The Federal Aviation Administration (FAA) and National Park Service (NPS) jointly requested that the Federal Interagency Committee on Aviation Noise (FICAN)"provide advice on some matters related to the measurement and assessment of the effects of aircraft noise due to overflights of units of the National Park System." FICAN findings and recommendations are included.

This study provides new insights into aircraft plume behavior that greatly surpasses historic understanding, and data for more accurate modeling of plume rise and spread from commercial aircraft at airports. This final report completes individual analysis of the LAX data set, initially reported in the related Preliminary Report published in September 2002. Additional studies are planned (based on available funding) to analyze potential changes in the derived parameters due to site characteristics (e.g., elevation, weather conditions) and will be reported on as the work continues.

Two procedures for adjusting as-measured test-day spectra to reference day conditions - the Society of Automotive Engineers' (SAE) Aerospace Recommended Practice (ARP) No. 866A (866A) and a procedure utilizing pure-tone absorption equations, developed in support of the International Organization for Standardization's (ISO) 9613-1 and the American National Standards Institute's (ANSI) S1.26-1995, and refined for application to one-third octave-band data- were evaluated and compared. The ISO and ANSI pure-tone absorption equations are identical to each other. The 866A procedure historically has...

Sounds associated with oversnow vehicles, such as snowmobiles and snowcoaches, are an important management concern at Yellowstone and Grand Teton National Parks. The John A. Volpe National Transportation Systems Center's Environmental Measurement and Modeling Division is supporting the National Park Service with its on-going Winter Use Planning program. As part of this support, acoustic measurements of ten snowcoaches and six snowmobiles were made at the south entrance to Yellowstone National Park from the 26th through the 28th of February 2008. Measurement methodologies were guided by SAE...

In March 1998, the Federal Highway Administration (FHWA) Office of Natural Environment, released the FHWA Traffic Noise Model (FHWA TNM) Version 1.0, a state-of-the-art computer program for highway traffic noise prediction and analysis. Since then, the FHWA, with assistance from the Volpe Center Acoustics Facility (Volpe Center) and Foliage Software Systems (FSS), have released updates of TNM (Versions 1.0a, and 1.0b) in March 1999 and August 1999, respectively. In support of the FHWA and the California Department of Transportation, the Volpe Center and FSS released Version 1.1 in September...