If you don’t, it could cost you money in the long run. Even in the brisk high-priced used aircraft sales climate, ones that are light on paperwork and missing maintenance logbook entries take a sizable hit in value. In some cases it could be as much as 50 percent or more. Even so, it always amazes me when owners take a cavalier attitude when it comes to missing logs and even paperwork related to STC modifications, upgrades and AD compliance.
A friend who was ready to spend a lot of dough on a big piston single called me at the last hour to ask if it mattered that there was no supporting paperwork for a major avionics upgrade that was installed in the aircraft a few years prior. It included an S-TEC autopilot, a couple of Garmin IFR GPS navigators and an ADS-B system. That’s a lot of paperwork to go missing and chances are it was either left at the shop (no longer in business) or the owner never put the paperwork in the aircraft. A sharp mechanic doing the prepurchase evaluation spotted it and told my friend that technically the aircraft wasn’t airworthy without it and he was correct. This supporting paperwork can be time-consuming and costly to reproduce.
Like the majority of STC’d equipment installed as major modifications, Garmin’s GPS navigators and the S-TEC autopilot, to name just two examples, require flight manual supplements that the installer generally customizes for the particular installation and aircraft. This paperwork package might contain the FAA Form 337s, ICA (Instructions for Continued Airworthiness), weight and balance and equipment list revisions and the flight manual supplement itself. The supplement is important because it might have the STC permission letter, operating limitations, emergency procedures for unusual and failed operating conditions and specific details on how the installed system interacts with the aircraft. Think of it as an extension of the aircraft’s POH—which is exactly what a flight manual supplement is.
In the case of this airplane, which was missing all of it, the task was to find an avionics shop that was willing to reproduce the paperwork. As the prospective buyer quickly found out, the job wasn’t exactly high on the list of priorities for three of the avionics shops in the area. One shop flat out refused the task, another said it would take it on but couldn’t get to it for at least a couple of months (which means it didn’t really want the job) and the third quoted two days of shop labor, which meant a $2200 invoice. He ended up passing up on this airplane over a different issue, but this is a lesson to all aircraft owners to safeguard the maintenance logbooks and paperwork. Moreover, you’re paying for it when you commit to an upgrade. Paperwork is time-consuming and shops surely bill it into the cost of a job. Don’t leave the shop without it.
Another friend who bought an otherwise decent Cessna 150 discovered that a major repair to the aircraft’s tail section after it was damaged in a ground accident didn’t have the FAA Form 337 to supplement a good repair. This wasn’t a deal breaker because a local IA who was familiar with the aircraft did the inspection and signed it off, but it still took effort. I’ve always said that aircraft with damage history simply aren’t a big deal as long as the repair was done correctly and the repair was well-documented in the logbooks. It’s becoming increasingly difficult as the fleet of aircraft ages as it’s nearly impossible to chase paperwork for repairs and modifications made 30-plus years ago.
And just because the aircraft is experimental doesn’t mean that paperwork and maintenance logs should be shortchanged. Marc Cook, my counterpart over at sister publication KITPLANES Magazine, was telling me of a local who bought a used experimental plane that needed avionics troubleshooting. The wiring a mess and there was no installation data, particularly interconnect drawings that showed how the interface was wired. When the aircraft’s new owner questioned the shop that did the installation (it was a popular established shop that should have known better), he was told that since the aircraft was experimental, the installation didn’t really need wiring diagrams. That’ll add big to the troubleshooting invoice. If you’re shopping for an avionics upgrade, ask the shop if it plans to provide basic diagrams for how it interfaces the equipment. If it refuses, or wants to charge extra, find another shop. It’s that important. Last, spend some time getting your existing aircraft logs and paperwork in order, making copies for backup. We looked at virtual maintenance logging in a report in the July 2022 Aviation Consumer.
We’re taking a fresh look at the Cessna 150/152 in an upcoming Used Aircraft Guide in Aviation Consumer. We want to know what it’s like to own these two-placers, how much they cost to operate, maintain and insure and what it’s like to fly them. We can use good photos (full-size, high-resolution please) and input on support, reliability, operating expenses or anything else that can be helpful for buyers considering one.
Email by Jan. 25, 2024, to: [email protected] or reach out on Facebook.
