scope:

This standard describes noise measurement procedures to characterize the noise emissions, including directivity and non-linearity, from high performance military (supersonic jet flow) aircraft during ground and airborne operations. The data resulting from the procedures described in clauses 6.3 through 6.7 of this standard are appropriate as input for community noise propagation models such as NOISEMAP[12] and the Advanced Acoustic Model (AAM)[16]. NOISEMAP data have been converted and applied for use in the Federal Aviation Administration's Integrated Noise Model (INM)[7] to supplement community noise assessments.[24] These models will use the noise measurements collected in accordance with this standard for preparation of official documents such as community environmental impact statements and environmental assessments. Noise measurements collected in accordance with this standard will also be used to define aircraft support personnel noise exposures, aircraft noise reduction and propagation studies, and evaluation of aircraft and propulsion system compliance with noise requirements and regulations.

This standard describes methods for the measurement of noise from high performance military aircraft covering the following operation modes: ground run-up, flyover, conventional take-off and landing and short/vertical take-off and landing. This standard serves as a toolbox of recommended measurement locations and acquisition methods for specific types of test and non-test applications. There are separate methods for measuring personnel noise exposure (e.g., Figure 2), ground run-up (e.g., Figure 4), and flyover noise (e.g., Figure 7) for use in National Environmental Policy Act (NEPA) documents such as environmental impact statements, and for development uses such as measuring/validating the propagation of sound from a source or the effect of a noise reduction technology (e.g., Figures 3, 5, 8). These measurement methods can be conducted independently, or, in some instances, combined, to satisfy multiple goals and thus potentially minimize cost and test time. It is not required that all methods in this standard are employed to characterize the noise emitted from an aircraft. In some circumstances both ground run-up and flyover measurements will have to be used in combination to predict far-field noise levels from aircraft operations; however, they cannot be used interchangeably if accurate noise level exposure predictions are desired.

The data recording and reporting requirements are given in order to ensure compatibility with common noise exposure mapping tools. Noise measurement and signal processing procedures are defined in order to achieve accuracy within the defined measurement uncertainty.

This standard does not address the application of noise propagation models such as NOISEMAP, INM, or AAM in the NEPA-defined environmental processes. The results of the noise measurements conducted in accordance with this standard are limited to the characterization of noise emissions of high performance military aircraft. Additionally, this standard applies only to future measurements conducted after approval by ANSI. It is not intended to require the retest or re-measurement of aircraft noise measured prior to the publishing date of this standard.