SR-0 (25)
RLK: msh
C1ty.Council Meeting 09-10-79
Santa Monica, Cal~fornia
TO:
Mayor and Clty Councll
ffCJP-OO?'-03
FROM: City Staff
SUBJECT: Airport - Effect of Lower~ng the SENEL Llm~t
INTRODUCTION
On August 24, 1979, the Honorable Irvlng Hlll, ln the case
of Santa MOUlca Alrport Assoclat~on v. Clty of Santa Monica, rendered
Judg~ent In favor of the City and upheld the followlng ord~nances:
1. SENEL Llmltatlon - 10105B
2. Hellcopter Tralnlng Ban - lOl05A2
3. Touch-and-Go Restrlctlons - 10111C
4. Nlght Curfew - 10101
At the same tlme, Judge Hlll ordered judgment against the City and struck
dmvn the Clty'S "Jet ban" (lOI05A). The court order, by upholdlng the
SENEL ordlnance, affirmed the rlght of the City to llmlt alrcraft
nOlse by controlllng slngle event llm~ts and also to adopt reasonable
regulations to control alrcraft nOlse.
Wlth respect to the Jet ban, the eVldence wlthout questlon
establlshes that a number of small Jet alrcraft when operated at the
Santa Monica Municlpal Alrport would not generate, at the noise monltor
statlon, nOlse In excess of 100 SENEL. Nevertheless, openlng up
the airport to these jet aircraft, WhlCh were prevlously banned, would
result In an overall lncrease ln the amount of hlgh lntensity alrcraft
no~se In the enVirons of the airport slmply because lt would add
aircraft of the nOlSlest variety permitted at Santa Monica WhlCh
aircraft had prevlously been prohlblted.
In addition to the adverse effects on the people llvlng near the
airport that would ensue from this addltlonal Jet nOlse, It lS known
that the nOlse from a number of older, small propeller alrcraft operatlng
at the alrport lS a source of annoyance and disturbance to the communlty.
Since the tlme of manufacture of many of these "nolsier"
KLK:msn
C~ty Counc~l Meet~ng 09-10-79
a~rcraft, both propeller and jet, there have been technolog~cal
advances ~n the des~gn of a~rcraft engines that have resulted ~n
eng~nes that are considerably qu~eter for a g~ven amount of propulsion
power than were prevlously avallable. Indeed, s~nce 1974, the FAA
has set No~se Compl~ance Limits for both s~all propeller and Jet
alrcraft that must be met before a given alrcraft model can be
certlflcated and allowed to operate in the Unlted States. These
FAA Noise Compl~ance Llmits are conslderably below the equlvalent
level of 100 SENEL at the Santa MODlca NOlse Monltor Statlons.
Torrance Alrport which is also a munlclpally owned general aVlatlon
airport has set a SENEL Ilmit of 88 in order to further noise
abatement goals by reducing a~rcraft nOlse impact on the community
surroundlng the airport.
Parallel w~th the advances made ~n alrcraft and alrcraft oper-
at~ons with respect to nOlse reductlon, there has been an lncrease
ln knowledge concernlng the adverse effect of aircraft nOlse on
people and the establlshment of quantltat~ve, validated relatlons
between physlcal measures of the alrcraft nOlse and lts effects
on lndivlduals and populat~ons of people.
The SENEL (Slngle Event No~se Exposure Level) and the CNEL
(average 24-hour Composlte Noise Exposure Level) are reasonably
accurate and acceptable methods, among others, of quant~fying a~rcraft
no~se ln communitltes and predlctlng from them the effects of the
no~se on people.
The report to follow prov~des an analysls of the lropact of
var~ous SENEL level Ilm1ts upon the tle-down fleet, the number
of operat~ons, the nelghbor~ng comnun~ty (CNEL) and other technlcal
-2-
RLK:msh
C~ty Counc~l Meeting 09-10-79
informat~on that would be of ass~stance ~f ~t ~s deemed necessary
to prepare an ord~nance whlch would take lnto account the recent
developments concern~ng the Santa Mon~ca Alrport and the industry
at large.
