MARPA recently filed comments on the FAA Engine and Propeller Directorate’s draft Advisory Circular 33-Geometry, discussing geometry and dimensional considerations for comparative test and analysis for turbine engine and APU replacement parts. In a previous blog post we observed that AC identified a number dimensional and geometric factors that the FAA expects to be assessed in ensuring the integrity of dimensional characteristics for the purposes of showing similarity.
We requested feedback from our members describing to what extent the FAA’s expectations were reasonable and practicable, and identifying any issues with the proposed guidance on which MARPA should comment. We received several very helpful responses from our members that helped us shape our comments to the proposed AC. Among the issues members identified were:
Feedback from our members is both helpful and valuable to our comments, as it helps us to identify issues that directly affect members’ businesses, and helps us to better focus our resources on those matters that are important to the PMA community. The result is more detailed and on-point responses to the FAA to better help shape the guidance material that will ultimately be issued.
We greatly appreciate the feedback we received from our members on this Advisory Circular, and we hope that our members will continue to answers our requests for responses as additional guidance and rulemaking documents are issued. Together we can work with the FAA to develop the best possible guidance for our industry.
The FAA is currently seeking comments on its Draft Advisory Circular Engine Overtorque Test, Calibration Test, Endurance Test, and Teardown Inspection for Turbine Engine Certification (§§ 33.84, 33.85, 33.87, 33.93).
As the title suggests, the AC offers guidance on compliance with the engine overtorque, calibration, and endurance tests, and teardown inspection called out in Part 33 of the Federal Aviation Regulations. Although the guidance is directed at engine manufacturers, foreign regulatory authorities, applicants for engine type design approval, and FAA designees, it also notes that parts manufacturer approvals “may require running certain endurance testing for compliance with § 33.87″ and refers to AC 33.87-2 for guidance on showing compliance by comparative test methods.
MARPA would like to know to what extent members anticipate this AC might effect them, and whether we should submit comments. If you plan on submitting comments, or have already done so, we would would like your feedback so that we can incorporate member concerns into our comments.
Comments on the Draft AC are due next week, so if you have feedback for us please submit them to email@example.com soon!
Today, the FAA announced the issue of AC 21.3o3-4. The title of this AC will be “Application for Parts Manufacturer Approval Via Tests and Computations or Identicality.”
As of this time, the AC is not yet available to the public. When it is available to the public, it is expected to be posted online at this location:
Note: the issue date published on the FAA’s website is March 21, 2014; however the AC is not yet available through the FAA’s online advisory circulars, nor through the Regulatory and Guidance Library (RGL). The note on the FAA’s website states “This document‘s content is not currently available.”
The FAA Engine and Propeller Directorate has issued a new draft Advisory Circular that could have a significant effect on companies seeking PMAs, STCs, or approval of repair or alteration of turbine engine and APU parts. Draft AC 33-Geometry: Geometry and Dimensional Considerations for Comparative Test and Analysis for Turbine Engine and Auxiliary Power Unit (APU) Replacement, Redesign, and Repaired Parts is directed at applicants who use comparative techniques to reproduce dimensional characteristics of parts during the reverse engineering process.
The AC is intended to provide guidance to help PMA (and other) applicants assess their reverse engineering methods to identify possible causes of dimensional inaccuracies, as well as helping applicants develop adequate criteria for determining dimensional similarity between the PMA design and the sample. To that end, the draft AC identifies several dimensional and geometric factors that the FAA expects should be assessed in seeking to ensure the integrity of dimensional characteristics for the purposes of showing similarity. These factors range from geometric relationships to precision and accuracy to influence on critical parts.
The background section of the draft AC states that because reverse engineering methods vary in their measurement techniques, interpretation and combination of data, and in dimensioning systems, they do not typically produce a design with the exact same dimensional properties as the type design part. It further explains that because dimensional differences may exist, functional assessments–which may include both test and supplemental analytical data–will be necessary to safeguard type design functional properties, as well as capabilities of interfacing and higher level assemblies. Such explanations help to illuminate the FAA’s expectations of an applicant in making showings of dimensional similarity. MARPA would like feedback from our members describing to what extent such test data is currently available and practical within the industry.
