Technical Standard Order TSO-C85 was originally developed around specific products each with specific performance characteristics that were limited by the designs and the components available at that time. These original product designs, though improved in various ways, are now over 40 years old and are still the basis of both TSO-C85 and AS4492. Advancing technologies in materials, batteries, and light sources (specifically LEDs) provide an opportunity to improve survivor location light performance, reliabililty, and cost effectivity. This revision of AS4492 is intended to provide for an optional approach for the Type I (steady-type) and Type II (flashing) lights, which take advantage of the latest advantages in LED and battery technology.
This revision of AS4492 is additionally intended to provide compliance guidelines addressing changes in the minimum performance standards (MPS) for survivor locator lights from the most recent version of FAA Technical Standard Order TSO-C85b/EASA Technical Standard Order ETSO-C85b.