most timely manner possible.
  4. Maintenance Control

    The air operator must establish and implement procedures to ensure that where required, all maintenance actions required to rectify a defect are initiated in the most timely manner possible.
  5. Records

    In addition to the existing maintenance record keeping requirements, air operators must indicate what records will be used for this program. Of primary interest will be records that convey maintenance approval for a MEL item interval extension and any other records that indicate maintenance, parts, or equipment control actions. A control sheet or other similar means should be used to track all events related to the extended MEL item up to and including rectification. The air operator must be able to provide all records necessary to clearly justify a MEL interval extension, when requested.
  6. Audits

    The air operator must include the MEL Item Interval Extension Program in their system of internal audits at an initial frequency of 12 months or less.

3.12.4POI/PMI Communications

Transport Canada Regional M&M and Operations Inspectors responsible for each operator requesting this authority must establish clear lines of communication throughout the approval and ongoing surveillance of this program. Communication should ensure that where an air operator reports the use of an internal extension, both the PMI and the POI are made aware of this report on an urgent basis. The operator has a requirement to report the use of a MEL item repair interval extension to the PMI or POI within one working day. It is the responsibility of the TC Inspector who receives notification from an air operator to ensure that her/his counterpart is made aware of the extension as soon as possible.

3.12.5Program Administration

Events beyond the Operator's Control

The core of this program is to ensure that air operators do not substitute MEL item repair interval extensions as a means to reduce or eliminate the need to repair MEL defects in accordance with the established category limit. Air operators are not to use the extension program as a normal means of conducting MEL item repairs. Extensions will only be considered valid and justifiable when events beyond the air operator's control have precluded rectification.

It is recognized that while MEL item repair interval categories have been established, it may not be possible in every case to repair aircraft in the time allotted for each MEL item. Several factors may influence the air operator's ability to comply with the specified interval.

These factors include:

  1. Parts shortages from manufacturers that affect all air operators equally. Parts shortages can result from material, labour, or shipping problems but must be clearly outside the air operator's control.
  2. Inability to obtain equipment necessary for proper troubleshooting and repair. Operators must, to the maximum extent possible, have the necessary equipment available to perform troubleshooting and repair of MEL items. Equipment shortages or unserviceabilities may be encountered that cannot be directly controlled by the air operator for the specified MEL item.

An unwillingness on the part of the air operator to obtain parts or equipment to rectify the defect in the most timely manner possible will be grounds for review of this authority. A recommendation to remove this authority will be forwarded to the Regional Director Airworthiness for transmission to the Regional Manager Commercial and Business Aviation, or Chief, Airline Inspection, where justified.

Abuse, as determined by the operator's PMI and POI will result in withdrawal of self-extension privileges. To ensure compliance with the spirit and intent of this authorization, air operators not previously exercising this authority may be subject to an evaluation period up to 12 months, as determined by TC. During the period of evaluation, Transport Canada concurrence and pre-approval will be required for extensions to all repair item categories.

3.12.6Program Compliance

Attempts have been made to define abuse of this program in quantitative terms. As with other delegated authorities, abuse can been determined based on the correct application of approved procedures. Airworthiness and Operational personnel must ensure that operators establish and implement a sound program to address this authority and that ongoing surveillance ensures compliance with approved procedures. The number of times this privilege is used is expected to be low. The actual number of MEL interval extensions will vary from one air operator to another due to individual circumstances. Emphasis should not be placed on how many MEL item repair interval extensions are used, but rather on the correct application of approved procedures for the issue of the extension.

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