Staff Instruction (SI) No. 521-007

Part Design Approvals

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Issuing Office: Standards Document
SI 521-007
File Classification No.: Z 5000-32 Issue No.: 01
RDIMS No.: 5612315-V31 Effective Date: 2012-03-16


1.1  Purpose

  1. The purpose of this Staff Instruction (SI) is to provide general information and basic procedures relating to:

    1. the review and approval of aeronautical products through the issue of a Part Design Approval as governed by Subpart 521 of the Canadian Aviation Regulations (CARs); and

    2. the original issue of Part Design Approvals (PDAs) and follow-on revisions;

  2. This document is to be used in conjunction with SI 521-004.

1.2  Applicability

  1. This document applies to all Transport Canada Civil Aviation (TCCA) employees and Ministerial Delegates. This information is also available to the aviation industry for information purposes.

1.3  Description of Changes

  1. Not Applicable.


2.1  Reference Documents

  1. It is intended that the following reference materials be used in conjunction with this document:

    1. Aeronautics Act (R.S., 1985, c. A-2);

    2. Part I, Subpart 4 of the Canadian Aviation Regulations (CARs)—Charges;

    3. Part V, Subpart 21 of the CARs—Approval of the Type Design or a Change to the Type Design of an Aeronautical Product;

    4. Staff Instruction (SI) 500-018—Design Approval Document Transfers under CAR 521: Division VIII – Responsibilities of a Design Approval Document Holder;

    5. SI 521-004—Changes to the Type Design of an Aeronautical Product;

    6. Advisory Circular (AC) 521-002—Type Certification Requirements of Aircraft, Engines and Propellers;

    7. AC 521-007— Part Design Approvals; and

    8. Notice of Proposed Amendment (NPA) 2010-021Approval of the Type Design or Change to the Type Design of an Aeronautical Product.

2.2  Cancelled Documents

  1. As of the effective date of this document, the following documents are cancelled:

    1. SI 513-009, Issue 01, 2006-04-01 —Part Design Approval Procedures.

  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:

    1. Aeronautical Product: an aircraft, aircraft engine, aircraft propeller or aircraft appliance or part, or a component part of any of those things, including any computer system and software (Ref. Aeronautics Act and Section 521.01 of the CARs). This SI does not apply to products approved by a Canadian Technical Standard Order (CAN-TSO) design approval.

    2. Certification Basis: refers to the applicable standards as established in Section 521.157 of the CARs, as appropriate, including any special conditions—airworthiness (SCA), findings of equivalent level of safety, and exemptions applicable to the product to be certified.

    3. Conformity with the Certification Basis: demonstrating compliance with all of the applicable standards and requirements of the certification basis.

    4. Delegate: any person or class of persons authorized under the authority of Subsection 4.3(1) of the Aeronautics Act to perform functions on behalf of the Minister, subject to the requirements in Chapter 505 of the Airworthiness Manual (AWM).

    5. National Aeronautical Product Approval (NAPA) System: an automated system that provides staff in aircraft certification with the tools necessary to track the certification of aeronautical products and issue the design approval documents. This system also provides a database of the projects and supporting data for this certification.

    6. Part Design Approval (PDA): a document that is issued by the Minister to record the approval of the type design of a replacement part, identified by a part number or by some other means of identification unique to the part, for use on an aeronautical product that is identified by type or model (Subsection 101.1(1) of the CARs).

    7. Standards of Airworthiness: design requirements as defined in the AWM. For design changes, the standards of airworthiness may also be listed on the type certificate data sheet (TCDS).

    8. Type Design:

      1. the drawings and specifications, and a listing of those drawings and specifications that are necessary to define the design features of an aeronautical product in compliance with the standards applicable to the aeronautical product;

      2. the information on dimensions, materials and manufacturing processes that is necessary to define the structural strength of an aeronautical product;

      3. the approved sections of the aircraft flight manual, where required by the applicable standards of airworthiness;

      4. the airworthiness limitations section of the instructions for continued airworthiness (ICA) specified in the applicable chapters of the AWM; and

      5. any other data necessary to allow, by comparison, the determination of the airworthiness and, where applicable, the environmental characteristics of later aeronautical products of the same type or model.