Although this AC, like all Advisory Circulars, is neither mandatory nor regulatory, such guidance documents do sometimes become ingrained and relied upon in considering applications. It is therefore important to review the draft and offer comments to the FAA to ensure the guidance reflects the realities of our industry. MARPA will be closely reviewing the guidance and offering comments on behalf of the PMA community. If you identify any particular issues within the guidance, please bring them to our attention so we can incorporate them into our comments. Email your concerns to firstname.lastname@example.org. We also recommend that members who identify concerns file their own comments on the guidance. Comments are due July 3, 2014 and should be submitted to Mark Bouyer of the Engine and Propeller Directorate, at email@example.com
In recent weeks the FAA has released final versions of two important pieces of guidance. FAA Order 8110.42D – Parts Manufacturer Approval Procedures, which cancels revision C, was published on April 10, and FAA AC 21.303-2 – Application For Parts Manufacturer Approval Via Tests and Computations Or Identicality, was published on April 7. Both of these documents have a direct effect on PMA producers.
MARPA submitted comments addressing issues in these guidance documents in September, 2013. Among the issues MARPA noted was the intended use in Order 8110.42D of the FAA’s Risk Based Resource Targeting Tool (RBRT tool) to prioritize PMA projects. MARPA observed that the RBRT tool as intended relied on subjective assessments of project risk that could result in unfair treatment of certain PMA projects. The FAA agreed that the RBRT tool was not quite ready for prime time and has removed it from the Order. MARPA will remain vigilant, however, as guidance for use of the RBRT tool will be addressed in a future Order.
MARPA also worked with its members to offer comments and feedback to the FAA regarding AC 21.303-2. This new AC consists primarily of guidance to PMA applicants that formerly appeared in the now-cancelled Order 8110.42C. MARPA offered comments addressing the expected sample sizes needed for PMA applications based on test and computation, origins of samples, and discretion for establishing sample sizes. The FAA’s adoption of these comments should better help square the advisory guidance with the realities of industry sampling.
MARPA also commented that references to Order 8110.119 - Streamline Process for Parts Manufacturer Approval (PMA) should be included in both documents to encourage use of the Streamlined PMA process when applicable. We are pleased that the FAA agreed and adopted references to the Order in both guidance documents. We are hopeful that the inclusion of references to Order 8110.119 in both Order 8110.42D and AC 21.303-2 will further promote ACO acceptance and PMA applicant use of the Streamlined PMA process.
Both of these guidance documents are now active. Members should familiarize themselves with the guidance, as it will inform the nature of the application process and the relationship with the FAA and your ACOs. In reviewing the two documents, if you notice anything troubling or that seems out of place, please bring it to our attention so that we can work with the FAA to find a solution. Send your thoughts on Order 8110.42 revision D and AC 21.303-2 to firstname.lastname@example.org.
In January, we wrote in this space about two new FAA Policy Statement proposals aimed at increasing coordination between FAA offices in the cases of certain engine PMA and propeller PMA applications. MARPA is always on the lookout for those potential regulations and policies–whether large or small–that could effect our members. In an effort to best support the industry, MARPA solicits feedback from members and files comments addressing the concerns of the PMA community with the FAA. MARPA also works to support the FAA in order to provide industry’s perspective and needs in order to help develop the best rules, policy, and guidance possible.
Last week we filed comments on draft policy statements PS-ANE-33.3-05 and PS-ANE-35.15-02. These two statements were substantially similar in content, and therefore raised similar concerns. The policy statements are intended to create a uniform policy describing the engine and propeller PMA projects for which an ACO is required to use the national certification project notification (CPN) database to alert the Certification Management ACO (CMACO) and Engine and Propeller Directorate (EPD) about the project. The purpose is to enable the CMACO and EPD to provide relevant input when the PMA application is for a project the failure of which may result in a loss of thrust or power.
MARPA noted several possible issues with the proposed Policy Statements. First, our comments noted that the policy as proposed could run the risk of burdening PMA applicants by delaying response time, as each FAA office took the opportunity to review the project. MARPA also noted the risk that differences of opinion between offices could be hashed out using an individual PMA application as the mechanism. This could also result in undue burden to the applicant. Finally, MARPA noted that inquiries by FAA offices about certain PMA projects could inadvertently alert TC holders of possible competition in a particular part market, and give that TC holder the opportunity to lock up the market before the PMA package is ever approved; a clear unfair competitive advantage.
