Boston Logan Airport Noise Study
left image Welcome Study Phase 1 Phase 2 Phase 3 Document Library right image

Text Size Decrease Font Size Increase Font Size

A-D | E-H | I-L | M-P | Q-T | U-Z




ENPLANED PASSENGERS - The passengers on aircraft outbound (departing) from an airport. The total annual number of passengers at an airport is the total of enplaned and deplaned passengers (see also).

ENVIRONMENTAL ASSESSMENT (EA) - An assessment of the environmental effects of a proposed action for which federal financial assistance is being requested or for which federal action or authorization is required. The EA serves as the basis for an FAA Environmental Impact Statement (EIS) or Finding of No Significant Impact (FONSI), as specified in FAA Order 5050.4A.

ENVIRONMENTAL IMPACT STATEMENT (EIS) - A statement prepared under the requirements of the National Environmental Policy Act of 1969 (NEPA), Section 102(2)(c). The EIS represents a federal agency's evaluation of the effects of a proposed action on the environment. Regulations relating to the preparation of an EIS are published in FAA Order 5050 4A.

EPA U.S. - Environmental Protection Agency.

EQUIVALENT SOUND LEVEL - Noise metric that represents the total sound exposure for the period of interest or an energy average noise level for the period of interest. Abbreviated Leq.


FAA ADVISORY CIRCULAR (AC) 150/5300-13 - This document, titled "Airport Design," contains airport design standards, including descriptions of various subdivisions of FAR Part 77 (see also) such as obstacle free zones (OFZs), object free areas (OFAs), and runway protection zones (RPZs)- formerly referred to as "clear zones" -on airports. According to Paragraph 211, "Safe and efficient operations at an airport require that certain areas on and near the airport be clear of objects or restricted to objects with a certain function, composition, and/or height." To achieve this requirement, object clearing criteria contained in the AC describe the types of objects tolerated within various subdivisions of FAR Part 77. Aircraft are controlled by aircraft operating rules and not by these criteria. However, objects not in conformance with these criteria may result in aircraft operating restrictions.

FAA HANDBOOK 7400.2 - This document, titled "Procedures for Handling Airspace Matters," contains procedures and guidelines for analyzing aeronautical operating conditions and determining the effects of existing or proposed objects that exceed FAR Part 77 (see also) standards. Objects that exceed FAR Part 77 standards are subject to an aeronautical review and are presumed to be hazards to air navigation unless an aeronautical review determines otherwise. However, once an aeronautical review is initiated, FAR Part 77 standards are no longer the basis for determining whether or not an object would be a hazard. Other criteria, including operational, procedural, and electronic requirements, are used to determine if the object in question would be a hazard to air navigation. The outcome of an FAA aeronautical review is either a "Determination of No Hazard" or "Determination of Hazard to Air Navigation."

FAA HANDBOOK 8260.3B - This document, titled "TERPS" (terminal instrument procedures), contains obstruction clearance criteria for instrument procedures. Imaginary surfaces for each type of instrument procedure are described. If an object would penetrate the imaginary surfaces for a particular instrument procedure and could not be relocated or sufficiently reduced in height, one of the following would be necessary: (1) alteration of the procedure to minimize or eliminate effects; (2) increase in the minimum cloud ceiling and/or visibility requirements for conducting the procedure; (3) some combination of (1) and (2); or (4) preclusion of the particular procedure.

FAA ORDER 1050.1E - This document, entitled “Polices and Procedures for Considering Environmental Impacts,” was prepared in response to CEQ 1500 Regulations and provides guidance for preparing EAs and EISs for FAA actions.

FAA ORDER 5050.4A - This document, entitled "Airport Environmental Handbook," was published by the FAA on October 8, 1985. It contains all of the essential information an airport sponsor needs to meet both procedural and specific environmental requirements.

FEDERAL AVIATION REGULATIONS (FAR) PART 36 - This regulation, titled "Noise Standards: Aircraft Type and Airworthiness Certification," establishes noise standards for the civil aviation fleet. Certain extensions for compliance are included in the Aviation Safety and Noise Abatement Act of 1979 (see also).

FAR PART 77 - This regulation, titled "Objects Affecting Navigable Airspace," establishes standards for determining obstructions and their potential effects on aircraft operations. Objects are considered to be obstructions to air navigation according to FAR Part 77 if they exceed certain heights or penetrate certain imaginary surfaces established in relation to airport operations. Objects classified as obstructions are subject to an FAA aeronautical analysis to determine their potential effects on aircraft operations.

FAR PART 91 - This regulation, titled "General Operating and Flight Rules," includes an amendment issued by the FAA on September 25, 1991 (to 14 CFR 91) in conformance with requirements of the Airport Noise and Capacity Act of 1990 (see also). The amendment to the aircraft operating rules requires a phased transition to an all Stage 3 aircraft fleet operating in the 48 contiguous United States and the District of Columbia by December 31, 1999. The amendment places a cap on the number of Stage 2 aircraft allowed to operate in the United States and provides for a continuing reduction in the population exposed to noise from Stage 2 aircraft.

