2-3 Pursuant to 14 CFR § 21.1(b)(6), “product” means an aircraft, aircraft engine, Note:
or propeller.
2.4 Deviation Definition.
A deviation is any alternative method used to meet performance criteria specified in the TSO. A deviation must have an equivalent level of safety (ELOS) determination instead of literal compliance with the TSO requirement (§ 21.618(a)).
When Do You Need a Deviation? 2.4.1 The FAA requires you, the applicant, to obtain FAA approval for any deviation from the applicable TSO, regardless of the significance of the TSO criteria from which you want to deviate. For example, the FAA requires you to obtain a deviation approval when you propose to use a more recent version of an industry standard than the one referenced in the specific TSO.
How Do You Obtain Deviation Approval from the FAA? 2.4.2 See paragraph 3.11 for detailed instructions. You must request a deviation from the appropriate ACO, and must show that compensating features or factors create an ELOS to the TSO performance requirement(s) from which you propose to deviate.
2.5 TSOA or LODA Are Not Mandatory.
TSOA and LODA are not mandatory. Per 14 CFR 21.8(b), TSOAs and LODAs are one way to get an article approved. You may also use the other provisions in § 21.8 to have your article approved.
2.6 TSO Markings.
The FAA does not allow anyone to mark an article stating it meets a specific TSO unless the FAA has issued them a TSOA or LODA. The article must be produced pursuant to part 21 subpart O or under the provisions of an agreement between the United States and another country or jurisdiction for the acceptance of products and articles.
A TSO marking on an article made under a TSOA or LODA means: 2.6.1
2.6.2 The article’s design meets the TSO standards for which it is marked. 2.6.2.1 The article was produced under an approved quality system and conforms 2.6.2.2 to the TSO-approved design.
A TSO marking on an article made under a TSOA or LODA does not mean: 2.6.3
2-4 The article’s design meets airworthiness regulations for the product. 2.6.3.1 The article is approved for installation on a product. 2.6.3.2
3-1 CHAPTER 3. TSOA AND LODA APPLICANT RESPONSIBILITIES
3.1 Certify That Your Article Complies With the Applicable TSO Standard.
As an applicant for a TSO authorization, you certify that the design of your article meets all the requirements of the applicable TSO.
If the TSO specifies a method for substantiation, you must use that method to 3.1.1 substantiate your article unless you propose other means of compliance (for example, analysis versus test). Use of a method other than the one specified in the TSO requires a deviation (refer to § 21.618).
All substantiation must be completed (pursuant to § 21.611) before submitting your 3.1.2 application for TSO Authorization unless otherwise agreed to by the responsible Aircraft Certification Office (ACO). You should coordinate with the FAA any potential issues with your article before submitting your application.
You are responsible for a process that documents how you conform to the requirements 3.1.3 of the current TSO, including the use of a compliance matrix or equivalent procedure to verify the conformance to the requirements of the TSO.
3.2 Compliance Matrix To help the FAA process applications more efficiently and effectively, an applicant 3.2.1 should submit a TSO compliance checklist or matrix. The checklist or matrix is simply a list of each TSO requirement and how the applicant has met the requirement (for example, by documentation, analysis, or test). The compliance matrix is not a regulatory requirement but it provides the ACO a standardized summary of how an applicant shows compliance to the applicable regulations.
Appendix B to this AC provides an example of a compliance matrix. If a compliance 3.2.2 matrix is not used, you must have an active system (pursuant to § 21.607, § 21.616) in place that:
Defines all the requirements needed to comply with each TSO and part 21, 3.2.2.1 subpart O requirement.
Ensures each requirement is met before you submit the letter of 3.2.2.2 conformance to the FAA.
Documents the substantiating data for compliance with each requirement. 3.2.2.3
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3.3 Control the Design and Quality of Your Article.
You must control both the design and the quality system (pursuant to § 21.607) for the production of the article. This includes controlling the design and quality of any items you receive from a supplier to the extent necessary to ensure the article meets the TSO.
To control the design of the article means you have the responsibility for the 3.3.1 development and the management of each component, features, and functions regardless of where that process takes place or with whom you have contracted.
