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Home My WebLink AboutCC 15 AIRPORT STATUS 11-07-94 11-7-94 Inter-Com 0ATE: NOVEMBER 7, 1994 TO: FROM: SUBJECT: WILLIAM A. HUSTON, CITY MANAGER COMI~-JNITY DEVELOPMENT DEPARTMENT AIRPORT STATUS REPORT RECOMMENDATION Receive and file. FISCAL IMPACT The City retains the consulting firm of J. J. Van Houten and Associates, Inc. for review of noise related items and there is a limitation of one-thousand dollars $1,000) per review of each JWA Quarterly Noise Report. DISCUSSION J.J. Van Houten and Associates, Inc , Tustin's noise consultants, reviews County-prepared John Wayne Airport Noise Abatement Program quarterly reports. A copy of their analysis for the fourth quarter of 1993 is attached. During the fourth quarter of 1993 the Community Noise Equivalent Level (CNEL) at monitoring station M7 in Tustin was 56.6 dB, which is four-tenths (,4) of a decibel less than the third quarter of 1993. However, during the fourth quarter, the number of aircraft operations increased to a total of 16,766 for the quarter from the previous quarter total of 16,704. Based on data for all of the quarters of 1993, the annual average CNEL at station M7 was 56.7 dB for 1993. This is four-tenths (.4) of a decibel higher than the average annual CNEL of 56.3 dB for 1992. However, this is still below the City, County, and State criteria of 65 dB for residential areas. The number of quarterly noise complaints received for the Tustin/Orange area was significantly less for the fourth quarter although the average CNEL and number of flights remained relatively the same. This decrease in noise complaints does not correlate with the increase in the number of Class A and AA aircraft being used, which are the noisiest type of aircraft. City Council Report Airport Status Report November 7, 1994 Page 2 The consultant has again analyzed the relationship between changes in CNEL and the number of quieter aircraft put into service at John Wayne Airport. The analysis shows that the percentage of quiet Class E aircraft remained about the same or approximately 23% for the fourth quarter. Class E aircraft are the quietest of the three types of aircraft (Class A, AA and E) unique to John Wayne Airport. However, the classification only applies to departures and in some cases, aircraft classified as Class E are actually noisier on arrival than some Class A and AA aircraft. Therefore, the percentage of Class E aircraft does not significantly affect noise levels at Tustin's noise monitoring station. As a result, it is difficult to correlate the types of aircraft flown with the measured CNEL and its affect to Tustin residents since the criteria applies to departures and not arrivals. CONCLUSION Because the issues discussed above are of considerable importance to the City of Tustin, the Community Development Department will continue to monitor airport issues unless otherwise directed by the City Council. ~ E. Bonn~ Associate Planner Assistant Director of Community Development Attachments: Report from J.J. Van Houten and Associates J.J. VAN HOUTEN & -- RECEIVED OCT 2 7 ~OI~UNIPf ASSOCIATES, INC. John J. Van Houten, RE. David L. Wieland Principal Consultant October 19, 1994 Project File 2306-91 CITY OF TUSTIN Community Development Department 300 Centennial Way Tustin, CA 92680 Attention: Ms. Rita Westfield Subject: Review of John Wayne Airport Noise Abatement Program Quarterly Report, 4th Quarter 1993 Reference: 1. "Data Evaluation and Aircraft Noise Impact Study for the City of Tustin," J. J. Van Houten and Associates, Inc., January 8, 1990 "Noise Abatement Program Quarterly Re- port for the Period: October 1, 1993 through December 31, 1993," John Wayne Airport Dear Ms. Westfield: As requested,, we have reviewed the referenced quarterly report for the noise abatement program at John Wayne Airport. The follow- lng provides our findings with regard to airport operations and their impact on the City of Tustin: Referring to Figures 1 and 2, the average annual CNEL at station M7 was 56.7 dB for 1993 based upon data for the 1st through 4th quarters. This is 0.4 dB higher than the average annual CNEL of 56.3 dB for 1992. (NOTE: The noise con- tours for John Wayne Airport are based on average annual CNEL values measured at each remote monitoring station.) ~1 Richter Avenue Suite 108 Irvine, CA 92714 714/476-0932 FAX 714/476-1023 CITY OF TUSTIN p~o)ect File 230691 It should be noted that the average annual CNEL is skewed by a lack of data for the entire month of January, 12 additional days throughout the 1st quarter, 25 days through- out the 2nd quarter (including a continuous 21 day period in April and May), 11 days throughout the 3rd quarter, and 21 days throughout the 4th quarter. Referring to Figure 2, there does not appear to be