On takeoff in the RV-10 the other day, I had a very fast airspeed fluctuation on rotation. It only did it once and only for a moment. IIRC, the AS indication went down then back up and stabilized. After the flight, I decided to wash the plane. When I grabbed the pitot mast to wash it, it fell from the bottom of the wing hanging by the wires and pitot/AOA tubing. I have Dynon Pitot and Safeair pitot mast. You can imagine what damage this could have cased to the bottom of the wing if it fell during flight! I did some research and found on Safeair's website that they have had a couple of failures just like mine reported. The mast to the mounting flange weld cracks and fails. As a result, they have a new and improved pitot mast available so check to make sure you have the newer version. http://safeair1.com/averytools/pitotmast.php
Failed pitot mast weld
Failed pitot mast weld