David Linebaugh is a Senior Pricipal Engineer from Delta Airlines. He is the lead engineer in Delta’s PMA Program.
Linebaugh has found that PMA parts provide a variety of advantages to the air carrier. The opportunity to have greater competition for parts provides his carrier with an alternative to yearly increases in OEM prices. But he also has found that PMA parts provide other advantages. He explained that PMA manufacturers seem very open to working with Delta on developing improvements in order to increase safety and reliability, and PMA parts are often more available than their OEM corollaries. He said that he has often had to set aside another project in order to reviews proposed engine part that is being adopted for use at Delta because the OEM corollary is unavailable to meet Delta’s needs, and the proposed PMA is available immediately.
There is a two-step process for getting a part in to Delta. The Supply Chain group reflects the “front door” to the application process. They analyze the business case to identify the likely advantages based on facyors like expected use, cost, and existing contracts. If it meets the Supply Chain process requierements, then the package will be passed to engineering.
At Delta, the PMA engineering process is implemented by Linebaugh and one other engineer. Linebaugh explained that his main focus is “does it work?” The engineering review process at Delta involves a review of the data package to confirm that the part meets Delta’s needs. Delta will ask the applicant to provide a copy of the risk assessment in order to support Delta’s own risk analysis.
- TIP: Make sure that the data package includes an introduction that explains what the part is and what it does.
- TIP: If you made changes to the OEM design, then clearly explain what they are and why you made those decisions, in the package.
The parts that go through the review process quickly are the ones where every question that the airline might ask has been anticipated and answered in the package. Don’t be offended by the airline questions, explains Linebaugh – they are simply trying to answer their questions that arise so that they can use the part.
In Linebaugh’s experience, one of the biggest reasons for rejecting a part is because of eligibility issues. Sometimes a PMA is approved for one model, but not for the specific model that Delta is flying. Applicants should make sure that the PMA supplement lists all appropriate eligible installations.
He would like to see eligibility be eliminated from the PMA mechanisms, because it would be easier for air carriers if the parts we simply replacements for the existing OEM part in all eligible installations.
His experience is that many customers have differing views of PMA use, but this appears to be a commercial issue, because the regulatory hurdles to PMA use no longer exist.
Something that he feels is useful to an applicant’s package, is explaining to the air carrier what goes into the reverse engineering process. One of the things that has sold him on PMA is his understanding of the reverse engineering process, because it shows him how much the PMA companies have put into the design process in order to make sure that the parts are right