Flutter clearance out to / past Vd
 

Commercial airplanes are flight demonstrated out to Vd and slightly beyond at a number of payloads and fuel loadings as part of flutter clearance flight testing. The speed / Mach margin between Vmo/Mmo and Vd/Md is set by dive recovery regulations such that an inadvertent dive from a condition at/below Vmo/Mmo will not result in exceedence of Vd/Md provided the crew takes reasonable corrective action.

The bottom line here is that a commercial airplane can be safely flown out to Vd/Md. Crews may have to report an incident where the overspeed horn goes off, but they should not have a problem flying home safely from an event that takes them out to Vd.