Several draft FAA Advisory Circulars are currently open for comment of which MARPA members should take note.
Today the FAA’s Engine and Propeller Directorate released draft AC 33.15-3 Parts Manufacturer Approval (PMA) Metallic Part Material Compliance Using Comparative Test and Analysis Method for Turbine Engines or Auxiliary Power Units. This AC is intended to provide guidance to assist PMA applicants in developing tests to demonstrate the equivalence of materials with that of the type design materials.
We will provide a more detailed analysis of this draft AC in the coming days, but want to encourage each of our members to review it and submit comments to the FAA addressing any potential problems you identify–or offering praise if you feel it is a useful document. MARPA will be offering its own comments, so if you do not wish to file on your own, please feel free to provide us with your thoughts and we will incorporate them into the association’s comments. These comments are due to the FAA by July 20.
Two other draft ACs are also open for comment and bear review. The first is AC 39-xx Alternative Methods of Compliance. This AC is intended to provide guidance to those applicants seeking approval of an AMOC. This guidance formerly appeared in FAA Order 8110.103A but has since been removed to a stand-alone AC. Comments are due May 30.
The other is AC 23.10 FAA Accepted Means of Compliance Process for 14 CFR Part 23. This AC provides guidance on how to submit applicant proposed means of compliance to the FAA for acceptance by the Administrator in accordance with proposed § 23.10 (which is one section of the current Part 23 proposed rule revision). Comments are due May 13.
Each of these proposed Advisory Circulars should be reviewed for potential effects on the PMA industry. MARPA will be undertaking its own reviews, but we encourage each of our members to do the same, and file such comments as they believe helpful. All draft materials and FAA contact information can be found at https://www.faa.gov/aircraft/draft_docs/ac/.
If you would like us to incorporate your comments, you should email them to VP of Government and Industry Affairs Ryan Aggergaard at email@example.com
The FAA has released a Draft Policy Statement related to Order 8110.42D that is directly applicable to the PMA community. PS-AIR-21-1601 – FAA Order 8110.42D, Parts Manufacturer Approval Procedures – Use of Parts Manufacturer Approvals (PMA) for Minor Modifications to Products establishes FAA policy for “the gray area when a modification to a product does not rise to the level of a major change . . . and the producer of the modification article wishes to sell it in accordance with 14 CFR 21.9.”
The Draft Policy explains that historically there was not a consistent policy for issuing PMAs when the PMA made a modification that did not rise to the level of a major change under the regulations. Confusion existed as to whether a STC was appropriate for a modification article that did not constitute a major change to type design.
The Draft Policy clarifies the FAA’s position that:
PMA is a suitable method to approve an article, and provide for that article’s installation, in cases where the installation would not constitute introduction of a major change in a product’s type design.
The policy goes on to explain that the applicant must be able to identify the change resulting from installation of the article and justify it as not being a major change to the product and have the project ACO’s agreement.
On balance this looks like a positive policy for the PMA industry, clarifying modification PMAs that do not constitute a major change to a product’s type design can be approved through the PMA process and not require a STC. However we would still like to hear from our members to determine if there are any unintended consequences of this policy or ways in which the policy can be made more clear.
Comments on this policy statement are due May 1, 2016, so please email Ryan Aggergaard at firstname.lastname@example.org if you have any concerns about this policy or potential effects on the PMA industry.
Everyone in the PMA industry knows about the challenges that arises when selling PMA parts to customers operating leased aircraft. These challenges very often arise from restrictive clauses in lease agreements that prevent the use of PMA on the asset. This can cause particular headaches when the customer is a low cost carrier (LCC) whose business model should make them the ideal PMA customer, but whose largely (or exclusively) leased fleet means that restrictive clauses (either perceived or actual) restrict use of PMA.
The good news is that lessors’ position with respect to use of PMA appears to be loosening as lessees demand the right to use PMA, lessors become more familiar with PMA, and the industry continues its shift toward ever greater PMA acceptance.
