As far as I remember (which may not be that far after all), the following applies to FAR23 A/C :
Vd = design divespeed. At this speed, the aircraft must be able to withstand
a) A vertigal gust of 15 ft/sec without exceeding LLF (or does this one apply to Vne
:o ?)
b) Aerodynamic torsional forces and show no undesirable flight characteristics, including flutter.
Vne is thus established as Vd - 10%...
Regarding the descending turn thing : The descent gradient in a 60deg banked, coordinated turn will depend on the L/D ratio of the A/C and the powersetting. Speed changes may cause variation i g-forces, e.g. will a speed reduction result in momentarilu increased G and reduced ROD, but this will only apply to the transition, not to the stabilised case...
(as the humble man ends his sayings)...I believe
