[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: 14CFR150.9]

[Page 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. 150.9  Designation of noise systems.

    For purposes of this part, the following designations apply:
    (a) The noise at an airport and surrounding areas covered by a noise 
exposure map must be measured in A-weighted sound pressure level 
(LA) in units of decibels (dBA) in accordance with the 
specifications and methods prescribed under appendix A of this part.
    (b) The exposure of individuals to noise resulting from the 
operation of an airport must be established in terms of yearly day-night 
average sound level (YDNL) calculated in accordance with the 
specifications and methods prescribed under appendix A of this part.
    (c) Uses of computer models to create noise contours must be in 
accordance with the criteria prescribed under appendix A of this part.