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Talking To The Principal About PMA Replacement Parts

April 2021

PMA.jpgAs a decision maker in your flight department, you are continually looking for ways to keep a sharp eye on your bottom line, reducing costs, increasing reliability, and cutting downtimes.

When it comes to aircraft parts, a viable solution to all three is PMA (Parts Manufacturer Approval) replacement parts in place of buying new.

What is PMA?

PMA is not just the manufacturing process of aircraft parts but the FAA’s approval to manufacture specific aviation-related parts. It is issued for the production of modification or replacement parts, which includes materials, parts, processes, and appliances.

Gaining the FAA’s approval is not that simple and, in all cases, it must first be proven the parts manufacturer has the capabilities to produce the part and has a quality system in place to consistently produce these parts to the design specifications and airworthiness requirements for the part, which includes ensuring traceability of each part throughout the entire process.

Using PMA Makes Good Sense

PMA replacement parts are nothing new, but over time have become more widely accepted in the industry.

PMA is like a generic prescription. People were skeptical in the beginning, but as costs, quality, and lead times continued to improve, that philosophy changed and is preferred by customers as an alternative and often an improvement over the original.

Maintenance Cost Savings

PMA replacement part numbers can save operators hundreds, if not thousands, of dollars in maintenance costs.

Example #1

On a certain model aircraft, operators can get PMA replacement window dust panes for $100 each. That is an 86% aftermarket savings. Typically, when it comes to dust panes, if you are replacing one, you are replacing them all, which can be 10 to 20 panes per aircraft. As you can see, thousands of dollars can be saved by choosing the PMA option. Not only is there a cost-savings, but there is a time-savings as well; these dust panes are often more readily available with little to no lead time.

Parts Reliability

Many PMA replacement parts are an improvement of the original design because customers demanded something better. These design improvements are a result of the creative efforts to solve the original design issue.

Example #2

Concerned with how the main cabin curtains hang, bind, and drag along the tracks, some aircraft operators asked us to develop an improved design. Through a lot of trial and experimentation, we manufactured and certified a new PMA roller bearing curtain glide that operates smoothly in the tracks and along the curvature of the aircraft.


Parts availability is always a concern for operators, especially for legacy aircraft. Parts may no longer be available from the manufacturer, or there is an extremely long lead time to get them. This can delay a maintenance event for several weeks, if not months. PMA parts manufacturers typically keep an inventory of PMA replacement parts making them available when needed.

Duncan Aviation PMA Authority

Duncan Aviation was granted its first PMA Authority by the FAA more than 35 years ago, allowing us to manufacture aviation-related parts intended for installation on an aircraft. Initial PMA efforts were to support our STC (Supplemental Type Certificate) customers with parts when necessary.

Today, Duncan Aviation has an entire department dedicated to PMA certifications and manufacturing not only to support STCs, but to identify PMA opportunities for some of the most common aircraft parts not readily available.

Search Duncan Aviation’s PMA Library at www.DuncanAviation.aero/services/specialized-services/pma-library to find a PMA solution for your aircraft.

Previous Talking To The Principal Series Topics:

March: Talking To The Principal About Post Prebuy Projects

February: Talking To The Principal About Comparing Quotes

January: Talking To The Principal About COTS

December: Talking To The Principal About Cabin Management Obsolescence 

November: Talking To The Principal About Safety Management Systems

If you have topics you would like to see covered in this series, please send your suggestions to Intelligence@DuncanAviation.com