sr-022773-5e~~
CITY OF SANTA MO~,'ICA ~ 73-C-1d
DATE: February, 1473 ~~ ~-"~ `
TO: The Honorable City Council ~~~' ~ ~ ~<~
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FROM: City Manager .n~Y ~ t....~~~ ~r:,v
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SUBJECT: Ordinance Regulating Aircraft Noise for Takeoffs and
1.,andings at the Municipal. Airport
Pursuant to instructions of the City Council, the City Attorney has prepared.
the attached ordinance after consultation and recommendations by the firm of
Bolt, Beranek and Newman. In addition to the ordinance groper, .there is
attached hereto a communication from the consulting firm along with an
exhibit which identifies. the expected noise range- generated by the types of
aircraft using the Municipal Airport. It should be noted teat. the standard
included in the ordinance would probably preclude use of the Airport by the
following classes of planes:
Two-engine business. jet aircraft with turbojet engines
(Sabreliner, Lear Jet, Jet Ccmmander, etc. },
It is also more than probable that the regulations. will affect
some of the two-engine propeller aircraft with. a gross maxi-
mum weight of 1Z, 500 pounds or more.
y.
In the event it is the decision of the Council to adopt-the subject ordinance, it
i5 recommended that the Council also authorize. the installation of a noise
monitoring system and appropriate $35, 000 far the cost of the original installa-
tion.
ity Manager
cc: City Clerk
City Attorney '
Director of Municipal Airport
Director of Finance
CONSULTANTS IN +=.~?r!iiTECTURAL AND ENGINEERING ACOUSTICS --
LOS ANGELES OEFI CE
2t 720.V ANOWEN ST R.EE T
CANOGA PARK; CALIFORNIA 9'303.
TELEPHONE ;213) 347.-8360.
19 January 1973
Mr. Perrg Scott
City Manager
City of Santa P+ionica
Santa-Monica City Hall
1685 Main St.
Santa Monica,. California
Subjec~: Recam~mendation for proposed noise level limits for
aircraft operations at Banta Monica Mur_icipal Airport
BBN Project 153956
Dear Mr. Scott:
This letter presents our recommendatiohs regarding the specification
and establishment of noise level standards at the Santa Monica
Municipal Airport. Our study has been. directed toiaards s~ecifyir~g
a practical noise level limit which would hermit continued open
ati.on of smaller propeller-driven general aviatior. aircraft but..
which would nct allow the cperation of the noisier business or
Commercial turbojet and turbcfam powered aircraft. In Attach-
ment A, we have attempted to phrase specifications fcr the noise.
measurements and noise level limits in a form .that might be
adaptable for incorporation in a city ardir~ancee Thy remainders
of this letter discusses our basic appraach and assumptions and
the means of arriving at the. noise level limits.
h7e believe that the specified noise evel limit should be one
that can be accurately measured and monitored at any desired time.
To .avoid undue confusion, and to eliminate unusual expenses in
measurement instrumentation, we believe that the noise measure
specified.in the standards should be one that is, or likely will
be, in common use for measurement of aircraft noise. Thus, we
have specified the."single event noise exposure level-" (S~NEL),
adopted in the California Airport Noi.se'Star_dards, as the .noise
measure for aircraft takeoffs or landings. This noise measure
is based upon the A-weighted sound level, a noise measure fre-
auently used to describe community and aircraft noise. The SENEL
value represents an integration .with time of the A-weighted sound
.level during the aircraft flyover event. Thus, included in .the
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Mr. Perry Scott
19 January 1973
Page Two
SENEL value is the effect of both the maximum noise level reached
during the flyover and the duration of the flyover.
We have. also specified measuring equipment performance and accuracy
requirements that are identical to these of the California Airport
Noise Standards. This means that instrumentation recently
developed to meet the State requirements can be used at Santa.
Monica. It also means .that, in the. event that the Santa Monica
Municipal Airport is formally identified by the County of Los
Angeles as having a noise problem, any monitoring equipment will
be compatible with that required by the state.
