The U.S. Department of the Interior (DOI), National Park Service (NPS), and the U.S. Departmentof Transportation (DOT), Federal Aviation Administration (FAA) are jointly sponsoring a study toexamine the accuracy of existing models used for predicting tour aircraft noise in Grand CanyonNational Park (GCNP). In particular, three models will be included in the study: the NPS' NoiseOverflight Decision Support System (NODSS), the FAA's Integrated Noise Model (INM), and athird model, the Noisemap Simulation Model (NMSIM), which has been developed with fundingfrom both the U.S. Air Force and the National Aeronautics and Space Administration. A keycomponent of the GCNP Noise Model Validation Study is the collection of field data to support thevalidation effort. These field data will be translated into formats usable by the three noise predictionmodels. This common set of high quality field data will allow an unbiased comparison of the threemodels. This letter report addresses portions of the field data collection activity and associated dataanalysis.