Finally, MARPA noted that a certain provision uniquely included in PS-ANE-33.3-05 (the engine-PMA Policy Statement) was needlessly critical of PMAs and potentially harmful to the PMA industry. The sentence in question reads “[f]ailure of some of these engine PMA parts has resulted in unsafe conditions and the issuance of airworthiness directives.” MARPA explained that this sentence was inappropriate for two reasons. First, it incorrectly implies that PMA parts are abnormally unsafe and that TC products do not have a history of resulting in ADs. Second, the sentence in no way advances the purpose of the Policy Statement, which is to establish uniform standards for use of the CPN database. For these reasons, MARPA recommended the deletion of the sentence.
MARPA will continue to work for its members to advise and cooperate with the FAA in crafting fair and effective policy. Members comments on these issues are always welcome.
You can read MARPA’s comments in their entirety on the MARPA website under the Government Affairs tab at http://www.pmaparts.org/government/.
The FAA has issued two new PMA guidance documents for comment. One of these is a document affecting engine PMA applications (PS-ANE-33.3-05) and the other is a document affecting propeller PMA applications (PS-ANE-35.15-02). Each of them would require additional internal FAA coordination for certain engine and propeller PMA projects.
Under the new policy, when an Aircraft Certification Office (ACO) accepts an application for a PMA for an engine part or a propeller part, where a failure of that part could result in the total loss of thrust or power, the ACO is required to coordinate the project with the office that manages the type certificate and the Engine and Propeller Directorate. Coordination is accomplished by entering the project into the national certification project notification (CPN) database.
While better management of coordination should be a good thing, the reason for such coordination is to obtain more input from the other offices. There are two possible concerns associated with that additional input that should be addressed but that are not raised in this guidance: (1) decreased FAA efficiency in turning projects, and (2) increased potential for release of sensitive business data.
The guidance asserts that the CPN process should not add burden to the PMA applicant. This does not consider, however, whether the process may add additional lag time in processing the PMA applications. If the certificate management office and the Directorate request additional time to study the project and add their comments, then this could slow down the turn-around-time for reviewing packages. We have been made aware of instances where local offices disagreed with a directorate about a technical matter, and the PMA applicant was the real victim, as the two FAA offices brought the application to a stand-still while they hashed out their differences.
In addition, PMA applications are often considered to reflect sensitive company data, because they reveal the company’s business plan. If a certificate management office starts asking questions about a part, even without revealing which company has filed the PMA application, it could still alert a type certificate holder to the potential for competition and the type certificate holder may take action to protect their market in that part before the PMA part is approved (which would be unfair).
But one positive aspect of such coordination is that the certificate management office or the Directorate may have useful information not readily available elsewhere. For example, they may have service information that helps to show where the original type certificated part was not performing as expected. This information could give the PMA applicant an opportunity to improve the part so that it meets customer expectations.
The FAA has opened these two policies up for comment through March. MARPA members who want MARPA to comment on either of these draft policies should let us know by the end of February.
For years, PMA parts were a uniquely American product. But recent European events may suggest that others will be following our lead. BAE has been focused on obtaining design approval and production approval to create approved independent replacement parts under the European system.
On January 22, Graham Smith and Phil Beard explained how BAE has been obtaining replacement parts approval user EASA standards. They explained that BAE has been able to get European approvals that are very similar to US PMA approvals.
As with FAA PMA, they start with a significant review of a part in order to determine whether it is feasible to reverse engineer and produce the part. They perform a full reverse engineering operation. They develop their own engineering drawings. Like most modern PMA companies, they take special pains to avoid using OEM data to support their analysis in order to make sure tat they are avoiding misuse of someone else’s intellectual property.
Beard feels that the substantiation of these engineering documents is a little different from the U.S. process. He explained that EASA does not allow BAE to use identicality. Instead they must use positive substantiation of compliance with the airworthiness standards. He said that this generally comes from analysis, understanding of the part’s function, and testing.
