Which backcourse approaches are authorized for use with IESS in navigation?

In the context of the ERJ 170/175 and its navigation systems, backcourse approaches using an Instrument Landing System (ILS) feature specific limitations. When operating with the Inertial Reference System (IESS), it is important to understand that only certain types of approaches are authorized.

Backcourse approaches are those where the aircraft approaches an airport using the back side of a localizer signal. However, the use of IESS during these approaches is not sanctioned. This restriction is in place because the procedures developed for backcourse approaches typically do not account for the specific navigation reliability and performance requirements of IESS.

Therefore, the statement indicating that LOC Backcourse approaches are not authorized aligns with the operational limitations set forth in the aircraft's operational manuals and regulatory guidance. This ensures pilots operate within the safe and approved parameters of the aircraft's navigation systems. Understanding this limitation is crucial for maintaining safety and compliance during flight operations.