The first, and most important, step in greater PMA acceptance on leased aircraft is demand by the operators. We have already heard at least two air carriers–Delta Air Lines and Copa Airlines–state unequivocally that they will not sign leases with “no PMA” clauses in them. But at MRO Asia Pacific last week, we heard multiple parties–both LCCs and lessors–state that the use of PMA on leased aircraft was a common occurrence; the lessee (the air carrier) just has to ASK.
Lessors typically enter a lease negotiation with a set of boilerplate terms. Those terms, however, are subject to change to suit the lessee’s business model and to satisfy the needs of both parties. Ananta Widjaja from Sriwijaya Air pointed out that a lessor will never give a lessee anything outside of the boilerplate unless the carrier asks for it. This point was echoed by a number of lessors over the course of the conference, who recognize that use of PMA is a reality in virtually every air carrier’s operation.
This is an important point for PMA manufacturers to take to their customers. Remind air carriers that most lessors will permit PMA to be used on leased aircraft (with a few exceptions); the carrier just has to demand the right. As lessors continue to grow more familiar with PMA, and recognize that use of PMA does not in any way devalue their asset, they grow more willing to waive the “no PMA” clauses in their lease agreements. This is beneficial for the lessee and lessor, as the lessee can continue to realize the savings and reliability improvements provided by PMA, and the lessor opens up more potential customers by allowing the use of PMA.
A number of the LCCs at MRO Asia Pacific pointed out that they especially use PMA during the middle of the lease. The lessor community explained that the most important part of any lease is the return conditions, because these are the terms that dictate the condition of the aircraft for the next lessee. Lessees take advantage of this fact by using PMA throughout the term of the lease (as allowed by the lease terms) but if necessary return the aircraft to an “OEM-only” condition (such as exists, which we in the PMA community know is a fiction) during C-check prior to the return of the aircraft.
Lessors are becoming more accepting of PMA for a couple reasons. The first, which we’ve touched on, is demand by their customers. Lessors need to have their aircraft leased in order to realize a return on investment, so it makes sense to permit the customer to use PMA if that is what it takes to get the lease signed.
Second, lessors have begun to realize that it is simply not possible for many carriers to operate without any PMA. PMAs, especially on interiors and air frames, are a reality for a significant number of carriers. Some carriers simply cannot operate without the use of PMA to control costs and reliability. Air carriers, LCCs in particular, want to control costs and improve reliability to the greatest extent possible, and this drives use of PMA. (As an aside, if anyone manufactures a PMA lavatory mirror for the lav setup on the A320 family, Tigerair out of Singapore would love to hear from you.)
Lessors recognize this. Lessors have even started to realize that this is the case with respect to engines. And though most lessors remain squeamish about PMA in the gas path or life-limited PMA, the simple fact is there are very very few PMA that meet this description.
Finally, lessors are becoming more flexible in allowing PMA because it is impractical not to. When leasing older aircraft, lessors recognize that it is simply not possible to get “OEM” spares. They also recognize the significant lead times for OEM parts, when PMA parts are available off the shelf. This makes a big difference in turn time when delivering a leased aircraft to the next customer. Finally, lessors are beginning to understand that many new aircraft are, in fact, built new using PMA parts! It simply makes no logical (or legal) sense to demand no PMA be used when the aircraft are delivered new with PMA throughout.
There are still many hurdles for PMA in leased aircraft. Lessors remain nervous about PMAs in engine gas paths, LLP and rotable PMAs, and PMA in high-value components. The fear is that PMA could devalue these articles and reduce the resale or part-out value. This means that we as a community must continue to educate the leasing community and the valuation community to allay those concerns, by explaining that PMA meets the exact same standards as TC/PC parts, and must meet or exceed the performance of the OEM part.
