youngmic
Used to be that FAR 23 gust loads were based on a vertical component of 15 m/s believe it latter changed to 30m/s. But could be wrong on this.
may be may be not, whatever the case may be, if the aircraft was certified at the "old or previous" vertical component any later change is simply academic.
Think grandfathering and why it is unlikely that the type would not now be certified as is were it to be presented as a newbie, same as the B747 100.
It has always been a mystery to me (not really) why I hear so many youngsters speak in awe of a type that has such a long history. There is an inevitability and confluence of history, events and personalities here that I dare not yet discuss. When the times right perhaps.
Go to the reference to which
Brian refers and have a close look at the number of amendments for each section. There is a hard earned reason for every one of them the beneifts of which aircraft certified before each amendment did not necessarily share.