For a few years now FAA Federal Aviation Regulations have required all air carrier operators to operate with an approved airborne weather radar. The new airborne Doppler weather radars detect wind shear. The requirement for having this radar has greatly reduced the potential for accidents caused by microbursts. (Operations within the states of Hawaii and Alaska are exempt from these requirements.) These radars, however, are not capable of detecting turbulence in clear air at high altitudes. Always check our web site: Aviation Weather Law http://www.aviationweatherlaw.com/