Lessors are also concerned about the practices of many OEM repair shops to threaten to void the warrant of an engine if it includes PMA, or pull off PMA parts during maintenance and replace them with OEM parts (and bill for it), thus depleting maintenance reserves required under the lease. These protectionist tactics are something we will continue to fight.
Ultimately, lessors are becoming more and more accepting of PMA in leased aircraft. Air carriers must remember that everything is negotiable, and that if PMA plays and important part of their maintenance and cost saving strategy, they need to demand use of PMA be allowed by the aircraft lease. PMA manufacturers should make it a point to remind their customers that lessors will allow (or at least negotiate) the use of PMA. But they won’t allow anything if the carrier doesn’t ask.
MARPA is in Singapore this week for MRO Asia-Pacific promoting all things PMA. The first day of the MRO conference agenda dedicated substantial discussion (as they usually do) to market forecast and trends. Some of these trends could be an opportunity for PMA manufacturers, but others could mean significant challenges down the road if companies are unable to adapt.
The opening session presented a discussion of trends in supply chain logistics. One of the largest takeaways was the change in inventory management practices, especially in the Asia Pacific region, from a just-in-case model, to a just-in-time (JIT) model. This follows the trend in many other industries, including manufacturing and retail, which enable businesses to reduce costs by carrying less inventory.
PMA manufacturers are in an excellent position to benefit those customers shifting to a JIT model because PMA parts can help customers defray the costs associated with warehousing and inventory management, which is outside of the customers’ core competency. This applies to both operators and MRO facilities. This is because PMAers have the parts on the shelf ready to go, eliminating the need for users to maintain parts inventories themselves to ensure availability.
But the shift to a JIT model also presents certain challenges in Asia Pacific, particularly for AOG situations or other scenarios demanding quick turn times. In certain markets with well-established MRO markets, like Japan and Singapore, getting parts to the customer is often a fairly straight-forward exercise and can be done overnight from the United States. However, in less-developed markets and countries in the region, import and customs requirements can pose significant barriers, meaning delays of several days in clearing the shipment and getting the part to the customer. Those companies able to most efficiently navigate those challenges will be at a competitive advantage.
Another trend in Asia Pacific is the MRO spend focused on the narrow body fleet–namely the 737 and A320 families. The narrow bodies currently account for approximately 70% of the MRO spend in the region (and are the two largest fleets by type). This trend should continue over the next decade for two reasons: (1) a significant number of these aircraft have been delivered over the last decade (and continue to be delivered); and (2) the commonalities that exist between the current gen aircraft and the Max and neo versions of the aircraft.
Finally, an emerging trend that should be of great concern to PMA manufacturers is the shift by component and airframe OEMs toward power-by-the-hour agreements. The PMA industry has already seen the problems that are caused when OEMs use PbH agreements as engine OEMs have taken significant steps to lock up the engine spares market. Although the percentage of PbH agreements in component and airframe is still small, it is growing. PMA manufacturers need to get out in front of this trend and remind their customers that they are a) not obliged to sign such agreements and b) demonstrate the value of PMA in terms of cost, reliability, and customer service offered by PMA. It can also benefit smaller PMA companies to form partnerships with other manufacturers of complimentary product lines to offer greater benefits to customers.
MARPA will work to stay on top of these trends. We welcome any information or questions our members have that can help MARPA continue to craft its strategy.
Last week, MARPA participated at the Tokyo Aerospace Symposium 2015 in Japan. The event drew operators, part manufacturers, equipment and tooling manufacturers, and technology companies, among others, to the Tokyo Big Site convention center to discuss current and emerging manufacturing and regulatory issues, as well as display exhibitor capabilities on the trade floor.
