Page:CAB Accident Report, United Airlines Flight 21.pdf/80

  The need for adequate windshield wipers or other devices for improving vision from the cockpit under adverse atmosphere conditions is self-evident and was especially brought out at the Chicago hearing. The need for such a device has been long recognized by the industry and research has been conducted by the National Advisory Committee for Aeronautics and by some operators in an effort to develop a satisfactory windshield wiper. In order to further this project, and to encourage the most rapid development of an adequate windshield wiper, the Board recommends that the Administrator of Civil Aeronautics take steps through appropriate channels, including air carriers, to expedite the development and adoption of an adequate device.

The Board recommends that the Administrator of Civil Aeronautics stimulate the development of a more accurate means of measuring the rate of ice accretion and the adoption of an appropriate device for this purpose. The Board recommends further that the appropriate governmental agencies be requested to determine the relation of ice accretion to the terms generally used when reporting ice, namely, "light, medium and heavy".

The testimony of several pilots indicates that the formation of ice in and on the pitot tubes and on the pitot tube mast may lead to erroneous readings. It is understood that this problem is the subject of study and research by the air carriers and various governmental agencies. The Board recommends accelerated research in connection with the development and adoption of an air speed indicator which is not susceptible to incorrect readings due to formation of ice.

The Board recommends that the National Advisory Committee for Aeronautics continue and intensify its research looking toward the development 