More importantly, this new battery appears to have a steadier decline in voltage, prolonging the low battery indication which in turn, could allow the pilot up to three months to schedule maintenance. Universal Avionics has issued a battery modification that considerably extends the useful life of the batteries. At that time, operators will need to switch to the new Extended-Life battery modification. The original Universal Avionics FMS batteries are still currently available, however could at some point in the future be discontinued. However, we recommend that you tie the battery replacement to an airframe maintenance event already on a two-year general maintenance program. It is perfectly fine to retain the original Universal Avionics FMS batteries. After this failure is noted, the only way to replace the data is for pilots to manually re-enter the data after the batteries are replaced.īelow are two simple solutions to avoiding the sudden loss of battery power and potentially all of your stored pilot data. When there is sudden battery failure, you also lose valuable Pilot Data. Especially if it becomes necessary to order a rental unit from the OEM while your unit is sent in for battery replacement. Depending on your current flight schedule and where you are located, the downtime could be hours or even days. When this happens, the FMS becomes unusable until the battery is replaced. The crew may get a “Low Battery” message at start-up on the first leg of a flight, but then have a “CDU Data Bus Failure” message on the start-up of the return flight. It isn’t unusual for these batteries to begin to lose power or fail with minimal warning resulting in a CDU Databus Failure message being displayed.Īs previously stated, this failure can happen quite suddenly. The other is located on the GPS board and supports the GPS Almanac information. One is located on the CPU board that supports Flight Plans and Navigation databases. The Universal Avionics Flight Management System (FMS) has two batteries. Avoid Sudden Universal FMS Battery Failures January 2016