Jason Dickstein and Ryan Aggergaard from MARPA, joined by Akira “Jay” Kato, advisor to the Tokyo Metropolitan Government Aviation Industry Participation Support Project and President of JK Tech Consulting Inc., gave a panel presentation discussing PMA and MRO business trends and discussed ways manufacturers can partner with U.S. PMA companies to develop synergistic relationships that can benefit both U.S. and Japanese companies. Many of the manufacturing companies in attendance expressed an interest in seeking out U.S.-based manufacturing partners to develop a supplier or other type of business relationship, and some stated that they had already developed supplier relationships with U.S. PMA manufacturers.
The Tokyo Aerospace Symposium drew nearly 9,000 registered attendees over the course of the three-day event, with most of those attendees participating on multiple days. The MARPA booth saw significant traffic, and we took the opportunity to speak to as many attendees as possible, explain who we are and what we do, as well as the benefits of U.S. FAA-PMA, and discuss the businesses of our members. Several attendees asked for more information about the particulars of our members’ businesses in hopes of developing relationships.
MARPA hopes that our members will be able to participate with us–or provide us with promotional materials–in future years in Japan, because there is strong interest from the Japanese manufacturing community in developing U.S. relationships. As we explained in our panel presentation, the opportunities provided by partnering with high-quality manufacturers that are able to offer product lines that complement your current offerings can greatly expand your business opportunities, because customers often prefer suppliers that can meet as many of their needs as possible all in one place.
MARPA also took advantage of its presence in Japan to meet with a number of air carriers to promote the values and benefits of PMA. We were happy to find these operators are already familiar with PMA and use PMA in their fleets. However, as with all carriers, there is still significant room for growth. MARPA took the opportunity to explain how PMA parts provide great value and savings by solving reliability issues, quality issues, and sourcing issues, as well as offering the obvious benefit of reduced cost off the shelf.
The positive reception toward our discussion of PMA leads MARPA to believe there is still a lot of opportunity for sales expansion in the Japanese market.
There will be several representatives from Japanese carriers and suppliers at the MARPA Annual Conference in Las Vegas next week (October 28-29). The conference will be a great opportunity to network with existing and future customers as well as discuss potential relationships with Japanese suppliers. We look forward to seeing new business connections made!
A new proposed tasking from the FAA’s Aviation Rulemaking Advisory Committee (ARAC) on rotorcraft occupant protection may provide great opportunities for manufacturers of certain rotorcraft parts. The proposed task seeks recommendations on how current occupant protection standards should be made effective for newly manufactured rotorcraft, with a follow-up task asking how to incorporate such protection standards into the existing rotorcraft fleet.
Increasing safety is always the FAA’s number one concern. Over the past several decades, the FAA and industry have made a focused effort directed at reducing rotorcraft accidents in general, under the theory that a reduction in total accidents would result in a corresponding decrease in serious and fatal accidents. However, a recent study has indicated that while the total number of accidents has decreased, the number of fatal accidents has not followed a similar downward path.
A major contributing factor to this trend (or lack thereof) has been a slow incorporation of occupant protection mandates into the overall rotorcraft fleet. Specifically, crash resistant fuel system requirements and requirements related to blunt force trauma protection and dynamic seating, which have been in effect for more than twenty years, have been incorporated into only 16% and 10% of the U.S. fleet, respectively.
Why have these safety standards been so slow in spreading through the U.S. rotorcraft fleet? The answer is that retroactive laws and regulations are generally frowned upon in our legal system. Typically, unless Congress specifically authorizes retroactivity, new regulations can only be prospective in nature. The real world effect of this requirement means that the regulations to which a rotorcraft (or aircraft) must adhere are those that were in effect at the time the type design was approved (unless an AD or similar is issued). In other words, the type design doesn’t have to be continuously updated to keep up with changing regulations.
Even though the regulations relating to crash resistant fuel systems and dynamic seating were issued more than twenty years ago, most of the rotorcraft being manufactured today are being manufactured under type designs that are even older still. This means that the safety benefits of the crash resistant fuel systems and dynamic seating are not being incorporated in a large part of the fleet.
