Early in instrument training, my CFII covered the pitot static instruments with paper angled for visibility from the right seat. Having owned my mooney for three years, and used it for frequent traveling, my CFII was surprised that I could fly requested speeds . . .
But I had a first tonight. Been tied down in off-and-on rain for several days, was thinking about the static drains while driving top the field, then forgot about them. On takeoff roll, ASI didn't move. I started to pull the throttle, then distinctly remembered putting the pitot cover on the hatrack and kept going as the ASI came alive but seemd low. The ASI, IVSI and altimeter were quite jumpy for the first 15-20 minutes; it's quite unnerving to see the ASI jump up or down 10 mph, causing great swings also in the IVSI (usually several hundred feet per minute).
It wasn't until I was approaching to land an hour later that I remembered this:
Shoulda stopped and drained the static lines. Did it after landing, first time in 17 years' ownership that anything happened when I pressed the button, a few drops of water ran down my finger. Presed a few more times until a dry finger came away dry.
Ya'll be careful out there!