Because the FAA issues the TSO authorization to you, we the FAA hold you responsible for ensuring the design met the TSO. This also means each design change to the article or any of its components, features, or functions must also be controlled by you to ensure that, after the change, the article still meets the TSO and all required documentation delivered with each article is updated accordingly (pursuant to § 21.619).
To control the quality of the article means you must build your article in accordance 3.3.2 with the approved design. You are responsible for controlling all your suppliers and all changes they implement in their production line for any part, process, or service they are providing you, as needed.
If you integrate a TSO article from a supplier into your TSO design, you must also 3.3.3 control the TSO article from the supplier to the extent necessary to ensure your article meets the TSO for which you have the authorization (pursuant to § 21.607 and § 21.137(c)).
You are responsible for notifying the FAA of design changes within the time period 3.3.4 agreed to by the ACO at the time of TSOA issuance.
3.4 Set Up and Maintain a Quality System (QS).
If you are a TSOA applicant, you must set up and maintain a QS that meets § 21.607.
Before we can issue a TSOA we must have evidence that you have a quality system pursuant to § 21.607 that meets § 21.137. AC 21-43A, Production Under 14 CFR Part 21, Subparts F, G, K, and O, provides guidance on the type and content of documentation you must submit to allow us to make a determination as to whether you have an acceptable QS.
3.5 TSOA Application Requirements.
You must submit a TSOA application to the ACO in your geographical area, pursuant 3.5.1 to § 21.603. If your facility has multiple locations, the principal manufacturing facility or the associate facility that controls the design and quality of the article(s) submits the TSO authorization application.
3-3 You must use the applicable TSO that is effective on the date of application for that 3.5.2 article, pursuant to § 21.603. Otherwise, you must ask for an exemption to § 21.603, as outlined in 14 CFR part 11.
Pursuant to § 21.601, your TSOA application must include a copy of the technical data 3.5.3 and other documents required by the TSO and QS. This may include:
The TSO number for which the authorization is requested; 3.5.3.1 The manufacturer’s name and physical address of the principal facility that 3.5.3.2 controls the design and quality of the article;
A statement from the manufacturer certifying that it meets the 3.5.3.3 requirements of part 21, subpart O, and the specific requirements of the applicable TSO;
A copy of the technical data required by the TSO; 3.5.3.4 A description of the applicant’s organization as required by § 21.605; and 3.5.3.5 A manual describing the applicant’s quality system that meets the 3.5.3.6 requirements of § 21.607 as required by § 21.608. Applicants who currently hold TSOAs must submit revisions to the existing quality manual as necessary.
Any Non-TSO Functions (NTF) data for which you seek acceptance. 3.5.3.7 The TSOA will be granted for a specific model and specific part number(s) that define 3.5.4 the article configuration. We suggest you include with your application a part numbering methodology pursuant to § 21.603(b) that uses open brackets to define minor changes. The part numbering methodology should include open brackets after the base part numbers to identify specific design configurations as minor changes occur. Refer to the example below for part numbers with open brackets. Refer to paragraph 4.4 of this AC for more information on design changes.
Example:
Initial Part number: 12345[ ] Part number with change 1: 12345[1] It is our experience that applications are processed more efficiently when an applicant 3.5.5 submits to the FAA a TSO compliance checklist or matrix (see Section 3.2 of this AC).
Discuss with the responsible ACO for an FAA recommended means for TSOA 3.5.6 applicant or holder to demonstrate that their organization has and will maintain the capabilities needed to conform to the requirements for each TSO for which they hold an approval.
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3.6 LODA Application Requirements.
You must submit a LODA application to the Civil Aviation Authority (CAA) for your 3.6.1 country. Your CAA must certify that the article has been examined, tested, and found to meet the applicable TSO or the applicable performance standards of the State of Design and any other performance standards the FAA may prescribe to provide an equivalent level of safety to the TSO. Once the CAA determines your LODA application meets all the above mentioned requirements, the authority must make a certifying statement to the FAA that it finds your article meets the TSO and other performance standards the FAA may prescribe (pursuant to § 21.621).
