What is the maximum RPM for the engines in normal operations?

The maximum RPM for the engines in normal operations is set at 90% N1. This value is critical for ensuring the engines operate within their designed parameters, particularly during various flight phases. Operating the engines at or below this threshold allows for optimal performance, reliability, and efficiency, thereby preventing excessive wear and potential damage. Exceeding this RPM could lead to engine strain, reduced performance, or failure, which is why it is essential for flight crews to adhere to this limitation during normal operations.

Choosing this RPM level is based on extensive testing and data that show it provides a balance between performance and engine longevity under typical operating conditions. It is aligned with Boeing and Embraer operational specifications for the ERJ 170/175 aircraft. Understanding this limit is vital for pilots and flight engineers to ensure both safety and compliance with operational standards.