As we all learned in Flight School 101, airspeed indication is a measurement of the difference between ram air and static air. Since the pitot tube points right into the relative wind, taking in the ram air, it is also exposed to any debris in the air that you’re flying through. It’s not entirely uncommon for the tiny little hole to get plugged by bugs or other airborne objects. A little practice will eliminate the potential panic as the airspeed unexpectedly indicates zero.
By grabbing one of your pilot friends or an instructor, you can practice flying without using the airspeed indicator and create a fun and valuable learning experience. Have the right seat pilot cover up the airspeed indicator in a way that only he or she can still see it. Then fly at different airspeeds and different configurations at a safe altitude and see how accurately you can estimate your speed. There are several clues that allow you to make a guesstimate. The power setting, the sound of the engine and the airflow, and the outside picture all give good indications to the observant pilot.
Once you’ve gotten comfortable at a higher altitude, practice the same thing in the airport environment. It’s not necessary to take the practice all the way to a landing, but it’s worth practicing approaches without using the airspeed indicator. See if you can fly the pattern at the airspeeds you generally use for the airplane you’re flying, for example 85 knots on downwind, 75 knots on base, and 65 knots on final — the speeds, of course, depend on your airplane.
You can even make a fun game out of the airspeed lesson. Have the right seat pilot record your readouts and the actual airspeed while flying to your favorite destination. On the way back, switch seats. Once back on the ground at your home base you can compare score sheets, like after a round of golf.
No matter how comfortable you get flying without using your airspeed indicator, remember that the instrument is a required piece of equipment and you should never take off if you know it is not working properly. But this type of practice will be helpful should the airspeed indicator fail in flight.