Section

[Code of Federal Regulations]

[Title 14, Volume 3]

[Revised as of January 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 14CFR150.35]

[Page 81-88]

TITLE 14--AERONAUTICS AND SPACE

CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION

(CONTINUED)

PART 150_AIRPORT NOISE COMPATIBILITY PLANNING--Table of Contents

Subpart C_Evaluations and Determinations of Effects of Noise

Compatibility Programs

Sec. 150.35 Determinations; publications; effectivity.

(a) The FAA issues a determination approving or disapproving each

airport noise compatibility program (and revised program). Portions of a

program may be individually approved or disapproved. No conditional

approvals will be issued. A determination on a program acceptable under

this part is issued within 180 days after the program is received under

Sec. 150.23 of this part or it may be considered approved, except that

this time period may be exceeded for any portion of a program relating

to the use of flight procedures for noise control purposes. A

determination on portions of a program covered by the exceptions to the

180-day review period for approval will be issued within a reasonable

time after receipt of the program. Determinations relating to the use of

any flight procedure for noise control purposes may be issued either in

connection with the determination on other portions of the program or

separately. Except as provided by this paragraph, no approval of any

noise compatibility program, or any portion of a program, may be implied

in the absence of the FAA's express approval.

(b) The Administrator approves programs under this part, if--

(1) It is found that the program measures to be implemented would

not create an undue burden on interstate or foreign commerce (including

any unjust discrimination) and are reasonably consistent with achieving

the goals of reducing existing noncompatible land

[[Page 82]]

uses around the airport and of preventing the introduction of additional

noncompatible land uses;

(2) The program provides for revision if made necessary by the

revision of the noise map; and

(3) Those aspects of programs relating to the use of flight

procedures for noise control can be implemented within the period

covered by the program and without--

(i) Reducing the level of aviation safety provided;

(ii) Derogating the requisite level of protection for aircraft,

their occupants and persons and property on the ground;

(iii) Adversely affecting the efficient use and management of the

Navigable Airspace and Air Traffic Control Systems; or

(iv) Adversely affecting any other powers and responsibilities of

the Administrator prescribed by law or any other program, standard, or

requirement established in accordance with law.

Manager notifies the airport operator and publishes a notice of approval

or disapproval in the Federal Register identifying the nature and extent

of the determination.

(d) Approvals issued under this part for a program or portion

thereof become effective as specified therein and may be withdrawn when

one of the following occurs:

(1) The program or portion thereof is required to be revised under

this part or under its own terms, and is not so revised;

(2) If a revision has been submitted for approval, a determination

is issued on the revised program or portion thereof, that is

inconsistent with the prior approval.

(3) A term or condition of the program, or portion thereof, or its

approval is violated by the responsible government body.

(4) A flight procedure or other FAA action upon which the approved

program or portion thereof is dependent is subsequently disapproved,

significantly altered, or rescinded by the FAA.

(5) The airport operator requests rescission of the approval.

(6) Impacts on flight procedures, air traffic management, or air

commerce occur which could not be foreseen at the time of approval.

A determination may be sooner rescinded or modified for cause with at

least 30 days written notice to the airport operator of the FAA's

intention to rescind or modify the determination for the reasons stated

in the notice. The airport operator may, during the 30-day period,

submit to the Regional Airports Division Manager for consideration any

reasons and circumstances why the determination should not be rescinded

or modified on the basis stated in the notice of intent. Thereafter, the

FAA either rescinds or modifies the determination consistent with the

notice or withdraws the notice of intent and terminates the action.

(e) Determinations may contain conditions which must be satisfied

prior to implementation of any portion of the program relating to flight

procedures affecting airport or aircraft operations.

(f) Noise exposure maps for current and forecast year map conditions

that are submitted and approved with noise compatibility programs are

considered to be the new FAA accepted noise exposure maps for purposes

of part 150.

[Doc. No. 18691, 49 FR 49269, Dec. 18, 1984, as amended by Amdt. 150-2,

54 FR 39295, Sept. 25, 1989; Amdt. 150-4, 69 FR 57626, Sept. 24, 2004]

Appendix A to Part 150--Noise Exposure Maps

Part A--General

Sec. A150.1 Purpose.

Sec. A150.3 Noise descriptors.

Sec. A150.5 Noise measurement procedures and equipment.

Part B--Noise Exposure Map Development

Sec. A150.101 Noise contours and land usages.

Sec. A150.103 Use of computer prediction model.

