Advisory Circular (AC) No. 605-005

Subject: Alternative Means of Compliance (AMOC) with Airworthiness Directives Process

Issuing Office:	Civil Aviation, Standards
Document No.:	AC 605-005
File Classification No.:	Z 5000-34
Issue No.:	01
RDIMS No.:	15226327-V29
Effective Date:	2021-08-20

1.0 Introduction

(1) This Advisory Circular (AC) is provided for information and guidance purposes. It describes an example of an acceptable means, but not the only means, of demonstrating compliance with regulations and standards. This AC on its own does not change, create, amend or permit deviations from regulatory requirements, nor does it establish minimum standards.

1.1 Purpose

(1) The purpose of this document is to define a process by which an applicant can propose and receive Transport Canada approval for Alternative Means of Compliance (AMOC) with the requirements of an Airworthiness Directive (AD).

1.2 Applicability

(1) This document applies to Transport Canada Civil Aviation (TCCA) personnel, delegates, and the aviation industry.
(2) This document describes a process for AMOCs that will be approved by the Chief of the Continuing Airworthiness Division (AARDG).
(3) This document is effective upon publication, however it is not retroactive. For that reason AMOCs that were issued before the publication of this document may not comply with all of the requirements of this document, however they remain valid unless they are cancelled. Section 7 of this document defines the process for cancelling AMOCs.
(4) In addition to the process described in this document, since an AMOC or an exemption is considered a Canadian Aviation Document (CAD), it is subject to all the measures specified within the Aeronautics Act associated with CADs.

1.3 Description of changes

(1) Not applicable.

2.0 References and requirements

2.1 Reference documents

(1) It is intended that the following reference materials be used in conjunction with this document:
- (a) Aeronautics Act (R.S.C., 1985, c. A-2);
- (b) Part I, Subpart I of the Canadian Aviation Regulations (CARs) — General Provisions – Interpretations;
- (c) Part I, Subpart 4 of the CARs — Charges;
- (d) Part VI, Subpart 5 of the CARs – Aircraft Requirements subsections 605.84 (3) and (4);
- (e) Standard 625 of the CARs — Aircraft Equipment And Maintenance;
- (f) Airworthiness of Aircraft, Annex 8 to the Convention on International Civil Aviation; and
- (g) Aircraft Certification Policy Letter Number 5, Issue 1, Canadian Airworthiness Directives – Inspection interval tolerances.

2.2 Cancelled documents

(1) Not applicable.
(2) By default, it is understood that the publication of a new issue of a document automatically renders any earlier issues of the same document null and void.

