Technical standard order authorization and airworthiness approval considerations for aircraft weather radar systems

There have been many improvements and changes in the technology, design features, and displays for forward-looking turbulence and windshear, weather, and ground mapping pulsed radar systems. The paper summarizes the issues of forward-looking turbulence and windshear radars and the airworthiness design approval of these systems as they relate to [1]. The Federal Aviation Administration (FAA) issued TSO-C63d as the minimum performance standard for forward-looking turbulence and windshear, weather and ground mapping pulsed radar equipment. TSO-C63d addresses receiver/transmitter, processor, antenna, control, and range, including annunciation and detection performance for forward-looking turbulence and windshear systems. For forward-looking turbulence systems, TSO-C63d addresses detection performance probabilities common to three aircraft wing loading classes. The detection performance probability criteria were validated in National Aeronautics and Space Administration (NASA) Flight Tests of the Turbulence Prediction and Warning System (TPAWS) Program. The TSO provides procedures and alternatives for analysis and simulation verification of the turbulence detection performance in various turbulence wind field conditions. The TSO does not address hazard threshold setting requirement for forward-looking turbulence detection performance. For short range and long range forward-looking windshear systems, TSO-C63d addresses detection performance probabilities regarding windshear F-factor, and hazard threshold for caution, warning, and advisory alerts. These detection performance probability and alert criteria were validated in the NASA/FAA Airborne Windshear Program. The TSO also provides procedures for analysis and simulation verification of the windshear detection performance in various windshear and operating conditions.