-~-
RLK:msh
C~ty Cauncll Meetlng 09-10-79
I. IMPACT OF VARIOUS SENEL LIMITS
UPON THE EXISTING TIE-DOWN
FLEET AT SANTA MONICA AIRPORT
A. Purp~?e
The purpose of this section 1S to show Wh1Ch a~rcraft, how
many of these a1rcraft and what percentage of the ex~sting t~e-
down fleet would be excluded at the SENEL l~mits of 90, 87, 85
or 80. Note for example, that a 90 SENEL ind1cates that 90 dec1bels
15 the ~aXlrnurn nOlse allowable for a part1cular aircraft.
B. Method of Evaluation
1. Comp1latlon of Data
The comp11atlon of data necessary to draw stat1stical concluslons
concern~ng the impact of the varlOUS SENEL 11mits lS presented
1n Appendix A to thlS report.
In order to complle thlS lnformation, each alrcraft tied
down at SMa was ldentlfled by a1rcraft number and type, to determlne
the n01se emltted by each alrcraft. Flve bas1c sources were relled
upon.
CAVEAT: These flve sources are the most complete
and CUrrent data from all available sources. It
1S current through 5/29/79.
Sources of ~Olse Measurement
AC 36-1B: Department of Transportatlon Federal
AV1atlon Admlnlstratlon Advlsory Circular Number
36-lB dated 12/5/77 regardlng certlfled airplane
nOlse levels.
AC 36-2A: Department of Transportatlon Federal
AVlation Admlnlstration Advlsory Clrcular Number
-3-
RLK:msh
C~ty Counc1l Meet1ng 09-10-79
36-2A dated 2/6/78 regarding measured or
estimated (uncertified) a1rplane noise levels.
AC 36-3: Department of Transportat1on Federal
Aviation Admin1stration Adv1sory C1rcular Number
36-3 dated 5/29/79 regarding est1roated a1rplane
n01se levels 1n A-we1ghted dec1bels.
EPA: Un1ted States EnV1ronmental Protect1on
Agency ProJect Report. N01se Certlfication
Rule for Propeller Driven Small Alrplanes dated
11/25/74, Wash1ngton, D.C.
BBN (SENEL): Report prepared by Bolt, Beranek,
and Newman showlng est1mated nOlse levels In
SENEL of propeller dr1ven aircraft at SMO
monitor1ng statlons used as Plalnt1ff's Exh1blt
51 in S.M.A.A. v. Clty of Santa Monlca.
The figures obtained fron these sources are 11sted In the
r1ght hand sect10n of Appendix A under the t1tle ItMeasured/Est1mated
Levels. It
2. Rated Fleet
There are 415 a1rplanes that compr1se the exist1ng t1e-down
fleet at SMO. Of these, 200 alrplanes have been rated (the rated
fleet). There are no FAA, EPA, or BBN rat1ngs for the rema1n1ng
215 airplanes comprlslng 51.8% of the total tie-down fleet.
(See
Appendix B.) In order to determlne which a1rcraft will be arfected
at each SENEL level, a two-step process 1S requ1red. F1rst, a
conversion must be made from each or1ginal source flgure to an
est1mated SMO SENEL ~eter read1ng.
The two numbers lD parentheses below the measured/estimated
declbel level f1gure represent conversions to SENEL at Santa Monica
MOD1tor1ng Stat1ons. The number in parentheses on the left and
right lS the SENEL of that a~rplane on approach and takeoff,
-4-
RLK:msh
City Counc11 Meet1ng 09-10-79
respect1vely. The converS1ons are requ1red because d1fferent metrlcs
and/or different monitor placement was used in the source data.
Once a standard f1gure for SMO SENEL 1S computed, it 1S
necessary to rank the source mater1al accordlng to lts rel1ab1lity.