2.3 Definitions and abbreviations

(1) The following definitions are used in this document:
- (a) Alternative Means of Compliance (AMOC): An approval issued by the Minister or foreign approval accepted by the Minister pursuant to CAR 605.84(2) that provides alternative means to comply with an AD, where the proposed alternative will maintain the level of safety that is provided for by the compliance time, the modification, the restriction, the replacement, the special inspections or the procedure set out in the AD.
- (b) AMOC mailbox: Email account that is used by TCCA, National Aircraft Certification Branch (AARD), Continuing Airworthiness Division (AARDG) to receive and reply to AMOC proposals. The address is tc.amoc.tc@tc.gc.ca and the mailbox is titled "Alternate Means of Compliance / Autres moyens de conformité (TC)".
- (c) AMOC number: A unique number assigned to each approved AMOC. It takes the form AARDG YYYY/A## where YYYY is the calendar year that the AMOC application is received by the Division and ## are numbers that are assigned in sequence, e.g. AARDG 2019/A32.
- (d) Continuing Airworthiness Web Information System (CAWIS): A TCCA web-based information system that can be used by the public as a source, but not the only source, for collecting or identifying mandatory continuing airworthiness information (MCAI) or ADs or AMOC of general applicability issued by TCCA or other States of Design that may be applicable to a Canadian registered aircraft or an aeronautical product installed, or intended to be installed on a Canadian registered aircraft.
- (e) Design Approval Document (DAD): Means a type certificate, a supplemental type certificate, a repair design approval (RDA), a part design approval or a Canadian Technical Standard Order design approval.
- (f) Design Approval Document Holder (DADH): A natural or legal person to whom the Minister has issued a DAD.
- (g) National DADH: A national DADH is a DADH that typically works in collaboration with the National Aircraft Certification Branch for issues related to aeronautical product certification and continuing airworthiness. These DADHs are typically holders of type certificates.
- (h) Regional DADH: A regional DADH is a DADH that typically works in collaboration with a TCCA Regional Office (RO) for issues related to aeronautical product certification and continuing airworthiness. These DADHs are typically holders of supplemental type certificates, repair design approvals and part design approvals.
- (i) Type Club: Aircraft type clubs are affinity or enthusiast groups that are typically composed of aircraft owners and pilots. Type clubs exist to further the collective interest in, and support of, a specific aircraft make, model, or design. If a type certificate is surrendered by the DADH, or if the DADH ceases to exist, a type club may pool their effort/resources to maintain the airworthiness of the type.
(2) The following abbreviations are used in this document:
- (a) AC: Advisory Circular;
- (b) ACE: Aircraft Certification Engineer;
- (c) AD: Airworthiness Directive;
- (d) AMOC: Alternative Means Of Compliance;
- (e) AWL: Airworthiness Limitation;
- (f) CAA: Civil Aviation Authority;
- (g) CAD: Canadian Aviation Document;
- (h) CAR: Canadian Aviation Regulations;
- (i) CAWIS: Continuing Airworthiness Web Information System;
- (j) DADH: Design Approval Document Holder;
- (k) EASA: European Union Aviation Safety Agency;
- (l) FAA: Federal Aviation Administration;
- (m) MCAI: Mandatory Continuing Airworthiness Information;
- (n) PAI: Principal Airworthiness Inspector;
- (o) RDA: Repair Design Approval;
- (p) SLA: Service Level Agreement;
- (q) STC: Supplementary Type Certificate;
- (r) RDIMS: Records, Documents and Information Management System;
- (s) TCC: Transport Canada Centre; and
- (t) TCCA: Transport Canada Civil Aviation.

3.0 Background

3.1 Airworthiness Directives (ADs)

(1) CAR 101.01 defines an AD as “an instruction issued by the Minister or a Civil Aviation Authority (CAA) responsible for the aeronautical type design, which mandates a maintenance or operation action to ensure that the aeronautical product conforms to its type design and is in a condition for safe operation.” This can include a change to the design of the product. ADs are Mandatory Continuing Airworthiness Information documents in accordance with Annex 8 to the Convention on International Civil Aviation, Airworthiness of Aircraft. ADs mandate actions to restore an acceptable level of safety to aeronautical products in which an unsafe condition has been identified.
(2) Under CAR 521.427, the Minister shall issue an AD against any aeronautical product for which an unsafe condition has been identified and that is likely to exist or develop in other aeronautical products and for which a design approval document has been issued or accepted by the Minister.
(3) Under CAR 605.84(1)(b) and (c):
- (a) ADs issued by the Minister in accordance with CAR 521.427 are considered mandatory.
- (b) ADs or notices equivalent to ADs are considered mandatory when issued by the competent foreign civil aviation authority of:
  - (i) The state of design that is responsible for the type certification of the aeronautical product; and
  - (ii) The state of manufacture that is responsible for the manufacture of an aeronautical product for which no type certificate has been issued.
(4) ADs contain:
- (a) Identification of the affected aeronautical products;
- (b) A description of the unsafe condition;
- (c) The corrective actions required;
- (d) The schedule for completion of the required corrective actions; and
- (e) The date when the AD becomes effective.

