On 2/11/2015 11:25 AM, SF wrote:
Well here is what I did...
Snip...
Without thinking about it too much I repeated the Split S a few seconds
later. The rapid advance of the ASI towards red line was impressive and
relentless.

Between this and JJ's recent "thunderstorm" thread, methinks we're seeing
evidence of winter in the northern hemisphere; contributors are willing to
share some survived sillinesses! That's a good thing, and I thank all for sharing.

I happened to read the original question posed in this thread ("If you
inadvertently fly into the yellow range and kiss the red range, and you get
into the high speed vibration, what is the best way to slow before the wings
depart the glider. My sense is to reach for the spoilers and slowly extend to
slow.") late in the PM before retiring to Zonkland, and will admit the
2nd/declarative sentence, and a personally compelling interest in soaring
safety, triggered a mental alarm bell. I'll elaborate on "Why?" shortly.

But first, even if the question is simply a cleverly designed attempt to
initiate a broad-in-scope discussion (as distinct from reflecting the O.P.'s
personal/presently-felt state of knowledge), it's a good one! The devil is
always in the details, and the details of gliders' load-bearing construction
commonly include structures composed of wood, steel tube and fabric, sheet
aluminum, 1st-generation fiberglass, and carbon fiber. Each has distinctly
different toleration to "high speed vibration"...which itself is a concept
worthy of lengthy definition, perhaps! Bottom line is these details may prove
to be compellingly important to Joe PIC, particularly in the time granted by
the structure to implement "the proper response." Arguably, 1st-generation
glass structures may simultaneously be most likely display to "high speed
vibration", and, to grant Joe PIC the greatest length of time to correct it
before something disastrous happens to the structure; wood and sheet metal may
be least generous with pre-failure time. Regardless of structure, "high speed
vibration" *will* get your attention...as well it should!

I could be reading way too much into original question/and "sense" of the
O.P., but here's why the sentence pair triggered an alarm bell. Is any reader
aware of any glider manufacturer's ship documentation that recommends as the
*first* corrective step for anything (other than pattern work, and perhaps,
tow-related height correction) to open the spoilers? Others have sensibly
noted several structural reasons that doing so at "too high a speed" may be
distinctly unwise, and I'm a fan of undoing first what caused the
problem...which in the case of high speed, certainly wasn't the spoilers.

So...no snark intended in my original reply. Anyone who finds themselves with
a case of "inadvertent imminent overspeed" surely had BETTER be alarmed, and,
have a sensible, pre-planned course of action ready for immediate implementation.

Good, thought-provoking scenario...

Bob W.

P.S. My own glider thunderstorm story involves the usual "made sense at the
time" rationales, resulted in a go-around initiated on short final from the
full-flap condition in an HP-14, in blinding rain and strong lift, in order to
avoid an overshoot into a tree lined mini-canyon/defile. It happened with
somewhere between 300 and 400 total hours...and served as "fair warning"
regarding thunderstorms...not that I should have needed - or been granted -
any. Even though I got away with it, I really should've landed out at the last
usable field 10 or so miles away. My most compelling rationale for continuing
was a really lousy trailer, though wanting to complete the contest task played
a part too. As I recall, only 4 or 5 of 30 did...and it wasn't the
thunderstorm over the field that put 'em on the ground!