any correlation between the average ~nmber of noise complaints received from the Tustin/Orange area and the average quarterly aircraft CNEL or the average quarterly number of jet operations. As indicated in the figure, the number of noise complaints .was significantly lower in the fonrth quarter of 1993 than in the second and third quarters even though the average quarterly CNEL and total jet operations remained essentially the same. Referring to both Table 2 and Figure 2, the num- ber of complaints also does not correlate with the percentage of noisier aircraft (Class A and AA) landing at the airport. Between the third and fourth quarters of 1993, the number of complaints decreased significantly though the percentage of noisier:aircraft remained the same. As indicated in Item 1, above, the annual average CNEL measured at station M7 was 56.7 dB based on information for 1993. This is slightly less than the 58 dB that was estimated for the station in the referenced aircraft noise impact study for the Phase 2 Access Plan (Reference 1). AIRCRAFT NOISE CONTOURS In 1988, an exterior aircraft noise monitoring effort was conducted throughout the City of Tustin by the John Wayne Airport Noise Abatement Office and by J. J. Van Houten and Associates, Inc. (Reference 1). Aircraft-generated single event noise exposure levels (SENEL's) were measured at twelve locations in Tustin over a five month period. As a result of this effort, noise contours were developed for John Wayne Airport as they impact the City of Tustin. Although the shape of the contours does not change (since flight tracks are fixed), the value of the noise contours does change with different levels of operations a't the airport and different mixes of aircraft. Figure 3 provides the approximate location of the John Wayne Airport noise contours for 1990 based on measurements obtained at monitoring station M7 throughout the year. Referring to the figure, the community noise equivalent level (CNEL) ranged from 53 to 59 dB in the City of Tustin, with a CNEL of about 55 dB at station M7. J. J. VAN HOUTEN & ASSOCIATES, INC. C~FY OF TUSTIN Based on data through all four quarters, the annual average CNEL at station M7 was 56.7 dB in 1993. The existing and future Phase 2 contours (based on 1993 data) are provided in Figure 4. Referring to the figure, it is estimated that in 1993 the aircraft- generated CNEL will range from 55 to 61 dB. This is well below the City, County, and State criteria of 65 dB for residential areas. USE OF QUIETER AIRCRAFT AT JWA As requested, we have analyzed the correlation between the increasing use of quieter aircraft at JWA and the change in CNEL within the City of Tustin. The Federal Aviation Administration (FAA) classifies aircraft into three categories based on noise levels. In order of decreasing noise levels, there are Stage I, Stage II, and Stage III aircraft. John Wayne Airport has only permitted Stage III aircraft since the early 1970's. The airport has its own classification scheme for passenger aircraft. In order of decreas- ing noise level, these are Class A, Class AA, and Class E aircraft. Table 1 provides the estimated number of each class of aircraft that used the airport between the first quarter of 1992 and the fourth quarter of 1993. Also provided is the measured average quarterly CNEL at monitoring station M7. Table 2 provides the same information, but the values have been normalized to 17,000 aircraft operations (takeoffs and landings) per quarter. In this way, a correlation can be established between the quarterly CNEL and the mix of aircraft types. Referring to Table 2 and Figure 5, the percentage of quieter Class E aircraft using John Wayne Airport was the same in the 4th quarter of 1993 as in the 3rd quarter (about 23%). There was a decrease in Class A aircraft that was offset by an increase in the use of the quieter Class AA aircraft. With this decrease in noisier aircraft the weighted average quarterly CNEL decreased slightly. If you have any questions, please contact the undersigned at 714/476-0932. Very truly yours, II:\wla51 \~epor~\2300-49\23064q93 3 J. J. VAN HOU.TEN & ASSOCIATES, INc. (BP} ]~NO 80 Average Quarterly AJrcralt CNEL, M7 1 u~ 6O Z 1~ 40 o~ 20 0 1Qtr92 2Qtr92 3Qt,'92 4Qt~92 1Qtr93 2Qtr93 3Qtr93 4Qt~93 Quarter/Year Total Quarterly Jet Operations, M71 20 E 15 ~ ~ 10 0 5 0 100 1QU92 2QtrCJ2 3Qtr92 4Qtz92 1Qtr93 2Qt~93 Quarter/Year Average Quarterly Noise Complaints 3Qtr93 4Qtz93 80 60 40 20 0 1Qtr92 2Q1~32 3Qt~92 4Qtr92 1QtJ'93 2Qtr93 Quarter/Year 3Qtr93 4Qtr93 Figure 2 6 // Il II Figure 3. Approximate Location of John Wayne Airport Noise Contours, 1990 M-7 II II 6 58 57 55 Figure 4. Approximate Location of John Wayne Airport Noise Contours, 1992 8 I spu~snoqj. 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