3.2 Exemptions from ADs

(1) Pursuant to section 5.9(1) of the Aeronautics Act, certain regulations have been made that include terms and conditions (criteria) under which an exemption (authorisation) may be granted. CAR 605.84(3) provides for a possible exemption (authorisation) for an owner of a Canadian-registered aircraft from the requirement to comply with all or part of an AD.
(2) Subsequent to a request by the owner of a Canadian-registered aircraft, CAR 605.84(3) provides that the Minister shall grant an exemption (authorisation) where the conditions relating to aviation safety, as specified in Appendix H of CAR Standard 625 - Aircraft Equipment and Maintenance , have been met and where the owner demonstrates to the Minister that (a) under circumstances specified in the exemption (authorisation) request, compliance is impractical or unnecessary; and (b) the exemption (authorisation) will provide a level of safety that is equivalent to that required by the airworthiness directive.
(3) In accordance with CAR Standard 625 Appendix H, section (4), the application for exemption (authorisation) from a Canadian or foreign AD is to be made, in writing, to the local Transport Canada Centre (TCC). When submitting an application for exemption (authorisation), justification shall be provided by the owner that demonstrates that the criteria of CAR 605.84(3)(a) and (b) are met. The application shall further provide the complete details required under CAR Standard 625 Appendix H, paragraphs (4)(c)(i)-(vi) and (ix), and paragraphs (4)(c)(vii)-(viii) as may be required by the particular case.
(4) Type certificate holders of aeronautical products may apply for an exemption (authorisation) on behalf of the owners of their products. If the exemption (authorisation) is granted, the type certificate holder will be asked to communicate the information to the owners, together with a copy of the exemption (authorisation) and any conditions specified.
(5) In accordance with CAR Standard 625 Appendix H, subsection (4)(d), approval of an exemption (authorisation) from an AD shall be indicated in a letter issued by the Chief, Continuing Airworthiness Division (AARDG). The letter shall be retained by the owner with the aircraft technical records.
(6) This AC does not further discuss the subject of exemptions pursuant to a regulation with criteria (authorisation).

3.3 AMOC with ADs

(1) CAR 605.84(4) states that the Minister shall approve an AMOC with an AD, for reasons set out in the approval, where the Minister is satisfied that the proposed alternative will maintain the level of safety that is provided for by the compliance time, the modification, the restriction, the replacement, the special inspection or the procedure set out in the AD.
(2) Standard 625 Appendix H – Airworthiness Directives (CAR STD 625 Appendix H) provides standards related to ADs, Exemptions and AMOCs.

4.0 AMOC process overview and responsibilities

4.1 AMOC Characteristics

(1) Every AMOC will include one or more alternatives to the corrective actions required by the AD. The alternative actions permitted by an AMOC may include but are not limited to:
- (a) Alternative repairs or modifications, including installation of parts that are not affected by the AD;
- (b) Alternative inspection procedures/intervals;
- (c) Alternative maintenance procedures/intervals;
- (d) Extended compliance deadlines; and/or
- (e) Specified operating procedures or limitations.
(2) When submitting an AMOC proposal, the applicant will describe the proposed alternative actions and substantiate that those actions maintain the level of safety achieved by the AD corrective actions (refer to paragraph 5.1(1)(h) of this AC). The applicant may also explain to TCCA why they are proposing the AMOC. Possible reasons for a proposed AMOC include, but are not limited to:
- (a) Shortage of parts required for compliance with the AD;
- (b) Environmental and/or operational factors specific to the applicant make the corrective actions required by the AD unnecessary or require that the AD corrective actions be adjusted to reflect the effects of the applicant’s operations;
- (c) Logistical factors such as the lack of available local resources required to perform the AD corrective actions. The applicant has to fly their aircraft to a place where the AD-mandated action can be performed because the resources to perform the action are not available at the current location of the aircraft, however poor maintenance planning is not an acceptable reason for the approval of an AMOC;
- (d) A previous design change or modification to the applicant’s aircraft has already eliminated the unsafe condition identified by the AD or has made it impossible to comply with the AD;
- (e) The applicant has developed and substantiated an alternative means of correcting the unsafe condition that maintains the level of safety achieved by the AD; or
- (f) A superseding AD has invalidated previous AMOCs with the superseded AD. The AMOCs are specifically identified as ‘no longer valid’ or ‘cancelled’ in the superseding AD. In this situation the applicant should explain how the previous AMOC has been modified in response to the concerns identified in the superseding AD.
(3) An AMOC does not need to address all of the requirements of an AD. The AD requirements that are not impacted by the AMOC will continue to apply.
(4) An AMOC is not a flight authority. However, an AMOC could be granted for an AD to facilitate the issuance of a flight authority. An application for an additional flight authority may be required (See CAR STD 507 Flight Authority and Certificate of Noise Compliance).
(5) An AMOC cannot be used to approve deviation from airworthiness limitations (AWLs) or maintenance schedules unless the AWL or maintenance requirement is required by an AD corrective action. For deviation from an AWL or maintenance requirement that is required by an AD corrective action, the AMOC application will have the concurrence of the operator’s Principal Airworthiness Inspector (PAI), see section 5.2(3) of this AC for additional information.
(6) AMOCs issued by the Minister are only valid in Canada unless the CAA responsible for a foreign-registered product accepts TCCA AMOCs. Information about acceptance of TCCA AMOCs by certain foreign CAAs may be found in implementation procedures for bilateral agreements or administrative arrangements between Canada and the foreign state or their competent CAA. Information on bilateral agreements and administrative arrangements is available from this TCCA web page: https://www.tc.gc.ca/en/services/aviation/aircraft-airworthiness/international-agreements-arrangements.html.
(7) Canada has entered into bilateral aviation safety agreements with the United States of America and with the European Union. The implementation procedures for these agreements provide for some mutual recognition of global AMOCs issued by their respective CAA. TCCA accepts both European Union Aviation Safety Agency (EASA) and Federal Aviation Administration (FAA) global AMOCs subject to limitations stated in CAR STD 625 Appendix H. The implementation procedures also require each CAA to provide copies of their global AMOCs to each other. For that reason, the Transport Canada Civil Aviation, National Aircraft Certification Branch, Continuing Airworthiness Division AMOC process requires that global AMOCs be distributed to the CAAs for those two jurisdictions, the EASA and the FAA.
(8) If the AD that is the subject of an approved AMOC is revised, that AMOC remains valid unless the revised AD specifically states otherwise. A revised AD will have the same number as the original AD. The revision number will be added to the AD number. For example, AD CF-2019-20R1 is the first revision of AD CF-2019-20.
(9) If the AD that is the subject of an approved AMOC is superseded, that AMOC is no longer valid unless the superseding AD specifically states otherwise. An AD that cancels and supersedes a previous AD will have a different AD number. For example, AD CF-2019-02 cancels and supersedes ADs CF-80-06, CF-81-07R2, CF-95-12 and CF-2000-14.

