Those who attended MARPA’s inaugural European conference last month in Istanbul were treated to an excellent presentation by Delta Air Lines Manager of Component Engineering and MARPA Air Carrier Committee Chairman Mike Rennick on the impressive reliability benefits of PMA parts in Delta’s fleet.
As many know, Delta operates a very diverse fleet of aircraft, which are on average older aircraft than many other carriers’ fleets. Yet Delta also operates one of the most reliable mainline fleets in the world. In 2014, Delta had an impressive 169 maintenance cancellation free days; a metric that has improved each of the last three years. Mr. Rennick pointed out that one of the important contributing factors to this success was the widespread use of PMA parts.
MARPA and its members frequently tout the many benefits PMA provide to operators. Operators are generally aware of the lower prices offered by PMA parts. They are also aware that PMA parts may be their only option, or one of very few options, for replacement parts for legacy aircraft. However, operators may not be aware of the significant reliability benefits that PMA parts also provide.
Mr. Rennick explained that in order to maintain its fleet to the level it requires Delta wants options. Service experience has demonstrated that PMA parts match, and in some cases exceed, the performance of OEM parts. Based on this experience Delta has found PMA parts to be acceptable for use throughout the aircraft, components, and engines.
Mr. Rennick’s presentation included exciting metrics showing an upward trend in Mean Time Between Unscheduled Removals (MTBUR) and Mean Time Between Failures (MTBF) on certain applications in which Delta had utilized a PMA solution. Metrics like these indicate the great value proposition that PMA’s can offer air carriers; not only from a purchase price standpoint, but importantly, from a reliability standpoint. These metrics, along with shortened lead times, are part of the greater holistic value proposition offered by PMA parts and something we should remember to emphasize when talking to potential customers.
Mr. Rennick also stated that because of Delta’s close cooperation with its vendors it is able to address issues more quickly than might otherwise be possible.
Delta’s comfort level born of experience with PMA parts has led to the carrier using PMAs in even very critical applications, including engine gas path and rotating parts, life limited parts, and power generation.
The emphasis on the reliability of PMA parts is one that we, as an industry, should be sure to promote to our customers. Cost savings means more than just lower prices (an obvious benefit of PMA!) Keeping aircraft safely and reliably operating without unscheduled removals and increasing time between failures generates cost savings for operators by allowing them to get planes turned quickly and keeping their passengers happy. MARPA always makes it a point to emphasize the reliability benefits of PMA wherever we go.
If you were unable to join us in Istanbul you will still have a chance to see this great presentation on the reliability benefits of PMA parts. We anticipate Mr. Rennick giving a similar presentation at the 2015 MARPA Annual Conference. This will be a great opportunity for PMA manufacturers to hear directly from Delta on the air carrier’s take on PMA parts, and an excellent opportunity for operators to see how one carrier is making PMA parts an important element of their maintenance program success. Register today to take advantage of Early Bird rates!
Do you want to serve on a FAA working group that will help the FAA shape regulations affecting safety? Do you have expertise in composite and other nonmetallic airframe materials? Can you add to a discussion about airframe crashworthiness?
The FAA has asked the Aviation Rulemaking Advisory Committee (ARAC) to provide recommendations regarding airframe-level crashworthiness and ditching standards that would be incorporated into the FAA’s regulations. TYhe group would also prepare advisory materials.
During the development of current airworthiness standards and regulatory guidance, the FAA assumed that airframe structure for transport airplanes would be constructed predominantly of metal, using skin-stringer-frame architecture. Therefore, current regulatory requirements either do not address all of the issues associated with nonmetallic materials, or have criteria that are based on experience with traditionally-configured large metallic airplanes.
With respect to crashworthiness, there is no airframe-level standard for crashworthiness. Many of the factors that influence airframe performance under crash conditions on terrain also influence airframe performance under ditching conditions. Past studies and investigations have included recommendations for review of certain regulatory requirements and guidance material to identify opportunities for improving survivability during a ditching event; consideration of these recommendations is included in this tasking.
You can find a full discussion of the working group’s task, online.
If you wish to become a member of the Transport Airplane Crashworthiness and Ditching Working Group, you can express that desire by contacting:
Federal Aviation Administration
1601 Lind Avenue SW.
Renton, WA 98055,
phone number 425-227-2145
facsimile number 425-227-1232
Please describe your interest in the task and state the expertise you would bring to the working group. The FAA must receive all requests by July 6, 2015. The ARAC and the FAA will review the requests and advise you whether or not your request is approved. For MARPA members, if you would like MARPA’s endorsement for such a position, please contact us before the deadline.