        (Ref: Section 101.01 of the CARs).


  1. With the implementation of Subpart 521 of the CARs new documents have been created to support the regulations. All guidance material such as SIs, ACs and Policy Letters,  that supported the previous CARs including Chapters 511, 513, 591 and 593 of the AWM have been reviewed and the relevant material included in the 521 series ACs and SIs.

  2. This SI is organized to mirror Sections and Subsections of Division VII of Subpart 521 of the CARs, so that it can be easily read in conjunction with Subpart 521 of the CARs.

  3. Although Subpart 521 of the CARs introduced a change in terminology in the English version from “compliance” to “conformity” this SI will be using “compliance” wherever possible to minimize confusion.

    In December 2010, a Notice of Proposed Amendment (NPA) to Subpart 521 of the CARs (NPA 2010-021) was introduced to revert the terminology “conform” and “conformity” back to “comply” and “compliance.”

  4. The PDA was introduced to allow the approval of replacement parts where the design of that replacement part represents a negligible change to the fit, form and function of the part it is intended to replace. The replacement part must meet the applicable airworthiness requirements as stated in the TCDS of the original equipment manufacturer product. In addition, the replacement part does not enhance the functionality of the part it is intended to replace, nor of the aeronautical product on which the part is installed.


  1. The requirements that must be fulfilled to obtain a PDA as a result of a replacement part are defined in Divisions IV, Changes to a Type Design and VII, Part Design Approvals of Subpart 521 of the CARs,. This SI should be used in conjunction with SI 521-004.

  2. Sections 521.301 to 521.303 of the CARs define the requirements of an applicant for a PDA. Sections 521.304 and 521.305 of Division VII of the CARs and Sections 521.157 to 521.160 of Division IV of the CARs establish the certification requirements as well as the requirements for demonstrating that the replacement part complies with all certification requirements. Sections 521.306 and 521.307 of Division VII of the CARs and Section 521.161 of Division IV of the CARs define the design approval issuance and subsequent revision requirements.


5.1  Application - Section 521.301

  1. This SI applies to applications for a Canadian PDA under Division VII of Subpart 521 of the CARs.

  2. Any Canadian individual or organization may apply for a PDA. Canadian design approval documents are not issued directly to foreign applicants. Refer to Division XI of Subpart 521 of the CARs for more information on foreign aeronautical products.

5.2  Eligibility Requirements - Section 521.302

  1. Section 521.302 of the CARs requires the applicant to have or have access to the required technical capabilities specific to the replacement part under consideration. An applicant could meet this requirement by:

    1. Having a level of knowledge and capability appropriate for the replacement part, or;

    2. Showing that an arrangement exists for the applicant to have access to a level of knowledge and capability appropriate for the replacement part.

  2. For more detailed information on how the Minister determines technical capability, refer to AC 521-002.


6.1  Application for a Part Design Approval - Section 521.303

  1. Applications for a PDA are processed in accordance with the procedures defined in SI 521-004.

  2. The replacement part shall not:

    1. be subject to an airworthiness limitation;

    2. be a standard part or a commercial part;

    3. constitute a change to the type design of the aeronautical product; or

    4. create an airworthiness limitation.

  3. See AC 521-007 for a complete list of eligibility criteria for PDAs.

6.2  Establish Certification Basis - Section 521.304

  1. Establishment of the certification basis is to be conducted in accordance with Subsection 521.158(2) of the CARs.


  1. SI 521-004 provides information on establishing means of compliance and TCCA’s level of involvement.


8.1  Compliance with Certification Basis - Section 521.305

  1. The applicant’s compliance demonstration with the certification basis is to be conducted in accordance with the procedures defined in SI 521-004 (Section 521.160 of the CARs).