4.2 Types of AMOC

(1) There are four (4) types of AMOC that may be issued. In each case, the AMOC will be issued in the form of a letter from the Chief of the Continuing Airworthiness Division (AARDG):
- (a) A Specific AMOC applies to a single applicant. This type of AMOC may address one or multiple aeronautical products as identified by the applicant. Each affected product is identified on the AMOC. Specific AMOCs will be issued in the applicant’s preferred official language.
  - (i) In some cases, a Specific AMOC will have provisions to apply the AMOC to existing aeronautical products owned/operated by the applicant and to products that may be added in the future. In this case, the details (serial number, registration) of the future product are not known and will not be available for inclusion in the AMOC proposal or in the AMOC approval letter from the Continuing Airworthiness Division (AARDG). The AMOC approval letter will be written so that it is clear it can be applied to future additions without the need to issue a new AMOC approval letter.
  - (ii) The ‘Ferry Flight AMOC’ is a sub-type of the Specific AMOC. The Ferry Flight AMOC is typically used to apply operational restrictions to mitigate risk when an aeronautical product with outstanding AD corrective actions has to be moved from its current location to another location where the resources are available to accomplish AD corrective actions. Paragraph 5.1(1)(i)e of this AC provides examples of the types of operational restrictions that are typically included in Ferry Flight AMOCs to achieve the necessary risk mitigation.
- (b) A Blanket AMOC typically applies to multiple owners/operators of affected Canadian- registered aeronautical products. Blanket AMOCs are distributed to affected operators using the same distribution method that is used to distribute ADs. A Blanket AMOC may have been applied for by an individual, an organization or a type club. They may also be initiated by the Continuing Airworthiness Division (AARDG), without an application from an external applicant, in order to resolve an issue that is making implementation of a foreign AD problematic. These are only examples of situations where the Division may determine that a Blanket AMOC is the appropriate type of AMOC to satisfy the applicant’s requirements. The distinguishing feature of a Blanket AMOC is that it is issued to multiple owners/operators, available in both official languages and distributed using the same process that is used to distribute ADs.
- (c) A Global AMOC typically applies to all aeronautical products of the same type. However, it may be limited to a subset of a type. An example of such a configuration-limited AMOC would be one that is targeted at a range of serial numbers that were manufactured to a configuration where the AD corrective action cannot be applied as defined in the AD. Global AMOCs may be initiated by the Division without an application from an external applicant. Global AMOCs are issued to a DADH for distribution to all affected owners/operators. This type of AMOC is referred to in some other jurisdictions as an AMOC of general applicability or a generic AMOC. Global AMOCs will generally be issued in English only because that is generally the business language of the foreign CAAs that will receive a copy of the AMOC. However, if the applicant’s preferred language is French then TCCA will provide copies of the AMOC in both official languages.
- (d) An AMOC-equivalent letter is a document issued to an applicant who intends to propose an AMOC with an AD issued by a foreign CAA or a TCCA AD that has been adopted by a foreign CAA where that CAA does not recognize or accept TCCA AMOCs. The applicant requests such a letter when they require the AMOC to apply to foreign-registered products for which TCCA has no jurisdiction. AMOC-equivalent letters are typically requested when the applicant wants to facilitate approval of an AMOC proposal by the foreign CAA. The process for applying for and providing an AMOC-equivalent letter is the same as the process for applying for and providing an AMOC.
(2) The Continuing Airworthiness Division (AARDG) may be asked to comment or concur with AMOC proposals that have been, or will be, submitted to foreign CAAs. This occurs most frequently when a Canadian DADH intends to propose an AMOC with an FAA AD. The Division may also be asked by a foreign CAA to comment on an AMOC application they have received. These sub-processes are described in Section 6 of this AC.

