Pitot system - odd event

On Wednesday, May 23, 2018 at 11:02:30 PM UTC-4, Del Jensen wrote:
Something clearly sent a shock through the pitot system

No... These exact symptoms can be caused....

Donkeys years ago I happened by a gliderport where I was assaulted by
an angry new glider owner. "Your instruments don't work worth crap!
P.O.S. !!! Go fly this glider and tell me what's wrong". And so forth.

I strapped on the shiny new plane and took off, noting incorrect ASI
on tow and general odd behavior. Enjoyed a nice flight and gave the new
owner some time to reflect on the error of his ways. Very peaceful
with no audio or instruments to distract from the pleasure of a nice
soaring day and the new-glider smell. Eventually I flew back home and
noted that as I rolled to a stop the ASI still read 45 knots.
New owner ran up and I pointed at the mechanical ASI...

The glider had been hosed down, and water was trapped in the low part
of the tube between the pitot probe and instruments. With enough airspeed
and agitation bubbles of air could get through the water, then the remaining
column of water acted like a water manometer. IIRC there was more than
a pint of water in the tube.

There was certainly no "burst diaphragm" in this instance but all other
symptoms match (including failure to correctly re-zero the electonic
ASI). Drying everything out (no compressed air EVER) cured all.

Please tell us the location of your pitot and the type of glider!

Hope that helps someone,
Best Regards, Dave