Sec. A150.105 Identification of public agencies and planning agencies.

Part C--Mathematical Descriptions

Sec. A150.201 General.

Sec. A150.203 Symbols.

Sec. A150.205 Mathematical computations.

[[Page 83]]

Part A--General

Sec. A150.1 Purpose.

(a) This appendix establishes a uniform methodology for the

development and preparation of airport noise exposure maps. That

methodology includes a single system of measuring noise at airports for

which there is a highly reliable relationship between projected noise

exposure and surveyed reactions of people to noise along with a separate

single system for determining the exposure of individuals to noise. It

also identifies land uses which, for the purpose of this part are

considered to be compatible with various exposures of individuals to

noise around airports.

(b) This appendix provides for the use of the FAA's Integrated Noise

Model (INM) or an FAA approved equivalent, for developing standardized

noise exposure maps and predicting noise impacts. Noise monitoring may

be utilized by airport operators for data acquisition and data

refinement, but is not required by this part for the development of

noise exposure maps or airport noise compatibility programs. Whenever

noise monitoring is used, under this part, it should be accomplished in

accordance with Sec. A150.5 of this appendix.

Sec. A150.3 Noise descriptors.

(a) Airport Noise Measurement. The A-Weighted Sound Level, measured,

filtered and recorded in accordance with Sec. A150.5 of this appendix,

must be employed as the unit for the measurement of single event noise

at airports and in the areas surrounding the airports.

(b) Airport Noise Exposure. The yearly day-night average sound level

(YDNL) must be employed for the analysis and characterization of

multiple aircraft noise events and for determining the cumulative

exposure of individuals to noise around airports.

Sec. A150.5 Noise measurement procedures and equipment.

(a) Sound levels must be measured or analyzed with equipment having

the ``A'' frequency weighting, filter characteristics, and the ``slow

response'' characteristics as defined in International Electrotechnical

Commission (IEC) Publication No. 179, entitled ``Precision Sound Level

Meters'' as incorporated by reference in part 150 under Sec. 150.11.

For purposes of this part, the tolerances allowed for general purpose,

type 2 sound level meters in IEU 179, are acceptable.

(b) Noise measurements and documentation must be in accordance with

accepted acoustical measurement methodology, such as those described in

American National Standards Institute publication ANSI 51.13, dated 1971

as revised 1979, entitled ``ANS--Methods for the Measurement of Sound

Pressure Levels''; ARP No. 796, dated 1969, entitled ``Measurement of

Aircraft Exterior Noise in the Field''; ``Handbook of Noise

Measurement,'' Ninth Ed. 1980, by Arnold P.G. Peterson; or ``Acoustic

Noise Measurement,'' dated Jan., 1979, by J.R. Hassell and K. Zaveri.

For purposes of this part, measurements intended for comparison to a

State or local standard or with another transportation noise source

(including other aircraft) must be reported in maximum A-weighted sound

levels (LAM); for computation or validation of the yearly

day-night average level (Ldn), measurements must be reported

in sound exposure level (LAE), as defined in Sec. A150.205 of

this appendix.

Part B--Noise Exposure Map Development

Sec. A150.101 Noise contours and land usages.

(a) To determine the extent of the noise impact around an airport,

airport proprietors developing noise exposure maps in accordance with

this part must develop Ldn contours. Continuous contours must

be developed for YDNL levels of 65, 70, and 75 (additional contours may

be developed and depicted when appropriate). In those areas where YDNL

values are 65 YDNL or greater, the airport operator shall identify land

uses and determine land use compatibility in accordance with the

standards and procedures of this appendix.

(b) Table 1 of this appendix describes compatible land use

information for several land uses as a function of YDNL values. The

ranges of YDNL values in Table 1 reflect the statistical variability for

the responses of large groups of people to noise. Any particular level

might not, therefore, accurately assess an individual's perception of an

actual noise environment. Compatible or noncompatible land use is

determined by comparing the predicted or measured YDNL values at a site

with the values given. Adjustments or modifications of the descriptions

of the land-use categories may be desirable after consideration of

specific local conditions.

major use of the site. If other uses with greater sensitivity to noise

are permitted by local government at a site, a determination of

compatibility must be based on that use which is most adversely affected

by noise. When appropriate, noise level reduction through incorporation

of sound attenuation into the design and construction of a structure may

be necessary to achieve compatibility.

(d) For the purpose of compliance with this part, all land uses are

considered to be compatible with noise levels less than Ldn

65 dB. Local needs or values may dictate further delineation based on

local requirements or determinations.