Do you rely on a Designated Engineering Representative (DER) to approve data for your business? Do you use DMIRs for issuing 8130-3 tags? If you do, then you know how critical designees can be to the parts approval process. Often, though, designees are required by the FAA to do things that the FAA employees themselves are not permitted to do, like require paperwork that is not required by law or regulation (this can be a violation of the Paperwork Reduction Act), or impose standards of conduct that are not required by law or regulation (this can be a violation of the Administrative Procedures Act). When this happens, the designee has no choice but to obey the instructions from the FAA-Advisor … even if they would be illegal if undertaken by the FAA’s employees.
Want to make sure that designees are not used to do things that FAA employees can’t do (by law)? The be sure to take the time to offer comments to the FAA Designee Management Policy that is now out for comment. The FAA has issued for public comment a draft change to the guidance document affecting designees. Although only parts are changed, it is a potential opportunity to comment on the entire document.
The original guidance is called “Order 8000.95, Designee Management Policy.” It was first issued in April of 2014.
This guidance document provides a wide variety of guidance on how to manage FAA designees. It has not and does not appear to cancel FAA Order 8100.8 (Designee Management Handbook), although some of the guidance appears to address some of the same issues as that guidance (failure to cancel 8100.8 might have been an oversight).
As a practical matter, designees (who are the people most directly affected by this guidance) will not be able to write comments that are critical to this guidance. This is because designees can be terminated for cause or without cause, at the discretion of the FAA. So the FAA can terminate a designee for exercising his or her First Amendment freedoms (as long as they come up with any other pretext for the action, including a termination ‘not for cause’). Designees are well aware of this and they regularly self-censor their comments because of the chilling effect that the FAA’s discretionary termination power has had. In some cases, designees have contacted me because they know that I will protect their anonymity.
The real-world issue us that designees rely on their designation from the FAA to ply their trade. If they are terminated (for-cause or not-for-cause) then they cannot simply be a designee for someone else. They need to choose a entirely different career path. So the process for reviewing designee termination is very important. And both the current policy and the draft policy are woefully inadequate, because they offer no standards for review, so the FAA employees are able to rubber stamp any termination decision on review. Honest review depends 100% on the personal integrity of the reviewing personnel – and there is no formal training for the employees who act as reviewers in that process (by comparison, state court judges typically attend judicial training).
The FAA’s failure to have effective standards actually undermines the FAA’s own interests. One example arises in the context of designee termination. The lack of effective standards means that individual FAA employees can cause the termination of a designee for any reason, including a reason that would have been considered to be illegal if it was used to terminate an employee, as long as the party who initiates the termination offers a pretextual reason. There is no formal inquiry into such pretext – it is taken at face value – and the VERY short time period for presenting a defense means that it is tough to be effective in assembling a defense: the full appeal including all supporting evidence must be submitted within 15 days – while the designee is given the charges, he or she has no opportunity to review the FAA’s underlying evidence. In comparison, the appeals panel has 45 days to consider the appeal and then another 15 days to notify the designee of their decision for a total of 60 days. We have seen evidence that FAA inspectors will use this period to gather more evidence to refute the defense and bolster the ‘prosecution’ so clearly the FAA is not bound to any sort of deadline for presenting its own case.
There is plenty that could be improved in the designee management process.
This is a great opportunity to help the FAA to better manage the designee community using effective processes that ensure fairness for everyone. MARPA members should strongly consider reviewing and commenting on this draft guidance.
Comments are dues to the FAA by January 7. Please send comments to MARPA, as well, so we can sure that our comments reflect your concerns.
|How to Comment:||Deliver comments by mail or hand to:
1625 K Street NW
Washington DC, 20006Email comments to: Susan.email@example.com
Email CommentsFax comments to:
(202) 223-4615, Attn: Susan Hill
My comment on the cancellation of FAA Order 8100.8 failed to take into account FAA Notice 8000.372. That Notice directs all AIR manufacturing personnel who oversee designees to stop using Order 8100.8 and being using 8000.95 on a schedule. The schedule reflects the implementation of the Designee Management System (DMS) in those offices.
Under that schedule, all MIDOs with designee management responsibilities should have transitioned to Order 8000.95 during the summer (of 2014). So Order 8000.95 will have supplanted 8100.8 for MIDOS (but not necessarily for ACOs and FSDOs). This means that DMIRs and DAR-Fs have transitioned. But DERs should still be under 8100.8 until they are formally transitioned (at which time they will fall under the instructions of 8000.95).
Special thanks to William Denihan for pointing this out!
We previously wrote in this space about a new Draft Policy Statement issued by the FAA concerning the vibration surveys and engine surveys required under section 33.83 of the Federal Aviation Regulations. The draft guidance attempts to more narrowly address the FAA’s concerns about full engine test for type certificate applicants.
