Aircraft Maintenance

While enjoying his morning cup of coffee, Bob boots-up his PC while a new nickel-cadmium battery arrives in the battery shop for deep cycle. He scans the battery's bar code, opens up an electronic work order, and starts his incoming inspection. The battery looks good, so Bob powers-up the charger/analyzer and clicks the analyze button on the screen.

The controller signals the charger/analyzer with the correct charge current from the battery database, and the top charge begins. Bob scans another battery while waiting for the battery management system to alert him all cells have reached the correct charge voltage. Then he uses his automatic watering system to record the amount of water added to each cell in the electronic work order via a wireless link.

Welcome to the next generation of aircraft battery maintenance automation. In the September 1995 AMT article, "A New Approach to Battery Maintenance, State-of-the-Art Documentation", I wrote about the importance of proper documentation and new tools for monitoring and printing battery service data. Now, advances in computers, data acquisition, and closed-loop control technology have made it possible to truly automate the battery shop.

Benefits to automation
Experienced technicians understand the importance of quality, efficiency, and productivity. The days of egg timers and clipboards are finally over.

How many times have you missed a critical capacity check reading? During the capacity check, it is necessary to measure each individual cell near the end of discharge to confirm all cell voltages are 1.00 volts or higher. When a capacity check is missed because you are not in the area, do not hear the timer go off, or are busy taking manual cell voltage readings on another battery, time is lost while the battery is recharged and the capacity check is run another time. Automation solves this problem by taking the required readings at the appropriate times and automatically recording the results.

Using a PC-based battery management system, technicians can see a digital picture of the battery shop including which batteries are connected to each charger/analyzer, processing status, and real-time servicing data including cell voltages, charge/discharge current, battery temperature, and amp-hour capacity. See Figure 1. This allows technicians to set priorities, make critical decisions in a timely manner and maximize productivity.