[[Page 84]]

(e) Except as provided in (f) below, the noise exposure maps must

also contain and indentify:

(1) Runway locations.

(2) Flight tracks.

(3) Noise contours of Ldn 65, 70, and 75 dB resulting

from aircraft operations.

(4) Outline of the airport boundaries.

(5) Noncompatible land uses within the noise contours, including

those within the Ldn 65 dB contours. (No land use has to be

identified as noncompatible if the self-generated noise from that use

and/or the ambient noise from other nonaircraft and nonairport uses is

equal to or greater than the noise from aircraft and airport sources.)

(6) Location of noise sensitive public buildings (such as schools,

hospitals, and health care facilities), and properties on or eligible

for inclusion in the National Register of Historic Places.

(7) Locations of any aircraft noise monitoring sites utilized for

data acquisition and refinement procedures.

(8) Estimates of the number of people residing within the

Ldn 65, 70, and 75 dB contours.

(9) Depiction of the required noise contours over a land use map of

a sufficient scale and quality to discern streets and other identifiable

geographic features.

(f) Notwithstanding any other provision of this part, noise exposure

maps prepared in connection with studies which were either Federally

funded or Federally approved and which commenced before October 1, 1981,

are not required to be modified to contain the following items:

(1) Flight tracks depicted on the map.

(2) Use of ambient noise to determine land use compatibility.

(3) The Ldn 70 dB noise contour and data related to

Ldn 70 dB contour. When determinations on land use

compatibility using Table 1 differ between Ldn 65-70 dB and

the Ldn 70-75 dB, determinations should either use the more

conservative Ldn 70-75 dB column or reflect determinations

based on local needs and values.

(4) Estimates of the number of people residing within the

Ldn 65, 70, and 75 dB contours.

TABLE 1--Land Use Compatibility* With Yearly Day-Night Average Sound Levels

----------------------------------------------------------------------------------------------------------------

Yearly day-night average sound level (Ldn) in decibels

Land use ---------------------------------------------------------------------------------

Below 65 65-70 70-75 75-80 80-85 Over 85

----------------------------------------------------------------------------------------------------------------

Residential

Residential, other than mobile Y N(1) N(1) N N N

homes and transient lodgings.

Mobile home parks............. Y N N N N N

Transient lodgings............ Y N(1) N(1) N(1) N N

Public Use

Schools....................... Y N(1) N(1) N N N

Hospitals and nursing homes... Y 25 30 N N N

Churches, auditoriums, and Y 25 30 N N N

concert halls.

Governmental services......... Y Y 25 30 N N

Transportation................ Y Y Y(2) Y(3) Y(4) Y(4)

Parking....................... Y Y Y(2) Y(3) Y(4) N

Commercial Use

Offices, business and Y Y 25 30 N N

professional.

Wholesale and retail--building Y Y Y(2) Y(3) Y(4) N

materials, hardware and farm

equipment.

Retail trade--general......... Y Y 25 30 N N

Utilities..................... Y Y Y(2) Y(3) Y(4) N

Communication................. Y Y 25 30 N N

Manufacturing and Production

Manufacturing, general........ Y Y Y(2) Y(3) Y(4) N

Photographic and optical...... Y Y 25 30 N N

Agriculture (except livestock) Y Y(6) Y(7) Y(8) Y(8) Y(8)

and forestry.

Livestock farming and breeding Y Y(6) Y(7) N N N

Mining and fishing, resource Y Y Y Y Y Y

production and extraction.

Recreational

Outdoor sports arenas and Y Y(5) Y(5) N N N

spectator sports.

Outdoor music shells, Y N N N N N

amphitheaters.

Nature exhibits and zoos...... Y Y N N N N

Amusements, parks, resorts and Y Y Y N N N

camps.

Golf courses, riding stables Y Y 25 30 N N

and water recreation.

----------------------------------------------------------------------------------------------------------------

Numbers in parentheses refer to notes.

[[Page 85]]

*The designations contained in this table do not constitute a Federal determination that any use of land covered

by the program is acceptable or unacceptable under Federal, State, or local law. The responsibility for

determining the acceptable and permissible land uses and the relationship between specific properties and

specific noise contours rests with the local authorities. FAA determinations under part 150 are not intended

to substitute federally determined land uses for those determined to be appropriate by local authorities in

response to locally determined needs and values in achieving noise compatible land uses.

