Updated: May 9
UPDATE AS OF 8 MAY: I put this information up on a Facebook airport noise forum. My comments were challenged by at least one pilot, but when I made specific requests of him to explain his comments in more depth, there was no answer.
My next step was to contact JohnWayne Airport to learn more about what they are doing to mitigate noise. I was able after a few calls to find the right person to talk about the work that is ongoing at JWA to identify noise mitigation departure thrust profiles. They are focused entirely on thrust, flaps, as opposed to looking at different tracks, which they feel they have a pretty good handle on. I sent the president of the group the report included below and we discussed. It appears that we have the potential where we can both help each other. I will be sitting in their next Board meeting. If we can do what they have done, we could bypass ANAC, the Airport Authority and the FAA.
Mission Beach has been impacted by noise from Lindbergh Field for some time. The objective of this document is to summarize recent thoughts and developments that might lead to noise reduction in the Mission Beach community from one noise mitigation approach, departure profiling. This is an attempt to control noise producing engine thrust over residential areas, including Pt. Loma, Midway, Ocean Beach, Mission Beach, Pacific Beach and La Jolla (Bird Rock).
At a recent aviation noise conference in San Diego, a United Airlines representative provided an early look into flight testing it was conducting at John Wayne Airport. The objective is to provide United and presumably other airlines insight into thrust, speed and altitude with regard to the noise limits established by the John Wayne Airport Noise Abatement Office.
There is one noticeable difference between John Wayne Airport and Lindbergh Field. The distance from the end of the runway to the coast at John Wayne Airport is 5 miles, while at Lindbergh the distance ranges from about 3 miles at ZZOOO to about 3.5 miles at PADRZ. The power reduction from takeoff to climb occurs upon reaching cleanup altitude of 1,000, or 1,500 feet. It appears from the profile data collected that 1,000 feet is the number used at both Lindbergh and JWA.
Apparently, it was decided that the best way to control noise levels over residential zones in Newport Beach was to define limits at different locations relative to the end of the runway, and then let the airlines decide how they can best meet the noise limit requirements. Figure 1 shows a layout of the John Wayne Airport including the location of the noise monitors for departure (i.e., 1S through 7S) and arrivals. Table 1 provides the exact details of where the noise monitors are located. And Table 2 shows the noise limits for each of the noise monitors.
It was thought that overlaying the noise monitor locations on the Lindbergh Field map also showing the noise limits might be useful. The JWA Noise Abatement Office chose to use an average of the Single Event Noise Exposure Level (SENEL) over a quarterly period as the limit. The SENEL is the Sound Exposure Level (SEL) for a defined noise threshold level. The SEL is a measure of the total “noisiness” of an event, that takes duration into account.
I then plotted the locations for the JWA noise monitors on a Google Earth Pro map of the JWA area. This is shown in Figure . I could then visualize and confirm my locations for the noise monitor system. The next thing I wanted to do was overlay the JWA Noise Monitor System (NMS) on the Lindbergh Field map. This is shown in Figure , including the SENEL noise limits at these locations. This is shown in Figure .
Lastly, I wanted to compare representative flight profiles for JWA and Lindbergh Field . The standard output to look at the time domain profiles includes the three main parameters, altitude, horizontal speed and vertical speed, where it is assumed that vertical speed is proportional to thrust and therefore noise. Len plotted 20 different departure profiles, all for PADRZ SID departures. There was very little consistency in the vertical speed profiles, except that there does seem to be more of an attempt to reduce the vertical speed directly after takeoff until the aircraft pass the Midway district, and then the values tend to increase. This is not always the case, but frequently it is.
In all cases, the aircraft do reach about 1,000 feet before they reduce thrust and therefore vertical speed. It is not clear where the most noise sensitive residential areas are in Newport Beach, but it is likely to be near the coast. It also appears that the target vertical speed is around 1,000 feet per minute. In case 1, this target is reached at about 4 miles, while in case 2, it is reached by mile 2. It is presumed that both of these departures meet the noise limits criteria, but it would be most helpful to confirm this point.
As mentioned previously, the vertical speed profiles are fairly inconsistent at Lindbergh. Again, the altitude is close to 1,000 feet before the vertical speed begins to decrease. In both of these cases, the vertical speed almost immediately drops to lower values, of less than 1,000 feet per second, before beginning to increase. The vertical speed continues to increase so that when the aircraft reaches SMB, the thrust values are both at about 3,000 feet per second and continues to climb at this rate until out over the ocean.
I could therefore be concluded, again presuming that vertical speed is proportional to thrust, that Mission Beach and beyond are being subjected to higher engine noise levels. There does not seem to be any rationale reason for this action by the pilots.