Hm. I thought it went like this: JAR 23 aircraft have Vno / Vne, while JAR 25 aircraft have Vmo / Mmo..?
Larger aircraft have a greater margin to Vd (design dive speed, where no excess flutter will occur etc; JAR 25-335) ... Because these are often jet engine powered; an upset in attitude (pitch down) is more difficult to arrest, and speed build-up more rapid, whereas a JAR 23 a/c will most probably have a propeller (more drag) and speed build-up is slower (pull to flight idle, and problem solved), allowing the pilot to correct the upset in a timely manner even though the margin to Vd is 10% (?).
Either way, I think the difference between Vno and Vmo is only in the safety margin. Large a/c = greater margin, and it is not safe to exceed Vmo anymore than it is to excee Vne.
Am I completely off the mark? Anyone?