Key to Table 1

SLUCM=Standard Land Use Coding Manual.

Y (Yes)=Land Use and related structures compatible without restrictions.

N (No)=Land Use and related structures are not compatible and should be prohibited.

NLR=Noise Level Reduction (outdoor to indoor) to be achieved through incorporation of noise attenuation into the

design and construction of the structure.

25, 30, or 35=Land use and related structures generally compatible; measures to achieve NLR of 25, 30, or 35 dB

must be incorporated into design and construction of structure.

Notes for Table 1

(1) Where the community determines that residential or school uses must be allowed, measures to achieve outdoor

to indoor Noise Level Reduction (NLR) of at least 25 dB and 30 dB should be incorporated into building codes

and be considered in individual approvals. Normal residential construction can be expected to provide a NLR of

20 dB, thus, the reduction requirements are often stated as 5, 10 or 15 dB over standard construction and

normally assume mechanical ventilation and closed windows year round. However, the use of NLR criteria will

not eliminate outdoor noise problems.

(2) Measures to achieve NLR 25 dB must be incorporated into the design and construction of portions of these

buildings where the public is received, office areas, noise sensitive areas or where the normal noise level is

low.

(3) Measures to achieve NLR of 30 dB must be incorporated into the design and construction of portions of these

buildings where the public is received, office areas, noise sensitive areas or where the normal noise level is

low.

(4) Measures to achieve NLR 35 dB must be incorporated into the design and construction of portions of these

buildings where the public is received, office areas, noise sensitive areas or where the normal level is low.

(5) Land use compatible provided special sound reinforcement systems are installed.

(6) Residential buildings require an NLR of 25.

(7) Residential buildings require an NLR of 30.

(8) Residential buildings not permitted.

Sec. A150.103 Use of computer prediction model.

(a) The airport operator shall acquire the aviation operations data

necessary to develop noise exposure contours using an FAA approved

methodology or computer program, such as the Integrated Noise Model

(INM) for airports or the Heliport Noise Model (HNM) for heliports. In

considering approval of a methodology or computer program, key factors

include the demonstrated capability to produce the required output and

the public availability of the program or methodology to provide

interested parties the opportunity to substantiate the results.

(b) Except as provided in paragraph (c) of this section, the

following information must be obtained for input to the calculation of

noise exposure contours:

(1) A map of the airport and its environs at an adequately detailed

scale (not less than 1 inch to 2,000 feet) indicating runway length,

alignments, landing thresholds, takeoff start-of-roll points, airport

boundary, and flight tracks out to at least 30,000 feet from the end of

each runway.

(2) Airport activity levels and operational data which will

indicate, on an annual average-daily-basis, the number of aircraft, by

type of aircraft, which utilize each flight track, in both the standard

daytime (0700-2200 hours local) and nighttime (2200-0700 hours local)

periods for both landings and takeoffs.

(3) For landings--glide slopes, glide slope intercept altitudes, and

other pertinent information needed to establish approach profiles along

with the engine power levels needed to fly that approach profile.

(4) For takeoffs--the flight profile which is the relationship of

altitude to distance from start-of-roll along with the engine power

levels needed to fly that takeoff profile; these data must reflect the

use of noise abatement departure procedures and, if applicable, the

takeoff weight of the aircraft or some proxy for weight such as stage

length.

(5) Existing topographical or airspace restrictions which preclude

the utilization of alternative flight tracks.

(6) The government furnished data depicting aircraft noise

characteristics (if not already a part of the computer program's stored

data bank).

(7) Airport elevation and average temperature.

this section shall not be less than 1 inch to 2,000 feet and shall

indicate heliport boundaries, takeoff and landing pads, and typical

flight tracks out to at least 4,000 feet horizontally from the landing

pad. Where these flight tracks cannot be determined, obstructions or

other limitations on flight tracks in and out of the heliport shall be

identified within the map areas out to at least 4,000 feet horizontally

from the landing pad. For static operation (hover), the helicopter type,

the number of daily operations based on an annual average, and the

duration in minutes of the hover operation shall be identified. The

other information required in paragraph (b) shall be furnished in a form

suitable for input to the HNM or other FAA approved methodology or

computer program.

Sec. A150.105 Identification of public agencies and planning agencies.

(a) The airport proprietor shall identify each public agency and

planning agency whose jurisdiction or responsibility is either

[[Page 86]]

wholly or partially within the Ldn 65 dB boundary.