4.3 Who can apply for an AMOC and who is an AMOC issued to?

(1) An AMOC with an AD may be applied for by any person.
(2) There may be cases where it is not obvious if an AMOC is required. A potential AMOC applicant may inquire about the need for an AMOC. This type of inquiry should be sent to the office identified in section 5.2 of this AC. No charges will be imposed for this service. An AMOC file in the Continuing Airworthiness Web Information System (CAWIS) will not be created for this type of inquiry.
(3) AMOCs are issued to the applicant unless the applicant requests that a third party be the holder of the AMOC. In the latter case, the AMOC will be issued to the third party specified by the applicant.

5.0 The AMOC process

5.1 Preparing the AMOC application

(1) AMOC applications should include the following information, in accordance with CAR STD 625 Appendix H section (4):
- (a) All aeronautical products involved, as identified by:
  - (i) Product type;
  - (ii) Make and model designation;
  - (iii) Serial number(s) and registration marks; and
  - (iv) The engine or the propeller serial number or both, as applicable.
  Note: For Global and Blanket AMOCs, registration numbers and individual serial numbers are optional. For these types of AMOCs, a range of affected serial numbers or a statement such as “all Canadian-registered products” may be sufficient. There has to be enough information in the application to clearly identify the products that will be subject to the AMOC and to distinguish them from products that will not be subject to the AMOC.
- (b) The type of AMOC being proposed (Specific, Blanket, Global or AMOC-equivalent letter);
- (c) The full name of the owner of the affected aircraft or of the natural or legal person making the application on behalf of the owner. Application can be made for an AMOC that will be applicable to the aeronautical products they operate as well as those operated by affiliated or subsidiary organizations of the applicant;
- (d) Contact information for the applicant;
- (e) The AD number and the specific corrective action requirement(s) that are affected by the AMOC application;
- (f) The date by which a response from TCCA is desired (optional) ;
- (g) An explanation of why an AMOC is required;
- (h) A detailed description of the corrective actions the applicant is proposing in place of those mandated by the AD, including any illustrations or other supporting documentation. If the application is for a Global or Blanket AMOC, it will be helpful if the applicant provides a summary of how the AMOC corrective actions should be described in the AMOC approval letter in order to protect the applicant’s proprietary information. These types of AMOC approval letter will be distributed by TCCA not just to the applicant but to other affected owners/operators and/or foreign CAAs; and
- (i) If the application is for a ‘ferry flight’ type of Specific AMOC, the following information:
  - (i) The current location of the affected product and the destination for the ferry flight;
  - (ii) The expected number of flight hours and flight cycles that will be required to accomplish the ferry flight;
  - (iii) The number of calendar days from receipt of the approved AMOC until the ferry flight is expected to be completed;
  - (iv) A list of all AD corrective actions that are past due and any mitigating inspections, functional checks or other actions that are proposed to be accomplished before the ferry flight; and
  - (v) A list of operational restrictions that will be applied to the ferry flight to mitigate risk. The following are examples of standard ferry flight AMOC operational restrictions:
    - (A) Only essential crew is allowed on board;
    - (B) The flight is to be non-pressurized, not flown over water and limited to Day VFR;
    - (C) Flight shall be conducted with the landing gear locked in the down position;
    - (D) Flight shall not to be conducted over populated areas; and
    - (E) Other operational restrictions proposed by the applicant.
- (j) Substantiation that the proposed corrective action and any other limitations will maintain the level of safety that is achieved by the AD; and
- (k) If the proposed AMOC is associated with a change to the type design such as an STC or an RDA, provide the details of the design change including contact information for the TCCA personnel (e.g. ACE) who are assigned to the design change project.
(2) If the proposed AMOC is associated with a change to the type design, those changes have to be approved separately from the AMOC approval. The normally-applicable certification procedures of Part V of the CAR will apply.