  2. In addition to any  compliance issues specified in SI 521-004 (Section 521.160 of the CARs), the following specific issues should be considered for PDAs:

    1. Part marking; and

    2. Methods of analyses (computation), inspections and test. Certification by inspection only, i.e. identicality is not sufficient means to satisfy compliance with the certification basis.


9.1  Issuance of a Part Design Approval - Section 521.306

  1. Issuance of a PDA is to be conducted in accordance with the procedures defined in SI 521-004 and the guidance provided in this section.

  2. A sample PDA is provided in Appendix A of this SI.

  3. The certificate format and numbering system for PDAs is as described in Appendix B of this SI.

  4. Only an appropriately authorized TCCA employee may issue PDAs.

  5. A PDA-specific Approval Document Checklist is provided in Appendix D of this SI. This checklist should be used in conjunction with the project checklist provided in SI 521-004.

  6. A transmittal letter template is provided in Appendix E of this SI.

  7. Additional guidance on the issuance of approvals for a change to a type design is provided in SI 521-004.


10.1  Change to a Part Design Approved in a Part Design Approval - Section 521.307

  1. Revisions for the purpose of adding references to new or revised engineering data, or for incorporating other necessary changes or corrections, shall be annotated with a vertical bar adjacent to the right hand margin to indicate the changes on the certificate.

  2. A change to a PDA that is classified as a major change (not minor) shall be applied for as either a new PDA (replacement part that does not modify the baseline aeronautical product), or shall be applied for as an supplemental type certificate (STC) that is separate from the original PDA, the new change being a modification of the baseline aeronautical product.

  3. Minor changes shall be dealt with in accordance with Section 521.154 of the CARs.


  1. It is not the intent that TCCA keep copies of the applicant’s supporting data after the approval is issued. The holder has retention obligations under Sections 521.365 and 521.366 of the CARs.

  2. TCCA files will retain key compliance related information such as certification plans, issue papers and decision records as well as any data cited on the approval document such as flight manuals and supplements, maintenance manuals/Instructions for Continued Airworthiness (ICA) and master document lists.

  3. After approval is issued, TCCA will upon request by the applicant, return paper copies of supporting data or otherwise shred or erase this data.


  1. Not applicable.


Suggestions for amendment to this document are invited, and should be submitted to:

Chief, Aircraft Certification Standards (AARTC) via the following e-mail address:

Original signed by

Jacqueline Booth
A/Director, Standards Branch
Civil Aviation
Transport Canada



Department of Transport

Part Design Approval

This approval is issued to: 
123456 Canada Inc.
Acme Aerospace Ltd.
8876 Any Street
Anytown, Alberta
T2M 1H8

Number: PDA09-50
Issue No.: 2
Approval Date: December 1, 2009
Issue Date: February 02, 2011

Responsible Office:

Aeronautical Product Type or Model:

Canadian Type Certificate or Equivalent:

Replacement Part:

Prairie and Northern

Pioneer P-400


Jack End Fitting

Installation/Operating Data,
Required Equipment and Limitations:

Jack End Fitting is to be manufactured in accordance with Acme Aerospace Ltd. Drawing P-400-03-31, Revision B, dated January 28, 2010 or later Transport Canada approved revision.

OEM p/n

Acme Aerospace Ltd. p/n

- End -


Conditions: The installation of the approved part is to be limited only to the type / model of aeronautical product(s) listed above

John Q. Rollins
For Minister of Transport

Canada wordmark


NAPA automatically assigns numbers for design approval documents.

The number assigned to a PDA is comprised of the following elements:

  1. An upper case “PDA”;

  2. Two numerical digits corresponding to the year of the approval date;

  3. A hyphen and sequential number, beginning with 1;

  4. The appropriate issue number, beginning with 1. (Non-numeric designations such as “N/C”, “IR”, or “no revision” are not acceptable).


