Tips for smooth trips, part 2: Pre-trip maintenance

July 18, 2014

In the last article, we reviewed the importance of having a maintenance plan for any extended cross-country trip. This time, let’s talk about getting the airplane ready for the trip.

Jeff SimonThe first step in preparing your aircraft for an extended trip starts with a review of your logbooks, airworthiness directives, and maintenance schedule. Aircraft have their own timetables, with planned maintenance intervals for things like oil changes, filter replacements, lubrication, etc. Unless you plan to conduct these maintenance tasks en route, you’ll want to get them all out of the way in advance. You may have 10 hours of flying left on that oil and filter, but if you’re planning 20 hours of cross-country flying it usually makes more sense to change it before you leave. And, while we’re on the subject, I don’t recommend timing any pre-trip maintenance for just before you leave. In the case of the oil change, give yourself enough time to see the results of your regular oil analysis. (You do have an oil analysis program … right?)

Oil changes and spark plug cleaning are somewhat obvious before a long trip, but you should also look through your logbooks for any recurring ADs or other potential legal “gotchas.” While it’s unlikely that the laws of physics will fail your airplane as soon as you miss a required AD inspection interval, they generally exist for a reason, and it’s paperwork, not physics, that ultimately makes our aircraft fly as far as the FAA is concerned.

I also recommend having your local A&P give the aircraft a good visual inspection at least two weeks prior to your planned departure. This will give you enough time to react to anything found.

Here is a list of common “trip interrupters” you should keep an eye out for, and where to focus your attention:

Exhaust failures: If there’s one thing that can really ruin your day, and your trip, it’s an exhaust failure. Inspect the system carefully, especially the risers and flanges where they meet the exhaust ports. Mounting points and supports should also be carefully checked. I’m not sure why this is a common issue when far from home. It may have something to do with Murphy’s Law and the fact that it pretty much guarantees you’ll be staying a while at an unplanned destination.

Alternator failures: These seem to take one of three forms: Failure of the alternator, failure of the belt drive (if equipped), or failure of the alternator mounting brackets. Of the three, the one you can prepare for in advance is the belt failure. The next time your propeller is off the airplane for maintenance, consider having your mechanic strap down a spare “emergency replacement” belt to the crankcase. It’s an old maintenance trick that makes it easy to replace the belt when away from home without having to remove the prop itself.

Starter failures: Starters are another common failure when away from home. The good news is that starters often give you warning signs before they fail. If you’ve had trouble with a sticking Bendix drive, don’t wait for it to get stuck for good; replace it before the trip.

Tire and tube failures: If you find yourself adding air on a regular basis to one or more of your tires, you might want to consider replacing the tube in a nice, controlled environment, rather than trying to find some air in the middle of nowhere next to that self-service pump with the cheapest gas you could find.

Vacuum pumps: It goes without saying that the dry vacuum pump is a weak point in general aviation aircraft systems. After all, I’ve received more than one “notice from our lawyers” over the years sent to all aircraft owners explaining how the manufacturer’s vacuum pump should not be relied upon as the sole attitude power source for IFR flight … not exactly confidence-inspiring. The good news is that many of the newer pump designs include inspection ports that will allow your mechanic to assess the wear on the fragile carbon pump vanes. You certainly don’t want to embark on your great adventure with 2,000 hours on your vacuum pump and pile of black soot at the pump outlet.

Autopilots: For some strange reason, an awful lot of autopilots seem to want you to get the full experience of hand-flying your aircraft during a long cross-country trip far from home. Perhaps they know you’re rusty and can use the practice. Regardless of the reason, the best you can do in advance is to give your autopilot a thorough checkout flight prior to embarking (and, perhaps, get some more practice hand-flying those ILS approaches).

A little pre-trip maintenance can go a long way to making your trip a smooth one. The key is to check everything out with plenty of time to react and repair what you find before your departure day arrives. Next time, we’ll talk about what to bring along with you and how to line up your resources just in case something happens along the way. Until then, happy flying!

Social FlightJeff Simon is an A&P mechanic, pilot, and aircraft owner. He has spent the last 14 years promoting owner-assisted aircraft maintenance as a columnist for several major aviation publications and through his how-to DVD series: The Educated Owner. Jeff is also the creator of SocialFlight, the free mobile app and website that maps over 10,000 aviation events. Free apps available for iPhone, iPad and Android, and on the Web at www.SocialFlight.com.