NTSB Issues Recommendation A-17-030 to National Weather Service Regarding Mountain Wave Reporting Criteria

The National Transportation Safety Board, identified by reference number DCA15SR001, has issued Recommendation A-17-030 addressed to the National Weather Service. This directive urges the agency to work jointly with the Federal Aviation Administration to revise both the Aeronautical Information Manual and Advisory Circular 00-45H. The goal is to establish standard criteria for reporting mountain wave activity within pilot weather reports, known as PIREPs. These revised criteria must include specific considerations acknowledging that not all hazardous mountain wave encounters involve turbulence. Additionally, the new standards require pilots to report airspeed fluctuation ranges, altitude fluctuation ranges, and any other necessary information to adequately describe the effects of the activity on the aircraft. The recommendation further mandates parameters for classifying the intensity level of conditions for both turbulent and smooth wave encounters. Finally, it calls for defining the threshold at which PIREPs for each type of encounter should be coded as urgent.