Delegate-Issued Certificates

Delegates do not have authority to issue PDAs.


The following provides guidance with respect to the development of certificates. Aircraft Certification personnel will use the NAPA system to generate the appropriate approval certificates.

Sections of the Certificate Description
This approval is issued to: The name and address of the certificate holder as identified on the application form.
Number: As generated by the NAPA system.  Number will be unique and reflect the type of approval, year of issue, and the next available sequential number.
Issue No.: As generated by NAPA System.  Next sequential number updated each time the approval is re-issued.
Approval Date: The date that the original part design is approved.  The original approval date does not change when a certificate is revised.
Issue Date: The date of issue of the approval, which must be equivalent to, or later than the approval date.
Responsible Office: Atlantic, Quebec, Ontario, Prairie & Northern, Pacific or Headquarters, as applicable.
Aeronautical Product Type/Model: The specified type (or types), and model designations, as referenced on the applicable type certificates.
Canadian Type Certificate or Equivalent: Identify the Canadian TCDS or accepted foreign TCDS if a Canadian TCDS does not exist.
Replacement Part: The title of the part.  This should convey the intent/affect/nature of the part, not necessarily a marketing trade name.
Installation / Operating Data, Required Equipment and Limitations: To read:

Part must be manufactured in accordance with (name of document holder, master document list/document number, revision level), Transport Canada approved (date of approval). *

*The phrase “or later TCCA approved revision” may be included.
Certification Basis: Not required to be cited on the PDA certificate since the basis of certification is specified as that of the TCDS for the aeronautical product as determined by Subsection 521.158(2) of the CARs.
End of text: If continuation sheets are required, add the note ‘– See Continuation Sheet –’.
The end of the text should be  marked: – End –
Signature/Seal: The individual holding signing authority should include their name and signature on a sealed certificate, on behalf of the Minister of Transport.

TCCA Project Engineers should only use their names and not include professional designations or degrees held.


The following checklist will aid the quality control of the approval certificate issued:

PDA#: __________

Item Details Yes No N/A
1 Is the holder legal name listed correctly?
2 Is the issue number correct? (i.e. if the last issue was a 2, then this would be a 3).
3 Are the approval and issue dates correct?
E.g. For Issue 1, the Issue Date and Approval Date must match.
4 Are the aeronautical product types or models listed correctly?
5 Are the type certificates listed applicable to the models listed?
6 Is the title of the part appropriate?
7 Are the installation instructions listed accurately?
8 Are the fabrication or manufacturing instructions listed accurately?
9 Are the maintenance instructions listed accurately?
10 Are the dates of the documents listed on the certificates the same as the approval/acceptance dates on the actual referenced documents?
11 Has the certificate been signed?
12 Has the stamp been embossed?


{Office Address}
{City, Province, Postal Code}    

{Your file no.}


{Our file no.}
{Our file no. 2}

{Company Address}


This Part Design Approval (PDA) is issued in response to your application. Included with the PDA are the documents bearing the original Transport Canada signatures.

The transfer of this PDA {Approval No.} in the name of another person requires the prior approval from the Minister in accordance with Section 521.357 of the Canadian Aviation Regulations (CARs).

The requirements of Subpart 561 of the CARs apply where parts are manufactured and offered for sale. The provision of Section 571.13 of the CARs allow for the installation of a replacement part approved under a PDA.

A Canadian holder is required to fulfill the responsibilities of a Design Approval Document Holder in accordance with Subpart 521, Division VIII of the CARs, including the reporting of any service difficulties experienced with their product. Therefore, should you become aware of any defect, malfunction or failure resulting from the replacement part; it is your responsibility to submit a Service Difficulty Report to Transport Canada.

Yours truly,

Regional office responsible for Aircraft Certification


Transport Canada documents or intranet pages mentioned in this document are available upon request.

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