As you will note in'Attachr•~ent A, we hav? specified Heise monitor-
ing for an initial position, located near Dewey Avenue-and 18th
Street. We also provide for-the possible additior. of other
monitcrinc positions. We have also suggested a review of noises
level limits at all monitoring positions after tie first six
months of actual field measurement.
The single monitoring position at Dewey Avenue and 18th Street
is located approximately 5400 feet from the start of the takeoff
roll for takeoffs from runway 21, and is about 1400 feet from the
landing threshold for approaches on runway 3. The position is
about 60 to 86 feet below the westerly. end of runway 3-21.
Table i shows the expected range of SENEL values for takeoffs
from runway 21 at this position,. The range of levels is based-
- upon tygical takeoff profiles for the different aircraft, and'
noise level information from references 1 and 2, F.?:A noise
certification data, as well as other noise information in our
"" files, acquired in previous aircraft noise studies.
At this position, SENEL. values for aircraft. landings on run~,~ay 3
will typically range from 5 to 10_dB lower than takeoff. noise
levels given in Table I.
Based on comparison of the noise level ranges of Table I, we
recommend a SENEL noise level limit of 100 dB, This would gen-
erally exclude all business jet aircraft powered with turbojet
engines. However, the noise level limits may occasionally be
exceeded during operations of heavier twin-engine propeller
aircraft,
I also should point out that one of the newest small business
jet aircraft, the Cessna Citation, .equipped :with high bypass
Nir. Perry Scott
19 Sanuary 1973
Page Three
ratio turbofan engines, car_ operate from the airport without
violating the noise level limits. Lve would anticipate that,..
over the. coming years, other types of business jet aircraft
powered with newer engines will be able to meet the noise level
specifications. However, uch operations will meet the intent
of the noise regulations which is tc eliminate the noisier air-
craft but not prohibit zircraft from operating from the airport
solely on basis of engine type.
with respect to the California Airport Neise Standards, I should
note that the initial measurement position {in the vicinity of
Dewey Avenue and 18th'Street) is not located within-the range
of distances from the airpoxt_saecified for SENEL monitoring
positions in the state star_dards. Thus in the event the City
is later required to monitor noise to meet state requirements,
a waiver for this position would be needed.. Informal discussion
.with state personnel indicates that such a waiver would probably
be granted,. if suitable justification is presented by the`City.
I believe that the. location of residential areas with respect
to the airport should provide sufficient justification to support
such a waiver,. if ever required.
I hope the information given in-this letter and attachment meets
your immediate needs. Please let me know if questions arise or-
further information is needed.
I hope. that we shall have the opportunity to .work with you '
further, as you proceed .with more detailed planning for. an air-
port noise monitoring system.
Very truly yours,
BOLT BERANEK AND NE7rIMAN INC.
f
Dwight E"e~Bishop
DEB:bj
Encl.asure
,SOLiNzRAPi E~{ Ai.D NFtil hlAt- c..
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TABLE I
Expected Range of SENEL Values at Dewey Avenue
and i8th Street for Takeoffs from Runway 21,
Santa Monica P3unicipal airport
Expected Range of SENEL
'Aircraft Type Values, ~B
Single engine prapeller
aircraft (typically.
under 500 hp) 80 to 92
Two engine propeller
aircraft (under
12,500 ibs maximum
gross. weight) 82 to 94
Two engine propeller
aircraft. (aver
12,500 lbs maximum
gross weight}
Two engine business
jet aircraft with
turbojet engines
{Sabreliner,.Lear-
Jet, Jet Co-mnander,
.etc,}
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REFERENCES
I. Wyle Laboratories Report No. WCR 70-3 (R)
"Suppcrting Information for the Adapted
.Noise F.egulatons for California Airports,'°
January, 1971.
2. BBN Report 2093 "Aircraft Noise Evaluations and
Projections, San Francisco. Bay Region,"
August, 1971.