It’s great that the FAA lets pilots do preventative maintenance on their airplanes, but I’m intimidated by many of the things we are allowed to do, especially those I’m not specifically trained on. My dad was a crew chief on C-47s (DC-3s) in the Pacific and an auto mechanic after World War II. He wouldn’t teach me anything about mechanics, because I was going to college. Well, I’m glad I went to college, but I think everyone will agree that there isn’t anything wrong with being an A&P. As a result, I have spent many years avoiding Federal Aviation Regulations (FAR) Part 43, Maintenance, Preventive Maintenance, Rebuilding, and Alteration.

Concorde Battery recently issued Technical Bulletin No. 10 “Parasitic Drain” in response to questions throughout the aviation community about the effect of parasitic drain on battery state of charge. A parasitic drain is an electrical load that takes power from the battery even when the master switch or battery switch is off. Examples of loads that cause parasitic drain include clocks, lights, relays, current sensors, and power-monitoring circuits. If an aircraft is inactive for a length of time, depending on the magnitude of the load, the battery may be depleted within weeks or even days.