[Code of Federal Regulations]
[Title 14, Volume 3]
[Revised as of January 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 14CFR150.7]

[Page 89-90]
 
                     TITLE 14--AERONAUTICS AND SPACE
 
CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION 
                               (CONTINUED)
 
PART 150--AIRPORT NOISE COMPATIBILITY PLANNING--Table of Contents
 
                      Subpart A--General Provisions
 
Sec. 150.7  Definitions.

    As used in this part, unless the context requires otherwise, the 
following terms have the following meanings.
    Airport means any public use airport, including heliports, as 
defined by the ASNA Act, including: (a) Any airport which is used or to 
be used for public purposes, under the control of a public agency, the 
landing area of which is publicly owned; (b) any privately owned 
reliever airport; and (c) any privately owned airport which is 
determined by the Secretary to enplane annually 2,500 or more passengers 
and receive scheduled passenger service of aircraft, which is used or to 
be used for public purposes.
    Airport noise compatibility program and program mean that program, 
and all revisions thereto, reflected in documents (and revised 
documents) developed in accordance with appendix B of this part, 
including the measures proposed or taken by the airport operator to 
reduce existing noncompatible land uses and to prevent the introduction 
of additional noncompatible land uses within the area.
    Airport Operator means, the operator of an airport as defined in the 
ASNA Act.
    ASNA Act means the Aviation Safety and Noise Abatement Act of 1979, 
as amended (49 U.S.C. 2101 et seq.).
    Average sound level means the level, in decibels, of the mean-
square, A-weighted sound pressure during a specified period, with 
reference to the square of the standard reference sound pressure of 20 
micropascals.
    Compatible land use means the use of land that is identified under 
this part as normally compatible with the outdoor noise environment (or 
an adequately attenuated noise level reduction for any indoor activities 
involved) at the location because the yearly day-night average sound 
level is at or below that identified for that or similar use under 
appendix A (Table 1) of this part.
    Day-night average sound level (DNL) means the 24-hour average sound 
level, in decibels, for the period from midnight to midnight, obtained 
after the addition of ten decibels to sound levels for the periods 
between midnight and 7 a.m., and between 10 p.m., and midnight, local 
time. The symbol for DNL is Ldn.
    Noise exposure map means a scaled, geographic depiction of an 
airport, its noise contours, and surrounding area developed in 
accordance with section A150.101 of appendix A of this part, including 
the accompanying documentation setting forth the required descriptions 
of forecast aircraft operations at that airport during the fifth 
calendar year beginning after submission of the map, together with the 
ways, if any, those operations will affect the map (including noise 
contours and the forecast land uses).
    Noise level reduction (NLR) means the amount of noise level 
reduction in decibels achieved through incorporation of noise 
attenuation (between outdoor and indoor levels) in the design and 
construction of a structure.
    Noncompatible land use means the use of land that is identified 
under this part as normally not compatible with the outdoor noise 
environment (or an adequately attenuated noise reduction level for the 
indoor activities involved at the location) because the yearly day-night 
average sound level is above that identified for that or similar use 
under appendix A (Table 1) of this part.
    Regional Airports Division Manager means the Airports Division 
Manager having responsibility for the geographic area in which the 
airport in question is located.
    Restriction affecting flight procedures means any requirement, 
limitation, or other action affecting the operation of aircraft, in the 
air or on the ground.

[[Page 90]]

    Sound exposure level means the level, in decibels, of the time 
integral of squared A-weighted sound pressure during a specified period 
or event, with reference to the square of the standard reference sound 
pressure of 20 micropascals and a duration of one second.
    Yearly day-night average sound level (YDNL) means the 365-day 
average, in decibels, day-night average sound level. The symbol for YDNL 
is also Ldn.

[Doc. No. 18691, 49 FR 49269, Dec. 18, 1984, as amended by Amdt. 150-1, 
53 FR 8724, Mar. 16, 1988; 53 FR 9726, Mar. 24, 1988; Amdt. 150-2, 54 FR 
39295, Sept. 25, 1989]