bspatz,
you may be right but it is an old (faded illegible writing) slide and when I was with JATE I cannot find any entry in my log books of ULLA at Hullavington. Everything else but not ULLA. Can't think why would not not as we did ULLA (single) at the much more restrictive South Cerney.
Speaking of the slides it is very odd how some have survived virtually unscathed and others have deteriorated so much.
As for voluntarily doing more balloon jumps, huge respect. One was enough for me.