(b) For those agencies identified in (a) that have land use planning

and control authority, the supporting documentation shall identify their

geographic areas of jurisdiction.

Part C--Mathematical Descriptions

Sec. A150.201 General.

The following mathematical descriptions provide the most precise

definition of the yearly day-night average sound level (Ldn),

the data necessary for its calculation, and the methods for computing

it.

Sec. A150.203 Symbols.

The following symbols are used in the computation of Ldn;

------------------------------------------------------------------------

Measure (in dB) Symbol

------------------------------------------------------------------------

Average Sound Level, During Time T............................ LT

Day-Night Average Sound Level (individual day)................ Ldni

Yearly Day-Night Average Sound Level.......................... Ldn

Sound Exposure Level.......................................... LAE

------------------------------------------------------------------------

Sec. A150.205 Mathematical computations.

(a) Average sound level must be computed in accordance with the

following formula:

[GRAPHIC] [TIFF OMITTED] TC15SE91.000

where T is the length of the time period, in seconds, during which the

average is taken; LA(t) is the instantaneous time varying A-

weighted sound level during the time period T.

Note: When a noise environment is caused by a number of identifiable

noise events, such as aircraft flyovers, average sound level may be

conveniently calculated from the sound exposure levels of the individual

events occurring within a time period T:

[GRAPHIC] [TIFF OMITTED] TC15SE91.001

where LAEi is the sound exposure level of the i-th event, in

a series of n events in time period T, in seconds.

Note: When T is one hour, LT is referred to as one-hour

average sound level.

(b) Day-night average sound level (individual day) must be computed

in accordance with the following formula:

[GRAPHIC] [TIFF OMITTED] TR10FE03.003

Time is in seconds, so the limits shown in hours and minutes are

actually interpreted in seconds. It is often convenient to compute day-

night average sound level from the one-hour average sound levels

obtained during successive hours.

accordance with the following formula:

[GRAPHIC] [TIFF OMITTED] TC15SE91.003

where Ldni is the day-night average sound level for the i-th

day out of one year.

(d) Sound exposure level must be computed in accordance with the

following formula:

[GRAPHIC] [TIFF OMITTED] TC15SE91.004

where to is one second and LA(t) is the time-

varying A-weighted sound level in the time interval t1 to

t2.

The time interval should be sufficiently large that it encompasses

all the significant sound of a designated event.

The requisite integral may be approximated with sufficient accuracy

by integrating LA(t) over the time interval during which

LA(t) lies within 10 decibels of its maximum value, before

and after the maximum occurs.

[Doc. No. 18691, 49 FR 49269, Dec. 18, 1984; 50 FR 5064, Feb. 6, 1985,

as amended by Amdt. 150-1, 53 FR 8724, Mar. 16, 1988; Amdt. 150-4, 69 FR

57626, Sept. 24, 2004]

Appendix B to Part 150--Noise Compatibility Programs

Sec. B150.1 Scope and purpose.

Sec. B150.3 Requirement for noise map.

Sec. B150.5 Program standards.

[[Page 87]]

Sec. B150.7 Analysis of program alternatives.

Sec. B150.9 Equivalent programs.

Sec. B150.1 Scope and purpose.

(a) This appendix prescribes the content and the methods for

developing noise compatibility programs authorized under this part. Each

program must set forth the measures which the airport operator (or other

person or agency responsible) has taken, or proposes to take, for the

reduction of existing noncompatible land uses and the prevention of the

introduction of additional noncompatible land uses within the area

covered by the noise exposure map submitted by the operator.

(b) The purpose of a noise compatibility program is:

(1) To promote a planning process through which the airport operator

can examine and analyze the noise impact created by the operation of an

airport, as well as the costs and benefits associated with various

alternative noise reduction techniques, and the responsible impacted

land use control jurisdictions can examine existing and forecast areas

of noncompatibility and consider actions to reduce noncompatible uses.

(2) To bring together through public participation, agency

coordination, and overall cooperation, all interested parties with their

respective authorities and obligations, thereby facilitating the

creation of an agreed upon noise abatement plan especially suited to the

individual airport location while at the same time not unduly affecting

the national air transportation system.

(3) To develop comprehensive and implementable noise reduction

techniques and land use controls which, to the maximum extent feasible,

will confine severe aircraft YDNL values of Ldn 75 dB or

greater to areas included within the airport boundary and will establish

and maintain compatible land uses in the areas affected by noise between

the Ldn 65 and 75 dB contours.

Sec. B150.3 Requirement for noise map.