Recognizing this impediment, the FAA and NTSB both recently recommended implementing a rule that would require crash resistant fuel systems to be installed in newly manufactured rotorcraft (the key wording being newly manufactured rather than newly certificated). This would make the rule retroactive with respect to the production of new rotorcraft, even if the TC of the rotorcraft was issued prior to the applicable crash resistant fuel system and dynamic seat regulations taking effect.
The working group that considers the proposed tasking will take these issues, and others, into consideration and make recommendations on how these protective standards can be made effective for newly manufactured rotorcraft, regardless of certification date. The follow-on task would then consider the incorporation of safety improvements into the existing fleet. This amounts to a significant number of rotorcraft that will be produced and/or retrofit with new equipment.
The recommendations presented by the working group will go a long way toward shaping the way in which the safety standards are implemented. In the past, these efforts have resulted in OEMs writing rules that effectively gave them a monopoly in the implementation of the safety solution. If your company manufacturers parts for rotorcraft, this could be a great opportunity to get involved with the working group and help shape the implementation of the safety standards going forward—allowing for the use of PMA and other non-OEM solutions that will drive price competition and improve safety.
Does your company manufacturer rotorcraft parts? Is this an issue MARPA should actively engage in? Let us know! We encourage our members who have an interest in this issue to contact the FAA ARAC and get involved.
The FAA has released for comment two guidance documents pertaining to Instructions for Continued Airworthiness (ICA): Draft FAA Order 8110.54B and Draft Advisory Circular 20-ICA. As many readers of the blog know, MARPA has done, and continues to do, a significant amount of work to ensure that ICA are available and accurate in accordance with the Federal Aviation Regulations.
Draft Order 8110.54B is guidance directed at FAA personnel and persons responsible for administering the requirements for ICA. Among other changes, the draft reorganizes the Order to reflect material moved to AC 20-ICA (below), and importantly incorporates guidance implementing the FAA’s Policy Statement PS-AIR-21.50.01, Type Design Approval Holder Inappropriate Restrictions on the Use and Availability of Instructions for Continued Airworthiness. MARPA and the PMA industry were closely involved with, and supportive of the FAA in, the adoption that Policy Statement intended to protect the industry from anti-competitive ICA restrictions.
Draft AC 20-ICA is a new Advisory Circular that removes industry-specific guidance from the internal FAA Order and places it in a stand-alone AC. This effort is similar to the FAA’s actions in revising Order 8110.42D – Parts Manufacturer Approval Procedures and developing the new AC 21.303-4 – Application For Parts Manufacturer Approval Via Tests and Computations Or Identicality. Like Draft Order 8110.54B, the draft AC implements the FAA policy on ICA established in the Policy Statement. The proposed AC provides guidance to design approval holders (DAH) and design approval applicants for developing and distributing ICA.
After a preliminary review these documents appear to offer very positive guidance for the PMA and aviation maintenance industries, and appear in line with the policy positions for which MARPA has advocated for many years. MARPA will be reviewing both of these documents closely and offering comments and support for these policies to the FAA. We encourage the PMA industry to review both documents as well.
Comments on both guidance documents must be submitted by October 6, 2015, and may be submitted to the FAA via email to 9-AVS-ICA@faa.gov. If you have comments or observations that you feel MARPA should include in its comments to the FAA, email them to Ryan Aggergaard at email@example.com so the we can include them.
The MARPA Air Carrier Committee, led by Michael Rennick, Delta Air Lines Component Engineering Manager, is hard at work supporting PMA users and MARPA members. In June, members of the MARPA Air Carrier Committee, including Air Wisconsin, American Airlines, Republic Airways, US Airways, Air Canada, and Delta Air Lines, submitted to the FAA a letter seeking clarification on the issue of PMA parts that are alternates to post modification Airworthiness Directive (AD) related parts.