Prior to submitting a LODA application, you should consult the applicable Note:
bilateral agreement to determine if the FAA will issue a LODA to an applicant in your country, or if an alternative process exists.
You must use the applicable TSO that is effective on the date of application for that 3.6.2 article, pursuant to § 21.603. Otherwise, you must ask for an exemption to § 21.603, as outlined in 14 CFR Part 11.
Your LODA application must include (pursuant to § 21.621): 3.6.3 The TSO number for which the approval is requested; 3.6.3.1 The manufacturer’s name and physical address of the principal facility that 3.6.3.2 controls the design and quality of the article;
A statement of conformance from the CAA certifying it has determined 3.6.3.3 that the applicant’s article meets the FAA’s applicable TSO pursuant to § 21.621(a)(2)(i);
A copy of the technical data and other documents required by the TSO; 3.6.3.4 Any requested deviations from the TSO (refer to paragraph 3.11 of this 3.6.3.5 AC); and Any NTF data for which you seek acceptance, if specifically permitted by 3.6.3.6 the applicable bilateral agreement.
3.7 Use of Subject Matter Experts in the TSOA Process.
Any person who has the expertise to review TSO data can assist a TSO applicant in drafting its statement of conformance. However, only the applicant can make the statement of conformance.
3.8 Provide Installation Instructions and Limitations.
The TSO installation instructions provide information for proper integration or attachment of the article into the product. Installation instructions are typically
3-5 a step-by-step procedure for use by the installer to accomplish this goal. A TSO installation limitation is information that helps an installer determine the applicability (that is, eligibility) of the article to be installed in the product. The TSO installation limitations ensure that the article, when installed according to the installation instructions, continues to meet the requirements of the TSO MPS. Note that since the TSOA does not convey product installation approval, the TSO installation instructions and limitations do not convey what is required to have a compliant installation per the applicable airworthiness requirements of the product.
As an applicant for a TSOA, you must establish and provide installation instructions, 3.8.1 limitations, and maintenance instructions to the ACO and the installer (pursuant to § 21.50 and § 43.13).
You must provide enough detail in the installation limitations for the installer to 3.8.2 determine if the TSO article is compatible with the product and with all foreseen equipment and systems with which the article is intended to interface. For example, the limitations section for avionics TSO articles should clearly state the software and hardware design assurance levels as well as interoperable versions/revisions so the installer can determine compatibility of the TSO article with the product it is installed in (pursuant to § 21.50).
You may choose to limit the TSO article to interface only with specific components or 3.8.3 equipment once installed in the product. Identify and describe any unique aspects of the TSO article, including all NTFs and any incomplete TSO article instructions and limitations, in the limitations section.
If you do not demonstrate by lab or simulator testing and/or by analysis that the 3.8.4 TSO article will perform its intended function when installed, list additional testing requirements in the installation instructions or procedures. The additional testing requirements should allow the installer to demonstrate that the article is compatible with the equipment it interfaces with, and will continue to meet the requirements of the TSO after installation.
Typically the TSO also requires that installation instructions, limitations, and 3.8.5 maintenance instructions be furnished with each article that is shipped. Generally, if a group of articles is being shipped to one location, it is acceptable to make one set of the documentation available for the entire group of identical articles. This is an acceptable practice unless the recipient wants a copy of the documentation for each article.
You must include in your installation and limitations documentation (pursuant 3.8.6 to § 43.13(a)):
Basic instructions on how your article is intended to be installed in the 3.8.6.1 product;
Specific steps to be followed for the integration of the article into the 3.8.6.2 product;
3-6 Tests or inspections to help verify that the article is installed correctly; 3.8.6.3 All installation and additional requirements for the installation of your 3.8.6.4 article necessary to ensure that your article will continue to meet the MPS specified in the TSO once installed in a product; and Details of any deviations per para 3.11.7 of this AC, as applicable. 3.8.6.5 In cases where you know the configuration of the product into which your article will 3.8.7 be installed, identify the limitations that need specific attention. Although the installation of the article is not your responsibility, we encourage you to develop a thorough set of installation instructions and limitations to help ensure your article will be installed and operated in a manner that continues to meet the TSO and the anticipated airworthiness regulations.