MARPA plans to provide comments on this Draft Policy Statement to the FAA and has sent a draft of our comments to the MARPA Technical Committee for review. If any of our members wish to review our draft comments to provide their feedback we would love to hear from you. Please email Ryan Aggergaard at firstname.lastname@example.org if there are particular issues in the draft statement you believe should be addressed so that we can incorporate our members’ concerns.
MARPA also encourages our members to file their own comments on the Draft Policy Statement. Comments are due to the FAA by November 21, 2014. Comments should be emailed to Dorina Mihail at email@example.com. Comments can also be mailed to her at:
Federal Aviation Administration
Engine and Propeller Directorate
Standards Staff, ANW-111
12 New England Executive Park
Burlington, MA 01803
MARPA looks forward to your comments.
The FAA has released two new advisory circulars that may affect the PMA community. Both advisory circulars are issued by the Transport Aircraft Directorate and apply to Part 25 aircraft (and parts thereof).
We would be interested in hearing from any MARPA member who is affected by one of these new advisory circulars.
The FAA has issued a new advisory circular for statistical analysis. This AC only applies to engine and APU parts.
The new advisory circular uses statistical analysis to arrive at correct sample sizes. This sample size formula is introduced for persons who are trying to correlate two populations of parts. MARPA had pointed out to the FAA that typically a PMA applicant does not correlate two different populations of parts – instead they derive the reasonable tolerances on one population of parts, and then design and produce within those tolerances. The FAA would like PMA applicants to arrive at their appropriate sample size, test the parts being reverse-engineered, and then produce an equivalent number of pre-PMA parts to test for the same properties (and then correlate the two populations). This is contrary to current FAA regulatory guidance, which requires the design to be approved and the requires the production quality system to ensure that parts are all produced within the approved design parameters. In essence, ACO engineers will now take control of the quality assurance system through the design process.
One of the problems with the AC is that it relied on statistical analysis for clinical trial sample size as the basis for assessing statistical analysis of reverse-engineering sample size. Clinical trials for pharmaceuticals typically rely on populations of hundreds or even thousands of people. Trying to test hundreds or thousands of parts in order to reverse-engineer them is simply not realistic. Furthermore, the degree of part-to-part difference under modern quality assurance systems does not support such large sample sizes.
For those cases where the equations in the advisory circular give a lower number for the appropriate sample size, the FAA has also established minimum sample sizes. The AC sets some minimum limits for the number of parts that must be tested in order to derive certain values (remember that you need that number of PC parts and also that number of reverse-engineered parts to meet the AC’s requirements):
Minimum Number of Parts to be Sampled
- For basic material properties that are more dependent on alloy constituency than on part manufacture process – 10 approved parts from three separate lots with at least three parts per lot
- For properties affected by how the material is processed during part manufacture such as high-cycle fatigue, low-cycle fatigue, creep, tensile strength, crack growth, etc. – 30 approved parts
- For fatigue testing – at least 25 tested parts that are run until they crack
- For parts exhibiting complex geometry or complex manufacturing variables, additional specimens may be required
- For parts considered to have a high degree of criticality, greater sample sizes may be required
No statistical basis is offered for these minimum sample sizes.
The new advisory circular provides guidance for statistical analysis of sample-size despite the fact that no regulation actually requires such a broad-based sample. The advisory circular appears to potentially change the regulations by increasing the burden on applicants. To the extent that this is true, it is inappropriate.
Our concern is that despite warnings that this is non-mandatory guidance, this guidance may be used as if it were a regulation, with offices refusing to accept PMA applications that are otherwise valid, but that failed to use this AC as a basis for identifying sample size.
If you find that this AC effectively changes the application obligations imposed on you as a PMA applicant, STC applicant, or other FAA-approval applicant, then please contact MARPA so we can raise this concern with the appropriate personnel at the FAA.
AC 33-10 is known by its full title: Statistical Analysis Considerations for Comparative Test and Analysis Based Compliance Findings for Turbine Engine and Auxiliary Power Unit Replacement, Redesign and Repaired Parts.
Some of you may be wondering where to find the FAA’s policy memo on design approval holder restrictions on ICA availability. Older MARPA links to the original position of that guidance are no longer valid because it has been moved. But it is still available if you know where to look!
Many MARPA members look for this policy memo because it clarifies that anti-competitive language in ICAs (restricting use of PMAs or third party repairs) is unacceptable to the FAA:
While not exhaustive, the FAA finds the following practices of using restrictive language in the ICA or through restrictive access or use agreements unacceptable under the provisions of 14 CFR §21.50(b) and related ICA airworthiness requirements:
1) Requiring the owner/operator to only install DAH-produced or authorized replacement parts, articles, appliances, or materials.
2) Requiring that alterations or repairs must be provided or otherwise authorized by the DAH.
3) Requiring the use of only maintenance providers or other persons authorized by the DAH to implement the ICA.