ThlS 15 requ1red because in the case where there 15 nore than
one f1gure available for a part1cular a1rcraft, a cholce must be made
as to WhlCh figure 1S to be used. The ranklng of the original
source flgure lS as follows:
RANK I: AC 36-3
RANK II: AC 36-lB and AC 36-2A
RANK-I:Ll: EPA
RANK IV: BBN (SENEL)
3. Rated Pleet Excluslon
The exclus10n levels for the rated fleet lS summarized in
Appendlx c. The ent1re rated fleet 15 llsted by a1rcraft type
and number of each type tled down at S!>10. An "X" 1n the r1ght
hand column 1nd1cates the level at whlch that alrcraft would be
excluded because the ratlng exceeds the Ilffilt on both takeoff
and approach.
(T) lndlcates exclusion because of takeoff ratlng
only.
(A) lndlcates excluslon because of approach rating only.
An exclus10n on takeoff or approach counts as an excluslon for
all purposes.
An exclus10n would eXlst for measured nOlse levels of 90.1
and above, 87.1 and above, 85.1 and above, or 80.1 and above in
each category of the same number. An alrcraft would not be excluded
for a ratlng of 90.0, 87.0, 85.0, or 80.0 1n the category of the
same number. The determlnative numbers used were mandated by the
-5-
RLK:msh
City Counc~l Meet~ng 09-10-79
rank of rel~ab~l~ty found ~n Section 2 above.
c. Analysis
1. Number of A~rcraft Excluded from SMO at Lower SENEL
The number of a1rcraft compr~s~ng the rated fleet wh1ch would
be excluded~ if the SENEL were lowered is:
SENEL 90 19 aircraft excluded
SENEL 87 46 aircraft excluded
SENEL 85 65 a~rcraft excluded
SENEL 80 136 a1rcraft excluded
2. T~pe of A~rcraft Excluded from S~O at Lower SENEL
If the SENEL were lowered, the followlng a1rcraft currently
a part of the t1e-down fleet would be excluded* from SMO:
Excluded at 90 SEUEL
Cessna 175
Cessna 185
Cessna 2l0L
Cessna 310C
Cessna 411
Cessna 421
Piper Cherokee PA 32-260
Beechcraft AGO
Beech Bonanza S 35
Beech Debona~re 35A33
Beech Tw1n BCE Baron 95A55
Excluded at 87 SENEL: All planes excluded* at
90 SENEL, plus:
*The exclusion 15 based on a close to worst case situation
prov~ded for in FAR-36. Many of the excluded planes can be operated
at sign1f1cantly lower levels by modifY1ng we1ght and operat1ng
condlt1ons to meet nOlse abatement goals.
-6-
RLK:msh
C~ty Council Meet~ng 09-10-79
Cessna 182P Skylane
Cessna 320E
P~per Cherokee PA 28-180
P~per PA 34-200
Beech Bonanza F33A
Beech Bonanza V35B
Beech Bonanza A36
Beech Debonaire 35B33
Aero Commander 680 FL
Excluded at 85 SENEL: All planes excluded* at
90 and 87 SENEL, plus:
Cessna 182H
Cessna 210
Cessna T210L
Cessna 310Q
Cessna T310R
P1per Comanche PA 24-250
P1per Comanche PA 24-260
P1per Comanche PA 24-260C
P1per Twin COManche PA 30
P1per Cherokee PA 32-300
Excluded at 80 SENEL: All planes excluded* at
90, 87, and 85 SENEL, plus:
Cessna 170
Cessna 172M
Cessna 172N
Cessna 175A
Cessna 175B
Cessna 177
Cessna 177RG Card1nal
Cessna 180
Cessna 182Q
Cessna T210M
Cessna 404
Cessna 414 Cardlnal
Cessna 421B
Piper Tri-Pacer PA 22-135
P~per Twin Apache FA 23-160
P1per Twin Aztec FA 23-250
Plper Cherokee PA 28-151
Plper Arrow PA 28R-200
Plper FA 31T
Piper FA 34-200T
Beech Bonanza 35
Mooney M20E
Mooney Executlve M20F
Bellanca 17-30
-7-
RLK:msh
City Counc11 Meet1ng 09-10-79
3. Percentage of Aircraft Excluded from SMO at Lower SENEL
The percentages of the rated fleet wh1ch would be excluded
from SMO 1f the SENEL were lowered are:
SENEL 90
9.5 %
SENEL 87
23.0 %
SENEL 85
32.5 %
SENEL 80
65.0 %
These conclusions are accurate for the rated fleet (48.2%
of the total fleet). The percentages could be greater or lesser
depend1ng on the n01se measurement levels for the 215 unrated
a1rcraft.