This clarification is necessary because confusion has sometimes arisen between operators and local regulators over the need for an Alternative Method of Compliance (AMoC) for post-modification AD-related PMA parts. It is the position of the MARPA Air Carrier Committee that if the PMA is an alternate to an OEM part contained in a post-AD configuration, no such AMoC is required.
When a PMA is issued for a replacement part for a post-modification AD-related OEM part, it is uncommon for the PMA applicant to request an AMoC to the AD, or for the FAA to note the AD on the PMA approval. This makes some sense because a post-AD PMA part is inherently an alternative method of compliance without being described as one. However, an issue arises because many ADs call out only the modified OEM part as a means of compliance. Because ADs are technically regulations under Part 39, alternate approvals such as PMAs might not satisfy the regulatory requirement and so an AMoC may be required.
It would be beneficial to both operators and PMA manufacturers to see this change.
The OEM part is the source of the condition giving rise to the AD. The post-modification part must resolve the condition in order to satisfy the AD. During the PMA approval process for the same part, the AD is also taken into consideration.. In order to receive PMA approval, the subject PMA part must resolve the condition resulting in the AD, just as the post-modification OEM part does. There should be no need to call out an AMoC for the PMA part related to the AD; the underlying condition that necessitated the AD has changed because the approved PMA part has replaced the post-AD OEM part. The PMA should be a valid terminating action for the AD.
There are limited circumstances in which this reasoning may not apply, but these limited circumstances are not the subject upon which the Air Carrier Committee seeks clarification. For instance an AMoC may be necessary in a scenario in which an AD applies to a higher level component or assembly. In this scenario the PMA replacement for the OEM part may not address the AD for the higher assembly because it is a replacement at the piece-part level, and thus an AMoC may be necessary for the higher assembly.
Generally, however, an AMoC should be inherent in an approved PMA part and therefore unnecessary as a separate approval. This is the policy clarification that the Air Carrier Committee seeks in the form of a formal FAA communication. If an approved PMA part is a replacement for a post-AD OEM part, the FAA’s policy should clearly state that the approved PMA is a terminating action for the AD and that no additional approval or discrete AMoC is required. In the alternative, an AMoC could automatically issue for each post-AD PMA to show compliance.
MARPA greatly appreciates the Air Carrier Committee’s work on this project. MARPA will be working with the FAA and the Committee to determine whether future ADs will list an approved PMA as a valid terminating action, or whether an automatic AMoC should automatically issue with a PMA to show compliance to the AD, or some other solution is desired. We will keep our members apprised of these developments.
If you are a MARPA member air carrier and want to get involved with the Air Carrier Committee, please email Katt Brigham at firstname.lastname@example.org. If you are not yet a MARPA member but would like to get involved, visit our membership application page. MARPA membership is free for air carriers!
Edited to clarify that ADs are regulations and identify possible solutions to the issue raised in the Air Carrier Committee’s letter.
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!
On Monday the FAA released new guidance that provides a method of compliance for the test requirements of 14 CFR § 33.84 – engine overtorque test – when the applicant chooses to run that test as part of the endurance test of § 33.87. The new guidance is AC 33.87-1A and can be found on the FAA’s website at http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_33_87-1A_.pdf.
The AC also provides information and guidance on the test requirements of § 33.85 (calibration test), § 33.87 (endurance test), and § 33.93 (teardown inspection).
The guidance is directed at engine manufacturers and engine type-design applicants, as well as foreign regulators and FAA designees. However, it is still worth reviewing the guidance to determine whether there are any ways in which you might be affected.
The AC explains that the primary effect of the guidance is to eliminate some previously approved methods of engine testing that were designed to represent expected in-service operations rather than the endurance cycle described in § 33.87. This is because § 33.87 is not intended to reflect in-service operation, but rather to demonstrate a minimum level of operability and durability throughout the engine’s assigned ratings and limitations.
We encourage all of our members to take a look at this (and any other) new guidance to make sure there are no surprises. If you see anything that concerns you please let MARPA know!