Pulling up the discussion, I was looking at JAR-27 and I couldn't find any relevant information about "HIGH NR". Or should I say, where can I read about the intention of raising RPM. It is logical to me, that rpm increase gives you a fighting chance in the event of critical powerplant failure, but its hard to have a forum debate as a reference.
Any literature, standards?
Another thing; is there an "AMC" to JAR-27 like in JAR-FCL, that would require standards like 135's 110 kts to autorotation safe speed of 90 kts in 1.7 seconds? I'm thinking this standard should contain increased rotor speed...