5.2 Submitting the AMOC application

(1) National DADH submit their AMOC proposals directly to the Continuing Airworthiness Division (AARDG) for consideration. The proposal will be submitted to the AMOC mailbox, tc.amoc.tc@tc.gc.ca.
(2) Regional DADH will submit their AMOC proposals through the TCCA Regional Office (RO) that issued, or is processing their application for the design approval document.
(3) Canadian owners/operators will send the proposal along with all supporting documentation to their PAI. The PAI will forward the proposal to the Continuing Airworthiness Division (AARDG) AMOC mailbox, tc.amoc.tc@tc.gc.ca, together with the results of their review of the proposal. If a Canadian owner/operator does not know who their PAI is, or cannot reach them, then they may submit their proposal to:
- (a) The appropriate TCCA RO; or
- (b) The appropriate TCC.

5.3 The AMOC response

(1) The AMOC response from the Continuing Airworthiness Division (AARDG) will be in the form of a letter. For Specific and Global AMOCs, the letter will be addressed to the applicant or to the person that the applicant designated in their original application. For Blanket AMOCs, the letter will be addressed, in general terms, to the group of owners/operators who were identified in the original application. The response will come directly from the Division.
(2) Where the AMOC is approved, the letter will contain a reference to the unique AMOC identification. That identification will be of the form AARDG YYYY/A##, where YYYY is the calendar year when the AMOC application was approved and ## is a sequential number assigned to AMOCs.
(3) The AMOC letter shall be retained in the aircraft technical records in accordance with CAR STD 625 Appendix H paragraph (4)(d).
(4) Where the AMOC is denied, the letter will not contain a unique AMOC identification. The letter will contain a justification for the denial.
Note: If the applicant considers the denial of the AMOC to be unjustified, they may request a review of the decision as per the guidelines described in the denial letter or in accordance with the provisions of the Aeronautics Act.
(5) For every AMOC proposal, the applicant will receive a copy of the AMOC response by e-mail. Global AMOCs will include a request that the applicant distributes the AMOC to all affected owners/operators. TCCA will automatically distribute a copy of all Global AMOCs to other CAAs where this is required by our bilateral agreements or administrative arrangements with those CAAs.
(6) In addition to being distributed to the applicant, Blanket AMOCs will be attached to the applicable AD in CAWIS. All registered owners/operators will receive automatic notification through CAWIS of the AMOC.
(7) Statement of transferability:
- (a) Each Specific AMOC will include a statement of non-transferability. If an owner of an AMOC wishes to transfer the approved AMOC to a new owner, an application for an AMOC from the new owner will need to be submitted as per the processes described in this document.

6.0 Applications for TCCA concurrence with AMOC proposals made to foreign CAA

(1) The Continuing Airworthiness Division (AARDG) may be asked to comment on, or concur with AMOC proposals that have been, or will be submitted to foreign CAAs. This type of request occurs most frequently when a Canadian DADH intends to propose an AMOC with a foreign AD that is equivalent to a TCCA AD issued against a Canadian state of design aeronautical product. The foreign CAA will often rely on TCCA concurrence with an AMOC proposal to ensure that the intent of the original (TCCA) AD is satisfied.
(2) The Division may also receive a request from a foreign CAA to concur with, or comment on, an AMOC proposal that the foreign CAA has received from an applicant within their jurisdiction and that is related to a Canadian state of design aeronautical product.
(3) Although there may be a TCCA Global AMOC letter already issued for the same AMOC, TCCA Global AMOCs have no validity in some foreign jurisdictions because the foreign CAA does not adopt foreign ADs or does not recognize foreign AMOCs.
(4) The applicant requesting concurrence with the proposed AMOC application should use their normal process to propose AMOCs, noting that the request is for comment/support of an application to a foreign CAA. The TCCA response will be in the form of an e-mail from the appropriate Division Section Manager rather than a formal letter from the Chief of the Division.
(5) The preceding discussion is not relevant to AMOC-equivalent letters. An AMOC equivalent letter is a form of AMOC and is covered in more detail in other portions of this AC.
(6) Applications for TCCA concurrence involve significantly less effort than a typical AMOC, so they are not subject to the AMOC process requirements discussed elsewhere in this AC. If, after initial review, a proposal from a Canadian client is determined to be significant in scope, the appropriate Division Section Manager will direct the applicant to submit an AMOC proposal.

