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Aircraft Maintenance: Buying used aircraft parts online

I am passionate about making aircraft ownership affordable to nearly anyone who dreams about flying his or her own airplane. I released “The Educated Owner” video series nearly 20 years ago and, although I no longer recognize the youthful host in those videos, they remain a popular item on ApproachAviation.com because the lessons haven’t changed. The bottom line is that an educated and involved aircraft owner will likely fly a safer aircraft, and do so for less money. You can be frugal and safe at the same time, but it takes education and attention to detail. There are no shortcuts.

This used autopilot trim servo from Kubick Aviation Services came with tags showing its traceability and testing prior to removal. Photo courtesy of Jeff Simon.

One of the ways that many aircraft owners control the costs of maintenance and upgrades is to consider sourcing serviceable used or new old stock (NOS) components when they need a part for their aircraft. Depending on the situation, the price difference can be substantial. For example, when my autopilot trim servo began acting up, a brief search on eBay showed dozens of used servos available at a fraction of the cost and trouble of sending mine out for overhaul. The challenge was determining whether these were genuine deals, or just someone else’s problems.

It’s no secret that online sources such as eBay are overflowing with aviation parts. However, to play in this market you need to be able to identify parts that your mechanic can use. In order to install a component on an aircraft, the installing mechanic must be able to establish two things about it: traceability and airworthiness.

Traceability is basically the pedigree of the part, something you need to know in order to ensure that it isn’t what the FAA terms an “unapproved part.” Simply having a component in your hand with a part number printed on it isn’t enough. If the part is new, it should have paperwork from the manufacturer. If the part has been salvaged, you need to know the make, model, and registration and serial number of the aircraft from which it was removed. With no paperwork showing its origin, you have no way of knowing if it was retrieved from a scrap bin of non-airworthy parts (something that is surprisingly common) or isn’t a legal aviation part at all. Keep in mind that many aviation components begin life as automotive or other commercial parts. They only become legal as aviation parts after inspection, modification, or another process is performed on them by the holder who has FAA parts manufacturing approval (PMA) for the part. Take the case of something simple such as electric fuel pumps. Several aircraft manufacturers source commercially available fuel pumps and then test them for proper current draw and flow rates. Only after passing these inspections are the electric fuel pumps stamped PMA, serialized, and assigned an aircraft part number. Just because you find the same part in a tractor store doesn’t make it legal.

Once you have a part with a known pedigree, the mechanic needs to establish that it is airworthy before it can legally be installed on the aircraft. In some cases, they can do this through visual inspection. However, in most cases they will need more information to be sure that the part is within spec from the manufacturer and will perform as intended. There are two ways that this is commonly done: operational checks and certified inspection/overhaul.

If a component is removed from a working aircraft, the mechanic removing the part can attest to its functionality as part of the proper functional testing of the system. For example, let’s say a shop removes a perfectly working starter motor from an aircraft in order to upgrade to a lightweight starter. They could test and verify proper operation of the old starter, then tag the part with all the information from the aircraft it was removed from, including a note about the testing that was done prior to removal. This would give the buyer proper pedigree for the starter, and at least some degree of confirmation of airworthiness. The installing mechanic should still inspect the brushes and perform whatever inspections are mandated by the manufacturer for routine maintenance before installing the used starter in another aircraft. But, they should have what they need to legally install the part.

The more reliable method of ensuring the airworthiness of a component is to have a certified repair facility inspect it according to the manufacturer’s published data. The best way to do this is to request an “Inspect and Repair as Necessary” (IRAN). You can always upgrade to a full overhaul if needed. For complex components such as avionics, having a full inspection will usually save you time and money in the long run because you can rule out the unit when debugging any post-installation issues.

When buying something online, start by vetting the seller and avoid people simply selling items of unknown origin from their basement. Find sellers that you can trust. Many sellers on eBay are licensed FAA repair stations and avionics shops that simply use eBay as a convenient way to sell their used inventory. This is the approach I took with my trim servo.

I found Kubick Aviation Services, a highly reputable avionics shop with a large inventory of used avionics components online. I called the company and spoke directly to Ben Cook, the parts and inventory manager, about the items listed on eBay. Cook was able to provide a history of the servo and all the information I needed to ensure that the part would be the right fit for my airplane. I also spoke with Kevin Leitz, Kubick’s business development executive, about the company’s used parts business. Leitz emphasized the importance of traceability and said that the company has built a strong online business based on being a reputable source for avionics. As a certified dealer for many avionics brands, Kubick Aviation Services can provide testing and service to back up many of the products it sells. As an added bonus, your avionics installer will know that the used equipment you’ve selected is coming from a licensed avionics shop. That alone will make the process a little easier when dealing with your own shop.

Ric Peri, vice president of government and industry affairs for the Aircraft Electronics Association, urges owners to respect the position that they are putting their mechanics in when sourcing parts online: “The regulations are actually pretty basic. The problem is that some owners don’t fully appreciate the responsibility of the installing mechanic to ensure that the part is both legal and airworthy.” As the owner or operator, the airworthiness of the aircraft is ultimately your responsibility. By understanding the regulations, you can make informed decisions about using parts that you find online. This allows you to manage the cost of your aircraft maintenance while ensuring that you are both safe and legal in the process. Until next time, I hope you and your families remain safe and healthy, and I wish you blue skies.

Jeff Simon
Jeff Simon
Jeff Simon is an A&P mechanic, IA, pilot, and aircraft owner. He has spent the last 22 years promoting owner-assisted aircraft maintenance and created the first inspection tool for geared alternator couplings available at ApproachAviation.com. Jeff is also the creator of SocialFlight, the free mobile app and website that maps more than 20,000 aviation events, hundred-dollar hamburger destinations, and also offers educational aviation videos. Free apps are available for iOS and Android devices, and users can also visit www.SocialFlight.com.
Topics: Aircraft Maintenance
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