3.9 Provide Maintenance Instructions for the Article.
Most TSO require you to develop and submit maintenance instructions for approval.
Instructions for Continued Airworthiness (ICA) are required for all products. You must submit TSO maintenance instructions that will allow the article to continue to meet the TSO requirements after it is installed (for the product to comply with § 43.13(a)).
These are not necessarily the same requirements for the product, but your instructions can be used by the type certificate (TC)/supplemental type certificate (STC) applicant as the basis for them to meet their responsibilities for ICA at the product level. You should submit the TSO maintenance instructions to the ACO with the TSO application package. Include in your maintenance and limitation instructions, as appropriate:
Inspection intervals; 3.9.1 Inspection procedures; 3.9.2 Recommended service life; 3.9.3 Wear limits; 3.9.4 Cleaning instructions; 3.9.5 Basic maintenance instructions; 3.9.6 Calibration information; 3.9.7 Information on any special tools required; 3.9.8 Acceptable repairs and repair procedures; and 3.9.9 Any other information necessary to maintain compliance with the TSO while in service. 3.9.10
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3.10 Submit Open Problem Reports (OPR).
If your TSOA article provides software or Airborne Electronic Hardware (AEH) functionality, you must submit a summary to the ACO of software or airborne electronic hardware problems (or potential problems) that have been identified, but not yet resolved. OPR with a potential safety effect, or which result in noncompliance with the TSO, must be corrected before approval. You should provide an OPR summary with functional impacts to applicants for installation approval of the article:
A sufficient description should be provided for proper assessment; 3.10.1 Any OPRs with potential safety impact should be corrected; 3.10.2 OPR information should be provided in the installation manual or supplemental data; 3.10.3 There should be a means for updating OPR summary if necessary; 3.10.4 The TSOA holder should provide contact information in case installer needs more 3.10.5 information;
The TSOA holder should have a means to accept problems reported from the field. 3.10.6 Note 1: This may require the ACO to review your process for classifying OPR or confirm the ACO agrees with each OPR classification.
Note 2: You must have a means for transmitting the summary of OPR to the installation approval holder and facilitate updates in case additional OPR are discovered after the TSOA is issued. You must have a means of entering problems reported from the installation approval holders and operators into a problem reporting system for tracking and disposition, and for providing OPR support to the installation approval holder.
3.11 Requesting Approval to Deviate From a TSO (§ 21.618).
A deviation may be granted by the FAA if the applicant demonstrates that factors or 3.11.1 design features provide an equivalent level of safety (ELOS) to compensate for the requirement from which a deviation is requested. A deviation request is specific to the article approval and must be re-submitted for new TSOA or LODA applications. For example, the FAA might approve a deviation to your TSOA for one particular article.
You cannot use that same deviation approval for another TSOA application without requesting another deviation from the MPS.
As an applicant for a TSOA, if you want to deviate from the TSO you must submit a 3.11.2 deviation request to the ACO regardless of the significance of the TSO requirement from which you want to deviate. For example, we require applicants to receive a deviation approval when they propose to use a version of an industry standard later than the one referenced in the specific TSO.
3-8 To receive our approval for a deviation, you must show that compensating features or 3.11.3 factors provide an equivalent level of safety (ELOS) to the TSO performance requirement(s) from which you propose to deviate.
We evaluate your deviation request, and approve the deviation if an ELOS can be 3.11.4 assured. The deviation approval may identify limitations for the approval, which you should consider when making subsequent design changes to ensure the limits continue to be met.
We encourage you to discuss and coordinate the deviation proposal with 3.11.4.1 the ACO before you submit your official deviation request. Discuss the application with your ACO to ensure you do not perform testing or analysis that we may not approve as a sufficient means to substantiate the ELOS. These discussions usually help establish agreement on whether your proposal establishes an ELOS and can save you significant time and resources. Do not consider discussions to be binding. We will evaluate your official deviation request once we receive it and we will respond in writing.
