The is a self-contained emergency power supply designed primarily for aircraft to provide critical standby power to attitude gyros and essential flight instruments in the event of a total electrical failure. Manufactured by L-3 Communications (now L3Harris) and supported by Extant Aerospace , this unit relies on sealed lead-acid batteries and requires strict adherence to its Component Maintenance Manual (CMM TP-483) to ensure flight safety. Core Maintenance Requirements
Batteries must be left in a discharged state, as this causes permanent damage. ps-855b maintenance manual
With no external power applied, press and hold the button for 5 seconds. The is a self-contained emergency power supply designed
The unit can reach 50% capacity within one hour at 25°C under normal flight conditions. ps-855b maintenance manual