These f1gures apply only to the eX1sting t1e-do\ffi fleet at
SMO. The effect on tranS1ent a1rcraft has not been analyzed 1n
this part of the report.
II. IMPACT OF VARIOUS SENEL LIMITS
UPON AIRPORT OPERATION AT SMO
A. Impact on Total Operat1on~
According to the Declaration of Colleen J. Clement, 8 May
1979, Santa Monica Airport Associat1on, et. al., v. C1ty of Santa
Mon1ca, the following percentages of total aircraft operations
(an average of takeoff and land1ng violat1ons) that would be
affected at the var10US SENEL l1m1ts are (See also Append1x D) :
SENEL 95
0.42 %
SENEL 90
3.36 %
SENEL 85
6.15 %
SENEL 80
14.83 %
-8-
KLK:msn
Clty Councl1 Meeting 09-10-79
B. Impact on Takeoff Operations
USlng the ldentical source data (see above) wh~Gh was used
~n determlning the total operation percentages, the followlng
evaluation was made for takeoff operatlons only. Slnce the ma]Orlty
of nOlse vlolatlons occur on takeoff, and the impact upon the
community 15 greater at this locatlon, the follow~ng percentages
were determlned:
SENEL 95
0.6 %
SENEL 90
6.0 %
SENEL 85
11.0 %
SENEL 80
25.0 %
III. IMPACT OF VARIOUS SENEL
LIMITS UPON THE C0M11UNITY
A. Effect upon the CNEL
Appllcatlon of the SENEL and CNEL metrlc to the alrcraft
nOlse from present operations, and from future operatlons under
varlous posslble noise limltat~ons, at the Santa Monica NOlse
Monltor Stat10ns reveals the followlng:
1. Llffilt of 100 SENEL and No Jet Ban. It 1S estimated
that In the viclnity of the NOlse Monitor Statlon, about 35%
of the people would be hlghly annoyed and about 55% disturbed
(speech, TV, radlo, sleep lnterference, and house vlbratlon) on
a dally basis by the aircraft noise. CNEL of about 65.
2. Llmit of 100 SENEL and Jet Ban.
(Present Ordinance.)
About 30% of the people are highly annoyed and about 45% dlsturbed
by the alrcraft no~se. CNEL of about 63.
-9-
RLK : msh
Clty Council Meeting 09-10-79
3. Llm~t of 90 SENEL. About 22% of the people would be
highly annoyed and 40% disturbed by the a~rcraft noise. CNEL
of about 58.
4. Llmlt of 87 SENEL. About 17% of the people would be
h~ghly annoyed and about 30% d~sturbed by the aircraft no~se.
CNEL of about 56.
B. Recommended CNEL
The U.S. EnVlronmental Protection Agency reconmends an Ldn
of 55 (wh~ch ~s equ~valent to a CNEL of 56) as a gu~dellne for
the maxlmum exposure to nOlse ~n resldentlal areas In order to
protect "health and welfare wlth an adequate margin of safety."
This recommendation can hardly be ]ustlfled as adequately protect~ve
of people exposed to aircraft nOlse lnaswuch as at that level
of exposure to a~rcraft nOlse about 17% are highly annoyed and
some 30% have var~ous activ~tles disturbed on a da~ly baS1S.
