Microbursts The extent to which wind shear presents a hazard to aircraft has been well documented in the last ten years. Since some wind shear can occur in otherwise relatively good weather, the most hazardous kind, a microburst, is associated with rain showers and thunderstorms even thought the parent storm may not be discernible. It was not until the early 1970's that the National Transportation Safety Board was able to obtain the level of data form flight recorders to quantify wind shear. This data became an invaluable tool to assist researchers as well as accident investigators. The physical conditions of