Keeping a flight log can be a great troubleshooting tool.
Not for Everyone
Maintaining accurate and up-to-date log books for your model airplanes is not for everyone. If you think it is far more trouble than it is worth for the type of flying that you do, then it probably is.
I do not keep flight logs, or logs of any type for that matter. Almost all of my flying is of short-lived prototypes. I build them and then fly them many times over a very short period of time. Once I have learned what I need to learn from it, I put it aside and never fly it again. There is no point in keeping a flight log, since everything about it will be fresh in my mind when I design its replacement.
For some, keeping a log of your flying activities serves a different purpose. Similar to keeping a diary, it is a record of your model flying journey. It can be a handy way to keep track of major milestones and to help you relive the memories. Those are great reasons for keeping a log, but is not really what I’m talking about here. I’m talking about keeping a log for troubleshooting or maintenance purposes.
Who Needs a Flight Log?
It is much more common to fly a given model airplane only once in a while. Many of us keep half a dozen or more models ready to fly. It is our “stable”. We like having a choice of models to fly. We pick one depending on the weather conditions or the type of flying that we want to do.
When you grab a model and head to the flying field, do you remember the whole history of that model? How many times have you flown it? When was the last time you had to fix something on it? How many dead stick landings has it done?
If you do not remember the answers to these questions, maintaining a flight log might make sense.
I have never been much of a fan of maintaining battery logs. I usually fly inexpensive airplanes. I’m always prepared to do a dead stick landing. I have never had a battery go bad on me during a flight, but plenty of other things have. With experience comes confidence in surviving unexpected problems.
Nowadays we have excellent tools for diagnosing battery problems. Regenerative discharge cyclers can simulate flight conditions on the bench. On some chargers like mine, a display of internal resistance values is just a button press away.
I am not sure that battery logs make sense for most of us anymore.
Full-size airplanes are required to keep maintenance logs. By law, an entry needs to be made every time the airplane is modified or repaired. Major inspections also receive log entries. Model airplanes tend to have only one pilot, so I consider the functions of a maintenance log as better served by a general purpose “airplane log”.
In a notebook, use a separate page for each model airplane. Make an entry every time you maintain or fly it.
Write as much or as little in the airplane log as you feel comfortable doing. It is better to write too little and stick to it than to write too much and stop after a short while.
Here’s an idea: assign a sequential number to your battery packs. That way, it is very easy to keep track of which battery was in the airplane when you flew it.
We usually know for how long we flew, so write that down too. Make a note of unusual weather or flying conditions. Six months or a year from now, being able to jog your memory about the model might just save you a lot of trouble.