Further, ln some communltles group appeals and legal actlons to
reduce the aircraft no~se can occur at an Ldn or CNEL of about
55.
c. Other Factors.
Some non-aircraft nOlses that may occur in residentlal areas
generally have less adverse effects on people than might be expected
on the bas~s of their composlte no~se levels and ln comparlson
to alrcraft noise of the same composlte level. Among the reasonS
belng that these noises are:
1. usually from relatively locallzed sources and, hence,
unllke a~rcraft noises from a relat~vely far d~stance, are not
transm~tted throughout as large a geographlc area and are more
-10-
KLK:msn
Clty Council Meetlng 09-10-79
readlly shielded;
2. the nOlses may not reach peak levels high enough to be
above the threshold of annoyance; and
3. the nOlses may be non-regularly recurrlng and even be
wanted sounds rather than nOlse. In any event, the presence of
other sounds or nOlses In an enVlronment that contalns alrcraft
nOlse cannot be expected to reduce the adverse effects, lf any,
of the alrcraft nOlse on people.
IV. CONCLUSION
SENEL REDUCTION REDUCTION OF PEOPLE PEOPLE CNEL
OF AIRPORT RATED TIE- HIGHLY DISTURBED
OPERATIONS * Dm\N FLEET ANNOYED
90 6% 9% 22% 40% 58
87 9% 23% I 17% 30% 56
85 I 11% 32%
I I 1.5% 22% 54
I
80 25% 65% I 12% 18% 52
It is found that a Ilmit of 90 SENEL at the Santa Monlca
NOlse Monltorlng Statlons wlll provlde some modest reductlons
ln the alrcraft nOlse enVlrOlli~ent at Santa Monlca, and 1S con-
slstent wlth nOlse 11ffilts prescrlbed by FAA for the certlflcatlon
of small alrcraft licensed to operate in the Unlted States.
A lim~t of 87 SENEL at the NOlse Monitor Stations w~ll
provide a slgnlflcant reductlon in the alrcraft nOlse envlronment
at Santa Monlca and is conslstent wlth recow~endatlons for
environmental nOlse in residental areas and also with technology
of bUllding qUleter a1rcraft. A few of the new small Jet aircraft
will be able to meet elther an 87 or 90 SENEL Ilmlt.
*
See oage lla.
-11-
RLK:msh
City Cauncll fleeting 09-10-79
*
It is presumed in the calculatlon of CNELs wlth
the SF.NEL limits set at 87 and 90, that the reduction
in operatlons that could ensue 1S only apparent, and
that the level of operations would rema1n the same
because newer, qUleter alrcraft, including Jets, would
replace those alrcraft operatlons now in excess of 87
or 90 SENEL.
However, there would be an effective (more or less)
long lastlng reduction in 7% of the operations all for
alrcraft at SENELs hlgher than 85, and about a 20%
reductlon ln the operat1ons of alrcraft at SENELs hlgher
than 80, were the SE!IEL linit set at 85 and 80 respectively.
Accordingly, the CNELs for the conditlons of an SE~EL
limit of 85 and for a limit of 80 SENEL are calculated on
the assumption that the nu~er of operations, ln the
highest SE~EL ranges, would be reduced by 30 wlth a liolt
af 85 SENEL and 62 with a lir.ut of 80 SmJEL.
-lla-
RLK:msh
Clty Councll Meetlng 09-10-79
The requlrements of FAA Regulatlon FAR 36, Part 36, related
rAA Advlsory Circulars AC 36-, the FAA Integrated N01se Model,
and procedures glven in thlS report prov1de bases for the determlnatlon
or estlmatlon by ill 1 lnterested part1es of the SENEL values to
be expected atthe Santa Monlca NOlse Moultor statlons for most,
lf not all, alrcraft certlfled to operate lU the Unlted States
slnce 1 January 1974.
