Turbulent Atmospheric Conditions Research Articles

Range requirements for airborne turbulence detectors.

H high-altitude aircraft are expected to encounter turbulent atmospheric conditions that may produce undesirable aircraft motions and loads. It has been suggested that such turbulence can be avoided by use of an airborne detector system (e.g., forward-looking radar or laser). The detector would see the turbulence ahead, and the aircraft would then be maneuvered to fly around the contaminated area (see Fig. 1). The purpose of this Note is to alert the designers of CAT (clear air turbulence)-sensing equipment to be aware that in their definition of range requirements for airborne CAT detectors they must consider 1) the comfort of the passengers, 2) the geometry of the to-be-avoided CAT areas, 3) the maneuver capability of the aircraft, and 4) the decisionmaking process of the pilot. Some back-of-the-envelope calculations were made to obtain an indication of the range requirements for such detectors—assuming that they were to be used onboard a supersonic aircraft (e.g., the SST). Each of the four aforementioned considerations is included in the calculations. The results of this exercise are summarized below and in Fig. 2 (for a Mach 3 airplane).