As with test and computation PMAs in the US, the substantiation process that BAE uses permits them to fully understand the part, which in turn permits them to remedy reliability problems with the original design or make other improvements desired by the customer. Beard offered an example during his discussion; he commented that if service history has shown evidence of unexpected corrosion, then BAE might change the coating in order to better protect against corrosion.
BAE has made good use of its Design Organisation Approval (DOA) system, which allows BAE to operate under a government-controlled system in order to make findings of compliance up which the government can rely (similar to the ODA system in the United States). Smith and Beard affirmed that this system has been invaluable to their parts approval efforts.
BAE’s initial efforts appear to be largely focused on parts for Regional Jet Aircraft; but they are approved and willing to undertake work on all fixed-wing aircraft types. This an exciting development for international trade in civil aircraft parts.
Last week MARPA filed comments with the FAA in response to two policy documents that directly affect PMA manufacturers. As we previously explained on this blog, both of these documents speak directly to the PMA approval process.
Draft revision D to FAA Order 8110.42 Parts Manufacturer Approval Procedures. Two notable changes made in the revision was the removal of guidance to PMA applicants (released as a stand-alone document as draft AC 21.303-PMA) and the inclusion of a section directing ACOs to apply the FAA Risk Based Resource Targeting (RBRT) tool. It also made certain technical changes to the Order to update citations and keep up with rule changes.
MARPA observed that the inclusion of RBRT in the Order creates the risk of unequal treatment across—or even within—different offices. This is because the RBRT tool attempts to create the appearance of objectivity by assigning numerical values to what are essentially subjective evaluations by FAA personnel. Because the tool offers no metric, rubric, or guidance to aid FAA personnel in assigning values, it is possible for even identical projects to be assigned different risk values based on the subjective assessments of personnel. The ultimate result is that highly similar projects could be allocated markedly different resources.
Draft Advisory Circular 21.303-PMA updates the FAA guidance to applicants for PMA of articles submitted on the basis of test and computation or identicality without a license agreement. This guidance is for the most part a recast of the guidance that formerly appeared in Order 8110.42C. MARPA offered suggestions for improving the guidance related to sample sizes required for test and computation analysis, as well as general comments seeking to clarify the guidance.
In both documents, MARPA commented that the FAA should include a section describing use of the Streamlined PMA application process.
We plan to meet with representatives from the FAA in person to further discuss these comments. FAA personnel will also be at the MARPA Conference in Las Vegas, October 23-25, and available to discuss PMA guidance and other initiatives. MARPA will continue to work with the FAA to ensure that the guidance enhances safety while limiting burden to our members and the industry.
We previously wrote in this space that MARPA will be attending the 2013 Aerospace Industry Exhibition Tokyo (ASET). As a benefit to our members, MARPA plans to feature member-company literature in our booth to allow you to make connections with the Japanese aerospace manufacturing market. This is just one of the benefits of MARPA membership. ASET offers an excellent opportunity get in front of a substantial segment of the Japanese aerospace manufacturing community; at the last conference over 23,000 people attended!
In order to help us feature member companies in the MARPA booth, members must ship their literature to us in Tokyo. To ensure we are able to showcase your literature, you must follow these steps:
1. Act quickly! ASET runs October 2-4. You should plan to have your literature arrive absolutely no later than Monday, September 23. This will allow adequate time to ensure your package clears customs.
2. Ship your package to:MARPA (Booth No. G-01) c/o AEROSPACE INDUSTRY EXHIBITION TOKYO 2013 2013 Management office Tokyo Big Site 3-11-1 Ariake, Koto-ku, Tokyo 135-0063, Japan
3. Email Katt Brigham at MARPA with your package tracking information. This should include the date the package was shipped and the estimated date of arrival. You should also include the contents of your package so we know what to look for.
4. Confirm your package arrives in Tokyo. When you have confirmed arrival email Katt to let us know as well.
Remember it will take about a week for your shipment to clear customs upon arrival in Japan. It is therefore vital that you ship your literature in time to ensure arrival by September 23.
MARPA is excited to be able to offer this opportunity to its members. If you have any questions about shipping, please contact Katt at (202) 628-6777 or by email at email@example.com.