Correlation Between Clear Air Turbulence and Aircraft Electrical Activity 660184

The results of a cooperative effort by Stanford Research Institute, United Air Lines, and Air Force Cambridge Research Laboratories to determine the correlation between regions of clear air turbulence (CAT) and aircraft electrical activity are described. Corona discharges from precipitation static dischargers on DC-8 aircraft were monitored and correlated with CAT encounters. A significant correlation was found to exist between CAT encounters and periods of electrical discharge. It is suggested that these electrical discharges may be caused by electric fields in the region of clear-air turbulence, particulate matter in the region that charges the aircraft, or a combination of both. The results of a meteorological analysis of the regions where turbulence associated with electrical activity was observed indicated that the CAT incidents were of typical kinds that are associated with jet streams.