Recent changes to aircraft approach and departure procedures enabled by more precise navigation technologies have created noise concentration problems for communities beneath flight tracks. There may be opportunities to reduce community noise impacts under these concentrated flight tracks through advanced operational approach and departure procedures and advanced aircraft technologies. A modeling method to assess their impacts must consider the contributions of aircraft engine and airframe noise sources as they vary with the position, thrust, velocity, and configuration of the aircraft during the flight procedure. The objective is to develop an analysis method to design, model, and assess the community noise reduction possibilities of advanced operational flight procedures performed by conventional aircraft and advanced procedures enabled by future aircraft concepts. An integrated analysis framework is developed that combines flight dynamics and noise source models to determine the community noise impacts of aircraft performing advanced operational approach and departure procedures. Aircraft noise due to the airframe and engine is modeled using an aircraft source noise module as each noise component varies throughout the flight procedure and requires internal engine performance states, the flight profile, and aircraft geometry. An aircraft performance module is used to obtain engine internal performance states and aircraft flight performance given the aircraft technology level. A force-balance-kinematics flight profile generation module converts the flight procedure definition into altitude, position, velocity, configuration, and thrust profiles given flight performance on a segment-by-segment basis. The system generates single-event surface noise grids that are combined with population census data to estimate population noise exposure for a given aircraft technology level and procedure. The framework was demonstrated for both advanced approach and departure procedures and advanced aircraft technologies. The advanced procedure concepts include modified speed and thrust departures as well as continuous descent, steep, and delayed deceleration approaches for conventional aircraft. The ability to model advanced aircraft technologies was demonstrated in the evaluation of using windmilling drag by hybrid electric aircraft on approach to allow the performance of steep and delayed deceleration approaches for noise reduction beyond the performance capability of standard gas-turbine aircraft.

Aviation noise remains the primary hindrance to expansion of airport and airspace capacity in the United States. This book describes the development and practice of U.S. aircraft noise regulation, as well as the practical consequences of regulatory policy. Starting in the pre-jet transport era, the book traces the development of the modern framework for characterizing, standardizing, predicting, disclosing, and mitigating aircraft noise and its effects on airport-vicinity communities. Among other matters, the book treats noise-related consequences of the 1978 deregulation of the airline industry; prediction and mitigation of community reaction to airport noise; land use compatibility planning; recent research and industry trends; and some suggestions for potential improvements to current policy. Initial chapters describe the assumptions underlying aircraft noise regulation, and lay out the chronology of U.S. aircraft noise regulatory practice. Later chapters provide overviews of population-level effects of aviation noise, including health effects, speech and sleep interference, and annoyance. Readers will learn why predictions of the prevalence of aircraft noise-induced annoyance have systematically underestimated adverse community response to aircraft noise, and how such underestimation has complicated approval and funding of airport and airspace improvement projects. They will also learn why attempts at noise-compatible land use planning are seldom fully successful.

Advanced aerial mobility is a newly emerging industry that aims to develop and operate new air vehicles potentially capable of safe, reliable, and low-noise vertical flight. The world has seen a recent increase in the adoption of electric vertical lift aircraft for urban, suburban and rural operations. These new innovations and technologies change the way that we move cargo and people, affecting industries across the economy. These changes will challenge today's airspace monitoring systems and regulatory environment. The U.S. government and its regulatory agencies need technical guidance to facilitate the development of these technologies, and to create the regulatory framework to foster the growth of this vertical flight industry to the benefit of the aviation industry. Advancing Aerial Mobility evaluates the potential benefits and challenges associated with this emerging industry. This report provides recommendations that seek to foster an environment in which the nation can maintain its leading position in developing, deploying, and embracing these new technologies. This publication presents a national vision for advanced aerial mobility, market evolution, and safety and security management.