FAR PART 150 - This regulation, titled "Airport Noise Compatibility Planning," sets forth criteria for developing an FAR Part 150 Noise Compatibility Program, an FAA assisted program designed to increase the compatibility of land and land uses in the areas surrounding an airport that are most directly affected by operation of the airport. The specific purpose is to reduce the adverse effects of noise as much as possible by implementing both on airport noise abatement measures and off airport noise mitigation measures. The basic products of an FAR Part 150 program typically include (1) noise exposure maps for the existing condition and for 5 years in the future; (2) workable on airport noise abatement measures (preferential runway use programs, new or preferential flight tracks), (3) off airport noise mitigation measures (land acquisition, soundproofing, or special zoning); (4) an analysis of the costs and the financial feasibility of the recommended measures; and (5) policies and procedures related to the implementation of on and off airport programs. Community involvement opportunities are provided throughout all phases of noise compatibility program development.

FAR PART 158 - This regulation, titled "Passenger Facility Charges," establishes a passenger facility charge (PFC) program. The regulation implements Sections 9110 and 9111 of the Airport Noise and Capacity Act of 1990 (see also), which requires the Department of Transportation to issue regulations under which a public agency may be authorized to impose a PFC of $1, $2, or $3 per enplaned passenger at a commercial service airport it controls. The proceeds from such PFCs are to be used to finance eligible airport related projects that preserve or enhance safety, capacity, or security of the national air transportation system, reduce noise from an airport that is part of such system, or furnish opportunities for enhanced competition between or among airlines. The rule sets forth procedures for public agency applications for authority to impose PFCs, for FAA processing of such applications; for collection, handling, and remittance of PFCs by airlines; for record keeping and auditing by airlines and public agencies; for terminating PFC authority; and for reducing federal grant funds apportioned to large and medium hub airports where a PFC is imposed.

FAR PART 161 - This regulation, titled "Notice and Approval of Airport Noise and Access Restrictions," establishes a program for reviewing airport noise and access restrictions on the operations of Stage 2 and Stage 3 aircraft. This regulation is in response to specific provisions in the Airport Noise and Capacity Act of 1990 (see also) and is a major element of the national aviation noise policy required by that Act. Even if such an airport noise and access restriction is proposed as an element of an FAR Part 150 Noise Compatibility Program, it is still subject to the guidelines of FAR Part 161 prior to approval. Some of the public notice requirements, however, may be met during development of the FAR Part 150 program.

FEDERAL AVIATION ADMINISTRATION (FAA) - The FAA, an agency of the U.S. Department of Transportation, is charged with (1) regulating air commerce to promote its safety and development; (2) achieving the efficient use of navigable airspace of the United States; (3) promoting, encouraging, and developing civil aviation; (4) developing and operating a common system of air traffic control and air navigation for both civilian and military aircraft; and (5) promoting the development of a national system of airports.

FINAL APPROACH FIX - Starting point where the final segment of an instrument approach to a runway begins.

FINDING OF NO SIGNIFICANT IMPACT (FONSI) - A finding by the FAA that a proposed action by an airport sponsor will have no significant impact (on the environment). Specific guidelines for preparing a report that receives a FONSI are included in FAA Order 5050.4A.

FLIGHT TRACK - The average flight path flown by aircraft within specific corridors. Deviation from these tracks occurs because of weather, pilot technique, air traffic control, and aircraft weight. Individual flight tracks within a corridor are "averaged" for purposes of modeling noise exposure using the FAA’s Integrated Noise Model (see also).


GATE - The designated location in a terminal building that contains an airline podium area where ticketed passengers check in for a specific flight. (See APRON.)

GENERAL AVIATION (GA) - All civil aviation except that classified as air carrier or air taxi. The types of aircraft typically used in GA activities vary from multiengine jet aircraft to single engine piston aircraft.

GENERAL PLAN - (sometimes referred to as a comprehensive plan or community plan) An overall plan of a political jurisdiction setting forth the goals and objectives of the jurisdiction, policies for development and redevelopment, and maps showing the spatial arrangement of land uses, circulation routes, and community facilities.

GEOGRAPHIC INFORMATION SYSTEM (GIS) - A system of hardware and software used for storage, retrieval, mapping, and analysis of geographic data.

GLIDE SLOPE - (1) the vertical (or altitude) profile followed by an aircraft during the approach and landing. (2) electronic vertical guidance provided by airborne and ground instruments for instrument approaches (see PRECISION INSTRUMENT APPROACH PROCEDURE) using equipment such as an instrument landing system (ILS) (see also); as well as visual ground aids, such as a visual approach slope indicator (VASI) (see also), for a visual flight rule (VFR) approach or for the visual portion of an instrument approach and landing.

GLOBAL POSITIONING SYSTEM (GPS) - A navigational system that uses a series of satellites orbiting the earth to provide non-precision guidance in azimuth, elevation, and distance measurement.

GROUND EFFECT - The excess attenuation of sound associated with absorption or reflection of noise by manmade and physical features on the ground surface.

GROUND TRACK - The trajectory of an aircraft flight path projected onto the ground surface.

HELIPAD - A small area designated for takeoff, landing, or parking of helicopters.

HUD - U.S. Department of Housing and Urban Development.

A-D | E-H | I-L | M-P | Q-T | U-Z

back to top