He very definitely did, as a (guest? I don't know) member of the Cumberland
Soaring Group in (at least) the early 1970s.
As a recent college grad, during my student instruction one morning (the '73
season), there was a flurry of activity among some of the more senior club
members around an older - unfamiliar to me - man (who appeared to be anywhere
from 45-65 years of age from my distance). Fuzzy memory says he eventually was
packed into another member's Libelle for a launch. Further instruction
activities on my part precluded my maintaining further daily awareness of his
day's soaring success.
Prior to my day's instruction, I was told by the chief instructor the man was
Wernher von Braun who liked to come out "as anonymously as possible"
(presumably to enjoy both soaring and the anonymity). I was also informed he
had a daughter who also participated at some level in soaring, but I don't
recall her being there that day.
That was the only time I saw him at the field.
Bob W.