Some benefits come with aging. My 33-year-old airplane no longer has teething pains, and I better understand its sounds and vibrations. However, things wear out, and (for me) mental lapses occur. For both of us, I have found that a preventative maintenance (PM) program can help to counter some of the more insidious effects of aging. The successful PM program that I developed started with improving existing checklists.
Aircraft reliability can be depicted by a "bathtub" curve, which shows that, once past its break-in period, equipment is usually reliable until age catches up with it. A good PM program will extend the span of that normal life in the middle of the curve. My PM program uses two checklists, one for the annual inspection and one for preflight.
Building the checklist
Good PM checklists are always personalized, and they include items based on experience (yours or others), your level of comfort, and the aircraft's environment. For many years I mistakenly thought that they were checklists just for the airplane, but I have since come to realize that they are actually "our" checklists based on how, when, and where the aircraft is flown, my tolerance for degraded performance, and compensation for mental lapses. Both checklists (annual and preflight) have become so-called living documents, revised as new items are discovered that need to be addressed.
In the early years of aircraft ownership, I mistakenly assumed that the maintenance shop knew everything that needed to be checked on the annual inspection. I also believed that the shop had every airworthiness directive (AD) and service bulletin and would check those against my aircraft. What on earth was I thinking?
For example, there are two ADs on ignition switches typically found on my model aircraft. My shop had been performing the wrong AD during my aircraft's annual inspection, and the correct one had been marked as "not applicable." My checklist now has all recurring ADs for my aircraft, as well as those that may have been issued since its last annual. The FAA's Web site has all the ADs, easily findable if you know the manufacturers and model/serial numbers of the equipment on your aircraft.
Other annual inspection checklist items are for rotating equipment, including the engine, propeller, magnetos, vacuum pump, and alternator. My airframe and powerplant (A) mechanics have always done a good job inspecting the engine and propeller, but an in-flight vacuum pump failure at 700 hours (IFR in good weather, fortunately) prompted me to be more proactive. My enhanced annual inspection checklist now has an item for inspection, repair, or replacement of the vacuum pump and other rotating items. My current A says that he appreciates the reminders.
Preflight checklists also benefit from personalization. I think I remember when I could successfully complete the preflight and not miss a thing through the judicious use of acronym soup. Maybe the checklist was shorter then. In any case, I have modified my preflight checklist over the years to accommodate my habits, preferences, and past mistakes. For instance, I start the airplane with only the battery split switch On and lean the mixture during the ground time, contrary to the factory-supplied checklist, but my improved checklist reminds me to turn the alternator split switch On, check for charging on the ammeter, and go to full rich before takeoff.
If I have the same memory lapse twice, it goes on the checklist. In spite of my avionics checklist items, I have launched without taking the transponder out of Standby mode. ATC's reminder added insult to injury, so now it is indelible on the checklist.
Each pilot/airplane pair should have a good checklist that suits their needs. To ensure that each checklist item is performed, I normally use a willing passenger/copilot to call out every item, and we do not move on until I acknowledge it as satisfactory. There's less chance of a finger slip that way.
My enhanced checklists have become a fundamental tool in my flight bag to offset aging effects, reflecting my airplane, skills, and flying environment. It helps to keep both the aircraft and me at our best levels.
Robert Levline, of Richland, Washington, is a 1,500-hour private pilot with instrument and multiengine ratings.
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