The N2 transient region begins at what N2 value?

• A. 103.01%
• B. 102.5%
• C. 108%
• D. 103%

Answer: (D)

The N2 transient region is defined by the system entering dynamic, non-steady response as N2 rises above its nominal value. The official onset is at 103% of N2, meaning once N2 reaches 103% of its nominal speed, transient effects start to dominate. This 3% margin accounts for measurement tolerances and mechanical inertia, so 103% marks the precise threshold. Values below that stay in steady-state behavior, while higher values are within or beyond the transient range. That’s why 103% is the correct starting point.