What are the forensic signs of 'Centrifugal Fly-out' in high-speed rotating rings?

'Fly-out' occurs when a ring expands due to centrifugal force and leaves the groove. Forensic signs include the ring being found 'loose' on the shaft, often with significant wear or heat-discoloration on its inner diameter from spinning against the shaft outside of the groove. Unlike a thrust failure, the groove itself might remain undamaged. To confirm this, the engineer should calculate the $N_{max}$ using the formula from ID 622. If the operating RPM was within $20\%$ of $N_{max}$, fly-out is highly likely. The remedy is to specify a 'Self-Locking' spiral ring or to increase the interference fit by reducing the ring's free diameter $D_i$.