New gliders can be especially exciting.

A few years back I was lurking about preparing to go fly,
when a guy landed back early after his first flight in his
just-off- the-boat supership, in a huge huff. He ran at me
yelling "Your damn instruments don't work. Now go fly that thing
and figure out what's wrong". Oooyyyy, I've heard this
before, and its not my stuff that's the problem ;-)

I strapped in and noticed the ASI reading 0 as I lifted off.
Had a lovely afternoon soaring in this gorgeous new machine,
gotta love that new-paint smell.
Without working instruments of course.
On landing still irate owner ran up to the glider (thought
I'd given him enough time to cool off). I popped the canopy
and pointed at the ASI - now indicating 50 knots.

There was about a quart of water in the static lines
and various other silliness. He hadn't washed it (literally
opened the trailer, got the paperwork, and flew).
Best guess is final wash at the factory?
I'm not sure how that much water can get in the statics.

I've also seen (not recently) logbooks recording test flights
that obviously never happened.

Take special care around new machines!

Hope that is helpful,
Best Regards, Dave