7.0 Cancelling AMOCs

(1) AMOCs are not revised. If a revision is required or applied for, a new AMOC will be issued stating that the original AMOC is cancelled.
(2) Circumstance when an AMOC will need to be cancelled include:
- (a) When there is a requirement to extend or reduce the applicability of the AMOC;
- (b) When a document referenced in the AMOC is revised or cancelled;
- (c) When further analysis has determined that the AMOC does not provide an equivalent level of safety; or
- (d) When the holder of the AMOC has proposed changes.
(3) The new AMOC will include a cancellation statement for the old AMOC i.e. “AMOC AARDG YYYY/AXX is cancelled”.
(4) The new AMOC will include a ‘description of changes’ section to explain what has changed.
(5) If a TCCA Global or Blanket AMOC is cancelled because further analysis has determined that it does not provide an equivalent level of safety, then the underlying AD will be cancelled and superseded if it is a TCCA AD. If the underlying AD is not a TCCA AD, then a unilateral Canadian AD will be issued to take the place of the foreign AD. The Background section of the AD will explain that the reason for the TCCA AD is to render a previously-issued TCCA AMOC non-valid.
(6) If TCCA determines that a foreign Global AMOC is unacceptable and the foreign AMOC is automatically accepted in Canada, a unilateral Canadian AD will be issued to take the place of the foreign AD. The Background section of the AD will explain that the reason for the TCCA AD is to render a foreign AMOC non-valid.
(7) If a Specific AMOC is cancelled because further analysis has determined that it does not provide an equivalent level of safety, then the Continuing Airworthiness Division (AARDG) will send a letter to the AMOC holder notifying them that TCCA proposes to revoke the AMOC and will state the reason for the proposed revocation. The letter will provide at least seven days for the AMOC holder to respond before the AMOC is cancelled. The AMOC cancellation letter will be routed through the PAI/ACE. If the AMOC is determined to be unsafe such that it creates an emergency situation, the notice and comment period may be waived, and the cancellation may be made effective immediately. An immediate cancellation may effectively ground the affected aircraft. The reasons for the emergency action will be stated in the letter.
(8) If an AMOC-equivalent letter has to be cancelled, the process will be the same as for the cancellation of a Specific AMOC, except that the holder of the AMOC-equivalent letter will be required to inform every foreign CAA that was provided with the original letter of the TCCA decision to cancel it.
(9) If the AMOC holder considers the cancellation of the AMOC to be unjustified, they may request a review of the decision as per the guidelines described in the cancellation letter or in accordance with the provisions of the Aeronautics Act.

8.0 Information management

(1) Details regarding any Specific AMOCs are considered proprietary information between TCCA and the product’s owner/operator or DADH, depending on who acted as applicant. Due to this proprietary nature, TCCA will not provide details about the technical nature of Specific AMOCs, and will not provide a copy of Specific AMOC approval letters to anyone that is not the AMOC holder.
(2) Blanket and Global AMOCs will be distributed more widely than Specific AMOCs. For that reason, they will typically contain less technical information than a Specific AMOC. When submitting an application for a Blanket or Specific AMOC, the applicant will provide TCCA with details about what technical information is acceptable to include in the AMOC and what technical information is to be withheld.

9.0 Document history

(1) Not applicable

10.0 Contact us

For more information, please contact:

Chief, Continuing Airworthiness Division (AARDG)
Phone: 613-773-8291
Email: tc.amoc.tc@tc.gc.ca

We invite suggestions for amendment to this document. Submit your comments to:
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Original signed by Andrew Larsen for

Félix Meunier
Director, Standards
Civil Aviation

AC 605-005 - Alternative Means of Compliance (AMOC) with Airworthiness Directives Process
(PDF, 474 KB)

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