Conversely, the airspeed indicator will show a decrease in airspeed when the aircraft descends. The pitot tube is susceptible to becoming clogged by ice, water, insects or some other obstruction.[5] For this reason, aviation regulatory agencies such as the U.S. Federal Aviation Administration (FAA) recommend that the pitot tube be checked for obstructions prior to any flight.[2] To prevent icing, many pitot tubes are equipped with a heating element.