本标准描述了测量未安装的军用飞机发动机的喷气噪声的程序 超音速排气流。这些方法适用于安装在室外试验台上的推进系统 具有适当的入口和代表性的喷嘴。详细的测量程序描述如下: 近场声学特性。这些数据可用于建立基线噪声水平，评估 降噪技术的有效性，估计人员噪声暴露，并提供全面的 用于改进发动机噪声模型的数据。本文描述了远场测量程序，以提供 社区噪声估计数据。本标准描述了所需的测量仪器， 信号处理、数据格式化和测量不确定度。本标准不适用于 商用发动机、两用发动机或FAA/ICAO噪音认证涵盖的其他发动机 要求。

This standard describes procedures to measure jet noise from uninstalled military aircraft engines with supersonic exhaust flows. The methods pertain to propulsion systems mounted on outdoor test stands with appropriate inlets and representative nozzles. Detailed measurement procedures are described for near-field acoustical characterization. These data can be used to establish baseline noise levels, assess effectiveness of noise reduction technologies, estimate personnel noise exposure, and provide full-scale data for refinement of engine noise models. Far-field measurement procedures are described to provide data for estimates of community noise. This standard describes required measurement instrumentation, signal processing, data formatting, and measurement uncertainty. This standard does not apply to commercial engines, dual-use engines, or other engines covered by FAA/ICAO noise certification requirements.