(a) It is required that a current and complete noise exposure map

and its supporting documentation as found in compliance with the

applicable requirements by the FAA, per Sec. 150.21(c) be included in

each noise compatibility program:

(1) To identify existing and future noncompatible land uses, based

on airport operation and off-airport land uses, which have generated the

need to develop a program.

(2) To identify changes in noncompatible uses to be derived from

proposed program measures.

(b) If the proposed noise compatibility program would yield maps

differing from those previously submitted to FAA, the program shall be

accompanied by appropriately revised maps. Such revisions must be

prepared in accordance with the requirements of Sec. A150.101(e) of

appendix A and will be accepted by FAA in accordance with Sec.

150.35(f).

Sec. B150.5 Program standards.

Based upon the airport noise exposure and noncompatible land uses

identified in the map, the airport operator shall evaluate the several

alternative noise control actions and develop a noise compatibility

program which--

(a) Reduces existing noncompatible uses and prevents or reduces the

probability of the establishment of additional noncompatible uses;

(b) Does not impose undue burden on interstate and foreign commerce;

part.

(d) Is not unjustly discriminatory.

(e) Does not derogate safety or adversely affect the safe and

efficient use of airspace.

(f) To the extent practicable, meets both local needs and needs of

the national air transportation system, considering tradeoffs between

economic benefits derived from the airport and the noise impact.

(g) Can be implemented in a manner consistent with all of the powers

and duties of the Administrator of FAA.

Sec. B150.7 Analysis of program alternatives.

(a) Noise control alternatives must be considered and presented

according to the following categories:

(1) Noise abatement alternatives for which the airport operator has

adequate implementation authority.

(2) Noise abatement alternatives for which the requisite

implementation authority is vested in a local agency or political

subdivision governing body, or a state agency or political subdivision

governing body.

(3) Noise abatement options for which requisite authority is vested

in the FAA or other Federal agency.

(b) At a minimum, the operator shall analyze and report on the

following alternatives, subject to the constraints that the strategies

are appropriate to the specific airport (for example, an evaluation of

night curfews is not appropriate if there are no night flights and none

are forecast):

(1) Acquisition of land and interests therein, including, but not

limited to air rights, easements, and development rights, to ensure the

use of property for purposes which are compatible with airport

operations.

(2) The construction of barriers and acoustical shielding, including

the soundproofing of public buildings.

(3) The implementation of a preferential runway system.

(4) The use of flight procedures (including the modifications of

flight tracks) to control

[[Page 88]]

the operation of aircraft to reduce exposure of individuals (or specific

noise sensitive areas) to noise in the area around the airport.

(5) The implementation of any restriction on the use of airport by

any type or class of aircraft based on the noise characteristics of

those aircraft. Such restrictions may include, but are not limited to--

(i) Denial of use of the airport to aircraft types or classes which

do not meet Federal noise standards;

(ii) Capacity limitations based on the relative noisiness of

different types of aircraft;

(iii) Requirement that aircraft using the airport must use noise

abatement takeoff or approach procedures previously approved as safe by

the FAA;

(iv) Landing fees based on FAA certificated or estimated noise

emission levels or on time of arrival; and

(v) Partial or complete curfews.

(6) Other actions or combinations of actions which would have a

beneficial noise control or abatement impact on the public.

(7) Other actions recommended for analysis by the FAA for the

specific airport.

must identify the agency or agencies responsible for such

implementation, whether those agencies have agreed to the

implementation, and the approximate schedule agreed upon.

Sec. B150.9 Equivalent programs.

(a) Notwithstanding any other provision of this part, noise

compatibility programs prepared in connection with studies which were

either Federally funded or Federally approved and commenced before

October 1, 1981, are not required to be modified to contain the

following items:

(1) Flight tracks.

(2) A noise contour of Ldn 70 dB resulting from aircraft

operations and data related to the Ldn 70 dB contour. When

determinations on land use compatibility using Table 1 of appendix A

differ between Ldn 65-70 dB and Ldn 70-75 dB, the

determinations should either use the more conservative Ldn

70-75 dB column or reflect determinations based on local needs and

values.

(3) The categorization of alternatives pursuant to Sec. B150.7(a),

although the persons responsible for implementation of each measure in

the program must still be identified in accordance with Sec.

150.23(e)(8).

(4) Use of ambient noise to determine land use compatibility.

(b) Previously prepared noise compatibility program documentation

may be supplemented to include these and other program requirements

which have not been excepted.