Two years ago, on my first flight of the year I saw that the airspeed indicator was not working (read zero). Feeling comfortable with approximate airspeeds I did a refresh on where close to stall was and went off on a 2 1/2 hour cross country flight with no problems. Kept the speed up and nose down a bit on pattern and landing. Looking into the nose area I found that the plastic tubing had slipped off the Pitot tube in the nose, probably from a long trailer ride. It is now secured with a Ty-wrap.