If you are applying for a LODA, we encourage you to have an unofficial 3.11.4.2 dialogue with the CAA. The CAA can coordinate with the FAA to ensure you do not perform testing or analysis that we may not approve as adequate for substantiating the ELOS. These discussions usually help establish agreement on whether your proposal establishes an ELOS and can save you significant time and resources. Do not consider discussions to be binding. We will evaluate the official deviation request once we receive it.
Substantiating the ELOS. 3.11.5 Ensure your deviation request includes substantiating data that specifically covers the compensating factors or features. The proposed TSO deviation must clearly establish an ELOS to the TSO.
Marking the Article for Approved Deviations (pursuant to § 21.618). 3.11.6 When granted a deviation for your article, you must mark the article in accordance with the instructions in the ACO letter that granted the deviation.
Documenting Details of an Approved Deviation. 3.11.7 When you are granted a deviation you must list the specific details of the deviation in your installation manual. This is necessary to alert installers to evaluate the article installation or operational limitations affected by the deviations. Describe the details of all deviations and document all known impacts to performance and functionality resulting from a deviation.
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3.12 Roles of the FAA and Applicant.
We coordinate between the ACO and the Manufacturing Inspection District Office (MIDO) to help you, the applicant, produce TSO articles according to the approved design. Approving a TSOA application requires the ACO to approve the design and the MIDO or Manufacturing Inspection Satellite Office (MISO) to approve the production system. A LODA is an FAA design approval only. Approving a LODA application requires the ACO to approve the design of the foreign-manufactured articles. The applicable CAA issues the corresponding production approval and oversees the production system. Figure 3-1 details the basic roles of the FAA and applicant in the TSO process.
3-10 Figure 3-1. Basic Roles of the FAA and Applicant in the TSO Process * Applicant AIR-100 ACO MIDO Control the design and quality of the article Show compliance with applicable TSO standard Set up and maintain a QS that meets § 21.607 or is in accordance with bilateral agreement Provide a statement of conformance to the applicable TSO(s) Request approval to deviate from TSO Establish and provide installation instructions, operational limitations, OPR summary, and maintenance instructions Provide maintenance instructions and installation limitations to each person who receives articles, to ensure the article continues to meet the MPS of the TSO after installation Mark each article according to § 45.15(b) and as specified in each applicable TSO Report service difficulties pursuant to § 21.3 Submit TSOA’s minor changes to the ACO Submit to the FAA document describing how its organization will ensure compliance Develop PSP with ACO as applicable Administer TSO program policy Develop and issue new TSO Determine when TSO require revisions Cancel obsolete TSO Determine if all TSOA for a particular TSO must be withdrawn, and publish intentions of withdrawal in the Federal Register before the withdrawal. If it is determined necessary, the process defined in the appropriate paragraph of Order 8150.1 will be followed Grant/deny deviation requests not delegated to the ACO Maintain records for TSO, including canceled TSO Process TSOA applications and LODA applications from a CAA, if applicable Recommend approval or denial of deviations to the TSO to AIR-100 Grant/deny deviations that Order 8150-1D or a specific TSO has delegated to the ACO Coordinate with MIDO (TSOA) or follow the procedures defined in the bilateral agreement (LODA) before issuing TSOA/LODA letters.
Witness various functions if deemed necessary (refer to § 21.610) Find that the article design complies with the applicable TSO Send applicant TSOA, LODA, or denial letter Investigate reports of service difficulties and noncompliance Submit enforcement reports when holders do not comply with part 21, subpart O As applicable, work with applicants to develop Partnership for Safety Plans (PSP)
Verify production system produces articles that conform to the approved design Approve the quality system Issue TSOA article production approval letter to ACO Conduct surveillance at the TSOA holder’s and supplier’s facilities, both domestic and foreign, if appropriate.
Investigate service difficulty reports and nonconformities.
Submit enforcement reports when holders do not comply with part 21, subpart O
* Refer to applicable TSO and part 21, subpart O, for further details.