4) Establishing, or attempting to establish, any restriction on the owner/operator to disclose or provide the ICA to persons authorized by the FAA to implement the ICA.
The FAA has released Notice 8110.116, which stresses the importance of writing clear notes in the Type Certificate Data Sheet (TCDS), and of ensuring that those notes are consistent with FAA policy. This new guidance can be very valuable to everyone in the industry. The value to TC applicants and holders (who create draft TCDS for FAA adoption) is obvious, but less obvious are the subtle and not-so-subtle admonitions against using the TCDS for anti-competitive effect.
One valuable element of this guidance is that it stresses certain things that should not appear in the TCDS. For example, in paragraph 6(a)(6), the guidance advises against language that limits work to a scope narrower than permitted by the regulations:
(6) Do not include requirement that is non-regulatory in the notes. For example: “This aircraft shall be maintained in accordance with the BHT-427 Maintenance manual.” This note implies that BHT-427 is the only source for maintaining the aircraft, and conflicts with 14 CFR 43.13(a) which states “Each person performing maintenance . . . shall use methods . . . or other methods acceptable to the administrator.”
This admonition is consistent with FAA guidance that has prohibited language limiting operators options in seeking repairs. E.g. PS-AIR-21.50-01: Type Design Approval Holder Inappropriate Restrictions on the Use and Availability of Instructions for Continued Airworthiness (March 23, 2012). In the past, there have been problems with manufacturer’s guidance that seeks to limit operators’ repair options, which in turn has had an adverse effect on independent repair stations who are qualified by the FAA to perform the same repairs. Other language in the guidance highlights the prohibition against anti-competitive statements by stating:
Avoid language promoting a TC holder or their suppliers as the sole source for maintenance or overhaul.
It is contrary to 14 CFR parts 43 and 21 to include a note that all repairs or modification schemes must be approved by the TC holder prior to FAA approval.
In a similar vein, the guidance also forbids use of notes that could be interpreted as statements of FAA General Policy. The obvious reason for this is because the TCDS should not be used as a vehicle for establishing FAA policy. The example that is given is useful in its own right, because this is clearly not a statement of FAA policy, despite the fact that some government prosecutors have tried to promote similar policies:
(8) Avoid notes that can be interpreted as FAA general policy. For example: “Reuse of parts and assemblies that have been involved in an accident is not permitted unless approved by FAA Engineering.”
In subsection 6(a)(10), the FAA advises against the use of brand names, but in subsection (11), the FAA requires that when a specific brand name is used, then the note must also advise of the possibility of using FAA-approved alternatives:
(11) If a specific brand name material needs to be listed, then you must state that an equivalent material is also may be approved. For example: “SOHIO BIOBOR JF biocide additive is approved for use in fuel at a concentration not exceeding 270 PPM. Use of other, equivalent material, may be approved by the FAA.”
Aviation is a competitive industry, but some companies have attempted to use FAA-approved and FAA-acceptable documents as levers to inhibit competition. The FAA has repeatedly asserted that its job is safety – not competition – and that it will not allow its approvals to be used as independent inhibitors of competition where no safety interest is served. While the main purpose of this new guidance is to standardize the layout of TCDSs, it also includes important admonitions that should help prevent anti-competitive behavior.
MARPA had a very good meeting today with Mark Bouyer and Ann Azevedo of the FAA’s Engine and Propeller Directorate (EPD).
The focus of the meeting was status on EPD policy that may affect PMA manufacturers.
Azevedo explained that she has responded to the comments on the Statistics Advisory Circular (AC), and hopes to have the final draft of that guidance available to the public by September. The Statistics AC is meant to address FAA concerns that have been recognized in practice, such as misusing statistical methods to show equivalence, and underestimating the appropriate sample sizes.
Bouyer expects the Materials AC to go out for public comment this month. The Materials AC will identify the essential data that is necessary when a PMA applicant is trying to replace the material used in the type design. MARPA members should watch for this one, and be prepared to offer their comments.
The FAA had published the Geometry AC for comment. This AC is meant to enhance awareness of how reverse engineering can introduce dimensional differences in replacement parts. MARPA Board members have expressed that the draft of this proposed guidance appeared to be very helpful to the industy.
The Burner Rig AC, which was also previously out for comment, is expected to be issued by September. It is expected to provide a method for establishing functional equivalence for certain degradation modes in parts such as oxidation, hot corrosion, erosion, etc. The AC is expected to identify existing technology as a means of compliance.
Finally, the FAA is internally reviewing AC 33.8 with a plan to update and clarify the AC. The updates are intended to make the AC easier to use.
The FAA has been very active and diligent in preparing guidance. In the immediate future (before the Conference), MARPA members should expect to see the release version of the Statistics AC and the Burner Rig AC, and they should expect to see the Materials AC go out for comment.
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.