It 15 noted that all models of small (less than 12,500
pounds) and Jet (less than about 20,000 pounds) a1rcraft must
be FAA certlf1ed after 1 January 1975 to not exceed a nOlse
level equlvalent to an SEKEL of 90 at the Santa Mon1ca NOlse
Monltor Stat1ons. New technology perm1ts, or may permlt, thlS
maXlffium noise Ilffilt for type cert1f1catlon to be reduced by
3dB or so, as a n1nlmum (l.e. to an equlva1ent SENEL of 87.)
V. PROPOSED ORDINANCE
A. EIR Requlrement
The Clty Attorney has determlned that an In1tia1 Study
shall be immedlately undertaken pursuant to the requ1rements
of the Callforn1a Env1ronmental Quallty Act, PubllC Resources
Code 21000 et seq. ThlS shall be carrled out In order to determlne
If the ordlnance may have a slgnif1cant effect on the enVlronment.
Thereafter, elther a Negatlve Declarat10n or an EIR shall be
prepared.
B. Ordlnance - Draft
Pursuant to the f1nd1ngs in thlS report, studles belng
conducted, and the outcome of 8.M.A.A. v. Clty of Santa Monica,
-12-
RLK:rrsh
Clty COUDCll r~etlng 09-10-79
an ordlnance has been drafted to cover the SENEL Ilmltatlon,
the authorlty of the Alrport Director to promulgate rules and
regulatlons, and a prohlbltion on tralnlng for hlgh performance
a1rcraft. The SENEL Ordinance has been amended to take lnto
account the recent actions by government agencies to standardize
the criter1a for controlllng alrcraft noise.
In order to further these government goals, several pre-
sumptions will apply to those aircraft that have been ass1gned a
~easured or estimated nOlse level rating by the FAA, FPA, aircraft
manufacturers or independent consultants. Flrst, as to any person
ownlng, operatlng or permlttlng the use of any alrcraft W!llCh ex-
ceeds the acceptable n01se level Ilmit at Santa ~IDnica as deter~1ned
under Subsectlor. (9) of the proposed amendment to Sectlon lOlOSB, lt
15 concluslvely presumed that that person intends to violate the
Santa Monlca nOlse limit. Secondly, as to any aircraft operator
who exceeds the acceptable nOlse level ll~lt whlle flYlng an alrplane
that has been determlned under Subsectlon (9) of the proposed amend-
ment to lOl05B to fall wlthln the acceptable noise group, lt 1S re-
buttably presumed that such alrcraft operator is guilty of an In-
tentional violatlon or a crlmlnally negllgent vlolation based on In-
approprlate pilot operating procedures. This presumptlon may be
rebutted by clear and convlncing eVldence to establ1sh condlt1ons
wholly beyond the control of the pilot. Third, as to any aircraft which
lS not rated as prov1ded for In Subsect10n (9) of the amencment to
lOlOSB, there lS a rebuttable presu0ption that such a1rcraft exceeds
the nOlse IlMits at Santa Monlca A1rport untll such t1me as sufflC-
ient techn1cal data is furnlshed to establ1sh that the part1cular
-13-
RLK:msh
Clty CounCl1 f~etlng 09-10-79
aircraft wl11 meet the nOlse Ilmlt set by the Clty.
The rule-maklng authorlty 15 added to set a standard for
the Airport Dlrector to follow In adoptlng rules and regulatlons.
The prohlbit1on on h1gh performance aircraft traln1ng 1S des1gned
to reduce repetltlve operatlons and to curtail the m1X of numerous
h1gh performance tralnlnq flights wlth the fllghts of other aircraft.
RECO~~~NDATION
It 15 staff's recommendation that the attached ordlnance be
lntroduced for flrst readlng and that the Clty Councll set the
SENEL limlt at that amount It deems approprlate to Meet the
comwunlty needs.
Prepared by:
Rlchard L. Knickerbocker, Clty Attorney
Sandra Henry, Deputy City Attorney
Colleen J. Clement, Legal psslstant
Karl Kryter, Ph.D., Psycho-Acoustlclan
-14-
~