TagPart 150(263)

In a September 1, 1992 letter to the FAA Administrator, the Regional Commission on Airport Affairs formally requests reconsideration of the FAA's August 14, 1992 decision approving Passenger Facility Charges (PFCs) at Seattle-Tacoma International Airport. The Commission, representing communities near Sea-Tac severely impacted by aircraft noise, argues that PFC funds should be redirected toward noise mitigation efforts rather than security improvements and preliminary studies, and that local governments were not properly notified or consulted during the PFC application process. The letter calls for increased funding levels for noise mitigation, cancellation of certain approved expenditures deemed inappropriate or excessive, and greater consideration of local government views in future PFC allocation decisions.

In this 1992 letter, acoustics expert James D. Chalupník explains to attorney Richard Aramburu how aircraft noise near Seattle's Sea-Tac Airport is measured and rated, focusing on the appropriateness of the Ldn metric and the data used in the FAA's Integrated Noise Model (INM). He outlines the key physical properties of noise—intensity, frequency distribution, and fluctuation over time—and describes how various weighting schemes, particularly the A-weighting (dBA) scale, are used to approximate human perception of loudness and annoyance. The letter also notes the limitations of simpler metrics and introduces more sophisticated rating methods such as Stevens' Loudness Level and Perceived Noise Level for evaluating aircraft noise.

The Seattle-Tacoma International Airport Noise Budget, effective January 1, 1991, is a formal agreement designed to limit and gradually reduce overall aircraft noise levels at Sea-Tac Airport. It establishes a system of noise allocations assigned to individual passenger and cargo carriers, measured through defined noise exposure levels, with limits enforced on both a quarterly and annual basis. The agreement outlines key definitions and rules governing how noise is measured, allocated, and managed, including provisions for new entrants, international carriers, and government aircraft.

This 1990 FAA document explains why the Day Night Average Sound Level (DNL) was chosen as the standard metric for measuring airport noise. DNL averages noise exposure over a full 24-hour period, applying a penalty for nighttime flights, and has been adopted by multiple federal agencies—including the EPA, DOT, HUD, and DOD—as the most reliable way to assess how aircraft noise affects surrounding communities. The FAA formally incorporated DNL into federal regulation through FAR Part 150, Airport Noise Compatibility Planning, in 1981.

This 1985 document, prepared by the Port of Seattle, outlines the Part 150 Airport Noise Compatibility Program for Seattle-Tacoma (Sea-Tac) International Airport. It combines two phases: Phase I, Noise Exposure Maps (officially submitted to the FAA in October 1984), and Phase II, a Noise Compatibility Program adopted by the Port Commission in January 1985. Together, these phases identify noise exposure around the airport and propose measures to address compatibility between aircraft noise and surrounding land uses.